Sol–gel approach to in situ creation of high pH-resistant surface-bonded organic–inorganic hybrid zirconia coating for capillary microextraction (in-tube SPME)

2005 ◽  
Vol 1062 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Khalid Alhooshani ◽  
Tae-Young Kim ◽  
Abuzar Kabir ◽  
Abdul Malik
1998 ◽  
Vol 519 ◽  
Author(s):  
Y. Yan ◽  
Z. Duan ◽  
D.-G. Chen ◽  
S. Ray Chaudhuri

AbstractThe insoluble, strongly hydrogen bonded organic pigment of 3,6-bis-(4-chlorphenyl)-l,4- diketopyrrolo [3,4-c] pyrrole was transiently blocked by adding carbamate groups, and consequently incorporated into organic-inorganic hybrid matrices by a sol-gel process. The homo- (pigment-pigment) and hetero-intermolecular (pigment-matrix) interactions were found to control both the assembly and dispersion of pigment molecules in the hybrid coating films. A weaker interaction between matrices and pigment molecules results in aggregation of the carbamate pigment in the methyl-silicate films. A stronger interaction forms a homogenous dispersion and coloration of the phenyl-silicate films. The as-prepared methyl- and phenylsilicate films doped with the organic pigment were distinguished by a morphology change and a blue (hypsochromic) shift in absorption from 550 to 460 nm. Thermal treatment can remove the carbamate groups and in-situ form the organic pigment in the hybrid films.


2002 ◽  
Vol 16 (17n18) ◽  
pp. 2454-2460 ◽  
Author(s):  
X. P. ZHAO ◽  
X. DUAN

In-situ sol-gel method to prepare colloidal hybrids of surfactant modified polysucchride and titanium oxide has been presented, and experiments indicated these highly ER active particles exhibited a remarkable ER effect. The static shear stress can be up to 37 k Pa (shear rate 5 S -1) under DC field of 4 kV/mm at root temperature, well above that of simple blends of starch and TiO 2. In the meanwhile, temperature dependence and sedimentation stability were also greatly improved. Based on recent experimental facts, we find that dielectric properties and surface (interface) activity are two necessary conditions fulfilling the requirement of high ER activity. Adequate grinding of particles with oil can effectively enhance the shear stress, which may be owed to the decline of the activation energy needed for restructuring. It has provided us a new horizon for preparation of excellent ER materials and further studies should be continued to make.


2017 ◽  
Vol 9 (10) ◽  
pp. 9070-9078 ◽  
Author(s):  
Xiaoying Dong ◽  
Xiao Zhuo ◽  
Jie Wei ◽  
Gang Zhang ◽  
Yongfeng Li

2005 ◽  
Vol 876 ◽  
Author(s):  
S. Li ◽  
M. S. Toprak ◽  
Y. S Jo ◽  
D. K. Kim ◽  
M. Muhammed

AbstractPolymer-inorganic hybrid materials composed of polymethyl methacrylate (PMMA) and zinc compounds were prepared by sol-gel in-situ transition polymerization of zinc complex in PMMA matrix. Zinc acetate dihydrate dissolved in ethanol was used as the inorganic precursor. Monoethanolamine (MEA) acted as a complexing agent to control the hydrolysis of zinc acetate to produce a zinc compound network, and then PMMA, formed in-situ through a radical polymerization, were chemically bonded to the forming zinc compound network to realize a hybrid material. Transparent homogenous hybrid materials with slight colours from pink to yellow were fabricated by varying the composition. TEM, FT-IR were employed to investigate structural and physical properties. The UV-shielding effect was evaluated by UV-VIS. The low content of zinc (around 0.02 wt%) and the fine particle size rendered it visibly transparent and capable of greatly attenuating UV radiation in the full UV range.


2011 ◽  
Vol 130-134 ◽  
pp. 410-413 ◽  
Author(s):  
Bao Hui Li ◽  
Bao Juan Tian

In this paper a novel hybrid organic–inorganic amino hybrid material monolithic column for capillary electro chromatography (CEC) is preparation and characterization. The amido hybrid material monolithic column was prepared in situ co-condensation of tetraethoxysilane (TEOS) with 3-aminoproplytriethoxysilane (3-APTES) via sol-gel procedure. The all kinds of factors that effect the morphology of monolith column were investigated. The results showed that the structure of monolithic column could be adjusted easily through altering the composition of sol solution.


2000 ◽  
Vol 628 ◽  
Author(s):  
Samuel Amanuel ◽  
Vivak M. Malhotra

ABSTRACTIn pursuit of our goal of forming organic-inorganic hybrid frictional materials, we produced two types of composites, i.e., conventional and hybrid. We formed conventional composites by dispersing fly ash, montmorillonite clay, or pre-formed nano-sized silica particles in phenolic matrix. Hybrid composites were fabricated from sol-gel technique using tetramethylor-thosilicate-phenolic mixtures. We subjected our samples to X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), in-situ transmission-Fourier transform infrared (ISTA-FTIR), and dynamic mechanical analyzer (DMA) measurements at 40°C < T < 310°C. Our results suggested that the curing behavior of the phenolic polymer was affected by the concentration of the silica and hybrid composites manifested mechanical properties, which were substantially different from that of conventional composites.


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