In Situ ATR-FT-IR Kinetic Studies of Molecular Transport and Surface Binding in Thin Sol−Gel Films:  Reactions of Chlorosilane Reagents in Porous Silica Materials

2001 ◽  
Vol 73 (3) ◽  
pp. 411-423 ◽  
Author(s):  
Dion Rivera ◽  
Joel M. Harris
Keyword(s):  
Sol Gel ◽  
Porous Silica ◽  
Molecular Transport ◽  
Kinetic Studies ◽  
Surface Binding ◽  
Silica Materials ◽  
Ft Ir ◽  
Sol Gel Films

Bioencapsulation in Sol-Gel Glasses

1998 ◽  
Vol 519 ◽  
Author(s):  
L. Bergogne ◽  
S. Fennouh ◽  
J. Livage ◽  
C. Roux
Keyword(s):  
Sol Gel ◽  
Porous Silica ◽  
Silica Matrix ◽  
Whole Cells ◽  
The Past ◽  
Wide Range ◽  
Activity Of Enzymes ◽  
Gel Glasses ◽  
Micro Organisms

AbstractBioencapsulation in sol-gel materials has been widely studied during the past decade. Trapped species appear to retain their bioactivity in the porous silica matrix. Small analytes can diffuse through the pores allowing bioreactions to be performed in-situ, inside the sol-gel glass. A wide range of biomolecules and micro-organisms have been encapsulated. The catalytic activity of enzymes is used for the realization of biosensors or bioreactors. Antibody-antigen recognition has been shown to be feasible within sol-gel matrices. Trapped antibodies bind specifically the corresponding haptens and can be used for the detection of traces of chemicals. Even whole cells are now encapsulated without any alteration of their cellular organization. They can be used for the production of chemicals or as antigens for immunoassays.

Kinetic Studies of Isophorone Diisocyanate-Polyether Polymerization with in situ FT-IR

2011 ◽  
Vol 16 (8) ◽  
pp. 584-590 ◽  
Author(s):  
Peng Fei Yang ◽  
Yan Hong Yu ◽  
Shun Ping Wang ◽  
Tian Duo Li
Keyword(s):  
Kinetic Studies ◽  
Isophorone Diisocyanate ◽  
Ft Ir

Kinetic Studies on the Polymerization of Dicyclohexylmethylmethane-4,4'-Diisocyanate with Polyoxytetramethylene Diol

2013 ◽  
Vol 791-793 ◽  
pp. 32-35
Author(s):  
Jian Cheng Wang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Activation Enthalpy ◽  
Kinetic Studies ◽  
Activation Entropy ◽  
Dimethyl Acetamide ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Activation

Dicyclohexylmethylmethane-4,4'-diisocyanate is used to react with polyoxytetramethylene diol at different temperatures. N,N-Dimethyl acetamide is used as solvent.In situFT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The polymerization has been found to be a second order reaction, and the rate constant increases with the rise of temperature. Activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the polymerization are respectively calculated out, which are very useful to reveal the reaction mechanism.

In situ ERD analysis of sol–gel films during thermal processing

2002 ◽  
Vol 190 (1-4) ◽  
pp. 199-202
Author(s):  
N. Dytlewski ◽  
P.J. Evans ◽  
J.T. Noorman ◽  
D.B. Garton ◽  
D.J. Cassidy
Keyword(s):  
Thermal Processing ◽  
Sol Gel ◽  
Sol Gel Films

scholarly journals Synthesis, Characterization and Photocatalytic Performance of Poly-3-Thenoic Acid/Cu-TiO2 Nanohybrid for Efficient Visible Light Assisted Degradation of Bismarck Brown R

2022 ◽  
Vol 19 (1) ◽  
pp. 1715
Author(s):  
Imandi Manga Raju ◽  
Tirukkovalluri Siva Rao ◽  
Miditana Sankara Rao
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Surface Area ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Anatase Tio2 ◽  
X Ray ◽  
Ft Ir ◽  
Nanohybrid Material

The present work reported on the synthesis and characterization of Poly-3-Thenoic acid/Cu-TiO2 nanohybrid (PCuT) for the photocatalytic degradation of organic azo dye pollutant from wastewater. The as-synthesized nanohybrid by an in-situ modified sol-gel method including chemical oxidative polymerization was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, UV-visible diffuse reflectance spectroscopy (UV-vis.DRS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and Brunauer-Emmet-Teller (BET) surface area analysis. The characterization results revealed the formation of small aggregates of polymer contained high crystalline anatase TiO2 nanoparticles (XRD) with narrowed bandgap energy (UV-vis.DRS), decreased particle size (TEM) with smooth surface morphology (SEM) and large surface area (BET). All the constituent elements of the polymer and Cu-TiO2 were found in the PCuT nanohybrid material (EDX) and their chemical interaction studied by FT-IR confirmed the stability of the nanohybrid. The photocatalytic activity of the nanohybrid was tested by the degradation of Bismarck Brown R dye under visible light irradiation. To enhance the photocatalytic efficiency, effects of various catalyst/dye reaction parameters such as polymer content, solution pH, catalyst dosage, and initial dye concentration were studied and optimized. HIGHLIGHTS Poly-3-Thenoic acid/Cu-TiO2 nanohybrid material was successfully synthesized by in situ modified sol-gel process Poly-3-Thenoic acid has enhanced the visible light absorption capacity of anatase TiO2 in nanohybrids Electron-hole recombination in TiO2 was effectively inhibited by Cu doping Bismark Brown R, an organic pollutant was successfully degraded in 75 min of visible light irradiation GRAPHICAL ABSTRACT

Highly uniform porous silica layer open-tubular capillary columns produced via in-situ biphasic sol–Gel processing for open-tubular capillary electrochromatography

2018 ◽  
Vol 1538 ◽  
pp. 86-93 ◽  
Author(s):  
Xin Liu ◽  
Shucheng Sun ◽  
Rongbin Nie ◽  
Jicheng Ma ◽  
Qishu Qu ◽  
...  
Keyword(s):  
Capillary Electrochromatography ◽  
Sol Gel ◽  
Porous Silica ◽  
Capillary Columns ◽  
Silica Layer ◽  
Gel Processing ◽  
Highly Uniform

The Effect of Trioxane in HF-Catalyzed Sol-Gel Reactions of Tetraethoxysilane

1988 ◽  
Vol 121 ◽  
Author(s):  
Paul B. Dorain ◽  
Joseph J. Rafalko ◽  
James E. Feeney ◽  
Charles E. Forbes ◽  
Raymond V. Carney ◽  
...  
Keyword(s):  
Organic Dyes ◽  
Sol Gel ◽  
Porous Silica ◽  
Water Systems ◽  
Time Dependent ◽  
Chemical System ◽  
Silica Glasses ◽  
Hydrolysis And Condensation ◽  
Ft Ir ◽  
Host Matrices

ABSTRACTPorous silica glasses have been prepared using an HF-catalyzed tetraethoxysilane(TEOS)-ethanol-water formulation. The optical and physical properties of these glasses, which find use as host matrices for optical organic dyes, can be further improved with the addition of 1,3,5-trioxane to the sol-gel chemical system. In order to understand the effect of trioxane, the time-dependent concentrations of the species involved in TEOS hydrolysis and condensation have been followed by Raman, FT-IR, and NMR spectroscopie methods in both HF-catalyzed TEOS-ethanol-water systems with and without trioxane.

Matrix-Assisted Formation of Metal Nanoparticles in Organosilica Sol-Gels

2002 ◽  
Vol 726 ◽  
Author(s):  
Sandie H. Cheung ◽  
Bakul C. Dave
Keyword(s):  
Metal Nanoparticles ◽  
Chemical Reduction ◽  
Sol Gel ◽  
Synthesis Method ◽  
Porous Silica ◽  
Ambient Conditions ◽  
Transmission Electron ◽  
Organically Modified ◽  
Structural Template

AbstractThe use of organosilica sol-gels for controlled in-situ formation of metal nanoparticles is investigated. The use of an organically-modified alkoxysilane precursor provides chemically interacting nanopores for the sequestration and binding of metal ions followed by chemical reduction to form metal nanoparticles. The sol-gel matrix acts as a structural template to enable growth of the metal nanoparticles within its porous silica framework, and prevents clustering to form precipitate. Furthermore, simple redox chemistry is used to convert pre-formed copper nanoparticles in the sol-gel matrix into silver and gold nanoparticles. A particularly important aspect of this synthesis method is that all the reaction chemistry is performed under ambient conditions. The particles are characterized by high resolution transmission electron microscopy for their sizes and size distribution. The elemental composition of the particles is determined by energy dispersive X-ray analysis.

In Situ FT-IR Studies of Oxide and Oxynitride Sol-Gel-Derived Thin Films

1984 ◽  
Vol 32 ◽  
Author(s):  
David M. Haaland ◽  
C. Jeffrey Brinker
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Temperature ◽  
Low Temperatures ◽  
Sol Gel ◽  
Ir Studies ◽  
Oxynitride Glass ◽  
Vibrational Bands ◽  
Ft Ir

ABSTRACTA high-temperature infrared cell was developed to study the gel-to-glass conversion of sol-gel-derived thin films. FT-IR spectra of matched thin-film borosilicate sol-gel samples were taken as the samples were heated at 100°C intervals to 700°C in either air or ammonia. The gels were converted to oxide and oxynitride glasses, respectively, by these heat treatments. The gel-to-glass conversion could be followed and compared for these two treatments by monitoring changes in the vibrational bands present in the spectra. Comparisons between the infrared spectra of NH3-treated and air-treated films heated above 500°C reveal the appearance of new B-N bonds at the expense of B-O-Si bonds for the NH3-fired films. These spectra also exhibit changes which may indicate the formation of Si-N bonds. Thus, ammonolysis reactions can result in thin-film oxynitride glass formation at relatively low temperatures.

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