Name: an efficient method for selective desalination of radioactive iodine anions by using gold nanoparticles-embedded membrane filter
Uploaded: 2018-07-13T14:00:00
Description: Watch this Scientific Journal Video about An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter at JoVE.com

This work was supported by the research grant from the National Research Foundation of Korea (Grant number: 2017M2A2A6A01070858).

1. Synthesis of Citrate-Stabilized Gold Nanoparticles
<ol>
	<li>Wash a two-neck round-bottom flask (250 mL) and a magnetic stir bar with aqua regia, a mixture of concentrated hydrochloric acid and concentrated nitric acid in a 3:1 volume ratio. 
	CAUTION: Aqua regia solution is extremely corrosive and may result in explosion or skin burns if not handled with extreme caution.</li>
	<li>Rinse the glassware thoroughly with deionized water to remove residual aqueous acid.</li>
	<li>Add 120 mL of chloroauric acid solut...

<ol>
	<li>Ojovan, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Advanced Radioactive Waste Conditioning Technologies. , (2011).</li><li>Abdel Rahman, R. O., Ibrahim, H. A., Hung, Y. -. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liquid+Radioactive+Wastes+Treatment:+A+Review.">Liquid Radioactive Wastes Treatment: A Review.</a> Water. 3, 551-565 (2011).</li><li>Khayet, M., Matsuura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radioactive+decontamination+of+water.">Radioactive decontamination of water.</a> Desalination. 321, 1-2 (2013).</li><li>McLaughlin, P. D., Jones, B., Maher, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+update+on+radioactive+release+and+exposures+after+the+Fukushima+Dai-ichi+nuclear+disaster.">An update on radioactive release and exposures after the Fukushima Dai-ichi nuclear disaster.</a> The British Journal of Radiolog. 85, 1222-1225 (2012).</li><li>Chernobyl Forum Expert Group 'Environment'. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+Consequences+of+the+Chernobyl+Accident+and+their+Remediation:+Twenty+Years+of+Experience.">Environmental Consequences of the Chernobyl Accident and their Remediation: Twenty Years of Experience.</a> International Atomic Energy Agency. , (2006).</li><li>Hou, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Iodine-129+in+seawater+offshore+Fukushima:+distribution,+inorganic+speciation,+sources,+and+budget.">Iodine-129 in seawater offshore Fukushima: distribution, inorganic speciation, sources, and budget.</a> Environmental Science &amp; Technology. 47, 3091-3098 (2013).</li><li>Mu, W., Yu, Q., Li, X., Wei, H., Jian, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adsorption+of+radioactive+iodine+on+surfactant-modified+sodium+niobate.">Adsorption of radioactive iodine on surfactant-modified sodium niobate.</a> RSC Advances. 6, 81719-81725 (2016).</li><li>Yang, D., Liu, H., Liu, L., Sarina, S., Zheng, Z., Zhu, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silver+oxide+nanocrystals+anchored+on+titanate+nanotubes+and+nanofibers:+promising+candidates+for+entrapment+of+radioactive+iodine+anions.">Silver oxide nanocrystals anchored on titanate nanotubes and nanofibers: promising candidates for entrapment of radioactive iodine anions.</a> Nanoscale. 5, 11011-11018 (2013).</li><li>Yang, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capture+of+radioactive+cesium+and+iodide+ions+from+water+by+using+titanate+nanofibers+and+nanotubes.">Capture of radioactive cesium and iodide ions from water by using titanate nanofibers and nanotubes.</a> Angewandte Chemie International Edition. 50, 10594-10598 (2011).</li><li>Cheng, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adsorption+of+gaseous+radioactive+iodine+by+Ag/13X+zeolite+at+high+temperatures.">Adsorption of gaseous radioactive iodine by Ag/13X zeolite at high temperatures.</a> Journal of Radioanalytical and Nuclear Chemistry. 303, 1883-1889 (2015).</li><li>Bennett, T. D., Saines, P. J., Keen, D. A., -C, T. a. n. J., Cheetham, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ball-Milling-Induced+Amorphization+of+Zeolitic+Imidazolate+Frameworks+(ZIFs)+for+the+Irreversible+Trapping+of+Iodine.">Ball-Milling-Induced Amorphization of Zeolitic Imidazolate Frameworks (ZIFs) for the Irreversible Trapping of Iodine.</a> Chemistry - A European Journal. 19, 7049-7055 (2013).</li><li>Huang, P. S., Kuo, C. H., Hsieh, C. C., Horng, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+capture+of+volatile+iodine+using+amorphous+molecular+organic+solids.">Selective capture of volatile iodine using amorphous molecular organic solids.</a> Chemical Communications. 48, 3227-3229 (2012).</li><li>Chapman, K. W., Chupas, P. J., Nenoff, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radioactive+Iodine+Capture+in+Silver-Containing+Mordenites+through+Nanoscale+Silver+Iodide+Formation.">Radioactive Iodine Capture in Silver-Containing Mordenites through Nanoscale Silver Iodide Formation.</a> Journal of the American Chemical Society. 132, 8897-8899 (2010).</li><li>Watanabe, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+Long-Term+Immobilization+Method+for+Radioactive+Iodine-129+Using+a+Zeolite/Apatite+Composite+Sintered+Body.">Novel Long-Term Immobilization Method for Radioactive Iodine-129 Using a Zeolite/Apatite Composite Sintered Body.</a> ACS Applied Materials &amp; Interfaces. 1, 1579-1584 (2009).</li><li>Massasso, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+iodine+adsorption+within+Hofmann-type+structures+M(L)[M'(CN)4]+(M+=+Ni,+Co;+M'+=+Ni,+Pd,+Pt):+impact+of+their+composition.">Molecular iodine adsorption within Hofmann-type structures M(L)[M'(CN)4] (M = Ni, Co; M' = Ni, Pd, Pt): impact of their composition.</a> Dalton Transactions. 44, 19357-19369 (2015).</li><li>Falaise, C., Volkringer, C., Facqueur, J., Bousquet, T., Gasnot, L., Loiseau, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capture+of+iodine+in+highly+stable+metal-organic+frameworks:+a+systematic+study.">Capture of iodine in highly stable metal-organic frameworks: a systematic study.</a> Chemical Communications. 49, 10320-10322 (2013).</li><li>Sava, D. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capture+of+Volatile+Iodine,+a+Gaseous+Fission+Product,+by+Zeolitic+Imidazolate+Framework-8.">Capture of Volatile Iodine, a Gaseous Fission Product, by Zeolitic Imidazolate Framework-8.</a> Journal of the American Chemical Society. 133, 12398-12401 (2011).</li><li>Zhang, Z. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+type+of+polyhedron-based+metal-organic+frameworks+with+interpenetrating+cationic+and+anionic+nets+demonstrating+ion+exchange,+adsorption+and+luminescent+properties.">A new type of polyhedron-based metal-organic frameworks with interpenetrating cationic and anionic nets demonstrating ion exchange, adsorption and luminescent properties.</a> Chemical Communications. 47, 6425-6427 (2011).</li><li>Li, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+efficient+I2+capture+by+simple+and+low-cost+deep+eutectic+solvents.">Highly efficient I2 capture by simple and low-cost deep eutectic solvents.</a> Green Chemistry. 18, 2522-2527 (2016).</li><li>Yan, C., Mu, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+of+ionic+liquids+for+efficient+removal+and+reliable+storage+of+radioactive+iodine:+a+halogen-bonding+case.">Investigation of ionic liquids for efficient removal and reliable storage of radioactive iodine: a halogen-bonding case.</a> Physical Chemistry Chemical Physics. 16, 5071-5075 (2014).</li><li>Choi, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+bioremediation+of+radioactive+iodine+using+biogenic+gold+nanomaterial-containing+radiation-resistant+bacterium,+Deinococcus+radiodurans+R1.">Efficient bioremediation of radioactive iodine using biogenic gold nanomaterial-containing radiation-resistant bacterium, Deinococcus radiodurans R1.</a> Chemical Communications. 53, 3937-3940 (2017).</li><li>Kim, Y. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+targeting+and+imaging+using+cyclic+RGD-PEGylated+gold+nanoparticle+probes+with+directly+conjugated+iodine-125.">Tumor targeting and imaging using cyclic RGD-PEGylated gold nanoparticle probes with directly conjugated iodine-125.</a> Small. 7, 2052-2060 (2011).</li><li>Choi, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gold-Nanoparticle-Immobilized+Desalting+Columns+for+Highly+Efficient+and+Specific+Removal+of+Radioactive+Iodine+in+Aqueous+Media.">Gold-Nanoparticle-Immobilized Desalting Columns for Highly Efficient and Specific Removal of Radioactive Iodine in Aqueous Media.</a> ACS Applied Materials &amp; Interfaces. 8, 29227-29231 (2016).</li><li>Mushtaq, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+and+selective+removal+of+radioactive+iodine+anions+using+engineered+nanocomposite+membranes.">Efficient and selective removal of radioactive iodine anions using engineered nanocomposite membranes.</a> Environmental Science: Nano. 4, 2157-2163 (2017).</li><li>Awual, M. R., Ismael, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+gold(III)+detection,+separation+and+recovery+from+urban+mining+waste+using+a+facial+conjugate+adsorbent.">Efficient gold(III) detection, separation and recovery from urban mining waste using a facial conjugate adsorbent.</a> Sensors and Actuators B: Chemical. 196, 457-466 (2014).</li><li>Awual, M. R., Hasan, M. M., Naushad, M., Shiwaku, H., Yaita, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+new+class+composite+adsorbent+for+enhanced+palladium(II)+detection+and+recovery.">Preparation of new class composite adsorbent for enhanced palladium(II) detection and recovery.</a> Sensors and Actuators B: Chemical. 209, 790-797 (2015).</li><li>Awual, M. R., Hasan, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fine-tuning+mesoporous+adsorbent+for+simultaneous+ultra-trace+palladium(II)+detection,+separation+and+recovery.">Fine-tuning mesoporous adsorbent for simultaneous ultra-trace palladium(II) detection, separation and recovery.</a> Journal of Industrial and Engineering Chemistry. 21, 507-515 (2015).</li><li>Awual, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ring+size+dependent+crown+ether+based+mesoporous+adsorbent+for+high+cesium+adsorption+from+wastewater.">Ring size dependent crown ether based mesoporous adsorbent for high cesium adsorption from wastewater.</a> Chemical Engineering Journal. 303, 539-546 (2016).</li><li>Awual, M. R., Miyazaki, Y., Taguchi, T., Shiwaku, H., Yaita, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Encapsulation+of+cesium+from+contaminated+water+with+highly+selective+facial+organic-inorganic+mesoporous+hybrid+adsorbent.">Encapsulation of cesium from contaminated water with highly selective facial organic-inorganic mesoporous hybrid adsorbent.</a> Chemical Engineering Journal. 291, 128-137 (2016).</li><li>Awual, M. R., Yaita, T., Taguchi, T., Shiwaku, H., Suzuki, S., Okamoto, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+cesium+removal+from+radioactive+liquid+waste+by+crown+ether+immobilized+new+class+conjugate+adsorbent.">Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent.</a> Journal of Hazardous Materials. 278, 227-235 (2014).</li><li>Awual, M. R., Suzuki, S., Taguchi, T., Shiwaku, H., Okamoto, Y., Yaita, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radioactive+cesium+removal+from+nuclear+wastewater+by+novel+inorganic+and+conjugate+adsorbents.">Radioactive cesium removal from nuclear wastewater by novel inorganic and conjugate adsorbents.</a> Chemical Engineering Journal. 242, 127-135 (2014).</li><li>Awual, M. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+detection+and+adsorption+of+cadmium+(II)+ions+using+innovative+nano-composite+materials.">Efficient detection and adsorption of cadmium (II) ions using innovative nano-composite materials.</a> Chemical Engineering Journal. 343, 118-127 (2018).</li><li>Awual, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+type+mesoporous+conjugate+material+for+selective+optical+copper(II)+ions+monitoring+&amp;+removal+from+polluted+waters.">New type mesoporous conjugate material for selective optical copper(II) ions monitoring &amp; removal from polluted waters.</a> Chemical Engineering Journal. 307, 85-94 (2017).</li><li>Awual, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+nanocomposite+materials+for+efficient+and+selective+mercury+ions+capturing+from+wastewater.">Novel nanocomposite materials for efficient and selective mercury ions capturing from wastewater.</a> Chemical Engineering Journal. 307, 456-465 (2017).</li><li>Awual, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solid+phase+sensitive+palladium(II)+ions+detection+and+recovery+using+ligand+based+efficient+conjugate+nanomaterials.">Solid phase sensitive palladium(II) ions detection and recovery using ligand based efficient conjugate nanomaterials.</a> Chemical Engineering Journal. 300, 264-272 (2016).</li><li>Awual, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+of+lead(III)+capturing+from+contaminated+wastewater+using+ligand+doped+conjugate+adsorbent.">Assessing of lead(III) capturing from contaminated wastewater using ligand doped conjugate adsorbent.</a> Chemical Engineering Journal. 289, 65-73 (2016).</li><li>Awual, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+facial+composite+adsorbent+for+enhanced+copper+(II)+detection+and+removal+from+wastewater.">A novel facial composite adsorbent for enhanced copper (II) detection and removal from wastewater.</a> Chemical Engineering Journal. 266, 368-375 (2015).</li><li>Kaushik, M., Moores, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review:+nanocelluloses+as+versatile+supports+for+metal+nanoparticles+and+their+applications+in+catalysis.">Review: nanocelluloses as versatile supports for metal nanoparticles and their applications in catalysis.</a> Green Chemistry. 18, 622-637 (2016).</li><li>Jang, H., Kim, Y. K., Ryoo, S. R., Kim, M. H., Min, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Facile+synthesis+of+robust+and+biocompatible+gold+nanoparticles.">Facile synthesis of robust and biocompatible gold nanoparticles.</a> Chemical Communication. 46, 583-585 (2010).</li><li>Bolisetty, S., Mezzenga, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amyloid-carbon+hybrid+membranes+for+universal+water+purification.">Amyloid-carbon hybrid membranes for universal water purification.</a> Nature Nanotechnology. 11, 365-371 (2016).</li><li>Zakrzewska-Trznadel, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+membrane+technologies+for+the+treatment+of+liquid+radioactive+waste.">Advances in membrane technologies for the treatment of liquid radioactive waste.</a> Desalination. 321, 119-130 (2013).</li><li>Rana, D., Matsuura, T., Kassim, M. A., Ismail, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radioactive+decontamination+of+water+by+membrane+processes+-+A+review.">Radioactive decontamination of water by membrane processes - A review.</a> Desalination. 321, 77-92 (2013).</li></ol>

In recent year, various engineered nanomaterials and membranes have been developed to remove hazardous radioactive metals and heavy metals in water based on their specific functionality in adsorption techniques25,26,27,28,29,30,31,32,<sup class="...

For several decades, huge amount of radioactive liquid wastes has been generated by medical institutes, research facilities, and nuclear reactors. These pollutants have often been a palpable threat to environment and human health1,2,3. Especially, radioactive iodine is recognized as one of the most hazardous elements from nuclear plant accidents. For example, an environmental report on the Fukushima and Chernobyl nuclear reactor demonstrated that the amount of released radioactive iodines including 131I (t1/2 = 8.02 days) and 129I (t1/2 = 15.7 million years) to the environment was larger than those of other radionuclides4,5. In particular, the exposure of these radioisotopes resulted in high uptake and enrichment in human thyroid6. Moreover, released radioactive iodines can cause severe contamination of soil, seawater and ground water owing to their high solubility in water. Therefore, a lot of remediation processes using various inorganic and organic adsorbents have been investigated to capture radioactive iodines in aqueous wastes7,8,9,10,11,12,13,14,15,16,17,18,19,20. Although extensive efforts have been devoted for the development of advanced adsorbent systems, the establishment of a decontamination method showing satisfactory performances under continuous in-flow condition was very limited. Recently, we reported a novel desalination process showing good removal efficiency, ion-selectivity, sustainability, and reusability by using hybrid nano-composite materials made of gold nanoparticle (AuNPs)21,22,23. Among them, gold nanoparticle-embedded cellulose acetate membranes (Au-CAM) facilitated highly efficient desalination of iodide ions under a continuous-flow system compared with those of existing adsorbent materials. Moreover, the whole procedure could be finished in a short time, which was another advantage for the treatment of nuclear wastes generated from post-use in medical and industrial applications. The overall goal of this manuscript is to provide a step-by-step protocol for the preparation of Au-CAM24. We also demonstrate a rapid and convenient filtration process for ion-selective capture of radioactive iodine using the engineered composite membranes. The detailed protocol in this report will offer a useful application of nanomaterials in the research field of environmental science.

<table border="0" cellpadding="0" cellspacing="0" style="width:813px;" width="813">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:351px;">Hydrochloric acid</td>
			<td style="width:177px;">DUKSAN</td>
			<td style="width:119px;">1129</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nitric acid&#160;</td>
			<td>JUNSEI</td>
			<td style="width:119px;">37335-1250</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Chloroautic chloride trihydrate (HAuCl4&#183;3H2O)</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">254169</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium citrate tribasic dihydrate</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">71402</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;">[125I]NaI&#160;</td>
			<td>Perkin-Elmer</td>
			<td style="width:119px;">NEZ033A010MC</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium chloride</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">S9888</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium iodide</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">383112</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium hydroxide</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">S5881</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Lithium L-lactate</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">L2250</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Citric acid</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">C1909</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:351px;">Sodium hydrogen carbonate</td>
			<td>JUNSEI</td>
			<td style="width:119px;">43305-1250</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:351px;">Urea</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">U1250</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Calcium chloride</td>
			<td>JUNSEI</td>
			<td style="width:119px;">18230-0301</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Magnesium sulfate</td>
			<td>SAMCHUN</td>
			<td style="width:119px;">M0146</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Potassium dihydrogen phosphate</td>
			<td>JUNSEI</td>
			<td style="width:119px;">84185A1250</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dipotassium hydrogen phosphate</td>
			<td>JUNSEI</td>
			<td style="width:119px;">84120-1250</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium sulfate</td>
			<td>JUNSEI</td>
			<td style="width:119px;">83260-1250</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ammonium chloride</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">A9434</td>
			<td>Synthetic urine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sea water</td>
			<td>Sigma Aldrich</td>
			<td style="width:119px;">S9148</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1x PBS</td>
			<td>Thermo</td>
			<td style="width:119px;">SH30256.01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cellulose acetate membranes (pore size: 0.20 &#956;m, diameter: 25 mm)</td>
			<td>Advantec MFS</td>
			<td style="width:119px;">25CS045AS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cellulose acetate membranes (pore size: 0.20 &#956;m, diameter: 47 mm)</td>
			<td>Advantec MFS</td>
			<td style="width:119px;">C045A047A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">47 mm Glass Microanalysis Holders</td>
			<td>Advantec MFS</td>
			<td style="width:119px;">KG47(311400)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Petri dish (50 mm diameter &#180; 15 mm height)</td>
			<td>SPL</td>
			<td style="width:119px;">10050</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;">Gamma counter</td>
			<td>Perkin-Elmer</td>
			<td>2480 WIZARD2</td>
			<td>Model number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">UV-vis spectrophotometer</td>
			<td>Thermo</td>
			<td style="width:119px;">GENESYS 10</td>
			<td>Model number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Transmission electron microscopy</td>
			<td style="width:177px;">Hitachi</td>
			<td style="width:119px;">H-7650</td>
			<td>Model number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:351px;">Field Emission Scanning electron microscope</td>
			<td style="width:177px;">FEI</td>
			<td style="width:119px;">Verios 460L</td>
			<td>Model number</td>
		</tr>
	</tbody>
</table>

an efficient method for selective desalination of radioactive iodine anions by using gold nanoparticles-embedded membrane filter

Here, we demonstrate a detail protocol for the preparation of nanomaterials-embedded composite membranes and its application to the efficient and ion-selective removal of radioactive iodines. By using citrate-stabilized gold nanoparticles (mean diameter: 13 nm) and cellulose acetate membranes, gold nanoparticle-embedded cellulose acetate membranes (Au-CAM) have easily been fabricated. The nano-adsorbents on Au-CAM were highly stable in the presence of high concentration of inorganic salts and organic molecules. The iodide ions in aqueous solutions could rapidly be captured by this engineered membrane. Through a filtration process using an Au-CAM containing filter unit, excellent removal efficiency (&gt;99%) as well as ion-selective desalination result was achieved in a short time. Moreover, Au-CAM provided good reusability without significant decrease of its performances. These results suggested that the present technology using the engineered hybrid membrane will be a promising process for the large-scale decontamination of radioactive iodine from liquid wastes.

We have demonstrated simple methods for the fabrication of Au-CAM using citrate-stabilized AuNPs and cellulose acetate membrane (Figure 1a). The surface of Au-CAM was observed by SEM which showed that the nanomaterials were incorporated stably on the cellulose nanofibers (Figure 2). The nanoparticles incarcerated on the membrane were sustained stably and were not released from the membrane by continual washing wi...

Watch this Scientific Journal Video about An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter at JoVE.com

An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter

An efficient method for the rapid and ion-selective desalination of radioactive iodine in several aqueous solutions is described by using gold nanoparticles-immobilized cellulose acetate membrane filters.

Here, we demonstrate a detail protocol for the preparation of nanomaterials-embedded composite membranes and its application to the efficient and ...

This method can help answer key questions in the water treatment and sustainable remediation field such as efficient removal of radioactive iodine from aqueous media by using hybrid nanocomposite materials. The main or the better thing of this technique is that radioactive elements in a mixed salt and organic substances can rapidly be removed by a simple filtration process in a highly efficient matter. Video demonstration of this matter is critical as the handling and the treatment of radioactive liquid waste requires special care including personal and environmental protection against the spread of radioactive contamination.Demonstrating the procedures will be Ha Eun Shim, a grad student from my lab. Add 120 milliliters of chloroauric acid solution to a washed two-neck round-bottom flask and heat it to reflux under constant stirring. Quickly add 12 milliliters of sodium citrate tribasic solution to the two-neck round-bottom flask.Reflux the resulting mixture for another 20 minutes for the complete reduction of the gold salt. Allow the colloidal suspension of nanoparticles to cool down to room temperature. Measure the concentration of the gold nanoparticles with UV-Vis spectroscopy at a wavelength of 520 nanometers using a quartz cuvette.Now, add a single drop of gold nanoparticle suspension onto a 400-mesh carbon coated copper grid. Dry the grid at room temperature before measuring the size of gold nanoparticles with transmission electron microscopy. Keep the colloidal gold nanoparticle suspension at four degrees Celsius.To prepare the gold nanoparticle-embedded membrane filter using a syringe unit, first wash a cellulose acetate membrane supported by a filter unit with deionized water three times. Withdraw 10 milliliters of citrate-stabilized gold nanoparticles with a sterile syringe and add it slowly into the pre-washed cellulose acetate membrane filter. Wash the filter unit with 10 milliliters of deionized water three times to remove non-immobilized gold nanoparticles.Alternatively, to prepare the gold nanoparticle membrane filter by vacuum pump, place the cellulose acetate membrane between a filter holder fritted glass support and a graduated funnel. Connect a combined unit of the fritted glass support and graduated funnel to a recover flask and a vacuum pump. Add 10 milliliters of citrate-stabilized gold nanoparticles into the graduated funnel.Then apply a vacuum until all gold nanoparticles are passed through the cellulose acetate membrane. Repeat the same procedure on the other side of the membrane to immobilize gold nanoparticles on both sides of the membrane. Analyze the surface of the gold nanoparticle-embedded cellulose acetate membrane or gold CAM using scanning electron microscopy under high-performance conditions with the accelerating voltages up to 15 kilovolts.Dilute radioactive iodine in three milliliters of pure water, one molar sodium chloride, or 10 nanomolar sodium iodide, and add each solution into a Petri dish. Standard radiation safety guidelines should be observed when working with radioactive iodine. Place the gold CAM that was prepared by using a vacuum filter into the radioactive iodine solutions.Shake them gently at room temperature. Withdraw 10 microliters of the radioactive iodine solution from the Petri dish at given time points. Then, measure the radioactivity of the aliquot using an automatic gamma counter.Rinse the gold CAM with purified water after 120 minutes. Finally, measure the amount of radioactivity captured on the membrane using the automatic gamma counter. To remove radioactive iodine anions using a gold CAM filter, dissolve the radioactive iodine in 50 milliliters of several aqueous solutions.Withdraw 50 milliliters of each solution with a sterile syringe and pass it through the gold CAM filter unit at an in-flow rate of about 1.5 milliliters per second using a syringe unit. Transfer five milliliters of the filtrate into a plastic vial for quantifying the radioactivity in the solution. Measure the amount of residual radioactivity in the filtrate solution using the automatic gamma counter.Finally, perform the reusability test on the gold CAM filter as described in the text protocol. After a 30-minute incubation, the gold CAM filter captured most of the radioactive iodine in pure water and in one molar of sodium chloride. On the other hand, the adsorption of radioactivity was inhibited completely in the presence of nonradioactive sodium iodide because the surface of the gold nanoparticles was occupied by iodide anions.The radioactive iodine solutions were passed through a filter unit containing gold CAM. The amount of the residual radioactivity in the filtrate was then measured. Excellent efficiency was obtained through the filtration step, decreasing the concentration of radioactive iodine significantly.In particular, the desalination performance of gold CAM was not suppressed by high concentration of inorganic salts such as sodium, cesium, and strontium. Furthermore, gold CAM could be reusable for repetitive desalination of radioactive iodine in synthetic urine and seawater. Though this method can provide insight into the remediation of radioactive waste from various aqueous media, it can also be applied to other radioisotopes and toxic heavy metals by introducing metal chelators and inorganic composite on the surface of gold nanoparticles.Following this procedure, the automatic contaminated water treatment system could be explored and designed for practical implementation of this study at large industrial scale. Don't forget that working with radioactive materials can be extremely hazardous, and precautions such as well-ventilated fume hoods, personal protections, and minimum exposure to hazardous material should always be taken while performing this procedure.

an-efficient-method-for-selective-desalination-radioactive-iodine

Research

JoVE Journal

Engineering

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75&#176;. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm2, respectively, has decreased the CA to near 15&#176;, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer&#8217;s surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of&#160;the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm2 and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103&#176;. The XPS results indicate ArF laser induced formation of Si&#8211;(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

We report on a process of in situ alteration of HF treated Si (001) surface into a hydrophilic or hydrophobic state by irradiating samples in microfluidic chambers filled with&#160;H2O2/H2O solution (0.01%-0.5%) or methanol solutions using pulsed UV laser of a relative low pulse fluence.

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of ...

Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

Because of the importance and extensive use of palladium, gold and cobalt metals in high-technology equipment, their recovery and recycling constitute an important industrial challenge. The metal recovery system described herein is a simple, low-cost means for the effective detection, removal, and recovery of these metals from the urban mine.

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in ...

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to neutral gold Au(0) by reducing agents, such as sodium citrate or sodium borohydride. The extension of this method to decorate iron oxide or similar nanoparticles with gold nanoparticles to create multifunctional hybrid Fe2O3-Au nanoparticles is straightforward. This approach yields fairly good control over Au nanoparticle dimensions and loading onto Fe2O3. Additionally, the Au metal size, shape, and loading can easily be tuned by changing experimental parameters (e.g., reactant concentrations, reducing agents, surfactants, etc.). An advantage of this procedure is that the reaction can be done in air or water, and, in principle, is amenable to scaling up. The use of such optically tunable Fe2O3-Au nanoparticles for hyperthermia studies is an attractive option as it capitalizes on plasmonic heating of gold nanoparticles tuned to absorb light strongly in the VIS-NIR region. In addition to its plasmonic effects, nanoscale Au provides a unique surface for interesting chemistries and catalysis. The Fe2O3 material provides additional functionality due to its magnetic property. For example, an external magnetic field could be used to collect and recycle the hybrid Fe2O3-Au nanoparticles after a catalytic experiment, or alternatively, the magnetic Fe2O3 can be used for hyperthermia studies through magnetic heat induction. The photothermal experiment described in this report measures bulk temperature change and nanoparticle solution mass loss as functions of time using infrared thermocouples and a balance, respectively. The ease of sample preparation and the use of readily available equipment are distinct advantages of this technique. A caveat is that these photothermal measurements assess the bulk solution temperature and not the surface of the nanoparticle where the heat is transduced and the temperature is likely to be higher.

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

We describe the synthesis and properties of multifunctional Fe2O3-Au nanoparticles produced by a wet chemical approach and investigate their photothermal properties using laser irradiation. The composite Fe2O3-Au nanoparticles retain the properties of both materials, creating a multifunctional structure with excellent magnetic and plasmonic properties.

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to ...

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells

Here, we demonstrate the incorporation of monovalent cation additives into CH3NH3PbI3 perovskite in order to adjust the optical, excitonic, and electrical properties. The possibility of doping was investigated by adding monovalent cation halides with similar ionic radii to Pb2+, including Cu+, Na+, and Ag+. A shift in the Fermi level and a remarkable decrease of sub-bandgap optical absorption, along with a lower energetic disorder in the perovskite, was achieved. An order-of-magnitude enhancement in the bulk hole mobility and a significant reduction of transport activation energy within an additive-based perovskite device was attained. The confluence of the aforementioned improved properties in the presence of these cations led to an enhancement in the photovoltaic parameters of the perovskite solar cell. An increase of 70 mV in open circuit voltage for AgI and a 2 mA/cm2 improvement in photocurrent density for NaI- and CuBr-based solar cells were achieved compared to the pristine device. Our work paves the way for further improvements in the optoelectronic quality of CH3NH3PbI3 perovskite and subsequent devices. It highlights a new avenue for investigations on the role of dopant impurities in crystallization and controls the electronic defect density in perovskite structures.

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells

Here, we present a protocol to adjust the properties of solution-processed CH3NH3PbI3 through the incorporation of monovalent cation additives in order to achieve highly efficient perovskite solar cells.

Here, we demonstrate the incorporation of monovalent cation additives into CH3NH3PbI3 perovskite in order to adjust the optical, excitonic, and electrical ...

Subsurface Defect Localization by Structured Heating Using Laser Projected Photothermal Thermography

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering thermal wave fields that are disturbed by the defect. This effect is measured and used to locate the defect. We form the destructively interfering wave fields by using a modified projector. The original light engine of the projector is replaced with a fiber-coupled high-power diode laser. Its beam is shaped and aligned to the projector&#39;s spatial light modulator and optimized for optimal optical throughput and homogeneous projection by first characterizing the beam profile, and, second, correcting it mechanically and numerically. A high-performance infrared (IR) camera is set up according to the tight geometrical situation (including corrections of the geometrical image distortions) and the requirement to detect weak temperature oscillations at the sample surface. Data acquisition can be performed once a synchronization between the individual thermal wave field sources, the scanning stage, and the IR camera is established by using a dedicated experimental setup which needs to be tuned to the specific material being investigated. During data post-processing, the relevant information on the presence of a defect below the surface of the sample is extracted. It is retrieved from the oscillating part of the acquired thermal radiation coming from the so-called depletion line of the sample surface. The exact location of the defect is deduced from the analysis of the spatial-temporal shape of these oscillations in a final step. The method is reference-free and very sensitive to changes within the thermal wave field. So far, the method has been tested with steel samples but is applicable to different materials as well, in particular to temperature sensitive materials.

This method aims at locating vertical subsurface defects. Here, we couple a laser with a spatial light modulator and trigger its video input to heat a sample surface deterministically with two anti-phased modulated lines while acquiring highly resolved thermal images. The defect position is retrieved from evaluating thermal wave interference minima.

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters

Here, we demonstrate the advantages of the laser Doppler vibrometer (LDV) over conventional techniques (the network analyzer), as well as the techniques to create an application-based microelectromechanical systems (MEMS) filter and how to use it efficiently (i.e., tuning the tuning-capability and avoiding both failure and stiction). LDV enables crucial measurements that are impossible with the network analyzer, such as higher mode detection (highly sensitive biosensor application) and resonance measurement for very small devices (fast prototyping). Accordingly, LDV was used to characterize the frequency tuning range and resonance frequency at different modes of the MEMS filters built for this study. This wide range frequency tuning mechanism is based simply on Joule heating from the embedded heaters and relatively high thermal stress with respect to the temperature of a fixed-fixed beam. However, we demonstrate that another limitation of this method is the resulting high thermal stress, which can burn the devices. Further improvement was achieved and shown for the first time in this study, such that the tuning capability was increased by 32% through an increase in the applied DC bias voltage (25 V to 35 V) between the two adjacent beams. This important finding eliminates the need for the extra Joule heating at the wider frequency tuning range. Another possible failure is through stiction and requirement of structure optimization: We propose a simple and easy technique of low frequency square wave signal application that can successfully separate the beams and eliminates the need for the more sophisticated and complicated methods given in the literature. The above findings necessitate a design methodology, and so we also provide an application-based design.

A protocol for a fixed-fixed beam design using a laser Doppler vibrometer (LDV), including the measurement of frequency tuning, modification of tuning capability, and avoidance of device failure and stiction, is presented. The superiority of the LDV method over the network analyzer is demonstrated due to its higher mode capability.

Here, we demonstrate the advantages of the laser Doppler vibrometer (LDV) over conventional techniques (the network analyzer), as well as the techniques ...

Controllable Nucleation of Cavitation from Plasmonic Gold Nanoparticles for Enhancing High Intensity Focused Ultrasound Applications

In this study, plasmonic gold nanoparticles were simultaneously exposed to pulsed near-infrared laser light and high intensity focused ultrasound (HIFU) for the controllable nucleation of cavitation in tissue-mimicking gel phantoms. This in vitro protocol was developed to demonstrate the feasibility of this approach, for both enhancement of imaging and therapeutic applications for cancer. The same apparatus can be used for both imaging and therapeutic applications by varying the exposure duration of the HIFU system. For short duration exposures (10 &#181;s), broadband acoustic emissions were generated through the controlled nucleation of inertial cavitation around the gold nanoparticles. These emissions provide direct localization of nanoparticles. For future applications, these particles may be functionalized with molecular-targeting antibodies (e.g. anti-HER2 for breast cancer) and can provide precise localization of cancerous regions, complementing routine diagnostic ultrasound imaging. For continuous wave (CW) exposures, the cavitation activity was used to increase the localized heating from the HIFU exposures resulting in larger thermal damage in the gel phantoms. The acoustic emissions generated from inertial cavitation activity during these CW exposures was monitored using a passive cavitation detection (PCD) system to provide feedback of cavitation activity. Increased localized heating was only achieved through the unique combination of nanoparticles, laser light and HIFU. Further validation of this technique in pre-clinical models of cancer is necessary.

This protocol demonstrates the controllable nucleation of cavitation in gel phantoms, through simultaneous exposure to both near-infrared pulsed laser light and high intensity focused ultrasound (HIFU). The cavitation activity can then be used for enhancing imaging and/or therapeutic uses of HIFU.

In this study, plasmonic gold nanoparticles were simultaneously exposed to pulsed near-infrared laser light and high intensity focused ultrasound (HIFU) ...

Using Flexible Gold-Titanium Reaction Cells to Simulate Pressure-Dependent Microbial Activity in the Context of Subsurface Biomining

Laboratory studies investigating subsurface microbial processes, such as metal leaching in deep ore deposits (biomining), share common and challenging obstacles, including the special environmental conditions that need to be replicated, e.g., high pressure and in some cases acidic solutions. The former requires an experimental setup suitable for pressurization up to 100 bar, while the latter demands a fluid container with high chemical resistance against corrosion and unwanted chemical reactions with the container wall. To meet these conditions for an application in the field of in situ biomining, a special flexible gold-titanium reaction cell inside a rocking high-pressure reactor was used in this study. The described system allowed simulation of in situ biomining through sulfur-driven microbial iron reduction in an anoxic, pressure-controlled, highly chemically inert experimental environment. The flexible gold-titanium reaction cell can accommodate up to 100 mL of sample solution, which can be sampled at any given time point while the system maintains the desired pressure. Experiments can be performed on timescales ranging from hours to months. Assembling the high-pressure reactor system is fairly time consuming. Nevertheless, when complex and challenging (microbiological) processes occurring in the earth&#39;s deep subsurface in chemically aggressive fluids have to be investigated in the laboratory, the advantages of this system outweigh the disadvantages. The results found that even at high pressure the microbial consortium is active, but at significantly lower metabolic rates.

This protocol describes microbial experiments under elevated pressures to study in situ biomining processes. The experimental approach employs a rocking high-pressure reactor equipped with a gold-titanium reaction cell containing a microbial culture in an acidic, iron-rich medium.

Laboratory studies investigating subsurface microbial processes, such as metal leaching in deep ore deposits (biomining), share common and challenging ...

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

We present microfabrication protocols for rendering intrinsically wetting materials repellent to liquids (omniphobic) by creating gas-entrapping microtextures (GEMs) on them comprising cavities and pillars with reentrant and doubly reentrant features. Specifically, we use SiO2/Si as the model system and share protocols for two-dimensional (2D) designing, photolithography, isotropic/anisotropic etching techniques, thermal oxide growth, piranha cleaning, and storage towards achieving those microtextures. Even though the conventional wisdom indicates that roughening intrinsically wetting surfaces (&#952;o &#60; 90&#176;) renders them even more wetting (&#952;r &#60; &#952;o &#60; 90&#176;), GEMs demonstrate liquid repellence despite the intrinsic wettability of the substrate. For instance, despite the intrinsic wettability of silica &#952;o &#8776; 40&#176; for the water/air system, and &#952;o &#8776; 20&#176; for the hexadecane/air system, GEMs comprising cavities entrap air robustly on immersion in those liquids, and the apparent contact angles for the droplets are &#952;r &#62; 90&#176;. The reentrant and doubly reentrant features in the GEMs stabilize the intruding liquid meniscus thereby trapping the liquid-solid-vapor system in metastable air-filled states (Cassie states) and delaying wetting transitions to the thermodynamically-stable fully-filled state (Wenzel state) by, for instance, hours to months. Similarly, SiO2/Si surfaces with arrays of reentrant and doubly reentrant micropillars demonstrate extremely high contact angles (&#952;r &#8776; 150&#176;&#8211;160&#176;) and low contact angle hysteresis for the probe liquids, thus characterized as superomniphobic. However, on immersion in the same liquids, those surfaces dramatically lose their superomniphobicity and get fully-filled within &#60;1 s. To address this challenge, we present protocols for hybrid designs that comprise arrays of doubly reentrant pillars surrounded by walls with doubly reentrant profiles. Indeed, hybrid microtextures entrap air on immersion in the probe liquids. To summarize, the protocols described here should enable the investigation of GEMs in the context of achieving omniphobicity without chemical coatings, such as perfluorocarbons, which might unlock the scope of inexpensive common materials for applications as omniphobic materials. Silica microtextures could also serve as templates for soft materials.

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

This work presents microfabrication protocols for achieving cavities and pillars with reentrant and doubly reentrant profiles on SiO2/Si wafers using photolithography and dry etching. Resulting microtextured surfaces demonstrate remarkable liquid repellence, characterized by robust long-term entrapment of air under wetting liquids, despite the intrinsic wettability of silica.