Questo studio è stato sostenuto dal centro di applicazione del polimero GreenPAC come parte del progetto 140413: "stampa 3D in produzione". Vorremmo riconoscere Albert Hartman, Corinne van Noordenne, Rens van Leeuwen, Anniek Bruins, Femke Tamminga, Jur van Dijken e Albert Woortman per facilitare le riprese video.

Attenzione: Si prega di consultare tutte le schede di dati di sicurezza (MSDS) prima dell'uso.
1. preparazione della resina fotocurabili
Nota: Si prega di utilizzare dispositivi di protezione individuale (occhiali di sicurezza, guanti, camice da laboratorio) durante la procedura seguente. Vedi il nostro precedente lavoro12 per maggiori dettagli su questa sezione.
<ol><li>Versare 50 g di 1,10-decanediol Diacrilato (SA5201) in una beuta da 500 mL.</li>
	<li>Aggiungere 1,0 g di diphenyl(2,4,6-trimethylbenzoyl) fosfinossido (TPO) e 0,40 g di 2,5 -bis(5 -tert-butil-benzoxazol-2-yl) tiofene (BBOT) al pallone.</li>
	<li>Dotare la beuta con un agitatore meccanico e agitare la miscela a 200 rpm per 5 min a temperatura ambiente per sciogliere TPO e BBOT nel monomero acrilato.</li>
	<li>Aggiungere 100 g di pentaeritritolo tetracrilato e 100 g di acrilato a resina epossidica multifunzionale (Vedi Tabella materiali) alla miscela.</li>
	<li>Mescolare il composto a 200 rpm per 30 min a 50 ° C per garantire una resina omogenea.</li>
	<li>Rimuovere l'agitatore meccanico e montare il recipiente con un tappo. Il pallone è avvolto in un foglio di alluminio per proteggere la resina fotopolimerica acrilato di biobased (BAPR) dalla luce. Nota: Il protocollo può essere messo in pausa qui.</li>
	<li>Coprire la piastra inferiore di un reometro con geometria di piatti paralleli con il photoresin.</li>
	<li>Impostare la distanza tra le piastre a 1 mm e coprire il reometro con un cappuccio resistente alle raggi UV.</li>
	<li>Misurare la viscosità della resina a temperatura ambiente a tassi del taglio da 0,1 a 100 s-1; ad esempio,0.100, 0.126, 0,158, 0,200, 0.251, 0.316, 0.398, 0,501, 0.631, 0.794, 1.00, 1.26, 1.58, 2.00, 2,51, 3.16, 3,98, 5.01, 6,31, 7,94, 10.0, 12,6, 15,8, 20.0, 25,1, 31,6, 39,8, 50,1, 63,1, 79,4 e 100 s-1.</li>
</ol>2. Stereolithographic stampa 3D con Biobased acrilati
Nota: Vedere il nostro precedente lavoro12 per maggiori dettagli su questa sezione.
<ol><li>Accendere la stampante 3D di SLA e selezionare la modalità di apertura.</li>
	<li>Avviare il software di preparazione del modello in un computer. Scegliere impostazioni di stampa desiderato: materiale (trasparente), versione (V4) e spessore dello strato (50 µm).</li>
	<li>Aprire il modello digitale del prototipo di forma complessa, un file di lingua (STL) standard a mosaico (vedere File di codifica supplementare) e scegliere la posizione e l'orientamento sulla piattaforma di compilazione.  Caricare il processo di stampa dal software di preparazione del modello per la stampante 3D di SLA. Nota: A seconda dell'architettura del prodotto, una struttura di sostegno può essere integrata nel modello 3D per stabilizzare il costrutto durante la fabbricazione. In caso il prototipo di forma complessa dimostrato qui, una struttura di supporto non è necessaria se stampato normale alla direzione di compilazione.</li>
	<li>Versare 200 mL del photoresin biobased in un serbatoio di resina. Aprire la stampante 3D e montare correttamente il serbatoio di resina.</li>
	<li>Montare la piattaforma di compilazione e chiudere la stampante 3D.</li>
	<li>Avviare il processo di stampa.</li>
	<li>Attendere che la stampante 3D fabbricare prototipi a forma complesse.  Non aprire la stampante fino a quando il processo di stampa è terminato. Nota: Prima di stampare, assicurarsi che la stampante 3D è livellata. Per il protocollo ha dimostrato, la lunghezza d'onda del laser UV è 405 nm. La data di stampa dell'oggetto è 2,5 h.</li>
</ol>3. post-trattamento del 3D stampato oggetti
Nota: Si prega di utilizzare dispositivi di protezione individuale (occhiali di sicurezza, guanti) durante la procedura seguente.
<ol><li>Al termine il processo di stampa, aprire la stampante. Rimuovere la piattaforma di compilazione, con pezzi prodotti collegati e chiudere la stampante.</li>
	<li>Aprire la stazione di lavaggio, riempita con alcool isopropilico e inserire la piattaforma di compilazione. Avviare la procedura e risciacquo per 20 min rimuovere qualsiasi resina non reagito.</li>
	<li>Una volta ultimata la procedura di risciacquo, rimuovere la piattaforma di compilazione dalla stazione di lavaggio e scollegare i prototipi dalla piattaforma di compilazione.</li>
	<li>I prototipi per aria, lasciare asciugare per 30 min. Nel frattempo, preriscaldare il forno UV a 60 ° C. Nota: Preriscaldamento richiederà almeno 15 min. La lunghezza d'onda UV del forno è 405 nm, identica alla lunghezza d'onda del laser di SLA.</li>
	<li>Aprire il forno UV e posizionare rapidamente i prototipi sulla piattaforma rotante. Chiudere il forno UV e cura per 60 min a 60 ° C per garantire la completa conversione.</li>
	<li>Una volta ultimata la procedura di post-vulcanizzazione, aprire il forno UV e prendere dei prototipi.</li>
</ol>4. caratterizzazione della morfologia superficiale dei prototipi di forma complessa
Nota: Vedere il nostro precedente lavoro12 per maggiori dettagli su questa sezione.
<ol><li>Taglio ca. 1 cm dell'elica interna dal prototipo a forma complesso utilizzando una lama di rasoio.</li>
	<li>Fissare il campione per il portacampioni con nastro conduttivo double sided carbonio.</li>
	<li>Prima di formazione immagine, rivestire il campione con 30 nm Pt/Pd (80: 20) su un sistema di sputtering.</li>
	<li>Inserire il campione in un microscopio elettronico a scansione a una tensione di accelerazione di 5 kV. Acquisire diverse immagini del campione a 30x e 120 ingrandimenti.</li>
</ol>

<ol>
	<li>Van Wijk, A., van Wijk, 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> 3D Printing with Biomaterials: Towards a Sustainable and Circular Economy. , (2015).</li><li>Gross, B. C., Erkal, J. L., Lockwood, S. Y., Chen, C., Spence, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+3D+Printing+and+Its+Potential+Impact+on+Biotechnology+and+the+Chemical+Sciences.">Evaluation of 3D Printing and Its Potential Impact on Biotechnology and the Chemical Sciences.</a> Analytical Chemistry. 86, 3240-3253 (2014).</li><li>Chia, H. N., Wu, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+3D+printing+of+biomaterials.">Recent advances in 3D printing of biomaterials.</a> Journal of Biological Engineering. 9, 4 (2015).</li><li>Mechels, F. P. W., Feijen, J., Grijpma, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+on+stereolithography+and+its+applications+in+biomedical+engineering.">A review on stereolithography and its applications in biomedical engineering.</a> Biomaterials. 31, 6121-6130 (2010).</li><li>Skoog, S. A., Goering, P. L., Narayan, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stereolithography+in+tissue+engineering.">Stereolithography in tissue engineering.</a> Journal of Materials Science: Materials in Medicine. 25, 845-856 (2014).</li><li>Bhatia, S. K., Ramadurai, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> 3D Printing and Bio-Based Materials in Global Health. , (2017).</li><li>Oskui, S. M., Diamante, G., Liao, C., Shi, W., Gan, J., Schlenk, D., Grover, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+and+Reducing+the+Toxicity+of+3D-Printed+Parts.">Assessing and Reducing the Toxicity of 3D-Printed Parts.</a> Environmental Science &amp; Technology Letters. 3, 1-6 (2016).</li><li>Gong, H., Beauchamp, M., Perry, S., Woolley, A. T., Nordin, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+approach+to+resin+formulation+for+3D+printed+microfluidics.">Optical approach to resin formulation for 3D printed microfluidics.</a> RSC Advances. 5, 106621-106632 (2015).</li><li>Zarek, M., Layani, M., Cooperstein, I., Sachyani, E., Cohn, D., Magdassi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+printing+of+shape+memory+polymers+for+flexible+electronic+devices.">3D printing of shape memory polymers for flexible electronic devices.</a> Advanced Materials. 28, 4449-4454 (2016).</li><li>Ligon-Auer, S. C., Schwentenwein, M., Gorsche, C., Stampfl, J., Liska, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toughening+of+photo-curable+polymer+networks:+A+review.">Toughening of photo-curable polymer networks: A review.</a> Polymer Chemistry. 7, 257-286 (2016).</li><li>Miao, S., Zhu, W., Castro, N. J., Nowicki, M., Zhou, X., Cui, H., Fisher, J. P., Zhang, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=4D+printing+smart+biomedical+scaffolds+with+novel+soybean+oil+epoxidized+acrylate.">4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate.</a> Scientific Reports. 6, 27226 (2016).</li><li>Voet, V. S. D., Strating, T., Schnelting, G. H. M., Dijkstra, P., Tietema, M., Xu, J., Woortman, A. J. J., Loos, K., Jager, J., Folkersma, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biobased+acrylate+photocurable+resin+formulation+for+stereolithographic+3D+printing.">Biobased acrylate photocurable resin formulation for stereolithographic 3D printing.</a> ACS Omega. 3, 1403-1408 (2018).</li><li>Ligon-Auer, S. C., Liska, R., Stampfl, J., Gurr, M., M&#252;lhaupt, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymers+for+3D+Printing+and+Customized+Additive+Manufacturing.">Polymers for 3D Printing and Customized Additive Manufacturing.</a> Chemical Reviews. 117, 10212-10290 (2017).</li><li>Weng, Z., Zhou, Y., Lin, W., Senthil, T., Wu, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure-property+relationship+of+nano+enhanced+stereolithography+resin+for+desktop+SLA+3D+printer.">Structure-property relationship of nano enhanced stereolithography resin for desktop SLA 3D printer.</a> Composites: Part A. 88, 234-242 (2016).</li><li>Scalera, F., Esposito Corcione, C., Montagna, F., Sannino, A., Maffezzoli, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+characterization+of+UV+curable+epoxy/hydroxyapatite+suspensions+for+stereolithography+applied+to+bone+tissue+engineering.">Development and characterization of UV curable epoxy/hydroxyapatite suspensions for stereolithography applied to bone tissue engineering.</a> Ceramics International. 40, 15455-15462 (2014).</li><li>Lee, H., Fang, N. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micro+3D+Printing+using+a+digital+projector+and+its+application+in+the+study+of+soft+materials+mechanics.">Micro 3D Printing using a digital projector and its application in the study of soft materials mechanics.</a> Journal of Visualized Experiments. (69), e4457 (2012).</li><li>Huemer, K., Squirrell, J. M., Swader, R., Pelkey, K., LeBert, D. C., Huttenlocher, A., Eliceiri, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+live+imaging+device+for+improved+experimental+manipulation+of+zebrafish+larvae.">Long-term live imaging device for improved experimental manipulation of zebrafish larvae.</a> Journal of Visualized Experiments. (128), e56340 (2017).</li><li>Decker, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-induced+crosslinking+polymerization.">Light-induced crosslinking polymerization.</a> Polymer International. 51, 1141-1150 (2002).</li><li>Elliot, J. E., Bowman, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predicting+network+formation+of+free+radical+polymerization+of+multifunctional+monomers.">Predicting network formation of free radical polymerization of multifunctional monomers.</a> Polymer Reaction Engineering. 10, 1-19 (2002).</li><li>Ellakwa, A., Cho, N., Lee, I. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+resin+matrix+composition+on+the+polymerization+shrinkage+and+rheological+properties+of+experimental+dental+composites.">The effect of resin matrix composition on the polymerization shrinkage and rheological properties of experimental dental composites.</a> Dental Materials. 23, 1229-1235 (2007).</li><li>Charton, C., Falk, V., Marchal, P., Pla, F., Colon, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+Tg,+viscosity+and+chemical+structure+of+monomers+on+shrinkage+stress+in+light-cured+dimethacrylate-based+dental+resins.">Influence of Tg, viscosity and chemical structure of monomers on shrinkage stress in light-cured dimethacrylate-based dental resins.</a> Dental Materials. 23, 1447-1459 (2007).</li></ol>

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Produzione additiva viene applicato nella fabbricazione di prototipi su misura e piccole serie, quando i più alti costi di produzione per pezzo possono competere con i processi convenzionali, poiché non vi è alcuna necessità di produzione di stampi e utensili. Nell'ultimo decennio, i ricavi da servizi e prodotti legati alla produzione di additivi sono cresciuti esponenzialmente13. La frazione più grande di vendita di materiale è da fotopolimeri. La crescita ha attirato l'attenzione e ha avvi...

Prototipazione rapida consente libertà di progettazione e produzione su richiesta e che la produzione efficiente di 3D costruisce in un modo a strati1. Di conseguenza, stampa 3D come una tecnica di fabbricazione è sviluppato rapidamente in anni recenti2. Varie tecnologie sono disponibili, tutti basandosi sulla traduzione di modelli virtuali in oggetti fisici e l'applicazione di processi come estrusione, deposizione di energia diretta, solidificazione di polvere, foglio di laminazione e fotopolimerizzazione. Quest'ultima coinvolge graduale indurimento UV delle resine in fotopolimero liquido. Nel 1986, scafo e colleghi di lavoro sviluppato apparato di stereolitografia (SLA), una stampante 3D basati su laser UV. Più recentemente, un processo simile chiamato digital light processing (DLP) è diventato disponibile, in cui fotopolimerizzazione è iniziata da un proiettore. Insieme, DLP e SLA vengono denominati per stereolitografia 3D stampa3.
SLA viene applicato in alta risoluzione prototipazione e realizzazione di dispositivi biomedicali4,5. Questa tecnologia è superiore all'ampiamente usata deposizione fusa modellazione (FDM) in termini di precisione, finitura superficiale e risoluzione6. A seconda dell'architettura del prodotto, una struttura di supporto è integrata nel modello 3D per stabilizzare il costrutto durante la fabbricazione. Inoltre, un trattamento post-stampa dei pezzi prodotti è richiesto7,8. In genere, oggetti stampati vengono lavati in un bagno di alcool per sciogliere la resina non reagita, e successiva polimerizzazione in forno UV viene eseguita per garantire piena conversione della polimerizzazione9.
In generale, resine per la produzione additiva basati su Litografia si affidano fotocurabili sistemi contenenti multifunzionale acrilati o epossidi10. Le resine fotopolimeriche attuale sul mercato commerciale sono basata sui combustibili fossili e costosi, mentre la disponibilità di basso costo rinnovabili resine è necessario per facilitare la produzione locale e senza sprechi di prodotti sostenibili 3D per un biobased economia1 , 6. recentemente, resine fotopolimeriche basate su rinnovabili acrilati erano sviluppate e applicate con successo in stereolitografia 3D stampa11,12. In questo protocollo dettagliato, dimostriamo la prototipazione rapida con resine biobased su un apparato commerciale stereolitografia. Particolare attenzione è rivolta ai passaggi critici della procedura, cioè, resina formulazione e post-stampa trattamenti, per aiutare gli operatori di nuovi nel campo della produzione additiva.

<table>
	<tbody>
		<tr>
			<td>Isobornyl acrylate&#160;</td>
			<td>Sartomer</td>
			<td>SA5102</td>
			<td>Acrylate monomer</td>
		</tr>
		<tr>
			<td>1,10-decanediol diacrylate</td>
			<td>Sartomer</td>
			<td>SA5201</td>
			<td>Acrylate monomer</td>
		</tr>
		<tr>
			<td>Pentaerythritol tetraacrylate</td>
			<td>Sartomer</td>
			<td>SA5400</td>
			<td>Acrylate monomer</td>
		</tr>
		<tr>
			<td>Multifunctional epoxy acrylate</td>
			<td>Sartomer</td>
			<td>SA7101</td>
			<td>Acrylate oligomer</td>
		</tr>
		<tr>
			<td>Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 97%</td>
			<td>Sigma Aldrich</td>
			<td>415952</td>
			<td>Photoinitiator</td>
		</tr>
		<tr>
			<td>2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene (BBOT), 99%</td>
			<td>Sigma Aldrich</td>
			<td>223999</td>
			<td>Optical absorber</td>
		</tr>
		<tr>
			<td>Isopropyl alcohol (IPA), 99%</td>
			<td>Bleko</td>
			<td>1010500</td>
			<td>For alcohol bath (applied in Form Wash)</td>
		</tr>
		<tr>
			<td>Paar Physica MCR300&#160;</td>
			<td>Anton Paar</td>
			<td>-</td>
			<td>Rheometer with parallel plate geometry</td>
		</tr>
		<tr>
			<td>Form 2 Printer</td>
			<td>Formlabs</td>
			<td>-</td>
			<td>Desktop SLA 3D printer</td>
		</tr>
		<tr>
			<td>Form Wash&#160;</td>
			<td>Formlabs</td>
			<td>-</td>
			<td>Washing station</td>
		</tr>
		<tr>
			<td>Form Cure</td>
			<td>Formlabs</td>
			<td>-</td>
			<td>UV oven</td>
		</tr>
		<tr>
			<td>Instron 4301 1KN Series IX</td>
			<td>Instron</td>
			<td>-</td>
			<td>Universal testing machine</td>
		</tr>
		<tr>
			<td>Philips XL30 ESEM-FEG&#160;</td>
			<td>Philips</td>
			<td>-</td>
			<td>Scanning electron microscope</td>
		</tr>
	</tbody>
</table>

stereolithographic 3d printing with renewable acrylates

L'accessibilità di costi competitivi materiali rinnovabili e la loro applicazione nella produzione di additivi è essenziale per un'economia efficiente biobased. Dimostriamo la prototipazione rapida di resine sostenibile utilizzando una stampante 3D di stereolithographic. Formulazione della resina avviene mediante semplice miscela di biobased acrilato monomeri e oligomeri con un photoinitiatior e assorbitore di ottico. Viscosità della resina è controllata dal monomero rapporto oligomero e viene determinato in funzione della velocità di taglio di un reometro con geometria parallela del piatto. Un apparato di stereolithographic addebitato con le resine biobased è impiegato per produrre prototipi a forma complessi con elevata precisione. I prodotti richiedono un post-trattamento, tra cui alcol risciacquo e irradiazione UV, per garantire una polimerizzazione completa. La caratteristica alta risoluzione e superficie eccellente finitura dei prototipi è rivelato da microscopia elettronica a scansione.

Quattro composizioni di resina rappresentante vengono visualizzati in tabella 1, insieme al loro contenuto di carbonio biobased medio (BC) derivato dal AC individuale dei componenti. La viscosità della resina (Figura 1) è influenzata dal rapporto di acrilato monomeri e oligomeri e in genere viene illustrato comportamento newtoniano. Le proprietà meccaniche di parti prodotte da varie resine sono state determinate mediante analisi di solleci...

Watch this Scientific Journal Video about Stereolithographic 3D Printing with Renewable Acrylates at JoVE.com

Stereolithographic 3D Printing with Renewable Acrylates

Un protocollo per la produzione additiva con resine fotopolimeriche rinnovabili su un apparato di stereolitografia è presentato.

Stereolithographic stampa 3D con rinnovabili acrilati

The accessibility of cost-competitive renewable materials and their application in additive manufacturing is essential for an efficient biobased economy. ...

stereolithographic-3d-printing-with-renewable-acrylates

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Chemistry

9.4K Views.  NHL Stenden University of Applied Sciences. Un protocollo per la produzione additiva con resine fotopolimeriche rinnovabili su un apparato di stereolitografia è presentato.

Video: Stereolithographic 3D Printing with Renewable Acrylates

Photodynamic Therapy with Blended Conducting Polymer/Fullerene Nanoparticle Photosensitizers

In this article a method for the fabrication and reproducible in-vitro evaluation of conducting polymer nanoparticles blended with fullerene as the next generation photosensitizers for Photodynamic Therapy (PDT) is reported. The nanoparticles are formed by hydrophobic interaction of the semiconducting polymer MEH-PPV (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]) with the fullerene PCBM (phenyl-C61-butyric acid methyl ester) in the presence of a non-compatible solvent. MEH-PPV has a high extinction coefficient that leads to high rates of triplet formation, and efficient charge and energy transfer to the fullerene PCBM. The latter processes enhance the efficiency of the PDT system through fullerene assisted triplet and radical formation, and ultrafast deactivation of MEH-PPV excited stated. The results reported here show that this nanoparticle PDT sensitizing system is highly effective and shows unexpected specificity to cancer cell lines.

This protocol describes a method for the fabrication of conducting polymer nanoparticles blended with fullerene. These nanoparticles were investigated for their potential use as a next generation photosensitizers for Photodynamic Therapy (PDT).

Terapia fotodinamica con Blended Condurre Polimero / Fullerene nanoparticelle fotosensibilizzanti

In this article a method for the fabrication and reproducible in-vitro evaluation of conducting polymer nanoparticles blended with fullerene as the next ...

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Chimica

Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls cause an increase in viscosity (often referred to as &#39;aging&#39;) during storage of bio-oils. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Additionally, carbonyls are also responsible for coke formation in bio-oil upgrading processes. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here, we present a modification of the traditional carbonyl oximation procedures that results in less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. While traditional carbonyl oximation methods occur at room temperature, the Faix method presented here occurs at an elevated temperature of 80 &#176;C.

Here we present a potentiometric titration technique for accurately quantifying carbonyl compounds in pyrolysis bio-oils.

Determinazione del carbonile gruppi funzionali in Bio-oli da potenziometrica Titolazione: Il Metodo Faix

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls ...

Temperature-programmed Deoxygenation of Acetic Acid on Molybdenum Carbide Catalysts

Temperature programmed reaction (TPRxn) is a simple yet powerful tool for screening solid catalyst performance at a variety of conditions. A TPRxn system includes a reactor, furnace, gas and vapor sources, flow control, instrumentation to quantify reaction products (e.g., gas chromatograph), and instrumentation to monitor the reaction in real time (e.g., mass spectrometer). Here, we apply the TPRxn methodology to study molybdenum carbide catalysts for the deoxygenation of acetic acid, an important reaction among many in the upgrading/stabilization of biomass pyrolysis vapors. TPRxn is used to evaluate catalyst activity and selectivity and to test hypothetical reaction pathways (e.g., decarbonylation, ketonization, and hydrogenation). The results of the TPRxn study of acetic acid deoxygenation show that molybdenum carbide is an active catalyst for this reaction at temperatures above ca. 300 &#176;C and that the reaction favors deoxygenation (i.e., C-O bond-breaking) products at temperatures below ca. 400 &#176;C and decarbonylation (i.e., C-C bond-breaking) products at temperatures above ca. 400 &#176;C.

Presented here is a protocol for the operation of a micro-scale temperature-programmed reactor for evaluating the catalytic performance of molybdenum carbide during acetic acid deoxygenation.

Deossigenazione temperatura programmata di acido acetico sulla Molibdeno Carbide Catalizzatori

Temperature programmed reaction (TPRxn) is a simple yet powerful tool for screening solid catalyst performance at a variety of conditions. A TPRxn system ...

Microfluidic-based Synthesis of Covalent Organic Frameworks (COFs): A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

Covalent Organic Frameworks (COFs) are a class of porous covalent materials which are frequently synthesized as unprocessable crystalline powders. The first COF was reported in 2005 with much effort centered on the establishment of new synthetic routes for its preparation. To date, most available synthetic methods for COF synthesis are based on bulk mixing under solvothermal conditions. Therefore, there is increasing interest in developing systematic protocols for COF synthesis that provide for fine control over reaction conditions and improve COF processability on surfaces, which is essential for their use in practical applications. Herein, we present a novel microfluidic-based method for COF synthesis where the reaction between two constituent building blocks, 1,3,5-benzenetricarbaldehyde (BTCA) and 1,3,5-tris(4-aminophenyl)benzene (TAPB), takes place under controlled diffusion conditions and at room temperature. Using such an approach yields sponge-like, crystalline fibers of a COF material, hereafter called MF-COF. The mechanical properties of MF-COF and the dynamic nature of the approach allow the continuous production of MF-COF fibers and their direct printing onto surfaces. The general method opens new potential applications requiring advanced printing of 2D or 3D COF structures on flexible or rigid surfaces.

Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

We present a novel microfluidic-based method for synthesis of covalent organic frameworks (COFs). We demonstrate how this approach can be used to produce continuous COF fibers, and also 2D or 3D COF structures on surfaces.

Sintesi microfluidica a base di strutture organiche COF (COF): uno strumento per la produzione continua di fibre COF e stampa diretta su una superficie

Covalent Organic Frameworks (COFs) are a class of porous covalent materials which are frequently synthesized as unprocessable crystalline powders. The ...

Preparation of Chitosan-based Injectable Hydrogels and Its Application in 3D Cell Culture

The protocol presents a facile, efficient, and versatile method to prepare chitosan-based hydrogels using dynamic imine chemistry. The hydrogel is prepared by mixing solutions of glycol chitosan with a synthesized benzaldehyde terminated polymer gelator, and hydrogels are efficiently obtained in several minutes at room temperature. By varying ratios between glycol chitosan, polymer gelator, and water contents, versatile hydrogels with different gelation times and stiffness are obtained. When damaged, the hydrogel can recover its appearances and modulus, due to the reversibility of the dynamic imine bonds as crosslinkages. This self-healable property enables the hydrogel to be injectable since it can be self-healed from squeezed pieces to an integral bulk hydrogel after the injection process. The hydrogel is also multi-responsive to many bio-active stimuli due to different equilibration statuses of the dynamic imine bonds. This hydrogel was confirmed as bio-compatible, and L929 mouse fibroblast cells were embedded following standard procedures and the cell proliferation was easily assessed by a 3D cell cultivation process. The hydrogel can offer an adjustable platform for different research where a physiological mimic of a 3D environment for cells is profited. Along with its multi-responsive, self-healable, and injectable properties, the hydrogels can potentially be applied as multiple carriers for drugs and cells in future bio-medical applications.

Here we describe a facile preparation of chitosan-based injectable hydrogels using dynamic imine chemistry. Methods to adjust the hydrogel&#8217;s mechanical strength and its application in 3D cell culture are presented.

Preparazione di idrogeli iniettabili a base di chitosano e la sua applicazione nella coltura cellulare 3D

The protocol presents a facile, efficient, and versatile method to prepare chitosan-based hydrogels using dynamic imine chemistry. The hydrogel is ...

Synthesis of Platinum-nickel Nanowires and Optimization for Oxygen Reduction Performance

Platinum-nickel (Pt-Ni) nanowires were developed as fuel cell electrocatalysts, and were optimized for the performance and durability in the oxygen reduction reaction. Spontaneous galvanic displacement was used to deposit Pt layers onto Ni nanowire substrates. The synthesis approach produced catalysts with high specific activities and high Pt surface areas. Hydrogen annealing improved Pt and Ni mixing and specific activity. Acid leaching was used to preferentially remove Ni near the nanowire surface, and oxygen annealing was used to stabilize near-surface Ni, improving durability and minimizing Ni dissolution. These protocols detail the optimization of each post-synthesis processing step, including hydrogen annealing to 250 &#176;C, exposure to 0.1 M nitric acid, and oxygen annealing to 175 &#176;C. Through these steps, Pt-Ni nanowires produced increased activities more than an order of magnitude than Pt nanoparticles, while offering significant durability improvements. The presented protocols are based on Pt-Ni systems in the development of fuel cell catalysts. These techniques have also been used for a variety of metal combinations, and can be applied to develop catalysts for a number of electrochemical processes.

&#160; The protocol describes the synthesis and electrochemical testing of platinum-nickel nanowires. Nanowires were synthesized by the galvanic displacement of a nickel nanowire template. Post-synthesis processing, including hydrogen annealing, acid leaching, and oxygen annealing were used to optimize nanowire performance and durability in the oxygen reduction reaction.

Sintesi di nanofili di platino-nichel e ottimizzazione per le prestazioni di riduzione di ossigeno

Platinum-nickel (Pt-Ni) nanowires were developed as fuel cell electrocatalysts, and were optimized for the performance and durability in the oxygen ...

Obtaining 3D Chemical Maps by Energy Filtered Transmission Electron Microscopy Tomography

Energy filtered transmission electron microscopy tomography (EFTEM tomography) can provide three-dimensional (3D) chemical maps of materials at a nanometric scale. EFTEM tomography can separate chemical elements that are very difficult to distinguish using other imaging techniques. The experimental protocol described here shows how to create 3D chemical maps to understand the chemical distribution and morphology of a material. Sample preparation steps for data segmentation are presented. This protocol permits the 3D distribution analysis of chemical elements in a nanometric sample. However, it should be noted that currently, the 3D chemical maps can only be generated for samples that are not beam sensitive, since the recording of filtered images requires long exposure times to an intense electron beam. The protocol was applied to quantify the chemical distribution of the components of two different heterogeneous catalyst supports. In the first study, the chemical distribution of aluminum and titanium in titania-alumina supports was analyzed. The samples were prepared using the swing-pH method. In the second, the chemical distribution of aluminum and silicon in silica-alumina supports that were prepared using the sol-powder and mechanical mixture methods was examined.

This paper describes a protocol to achieve 3D chemical maps combining energy filtered imaging and electron tomography. The chemical distribution of two catalyst supports formed by elements that are difficult to distinguish by other imaging techniques was studied. Each application consists of mapping overlapped chemical elements - respectively spaced-ionization edges.

Come ottenere mappe 3D chimiche di energia filtrata tomografia di microscopia elettronica di trasmissione

Energy filtered transmission electron microscopy tomography (EFTEM tomography) can provide three-dimensional (3D) chemical maps of materials at a ...

Methionine Functionalized Biocompatible Block Copolymers for Targeted Plasmid DNA Delivery

Reversible addition-fragmentation chain transfer (RAFT) polymerization integrates the advantages of radical polymerization and living polymerization. This work presents the preparation of methionine functionalized biocompatible block copolymers via RAFT polymerization. Firstly, N,N-bis(2-hydroxyethyl)methacrylamide-b-N-(3-aminopropyl)methacrylamide (BNHEMA-b-APMA, BA) was synthesized via RAFT polymerization using 4,4&#8217;-azobis(4-cyanovaleric acid) (ACVA) as an initiating agent and 4-cyanopentanoic acid dithiobenzoate (CTP) as the chain transfer agent. Subsequently, N,N-bis(2-hydroxyethyl)methacrylamide-b-N-(3-guanidinopropyl)methacrylamide (methionine grafted BNHEMA-b-GPMA, mBG) was prepared by modifying amine groups in APMA with methionine and guanidine groups. Three kinds of block polymers, mBG1, mBG2, and mBG3, were synthesized for comparison. A ninhydrin reaction was used to quantify the APMA content; mBG1, mBG2, and mBG3 had 21%, 37%, and 52% of APMA, respectively. Gel permeation chromatography (GPC) results showed that BA copolymers possess molecular weights of 16,200 (BA1), 20,900(BA2), and 27,200(BA3) g/mol. The plasmid DNA (pDNA) complexing ability of the obtained block copolymer gene carriers was also investigated. The charge ratios (N/P) were 8, 16, and 4 when pDNA was complexed completely with mBG1, mBG2, mBG3, respectively. When the N/P ratio of mBG/pDNA polyplexes was higher than 1, the Zeta potential of mBG was positive. At an N/P ratio between 16 and 32, the average particle size of mBG/pDNA polyplexes was between 100-200 nm. Overall, this work illustrates a simple and convenient protocol for the block copolymer carrier synthesis.

This work presents the preparation of methionine functionalized biocompatible block copolymers (mBG) via the reversible addition-fragmentation chain transfer (RAFT) method. The plasmid DNA complexing ability of the obtained mBG and their transfection efficiency were also investigated. The RAFT method is very beneficial for polymerizing monomers containing special functional groups.

Meticolosina Sistemi colatori di blocchi biocompatibili per la consegna mirata del DNA plasmide

Reversible addition-fragmentation chain transfer (RAFT) polymerization integrates the advantages of radical polymerization and living polymerization. This ...

Inkjet Printing All Inorganic Halide Perovskite Inks for Photovoltaic Applications

A method for synthesizing photoactive inorganic&#160;perovskite quantum dot inks and an inkjet printer deposition method, using the synthesized inks, are demonstrated. The ink synthesis is based on a simple wet chemical reaction and the inkjet printing protocol is a facile step by step method. The inkjet printed thin films have been characterized by X-ray diffraction, optical absorption spectroscopy, photoluminescent spectroscopy, and electronic transport measurements. X-ray diffraction of the printed quantum dot films indicates a crystal structure consistent with an orthorhombic room temperature phase with (001) orientation. In conjunction with other characterization methods, the X-ray diffraction&#160;measurements show high quality films can be obtained through the inkjet printing method.

A protocol for synthesizing inorganic-lead-halide hybrid perovskite quantum dot inks for inkjet printing and the protocol for preparing and printing the quantum dot inks in an inkjet printer with post characterization techniques are presented.

A getto d'inchiostro stampa tutti gli inchiostri di Perovskite alogenuro inorganici per applicazioni fotovoltaiche

A method for synthesizing photoactive inorganic&#160;perovskite quantum dot inks and an inkjet printer deposition method, using the synthesized inks, are ...

Reactive Inkjet Printing and Propulsion Analysis of Silk-based Self-propelled Micro-stirrers

In this study, a protocol for using reactive inkjet printing to fabricate enzymatically propelled silk swimmers with well-defined shapes is reported. The resulting devices are an example of self-propelled objects capable of generating motion without external actuation and have potential applications in medicine and environmental sciences for a variety of purposes ranging from micro-stirring, targeted therapeutic delivery, to water remediation (e.g., cleaning oil spills). This method employs reactive inkjet printing to generate well-defined small-scale solid silk structures by converting water soluble regenerated silk fibroin (silk I) to insoluble silk fibroin (silk II). These structures are also selectively doped in specific regions with the enzyme catalase in order to produce motion via bubble generation and detachment. The number of layers printed determines the three-dimensional (3D) structure of the device, and so here the effect of this parameter on the propulsive trajectories is reported. The results demonstrate the ability to tune the motion by varying the dimensions of the printed structures.

This protocol demonstrates the ability to utilize reactive inkjet printing to print self-motile biocompatible and environmentally friendly micro-stirrers for use in biomedical and environmental applications.

Stampa a getto d'inchiostro reattiva e analisi di propulsione di micro-agitatori semoventi a base di seta

In this study, a protocol for using reactive inkjet printing to fabricate enzymatically propelled silk swimmers with well-defined shapes is reported. The ...