The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
Stephen E Rankin - One of the best experts on this subject based on the ideXlab platform.
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fluorocarbon and hydrocarbon functional group incorporation into nanoporous silica employing Fluorinated and hydrocarbon surfactants as templates
Microporous and Mesoporous Materials, 2010Co-Authors: Gifty Oseiprempeh, Hans-joachim Lehmler, Annefrances Miller, Barbara L Knutson, Stephen E RankinAbstract:Abstract Ordered mesoporous hydrocarbon functionalized ( n -decyl) silica samples are synthesized by the ‘one-pot’ (direct) synthesis method using two cationic Fluorinated surfactants, C 6 F 13 C 2 H 2 NC 5 H 5 Cl (HFOPC) and C 8 F 17 C 2 H 2 NC 5 H 5 Cl (HFDePC), and a typical hydrocarbon surfactant, C 16 H 33 N(CH 3 ) 3 Br (CTAB), as templates. The properties of the Materials are compared to those of silica samples functionalized with a fluorocarbon functional group, heptadecafluoro-1,1,2,2-tetrahydro-decyl, whose fluorocarbon separating ability was reported earlier [33] . The pore characteristics, organic loading, and wetting properties of the resulting Materials are determined for the following combinations of surfactant/functional groups: hydrocarbon/hydrocarbon, hydrocarbon/fluorocarbon, fluorocarbon/hydrocarbon and fluorocarbon/fluorocarbon. Synthesis using the longer chain fluoro-surfactant (HFDePC) template results in the highest incorporation of both n -decyl and fluorocarbon functional groups, with a corresponding loss of long-range pore order in the Fluorinated Material. Materials synthesized using the HFOPC template have very low levels of functional group incorporation compared to the HFDePC-templated Materials. CTAB-templated Materials display greater long-range pore order than the fluorocarbon templated Materials. The incorporation of the fluorocarbon functional precursor is more effective (on a % yield basis) than the hydrocarbon functional precursor for silica Materials synthesized using CTAB. Similarly, the use of Fluorinated surfactant templates enhances fluorocarbon incorporation relative to hydrocarbon incorporation in the mesoporous Material. Solubility of the precursors ( n -decyltriethoxysilane and heptadecafluoro-1,1,2,2-tetrahydro-decyltriethoxysilane) in the synthesis medium and favorable aggregation behavior of the alkane/fluoroalkane functional groups with the surfactant micelles improves the incorporation of the functional group.
Thomas A. Zangle - One of the best experts on this subject based on the ideXlab platform.
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Soft lithography fabrication of index-matched microfluidic devices for reducing artifacts in fluorescence and quantitative phase imaging
Microfluidics and Nanofluidics, 2017Co-Authors: Michael A. Teitell, Thomas A. ZangleAbstract:Microfluidic devices are widely used for biomedical applications based on microscopy or other optical detection methods. However, the Materials commonly used for microfabrication typically have a high refractive index relative to water, which can create artifacts at device edges and limit applicability to applications requiring high-precision imaging or morphological feature detection. Here we present a soft lithography method to fabricate microfluidic devices out of MY133-V2000, a UV-curable, Fluorinated polymer with low refractive index that is close to that of water ( n = 1.33). The primary challenge in the use of this Material (and Fluorinated Materials in general) is the low adhesion of the Fluorinated Material; we present several alternative fabrication methods we have tested to improve inter-layer adhesion. The close match between the refractive index of this Material and aqueous solutions commonly used in biomedical applications enables fluorescence imaging at microchannel or other microfabricated edges without distortion. The close match in refractive index also enables quantitative phase microscopy imaging across the full width of microchannels without error-inducing artifacts for measurement of cell biomass. Overall, our results demonstrate the utility of low-refractive index microfluidics for biological applications requiring high-precision optical imaging.
Gifty Oseiprempeh - One of the best experts on this subject based on the ideXlab platform.
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fluorocarbon and hydrocarbon functional group incorporation into nanoporous silica employing Fluorinated and hydrocarbon surfactants as templates
Microporous and Mesoporous Materials, 2010Co-Authors: Gifty Oseiprempeh, Hans-joachim Lehmler, Annefrances Miller, Barbara L Knutson, Stephen E RankinAbstract:Abstract Ordered mesoporous hydrocarbon functionalized ( n -decyl) silica samples are synthesized by the ‘one-pot’ (direct) synthesis method using two cationic Fluorinated surfactants, C 6 F 13 C 2 H 2 NC 5 H 5 Cl (HFOPC) and C 8 F 17 C 2 H 2 NC 5 H 5 Cl (HFDePC), and a typical hydrocarbon surfactant, C 16 H 33 N(CH 3 ) 3 Br (CTAB), as templates. The properties of the Materials are compared to those of silica samples functionalized with a fluorocarbon functional group, heptadecafluoro-1,1,2,2-tetrahydro-decyl, whose fluorocarbon separating ability was reported earlier [33] . The pore characteristics, organic loading, and wetting properties of the resulting Materials are determined for the following combinations of surfactant/functional groups: hydrocarbon/hydrocarbon, hydrocarbon/fluorocarbon, fluorocarbon/hydrocarbon and fluorocarbon/fluorocarbon. Synthesis using the longer chain fluoro-surfactant (HFDePC) template results in the highest incorporation of both n -decyl and fluorocarbon functional groups, with a corresponding loss of long-range pore order in the Fluorinated Material. Materials synthesized using the HFOPC template have very low levels of functional group incorporation compared to the HFDePC-templated Materials. CTAB-templated Materials display greater long-range pore order than the fluorocarbon templated Materials. The incorporation of the fluorocarbon functional precursor is more effective (on a % yield basis) than the hydrocarbon functional precursor for silica Materials synthesized using CTAB. Similarly, the use of Fluorinated surfactant templates enhances fluorocarbon incorporation relative to hydrocarbon incorporation in the mesoporous Material. Solubility of the precursors ( n -decyltriethoxysilane and heptadecafluoro-1,1,2,2-tetrahydro-decyltriethoxysilane) in the synthesis medium and favorable aggregation behavior of the alkane/fluoroalkane functional groups with the surfactant micelles improves the incorporation of the functional group.
David Y. Son - One of the best experts on this subject based on the ideXlab platform.
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Polyarylene polyimides with hydrocarbon and semi-Fluorinated backbones: synthesis, characterization, and properties
Polymer Chemistry, 2020Co-Authors: Stephen M. Budy, Jamie Dore Hall, David Y. SonAbstract:A series of six new polyarylene polyimides (PAPI) was prepared from a highly phenylated phenylenediamine synthesized via a Diels–Alder reaction. The diamine was reacted with a variety of dianhydrides using a one-step microwave-assisted step-growth polycondensation reaction to give the PAPI. The polymerizations were complete in 10 to 30 minutes using isoquinoline as catalyst. Yields as high as 99% were achieved using nitrobenzene as the solvent. A semi-Fluorinated dianhydride was included to compare polyimide properties to the hydrocarbon Materials. Full characterization was carried out via1H and 19F nuclear magnetic resonance spectroscopy and attenuated total reflectance Fourier transform infrared spectroscopy. Thermal properties were characterized via thermal gravimetric analysis and differential scanning calorimetry. The onset of thermal degradation was approximately 550 °C in nitrogen and air atmospheres while the char yields at 1000 °C in nitrogen were almost 70%. The semi-Fluorinated polyarylene polyimide exhibited the highest char yield. Glass transition temperatures were in the range of 355 to 387 °C, with the semi-Fluorinated Material possessing the highest Tg and the most rigid Material affording the lowest Tg. Optical transparency was good in all the Materials, with the semi-Fluorinated Material having the largest optical window in the UV-Vis region. The polymers were colorless or pale yellow solids. Solubility was excellent in chloroform, tetrahydrofuran, toluene, and cyclohexanone. We are currently interested in these Materials and precursors for fuel cell and gas separation membranes, coatings, fibers, adhesives, and composite applications.
Haining Chen - One of the best experts on this subject based on the ideXlab platform.
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Simple spray deposition of a water-based superhydrophobic coating with high stability for flexible applications
Journal of Materials Chemistry A, 2017Co-Authors: Liqun Zhu, Huicong Liu, Haining ChenAbstract:Superhydrophobic coatings have attracted significant attention due to their wide potential applications. However, the practical applications of the present artificial superhydrophobic coatings are not only hindered by their environmentally hazardous components, containing Fluorinated Materials and pungent organic solvents, but also by their poor Material stabilities. Herein, a robust water-repellent organic–inorganic composite coating based on an aqueous dispersion was developed using a non-Fluorinated Material system consisting of a waterborne silicone–acrylic copolymer (SAC) and silica sol. Uniquely, the as-prepared SAC containing acid functional groups was first ionized in an alkaline environment, followed by introduction of the silica precursor into the SAC to generate the silica sol in situ. The abovementioned non-Fluorinated Material system favors the application of the simple spray technique for the superhydrophobic coating (157.7°) deposition, which can be flexibly employed on various substrates. The resulting composite coating, in which strong micro- and nano-scale roughness structures are embedded in the layer matrix, can withstand at least 200 abrasion cycles while retaining its superhydrophobicity. Moreover, the composite coating also shows significantly high resistance to acid/base, organic solvent, UV photodegradation (UVA light illumination for 96 h) and high-temperature heating (400 °C for 80 h). Furthermore, this environmentally friendly coating can be easily applied in the self-cleaning (in either air or oil environments) and oil/water separation fields.