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The objects of this research are to study the dispersion of CNT (carbon nanotube) in SDS (sodium dodecyl sulfate) aqueous solutions with kinetics approach and to obtain some information about mechanism for this dispersion. Firstly, I measured the UV-visible absorption at 260 nm of CNT in SDS aqueous solutions after different time of dispersion for different concentrations of CNT and SDS. Then, curves of the time-dependent absorbance were analyzed by various mathematical models and were found to fit well with equation of A = A∞ exp(-kobs t), where A∞ is the absorbance at infinite time and kobs is the observed rate constant. The values of A∞, kobs, and, minimum time for dispersion can be obtained. From the effects of concentrations of SDS and CNT on A∞ and kobs, the dissociation constant for CNT-SDS complex and the optimum ratio of [CNT]/[SDS] can be estimated. Finally, the mechanism for this dispersion may be proposed as' $\rm{b-CNT \xrightleftharpoons[\rm{k_{-1} \left[CNT\right]} ]{\rm{k_{1}}} CNT \xrightharpoon[]{\rm{k_{2} \left[SDS\right]}} CNT-SDS}$ where b-CNT, CNT, CNT-SDS, and, ki s are bounded CNT, exfoliated CNT, CNT-SDS complex, and, the rate constants, respectively. In this mechanism, b-CNT is firstly unbounded by supersonic energy to form CNT intermediate with rate constant of k1, which is proportional to the supersonic energy per time. The CNT intermediate then recombines to form b-CNT with rate constant k−1[CNT] or reacts with SDS to form CNT-SDS complex, which has absorbance at 260 nm in UV-visible spectrum, with rate constant of k2 [SDS]. Details of kinetics and mechanism will be discussed in this paper. [ABSTRACT FROM AUTHOR]

This research is to develop transparent and UV-shielding Epoxy/SR-494/APTMS/ZnO nanocomposite materials with high heat resistant and anti-static properties. Firstly, the APTMS (3-(acryloxypropyl)trimethoxysilane) performs the silanol intermediates by hydrolysis in pH 4∼5 acid solution. The inorganic anti-static fillers of powder ZnO can be successfully coupled and crosslinked to Epoxy/SR-494 organic matrixes with these silanols of APTMS coupling agents. The remained active -OH functional groups of the APTMS/ZnO complexes can network bonding with epoxy prepolymers. Therefore, the Epoxy/APTMS/ZnO complexes with good anti-static composites will be successfully prepared. Finally, in order to improve the thermal resistant and mechanical properties, the polyfunctionalized SR-494 (pentaery-thritol tetracrylate) acrylate monomers and the Epoxy/APTMS/ZnO composites are chain polymerized to form an excellent cross-linking structure of organic/inorganic nanocomposites. The chemical bonding formation and the best weight contents of reaction components are identified by FT-IR spectra. The thermal resistance, transparence, surface electric resistance, and hardness of these nanocomposites are measured by TGA, DSC, UV-Visible, surface resistant meter, and pencil hardness tester respectively. Experimental results show that these nanocomposites have 90% transmittance and the best Td value is 389.3 °C which is 109.0 °C and 78.6 °C higher than those of pure epoxy resin and pure SR-494 acrylate resin respectively. The glass transition temperature is not detected below 200 °C. The surface electric resistances of Epoxy/SR-494/APTMS/ZnO hybrid thin films are decreased from 3.14 × 1013 to 5.13 × 107 Ω/cm2. The hardness of these nanocomposites is as high as 8H, and those hybrid films have high UV-shielding properties. The morphology structures of the hybrid thin films are estimated by SEM. The results show that the optical thin films are evenly distributed with inorganic colloidal particles and the average particle size of these nanocomposites is 45∼80 nm, while the powder ZnO (particle size: 2∼5 μm) was used as inorganic filler. [ABSTRACT FROM AUTHOR]

New organic-inorganic hybrid materials and their anti-electrostatic hybrid membranes are prepared via sol-gel process. The polycondensation of epoxy oligomers and AEAPS/Al2O3 complexes which are organically surface modified submicrometer aluminum trihydroxide inorganic fillers with an active aminoterminal silane coupling agent, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPS), are performed. AEAPS enhances the interfacial interactions between the inorganic fillers and epoxy polymers. Meanwhile, this coupling agent maintains well dispersion of fillers in these composites. To improve the mechanical strength and thermal stability, pyromellitic dianhydride (PMDA) is used as curing agent. These hybrid films prepared from this method have excellent physical properties, such as UV-shielding, high transmission in visible resign (> 85%), high hardness (7∼8H) , high adhesive force (7∼8) and low relative surface resistance (9.71 × 1011∼1.26 × 1010 Ω/cm2) with anti-electrostatic characters. For thermal resistance, the best Td value of epoxy/PMDA/AEAPS/Al2O3 is 378.6 °C which is 85.4 °C higher than that of neat epoxy resin. Physical properties of these materials are almost the same as those of the nanocomposites prepared from expensive colloid Al2O3. Evidences from TEM micrograph show that the inorganic additives are dispersed evenly in organic matrix with nanometer scale. [ABSTRACT FROM AUTHOR]

New organic-inorganic hybrid materials and their anti-electrostatic hybrid membranes are prepared via sol-gel process. The polycondensation of epoxy oligomers and AEAPS/Al2O3 complexes which are organically surface modified submicrometer aluminum trihydroxide inorganic fillers with an active aminoterminal silane coupling agent, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPS), are performed. AEAPS enhances the interfacial interactions between the inorganic fillers and epoxy polymers. Meanwhile, this coupling agent maintains well dispersion of fillers in these composites. To improve the mechanical strength and thermal stability, pyromellitic dianhydride (PMDA) is used as curing agent. These hybrid films prepared from this method have excellent physical properties, such as UV-shielding, high transmission in visible resign (> 85%), high hardness (7∼8H) , high adhesive force (7∼8) and low relative surface resistance (9.71 × 1011∼1.26 × 1010 Ω/cm2) with anti-electrostatic characters. For thermal resistance, the best Td value of epoxy/PMDA/AEAPS/Al2O3 is 378.6 °C which is 85.4 °C higher than that of neat epoxy resin. Physical properties of these materials are almost the same as those of the nanocomposites prepared from expensive colloid Al2O3. Evidences from TEM micrograph show that the inorganic additives are dispersed evenly in organic matrix with nanometer scale. [ABSTRACT FROM AUTHOR]