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1.
Fluorinated organic–inorganic hybrid films were prepared by sol–gel process from tridecafluoroctyltriethoxysilane (PFAS),
3-glycidoxypropyltrimethoxysilane, and tetraethoxysilane (TEOS). It has been found that the fluorinated hybrid films possessed
fluorinated side chains originating from PFAS as top layer, and silica network as bottom layer, which had very low surface
energy and could be used as water repellent functional coatings. The outermost layer of the water-repellent film may be fully
covered by the perfluoroalkyl side chains as the molar ratio of PFAS/TEOS increases up to about 0.005:1. The addition of BPA
can enhance the cross-link density of fluorinated hybrid films, and make more perfluoroalkyl groups enriching at the coating
film-air interface to lower the surface free energy. However, the improvement of the cross-link density of fluorinated hybrid
films tends to exhibit brittleness and micro-cracks. Consequently, it can be concluded that a small BPA additive content is
preferred for the formation of fluorinated hybrid films with a smooth surface and less detectable cracks. 相似文献
2.
Four series of trifluorobenzoate liquid crystals have been synthesized. Their phase transition temperatures have been also measured by texture observation in a polarizing microscope and confirmed by DSC. The influence of the lateral fluoro-substitution and triple bond has been also discussed. 相似文献
3.
Melting gels are a class of organically modified silica gels that are rigid at room temperature, flow at temperature T1 and
consolidate at temperature T2 (T2 > T1), when crosslinking is complete. The process of (a) softening, (b) becoming rigid and
(c) re-softening can be repeated many times. Mixtures of mono-substituted alkoxysilanes and di-substituted alkoxysilanes have
been studied in a systematic way to identify suitable melting gel compositions. The mixtures and the resulting melting gels
have been characterized for their softening temperatures and consolidation temperatures. With an interest in using these materials
for sealing microelectronics, their physical properties have been measured. 相似文献
4.
Four novel organic–inorganic hybrid nicotinate-bridging dimeric rare-earth (RE)-containing phosphotungstates [H2N(CH3)2]8[RE(H2O)(NA)(α-HPW11O39)]2·24H2O (RE = HoIII for 1, ErIII for 2, TbIII for 3, DyIII for 4; HNA = nicotinic acid) have been synthesized from the reaction of trivacant Keggin precursor Na9[α-PW9O34]∙16H2O, RE(NO3)3·6H2O, HNA by employing dimethylamine hydrochloride as organic solubilizing agent in the conventional aqueous solution system, which have been further characterized by elemental analyses, IR spectra, thermogravimetric analyses and single-crystal X-ray diffraction. Structural analysis indicates that the hybrid dimeric {[RE(H2O)(NA)(α-HPW11O39)]2}8− polyoxoanion in 1–4 can be considered as two head-to-head mono-RE-containing Keggin [RE(H2O)(NA)(α-HPW11O39)]4− subunits bridged by two (η2,μ-1,1)-nicotinate linkers, which stands for the first organic–inorganic hybrid RE-containing phosphotungstates functionalized by nicotinate ligands. What's more, the solid-state photoluminescence properties and lifetime decay behaviors of 1–4 have been measured at room temperature and their photoluminescence spectra display the characteristic emission bands of corresponding trivalent RE cations. 相似文献
5.
Justin P. Moore Joseph A. Shumaker Marlene D. Houtz Lirong Sun Alexander N. Khramov John G. Jones 《Journal of Sol-Gel Science and Technology》2012,63(1):168-176
Current optical polymeric materials for advanced fiber laser development are susceptible to degradation due to the heat generated in high power usage. A suitable replacement light stripping material was explored to overcome this problem by examining optical and physical properties such as transmission/absorption, refractive index, thermal conductivity, and thermal stability. The synthesis and characterization of two new polyurea/silica ORMOSILs (ORganically MOdified SILicates) suitable for high temperature (up to 300 °C) optical applications are reported herein. A one-pot, room temperature synthesis is based upon commercially available bis-isocyanates and an amino-silane. These materials exhibit the combined traits of both glass and polymer by displaying optical clarity over a wide range of wavelengths stretching from the edge of the UV (250 nm) to well into the NIR (2,000 nm), refractive indices in the visible spectrum (n = 1.50–1.63), thermal conductivities of 0.26 ± 0.09 W/mK (ORMOSIL-A) and 0.27 ± 0.07 W/mK (ORMOSIL-B), and thermal stabilities up to 300 °C. The hybrid materials were found to be easily processed into films but thick casts (>2 mm) were subject to increased rates of cracking and longer curing times. Although this is typical of sol–gel chemistries, the organic constituents of ORMOSILs reduce this effect as compared to purely inorganic sol–gels. The effect of thermal aging on the materials’ properties will also be presented as well as a comparison of these materials and the current state of the art light stripping material. 相似文献
6.
Proton conductive inorganic–organic hybrid membranes were synthesized from 3-glycidyloxypropyltrimethoxysiane (GPTMS), phenyltriethoxysilane (PhTES) and hydroxyalkylphosphonic acid. Two kinds of hydroxyalkylphosphonic acids, 1-hydroxyethane-1,1-diphosphonic acid (HEDPA) and hydroxyethanephosphonic acid (HEPA), were incorporated into the membranes as functional molecules for proton conduction. FT-IR and Raman studies revealed the presence of phosphonic acid groups in the hybrid membranes. 13C and 29Si NMR confirmed that a three-dimensional siloxane network was formed in the prepared hybrid membrane by hydrolysis and condensation reactions. DTA-TG analysis showed that these membranes were thermally stable up to 200 °C. The HEDPA-based system was found to have higher proton conductivities than the HEPA-based one. The proton conductivities of the hybrid membranes increased with the phosphonic acid content and temperature up to 130 °C. The conductivities of the HEDPA/GPTMS/PhTES membranes = 1/1.6/0.4 were 1.0 × 10−1 and 4.5 × 10−4 S cm−1 at 100% relative humidity and non-humidified conditions, respectively, at 130 °C. 相似文献
7.
Kazuyoshi Kanamori Mamoru Aizawa Kazuki Nakanishi Teiichi Hanada 《Journal of Sol-Gel Science and Technology》2008,48(1-2):172-181
Novel aerogels and xerogels with methylsilsesquioxane (MSQ, CH3SiO1.5) networks have been prepared by a modified sol–gel process using surfactant and urea as a phase-separation inhibitor and as an accelerator for the condensation reaction, respectively. Optimized aerogels dried under a supercritical condition not only showed the similar properties as conventional pure silica aerogels such as high transparency and porosity etc, but also demonstrated outstanding mechanical strength against compression; the aerogel drastically shrank upon loading and then recovered when unloaded, which is called a “spring-back” behavior. On ambient pressure drying, the wet gel also exhibited the similar response against compression stress originated from the capillary pressure, and thus xerogels with the comparative structure and properties to those of corresponding aerogels have also been obtained. This unusual mechanical behavior is attributed to the trifunctional flexible networks of MSQ, low silanol concentration which prevents the irreversible shrinkage, and high concentration of a hydrophobic methyl group directly attached to every silicon atom which helps re-expansion after the temporal shrinkage. 相似文献
8.
Vikas Mittal 《Colloid and polymer science》2010,288(6):621-630
Hybrid organic–inorganic latex particles are synthesized to combine the beneficial properties of the constituents which thus
lead to synergistic improvement in the properties. The properties of hybrid particles are dependent on the successful hybridization
process, thus controlling or tuning of such processes by effective characterization is immensely important. Analytical ultracentrifugation
provides these characterization possibilities owing to its high statistical capability and ability to characterize multiple
parameters. The use of different detection methodologies can help in generating valuable information on the overall size and
density distributions of the particles. Apart from that, it is also possible to quantify the presence of any free polymer
and inorganic particles in the hybrid latex which would affect the properties of hybrid latexes. By following the densities
of the pure and hybrid particles, it is also possible to quantify the amounts of the constituent phases in the hybrid particles.
The density gradients generated in preparative ultracentrifugation also provide additional possibilities for the characterization
of the hybrid particles which have densities higher than the measurable range in the analytical ultracentrifuge. Evolution
of hybrid particles can also be studied as a function of time. It also provides advantage of separation of the various fractions
for further characterization. 相似文献
9.
Yuanjing Cui Jiancan Yu Junkuo Gao Zhiyu Wang Guodong Qian 《Journal of Sol-Gel Science and Technology》2009,52(3):362-369
A DCM derivative, namely 4-Dicyanomethylene-2-methyl-6-{[4′-(N-hydroxyethyl-N-methyl)amino]styryl}-4H-pyran (DCMH), has been synthesized and covalently incorporated into the inorganic silica network as pendants via a sol–gel process. Molecular
structures of the resultants are confirmed by elemental analysis, 1H NMR, DSC, TGA, FTIR and UV–Vis spectroscopy. Photoluminescence (PL) spectra shows that the emission of DCMH peaked at 625 nm is almost completely quenched in DMF solution with a concentration of 1 × 10−4 mol/L, however, in hybrid films, the PL intensity enhances obviously with increasing DCMH concentration even at the high loading content of 40 mol%. All the hybrid films exhibit PL emission around 646–650 nm and
the peak position reveal little dependence on the concentration of dye, suggesting they can be used as red emissive materials
in light-emitting diodes. The relationship between fluorescence lifetime and dye concentration is also investigated by time-resolved
PL measurements. 相似文献
10.
D. Tian Ph. Dubois R. Jérôme 《Journal of polymer science. Part A, Polymer chemistry》1997,35(11):2295-2309
The hydroxyl or vinyl end-groups of linear or three-arm star-shaped poly(ε-caprolactone) (PCL) chains have been derivatized into triethoxysilane groups reactive in the sol-gel process. New transparent hybrid materials that combine tetraethylorthosilicate (TEOS) and PCL known for biodegradability and biocompatibility have accordingly been prepared. The sol-gel process is, however, limited by the early vitrification of the reactive system. However, thermal posttreatment can overcome these diffusional and/or kinetic limitations as assessed by a set of analytical methods. The thermal stability of PCL is improved by incorporation into the silica network. Conversely, the thermal stability of the ceramer depends on the effective PCL content. The extent of PCL incorporation into the silica network depends on PCL molecular weight, number, and reactivity of the PCL functional groups. IR spectroscopy has shown that hydrogen bonding occurs between the ester groups of PCL and residual OH groups of the silicate component. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2295–2309, 1997 相似文献
11.
Yan Ding Hongli Chen Weilin Chen Enbo Wang Jingxin Meng 《Transition Metal Chemistry》2009,34(3):281-288
Four novel organic–inorganic hybrid compounds [Cu5
I(4,4′-bpy)3(2,2′-bpy)4][BW12O40] · H2O (1), [Ni0.5(2,2′-bpy)1.25][Ni(2,2′-bpy)3][Ni(2,2′-bpy)2(H2O)(SiW11VIWVO40)] · 0.5H2O (2), [H2bpy]2[Zn(2,2′-bpy)3]2[Si2W18O62] · 1.5H2O (3) and [CuII(2,2′-bpy)2]2[SiW12O40] · 2H2O (4) (2,2′-bpy = 2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine) have been synthesized under hydrothermal conditions and characterized
by elemental analysis, IR spectroscopy, thermal gravimetric analysis, electrochemical measurements and single-crystal X-ray
diffraction. Compound (1) is a novel [BW12O40]5− polyoxoanion bisupported by copper(I) coordination cations with mixed 2,2′-bpy and 4,4′-bpy ligands. Compound (2) is constructed from the [SiW11VIWVO40]5− polyoxoanions supported by [Ni(2,2′–bpy)2]2+. Compound (3) is composed of a novel [Si2W18O62]8− cluster and [Zn(2,2′–bpy)3]2+ complexes, which held together into a three-dimensional (3D) supramolecular network through hydrogen-bonding interactions.
Compound (4) shows a 2D layer framework constructed from a bisupporting Keggin polyoxoanion cluster and [Cu(2,2′–bpy)2]2+ coordination polymer fragments, resulting in 3D networks via supramolecular interactions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
Shuang Hu Yuan Hu Lei Song Hongdian Lu 《Journal of Thermal Analysis and Calorimetry》2011,103(2):423-427
Phosphorus-modified siloxanes monomer DOPO-IPDI-AMEO (DIA) was synthesized and characterized by 1H nuclear magnetic resonance (H NMR), 31P NMR, and Fourier transform infrared spectra (FTIR). It hydrolyzed and grew an organic–inorganic hybrid coating on the surface
of cotton fabrics via sol–gel process. The conversion of gel reaction was characterized by solid-state 29Si NMR. The effect of the modified organic–inorganic hybrid materials on thermal properties of cotton fabrics was investigated
by thermogravimetric (TG) analysis, real time Fourier transform infrared (RT-FTIR), and microscale combustion calorimetry
(MCC) experiments. In addition, thermogravimetry-Fourier transform infrared spectra (TG-FTIR) were used to investigate the
released degradation products. The characterization information represented that DIA has been prepared successfully. Also
the conversion of gel reaction was fairly high. The TG data showed that char residues increased with the addition of the DIA
coating. While the peak heat release rate (PHRR) decreased with the presence of the coating in MCC test. Moreover, the flammable
degradation products dropped obviously, which can be observed from the data of TG-FTIR. 相似文献
13.
14.
Chunlei Yan Rongjun Liu Yingbin Cao Changrui Zhang Deke Zhang 《Journal of Sol-Gel Science and Technology》2012,64(1):251-256
Zirconium carbide (ZrC) was synthesized from inorganic–organic hybrid precursor’s pyrolysis by solution-based processing. Zirconium-containing complexes, which were obtained by chelation of oxide bidentate ligands to zirconium, were used to combine with phenolic resin to form precursors for ZrC. The precursors using specific ligands including acetylacetone, ethyleneglycol, and salicylic acid transformed into pure ZrC at a relatively low temperature (1,550 °C) in addition to that using lactic acid. As a comparison, synthesis of ZrC only using zirconium oxychloride octahydrate (ZrOCl2·8H2O) and phenolic resin was also conducted. The synthesized powders had a small average crystallite size (~300 nm), and a low oxygen content (~2.5 at.%). The conversions from as-synthesized preceramic precursors to ceramics were studied by means of FTIR, SEM, EDS, XRD, and XPS. The oxidation behavior of the synthesized ZrC in air was studied by DSC-TG analysis. 相似文献
15.
Seung-Yeon Kwak Na Ree Kim Kangin Lee Jonghoon Yi Jae Hong Kim Byeong-Soo Bae 《Journal of Sol-Gel Science and Technology》2011,60(2):137-143
Fluorescent dye (DCM-OH) is covalently bridged to organic–inorganic hybrid material to prevent molecular stacking and to get
high fluorescence efficiency and laser property. Novel DCM-OH is synthesized to have hydroxyl functional groups and is bridged
to trialkoxysilane as a sol–gel precursor. It participates in sol–gel process to synthesize dye-bridged organic–inorganic
hybrid material (dye-bridged hybrimer) and solid-state dye laser sample is ready through polymerization. Fluorescence property
of dye-bridged hybrimer is compared with DCM-doped hybrimer that is simple mixture of DCM-OH and hybrimer matrix. The covalently
bridged structure of hybrimer with DCM-OH prevented the stacking of fluorescent molecules and enhanced concentration stability.
The dye-bridged hybrimer shows much higher fluorescence intensity and low color-shift until it reached high concentration
in comparison with DCM-doped system. And the proper lasing property is observed in dye-bridged hybrimer samples. 相似文献
16.
《Journal of Coordination Chemistry》2012,65(3):444-452
Polyoxometalate (POM)-based coordination polymers, [Cu(L)2][SiW12O40]·4py·H2O (1), [Ag(py)2]4[SiW12O40] (2) and [Co(L)3]2[SiW12O40]·py·7H2O (3) (L?=?pyridine-2-carboxylic acid, py?=?pyridine), have been obtained hydrothermally and characterized by elemental analyses, IR and single-crystal X-ray diffraction analyses. Electrochemical properties are also investigated. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(7):719-732
Two new inorganic–organic hybrid cobalt phosphomolybdates (Hdien)2[Co(dien)]2[Co(dien)(H2O)]2[CoMo12O24(HPO4)2(H2PO4)2(PO4)4(OH)6]?···?5H2O (1) and (H2dien)2[Co(dien)]2[Co(H2O)2]2[CoMo12O24(HPO4)4(PO4)4(OH)6]?···?7H2O (2) (dien?=?diethylenetriamine), involving molybdenum in the V oxidation state and covalently bonded transition metal complexes, have been prepared under mild hydrothermal conditions and structurally characterized by elemental analyses, IR spectra, TG analyses, and single-crystal X-ray diffraction. Compound 1 exhibits a one-dimensional (1D) chain framework, in which dien molecules adopt two kinds of coordination modes. Compound 2 shows a two-dimensional (2D) layer framework with three types of unusual tunnels. To the best of our knowledge, it is the first time [Co(dien)] units are directly incorporated into 1D and 2D skeletons of reduced molybdenum phosphates. The electrochemical properties of the two compounds were studied via the method of bulk-modified carbon paste electrodes. Furthermore, the magnetic properties of compound 2 are reported. 相似文献
18.
The synthesis and liquid crystalline properties of some new 2,6‐disubstituted anthracenes are described. Symmetrical alkylphenyl derivatives exhibit smectic mesophases, whereas simpler structures are non‐mesogenic. One unsymmetrically substituted anthracene exhibits a narrow nematic phase. The potential for these molecules to act as phototriggers has been investigated but efficient photodimerisation cannot be achieved. 相似文献
19.
《Journal of Coordination Chemistry》2012,65(13):2079-2087
A new coordination polymer having the formula [Pr(μ 5-S2O3)(μ 4-tp)0.5(H2O)] n (1) (S2O3 = thiosulfate dianion; tp = terephthalate dianions) was obtained by in situ reaction of Pr2(SO4)3 · 6H2O with H2tp ligands under solvothermal conditions (H2O/ethanol). The coordination polymer obtained was characterized by elemental analysis, FT-IR, thermogravimetry (TG), fluorescent spectra and single crystal X-ray diffraction analysis. The most intriguing structural feature is that the complex exhibits a 3D open framework resulting from bridge-linking coordination between ligands and praseodymium ions. Additionally, 1 has characteristic emission spectra of PrIII with good fluorescence properties. This is the first coordination polymer based on thiosulfate/terephthalate ligands and a rare earth metal and has an unprecedented pentadentate-bridge-linking coordination mode of the thiosulfate group. 相似文献
20.
Waseem Ahmad Shikha Sharma 《International journal of environmental analytical chemistry》2013,93(15):1604-1614
ABSTRACTContamination of groundwater by heavy metal is one of the most emerging and serious environmental problems. There are so many methods which are available to overcome these problems. Among various available methods, hybrid organic–inorganic ion exchange resin has become more popular due to certain advantages over other available conventional methods; hence, in the present proposed work, we synthesised a hybrid organic–inorganic composite material polyacrylamide zirconium (IV) iodosulphosalicylate by using the sol-gel technique. Synthesised resin was characterised by various methods like Infrared spectroscopy and Thermogravimetric analysis-Differential thermal analysis. Various samples of this ion exchange resin are prepared by changing the condition of synthesis, i.e. concentration of acrylamide to rationalise the ion exchange capacity of the synthesise hybrid organic–inorganic ion exchange resins. A mixture of 0.1 M potassium iodate, 0.1 M sulphosalicylic acid and 0.1 M acrylamide was added dropwise to 0.4 M zirconium oxychloride accompanied by constant stirring for 8 h using magnetic stirrer at 70°C to yield polyacrylamide zirconium (IV) iodosulphosalicylate with maximum ion exchange capacity. Ion exchange capacity of synthesised resin was determined by column method and the maximum ion exchange capacity was found for Pb(II). Determination of kd values shows that the resin was highly selective for Pb (II).The selectivity for Pb was also evaluated by using certain binary mixture separation such as Ni (II)-Pb(II), Cu(II)-Pb(II), Cd(II)-Pb(II), Sr(II)-Pb(II), Ba(II)-Pb(II),Zn(II)-Pb(II) and Mg(II)-Pb(II). 相似文献