Die Autoren danken Marko Nieuwenhuizen für die Unterstützung bei der DOSY-NMR.

<ol>
	<li>Palmer, L. C., Stupp, S. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+self-assembly+into+one-dimensional+nanostructures.">Molecular self-assembly into one-dimensional nanostructures.</a> Acc. Chem. Res. 41, 1674-1684 (2008).</li><li>Janssen, P. G. A., Vandenbergh, J., van Dongen, J. L. J., Meijer, E. W., Schenning, A. P. H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ssDNA+templated+self-assembly+of+chromophores.">ssDNA templated self-assembly of chromophores.</a> J. Am. Chem. Soc. 129, 6078-6079 (2007).</li><li>Bull, S. R., Palmer, L. C., Fry, N. J., Greenfield, M. A., Messmore, B. W., Meade, T. J., Stupp, S. 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+templating+approach+for+monodisperse+self-assembled+organic+nanostructures.">A templating approach for monodisperse self-assembled organic nanostructures.</a> J. Am. Chem. Soc. 130, 2742-2743 (2008).</li><li>Lortie, F., Boileau, S., Bouteiller, L., Chassenieux, C., Laupr&#234;tre, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chain+stopper-assisted+characterization+of+supramolecular+polymers.">Chain stopper-assisted characterization of supramolecular polymers.</a> Macromolecules. 38, 5283-5287 (2005).</li><li>Wang, X., Guerin, G., Wang, H., Wang, Y., Manners, I., Winnik, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cylindrical+block+copolymer+micelles+and+co-micelles+of+controlled+length+and+architecture.">Cylindrical block copolymer micelles and co-micelles of controlled length and architecture.</a> Science. 317, 644-647 (2007).</li><li>Besenius, P., Portale, G., Bomans, P. H. H., Janssen, H. M., Palmans, A. R. A., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlling+the+growth+and+shape+of+chiral+supramolecular+polymers+in+water.">Controlling the growth and shape of chiral supramolecular polymers in water.</a> Proc. Natl. Acad. Sci. U.S.A. 107, 17888-17893 (2010).</li><li>Besenius, P., van den Hout, K. P., Albers, H. M. H. G., de Greef, T. F. A., Olijve, L. L. C., Hermans, T. M., de Waal, B. F. M., Bomans, P. H. H., Sommerdijk, N. A. J. M., Portale, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlled+supramolecular+oligomerisation+of+C3-symmetrical+molecules+in+water:+the+impact+of+hydrophobic+shielding.">Controlled supramolecular oligomerisation of C3-symmetrical molecules in water: the impact of hydrophobic shielding.</a> Chem. Eur. J. 17, 5193-5203 (2011).</li><li>Smulders, M. M. J., Schenning, A. P. H. J., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+into+the+mechanisms+of+cooperative+self-assembly:+the+sergeants-and-soldiers+principle+of+chiral+and+achiral+C3-symmetrical+discotic+triamides.">Insights into the mechanisms of cooperative self-assembly: the sergeants-and-soldiers principle of chiral and achiral C3-symmetrical discotic triamides.</a> J. Am. Chem. Soc. 130, 606-611 (2008).</li><li>Jonkheijm, P., van der Schoot, P., Schenning, A. P. H. J., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+the+solvent-assisted+nucleation+pathway+in+chemical+self-assembly.">Probing the solvent-assisted nucleation pathway in chemical self-assembly.</a> Science. 313, 80-83 (2006).</li><li>Bosman, A. W., Janssen, H. M., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=About+dendrimers:+structure,+physical+properties,+and+applications.">About dendrimers: structure, physical properties, and applications.</a> Chem. Rev. 99, 1665-1688 (1999).</li><li>Veld, M. A. J., Haveman, D., Palmans, A. R. A., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sterically+demanding+benzene-1,3,5-tricarboxamides:+tuning+the+mechanisms+of+supramolecular+polymerization+and+chiral+amplification.">Sterically demanding benzene-1,3,5-tricarboxamides: tuning the mechanisms of supramolecular polymerization and chiral amplification.</a> Soft Matter. 7, 524-531 (2011).</li><li>Stals, P. J. M., Smulders, M. M. J., Mart&#237;n-Rap&#237;n, R., Palmans, A. R. A., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Asymmetrically+substituted+benzene-1,3,5-tricarboxamides:+self-assembly+and+odd-even+effects+in+the+solid+state+and+in+dilute+solution.">Asymmetrically substituted benzene-1,3,5-tricarboxamides: self-assembly and odd-even effects in the solid state and in dilute solution.</a> Chem. Eur. J. 15, 2071-2080 (2009).</li><li>De Greef, T. F. A., Smulders, M. M. J., Wolffs, M., Schenning, A. P. H. J., Sijbesma, R. P., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Supramolecular+polymerization.">Supramolecular polymerization.</a> Chem. Rev. 109, 5687-5754 (2009).</li><li>Smulders, M. M. J., Nieuwenhuizen, M. M. L., de Greef, T. F. A., Schoot, P. v. a. n. d. e. r., Schenning, A. P. H. J., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+distinguish+isodesmic+from+cooperative+supramolecular+polymerization?+Chem.">How to distinguish isodesmic from cooperative supramolecular polymerization? Chem.</a> Eur. J. 16, 362-367 (2010).</li><li>Besenius, P., Heynens, J. L. M., Straathof, R., Nieuwenhuizen, M. M. L., Bomans, P. H. H., Terreno, E., Aime, S., Strijkers, G. J., Nicolay, K., Meijer, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Paramagnetic+self-assembled+nanoparticles+as+supramolecular+MRI+contrast+agents.">Paramagnetic self-assembled nanoparticles as supramolecular MRI contrast agents.</a> Contrast Media Mol. Imaging. , (2012).</li></ol>

Keine Interessenskonflikte erklärt.

Die sich selbst organisierenden diskotischen Amphiphile in diesem Beitrag mit dem Gd (III)-DTPA-Komplex diskutiert werden derzeit untersucht, wie neuartige Magnet-Resonanz-Tomographie (MRT) Agenten, die einen hohen Kontrast kombinieren mit einstellbarer Ausscheidung Zeiten. 15 Daher sind die Angaben zu ihrem Selbst- Montage Verhalten und ihre Stabilität unter verschiedenen Bedingungen sind von entscheidender Bedeutung. Die Kombination aus spektroskopischen (CD-und NMR), (SAXS) und Mikroskopie (Cryo-TEM)-Techniken ermöglicht die Visualisierung der gebildeten Strukturen und die Quantifizierung ihrer thermodynamischen Parameter. Diese Kombination von Techniken ist allgemein anwendbar für sich selbst organisierenden Molekülen, solange eine bevorzugte Schraubensinns in das untersuchte System ermöglicht einen Unterschied in der Absorption von links und rechts-zirkular polarisiertes Licht.

<table border="1"><tbody><tr><td> Name des Reagenz / Ausrüstung </td><td> Firma </td><td> Katalog-Nummer </td><td> Kommentare </td></tr><tr><td> BTA-Gd (III)-DTPA </td><td></td><td></td><td> Made in-house </td></tr><tr><td> BTA-Y (III)-DTPA </td><td></td><td></td><td> Made in-house </td></tr><tr><td> CD-Spektroskopie </td><td> Jasco </td><td> Jasco J-815 Spektropolarimeter </td><td></td></tr><tr><td> NMR- </td><td> Varian </td><td> Varian Unity Inova 500-Spektrometer </td><td> 5-mm-ID-PFG-Sonde von Varian </td></tr><tr><td> Cryo-TEM </td><td> FEI </td><td> cryoTitan TEM </td><td></td></tr><tr><td> SAXS </td><td> Niederländisch-belgischen Beamline (BM26B) an der European Synchrotron Radiation Facility (ESRF) in Grenoble, Frankreich </td><td></td><td&gt; </td></tr></tbody></table>

controlling the size, shape and stability of supramolecular polymers in water

Für wässrige basierten supramolekularen Polymeren, ist die gleichzeitige Kontrolle über Form, Größe und Stabilität sehr schwierig ein. Zur gleichen Zeit, ist die Fähigkeit, dies zu tun sehr wichtig im Hinblick auf eine Reihe von Anwendungen in Funktionale Weiche Materie einschließlich Elektronik, Medizintechnik und Sensorik. In der Vergangenheit erfolgreicher Strategien, um die Größe und Form der supramolekularen Polymeren in der Regel auf die Verwendung von Vorlagen 2,3, 4 oder Verschließer Ende selektiven Lösungsmittel Techniken 5 fokussiert zu steuern. Hier veröffentlichen wir eine Strategie für sich selbst organisierenden diskotischen Amphiphile basiert, die der Kontrolle über die Stack-Länge und Form der geordneten, chirale kolumnare Aggregate führt. Durch den Ausgleich elektrostatische Abstoßung auf der hydrophilen Rand und attraktive nichtkovalente Kräfte innerhalb des hydrophoben Kerns des polymerisierenden Baustein schaffen wir es schaffen kleine und diskrete kugelförmige Objekte 6,7. Increasingen die Salzkonzentration zu screenen, die Ladungen induziert eine Kugel-zu-Stab Übergang. Interessanterweise wird dieser Übergang zu einer Erhöhung der Kooperativität in der temperaturabhängigen Self-Assembly-Mechanismus zum Ausdruck gebracht, und mehr stabile Aggregate erhalten werden. Für die Studie wählen Benzol-1 ,3,5-tricarboxamide (BTA) Kern mit einem hydrophilen Metallchelat über einen hydrophoben, fluorierten L-Phenylalanin Abstandshalter (Schema 1). Die Metall-Chelat ausgewählt ist ein Gd (III)-DTPA-Komplex, der zwei gesamten restlichen Ladungen pro komplex und notwendigerweise zwei Gegenionen enthält. Das eindimensionale Wachstum des Aggregats wird durch π-π Stapeln und intermolekularer Wasserstoffbrücken gerichtet. Jedoch sind die elektrostatischen, abstoßende Kräfte, die von den Ladungen auf der Gd (III)-DTPA-Komplex Start Begrenzung der eindimensionalen Wachstum der BTA-basierten diskotischen, sobald eine bestimmte Größe erreicht ergeben. Bei millimolaren Konzentrationen der gebildete Aggregat eine SPHErische Form und einen Durchmesser von etwa 5 nm, wie aus 1 H-NMR-Spektroskopie, Kleinwinkel Röntgenstreuung und Kryo-Transmissionselektronenmikroskopie (Cryo-TEM) abgeleitet. Die Stärke der elektrostatischen Abstoßung zwischen Molekülen kann durch Erhöhung der Salzkonzentration der gepufferten Lösungen reduziert werden. Das Screening der Ladungen induziert einen Übergang von kugelförmigen Aggregaten in längliche Stäbchen mit einer Länge&gt; 25 nm auf. Kryo-TEM ermöglicht, um die Änderungen in Form und Größe zu visualisieren. Darüber hinaus ermöglicht CD-Spektroskopie zur Ableitung der mechanistische Details der Self-Assembly-Prozesse vor und nach der Zugabe von Salz. Wichtig ist, dass die Kooperativität-ein wesentliches Merkmal, das die physikalischen Eigenschaften des hergestellten Polymeren supramolekularen-erhöht dramatisch beim Screening bestimmt die elektrostatischen Wechselwirkungen. Diese Erhöhung der Kooperativität führt zu einer signifikanten Erhöhung des Molekulargewichts der gebildeten supramolekularen Polymeren in Wasser.

Watch this Scientific Journal Video about Controlling the Size, Shape and Stability of Supramolecular Polymers in Water at JoVE.com

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Das Ziel dieses Experiments ist es, zu bestimmen und steuern die Größe, Form und Stabilität des self-assembled diskotischen Amphiphile in Wasser. Für wässriger Basis supramolekularer Polymere wie Maß an Kontrolle ist sehr schwierig. Wir wenden eine Strategie sowohl mit abstoßenden und anziehenden Wechselwirkungen. Die experimentellen Techniken angewandt, um dieses System charakterisieren, sind breit anwendbar.

Steuern der Größe, Form und Stabilität der supramolekularen Polymeren in Wasser

For aqueous based supramolecular polymers, the simultaneous control over shape, size and stability is very difficult1. At the same time, the ability to do ...

controlling-size-shape-stability-supramolecular-polymers

Research

JoVE Journal

Engineering

18.4K Aufrufe.  Westfälische Wilhelms-Universität Münster. Das Ziel dieses Experiments ist es, zu bestimmen und steuern die Größe, Form und Stabilität des self-assembled diskotischen Amphiphile in Wasser. Für wässriger Basis supramolekularer Polymere wie Maß an Kontrolle ist sehr schwierig. Wir wenden eine Strategie sowohl mit abstoßenden und anziehenden Wechselwirkungen. Die experimentellen Techniken angewandt, um dieses System charakterisieren, sind breit anwendbar.

Serie: Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Fine-tuning the Size and Minimizing the Noise of Solid-state Nanopores

Solid-state nanopores have emerged as a versatile tool for the characterization of single biomolecules such as nucleic acids and proteins1. However, the creation of a nanopore in a thin insulating membrane remains challenging. Fabrication methods involving specialized focused electron beam systems can produce well-defined nanopores, but yield of reliable and low-noise nanopores in commercially available membranes remains low2,3 and size control is nontrivial4,5. Here, the application of high electric fields to fine-tune the size of the nanopore while ensuring optimal low-noise performance is demonstrated. These short pulses of high electric field are used to produce a pristine electrical signal and allow for enlarging of nanopores with subnanometer precision upon prolonged exposure. This method is performed in situ in an aqueous environment using standard laboratory equipment, improving the yield and reproducibility of solid-state nanopore fabrication.

A methodology for preparing solid-state nanopores in solution for biomolecular translocation experiments is presented. By applying short pulses of high electric fields, the nanopore diameter can be controllably enlarged with subnanometer precision and its electrical noise characteristics significantly improved. This procedure is performed in situ using standard laboratory equipment under experimental conditions.

Feinabstimmung der Größe und Minimierung der Lärm von Solid-State-Nanoporen

Solid-state nanopores have emerged as a versatile tool for the characterization of single biomolecules such as nucleic acids and proteins1. However, the ...

Forschung

Ingenieurwesen

The Preparation of Electrohydrodynamic Bridges from Polar Dielectric Liquids

Horizontal and vertical liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields (8-20 kV/cm) and polar dielectric liquids. These bridges are unique from capillary bridges in that they exhibit extensibility beyond a few millimeters, have complex bi-directional mass transfer patterns, and emit non-Planck infrared radiation. A number of common solvents can form such bridges as well as low conductivity solutions and colloidal suspensions. The macroscopic behavior is governed by electrohydrodynamics and provides a means of studying fluid flow phenomena without the presence of rigid walls. Prior to the onset of a liquid bridge several important phenomena can be observed including advancing meniscus height (electrowetting), bulk fluid circulation (the Sumoto effect), and the ejection of charged droplets (electrospray). The interaction between surface, polarization, and displacement forces can be directly examined by varying applied voltage and bridge length. The electric field, assisted by gravity, stabilizes the liquid bridge against Rayleigh-Plateau instabilities. Construction of basic apparatus for both vertical and horizontal orientation along with operational examples, including thermographic images, for three liquids (e.g., water, DMSO, and glycerol) is presented.

Horizontal and vertical electrohydrodynamic liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields and polar dielectric liquids. The construction of basic apparatus and operational examples, including thermographic images, for three liquids (e.g., water, DMSO, and glycerol) is presented.

Die Herstellung elektro Bridges von Polar Schlags Flüssigkeiten

Horizontal and vertical liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields (8-20 kV/cm) and ...

Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation

Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor compression based cooling process. Nickel-Titanium (Ni-Ti) based alloy systems, especially, show large elastocaloric effects. Furthermore, exhibit large latent heats which is a necessary material property for the development of an efficient solid-state based cooling process. A scientific test rig has been designed to investigate these processes and the elastocaloric effects in SMAs. The realized test rig enables independent control of an SMA&#39;s mechanical loading and unloading cycles, as well as conductive heat transfer between SMA cooling elements and a heat source/sink. The test rig is equipped with a comprehensive monitoring system capable of synchronized measurements of mechanical and thermal parameters. In addition to determining the process-dependent mechanical work, the system also enables measurement of thermal caloric aspects of the elastocaloric cooling effect through use of a high-performance infrared camera. This combination is of particular interest, because it allows illustrations of localization and rate effects &#8212; both important for efficient heat transfer from the medium to be cooled.
The work presented describes an experimental method to identify elastocaloric material properties in different materials and sample geometries. Furthermore, the test rig is used to investigate different cooling process variations. The introduced analysis methods enable a differentiated consideration of material, process and related boundary condition influences on the process efficiency. The comparison of the experimental data with the simulation results (of a thermomechanically coupled finite element model) allows for better understanding of the underlying physics of the elastocaloric effect. In addition, the experimental results, as well as the findings based on the simulation results, are used to improve the material properties.

Experimental methods for investigation of solid state cooling processes and characterization of elastocaloric material properties of Shape Memory Alloys (SMA) are presented. A custom-built test rig has been designed for controlling and comprehensive monitoring of elastocaloric cooling processes. Furthermore, it provides a validation platform for thermomechanically coupled modeling approaches.

Experimentelle Methoden zur Untersuchung von Formgedächtnis-Based Elastocaloric Kühlprozesse und Modellvalidierung

Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor ...

Capillary-based Centrifugal Microfluidic Device for Size-controllable Formation of Monodisperse Microdroplets

Here, we demonstrate a simple method for the rapid production of size-controllable, monodisperse, W/O microdroplets using a capillary-based centrifugal microfluidic device. W/O microdroplets have recently been used in powerful methods that enable miniaturized chemical experiments. Therefore, developing a versatile method to yield monodisperse W/O microdroplets is needed. We have developed a method for generating monodisperse W/O microdroplets based on a capillary-based centrifugal axisymmetric co-flowing microfluidic device. We succeeded in controlling the size of microdroplets by adjusting the capillary orifice. Our method requires equipment that is easier-to-use than with other microfluidic techniques, requires only a small volume (0.1-1 &#181;l) of sample solution for encapsulation, and enables the production of hundreds of thousands number of W/O microdroplets per second. We expect this method will assist biological studies that require precious biological samples by conserving the volume of the samples for rapid quantitative analysis biochemical and biological studies.

Here, we demonstrate a simple production method for size-controllable, monodisperse, water-in-oil (W/O) microdroplets using a capillary-based centrifugal microfluidic device. This method requires only a small sample volume and enables high-yield production. We expect this method will be useful for rapid biochemical and cellular analyses.

Kapillar-basierten Kreisel Mikrofluidik-Vorrichtung zur Größe steuerbare Bildung von monodispersen Mikrotröpfchen

Here, we demonstrate a simple method for the rapid production of size-controllable, monodisperse, W/O microdroplets using a capillary-based centrifugal ...

Ice Generation and the Heat and Mass Transfer Phenomena of Introducing Water to a Cold Bath of Brine

We demonstrate a method for the study of the heat and mass transfer and of the freezing phenomena in a subcooled brine environment. Our experiment showed that, under the proper conditions, ice can be produced when water is introduced to a bath of cold brine. To make ice form, in addition to having the brine and water mix, the rate of heat transfer must bypass that of mass transfer. When water is introduced in the form of tiny droplets to the brine surface, the mode of heat and mass transfer is by diffusion. The buoyancy stops water from mixing with the brine underneath, but as the ice grows thicker, it slows down the rate of heat transfer, making ice more difficult to grow as a result. When water is introduced inside the brine in the form of a flow, a number of factors are found to influence how much ice can form. Brine temperature and concentration, which are the driving forces of heat and mass transfer, respectively, can affect the water-to-ice conversion ratio; lower bath temperatures and brine concentrations encourage more ice to form. The flow rheology, which can directly affect both the heat and mass transfer coefficients, is also a key factor. In addition, the flow rheology changes the area of contact of the flow with the bulk fluid.

Here, we present a protocol to demonstrate the generation of ice when water is introduced to a cold bath of brine, as a secondary refrigerant, at a range of temperatures well below the freezing point of water. It can be used as an alternative way of producing ice for industry.

Ice-Generation und die Wärme- und Stoffübertragung Phänomene der Einführung in Wasser zu einem Kältebad von Brine

We demonstrate a method for the study of the heat and mass transfer and of the freezing phenomena in a subcooled brine environment. Our experiment showed ...

Detecting the Water-soluble Chloride Distribution of Cement Paste in a High-precision Way

To improve the accuracy of the chloride distribution along the depth of cement paste under cyclic wet-dry conditions, a new method is proposed to obtain a high-precision chloride profile. Firstly, paste specimens are molded, cured, and exposed to cyclic wet-dry conditions. Then, powder samples at different specimen depths are grinded when the exposure age is reached. Finally, the water-soluble chloride content is detected using a silver nitrate titration method, and chloride profiles are plotted. The key to improving the accuracy of the chloride distribution along the depth is to exclude the error in the powderization, which is the most critical step for testing the distribution of chloride. Based on the above concept, the grinding method in this protocol can be used to grind powder samples automatically layer by layer from the surface inward, and it should be noted that a very thin grinding thickness (less than 0.5 mm) with a minimum error less than 0.04 mm can be obtained. The chloride profile obtained by this method better reflects the chloride distribution in specimens, which helps researchers to capture the distribution features that are often overlooked. Furthermore, this method can be applied to studies in the field of cement-based materials, which require high chloride distribution accuracy.

A protocol for obtaining a water-soluble chloride profile by using a high precision milling method is presented.

Die wasserlöslichen Chlorid Verteilung der Zementleim erkennen auf präzise Weise

To improve the accuracy of the chloride distribution along the depth of cement paste under cyclic wet-dry conditions, a new method is proposed to obtain a ...

Generation of Size-controlled Poly (ethylene Glycol) Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices

Uniform and size-controllable poly (ethylene glycol) diacrylate (PEGDA) droplets could be produced via the flow focusing process in a microfluidic device. This paper proposes a semi-three-dimensional (semi-3D) flow-focusing microfluidic chip for droplet formation. The polydimethylsiloxane (PDMS) chip was fabricated using the multi-layer soft lithography method. Hexadecane containing surfactant was used as the continuous phase, and PEGDA with the ultraviolet (UV) photo-initiator was the dispersed phase. Surfactants allowed the local surface tension to drop and formed a more cusped tip which promoted breaking into tiny micro-droplets. As the pressure of dispersed phase was constant, the size of droplets became smaller with increasing continuous phase pressure before dispersed phase flow was broken off. As a result, droplets with size variation from 1 &#181;m to 80 &#181;m in diameter could be selectively achieved by changing the pressure ratio in two inlet channels, and the average coefficient of variation was estimated to be below 7%. Furthermore, droplets could turn into micro-beads by UV exposure for photo-polymerization. Conjugating biomolecules on such micro-beads surface have many potential applications in the fields of biology and chemistry.

Generation of Size-controlled Poly ethylene Glycol Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices

Here, we present a protocol to illustrate the fabrication processes and verifying experiments of a semi-three-dimensional (semi-3D) flow-focusing microfluidic chip for droplet formation.

Größe-gesteuerte Poly (Ethylenglycol) Diacrylate Tröpfchen über Semi-3-dimensionale fließen mit Schwerpunkt mikrofluidischen Geräte-Generation

Uniform and size-controllable poly (ethylene glycol) diacrylate (PEGDA) droplets could be produced via the flow focusing process in a microfluidic device. ...

Near-Infrared Temperature Measurement Technique for Water Surrounding an Induction-heated Small Magnetic Sphere

A technique to measure the temperature of water and non-turbid aqueous media surrounding an induction-heated small magnetic sphere is presented. This technique utilizes wavelengths of 1150 and 1412 nm, at which the absorption coefficient of water is dependent on temperature. Water or a non-turbid aqueous gel containing a 2.0-mm- or 0.5-mm-diameter magnetic sphere is irradiated with 1150 nm or 1412 nm incident light, as selected using a narrow bandpass filter; additionally, two-dimensional absorbance images, which are the transverse projections of the absorption coefficient, are acquired via a near-infrared camera. When the three-dimensional distributions of temperature can be assumed to be spherically symmetric, they are estimated by applying inverse Abel transforms to the absorbance profiles. The temperatures were observed to consistently change according to time and the induction heating power.

A technique utilizing wavelengths of 1150 and 1412 nm to measure the temperature of water surrounding an induction-heated small magnetic sphere is presented.

Nah-Infrarot-Temperatur-Messtechnik für Wasser umgibt eine Induktion erhitzt kleine magnetische Kugel

A technique to measure the temperature of water and non-turbid aqueous media surrounding an induction-heated small magnetic sphere is presented. This ...

Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers

In this paper, fabrication methods that generate novel surfaces using the azlactone-based block co-polymer, poly (glycidyl methacrylate)-block-poly (vinyl dimethyl azlactone) (PGMA-b-PVDMA), are presented. Due to the high reactivity of azlactone groups towards amine, thiol, and hydroxyl groups, PGMA-b-PVDMA surfaces can be modified with secondary molecules to create chemically or biologically functionalized interfaces for a variety of applications. Previous reports of patterned PGMA-b-PVDMA interfaces have used traditional top-down patterning techniques that generate non-uniform films and poorly controlled background chemistries. Here, we describe customized patterning techniques that enable precise deposition of highly uniform PGMA-b-PVDMA films in backgrounds that are chemically inert or that have biomolecule-repellent properties. Importantly, these methods are designed to deposit PGMA-b-PVDMA films in a manner that completely preserves azlactone functionality through each processing step. Patterned films show well-controlled thicknesses that correspond to polymer brushes (~90 nm) or to highly crosslinked structures (~1-10 &#956;m). Brush patterns are generated using either the parylene lift-off or interface directed assembly methods described and are useful for precise modulation of overall chemical surface reactivity by adjusting either the PGMA-b-PVDMA pattern density or the length of the VDMA block. In contrast, the thick, crosslinked PGMA-b-PVDMA patterns are obtained using a customized micro-contact printing technique and offer the benefit of higher loading or capture of secondary material due to higher surface area to volume ratios. Detailed experimental steps, critical film characterizations, and trouble-shooting guides for each fabrication method are discussed.

Surface fabrication methods for patterned deposition of nanometer thick brushes or micron thick, crosslinked films of an azlactone block co-polymer are reported. Critical experimental steps, representative results, and limitations of each method are discussed. These methods are useful for creating functional interfaces with tailored physical features and tunable surface reactivity.

Herstellung von reaktiven Oberflächen mit Pinsel-Like und querverbunden Filme von Azlactone funktionalisiert Block-Copolymere

In this paper, fabrication methods that generate novel surfaces using the azlactone-based block co-polymer, poly (glycidyl methacrylate)-block-poly (vinyl ...

Design and Fabrication of an Optical Fiber Made of Water

In this report, an optical fiber of which the core is made solely of water, while the cladding is air, is designed and manufactured. In contrast with solid-cladding devices, capillary oscillations are not restricted, allowing the fiber walls to move and vibrate. The fiber is constructed by a high direct current (DC) voltage of several thousand volts (kV) between two water reservoirs that creates a floating water thread, known as a water bridge. Through the choice of micropipettes, it is possible to control the maximal diameter and length of the fiber. Optical fiber couplers, at both sides of the bridge, activate it as an optical waveguide, allowing researchers to monitor the water fiber capillary body waves through transmission modulation and, therefore, deducing changes in surface tension.
Co-confining two important wave types, capillary and electromagnetic, opens a new path of research in the interactions between light and liquid-wall devices. Water-walled microdevices are a million times softer than their solid counterparts, accordingly improving the response to minute forces.

This protocol describes the design and manufacture of a water bridge and its activation as a water fiber. The experiment demonstrates that capillary resonances of the water fiber modulate its optical transmission.

Konstruktion und Fertigung einer optischen Faser aus Wasser gemacht

In this report, an optical fiber of which the core is made solely of water, while the cladding is air, is designed and manufactured. In contrast with ...