纳米石墨薄片及聚合物/石墨纳米复合材料制备与功能特征研究

分析与总结了聚合物／石墨纳米功能复合材料制备方法,还根据制备纳米功能复合材料所需的纳米微观结构和功能特征介绍了石墨和膨胀石墨微观结构、膨胀石墨的物化性能,并对纳米石墨薄片制备和修饰进行研究,最后提出聚合物／石墨纳米功能复合材料发展方向。     

微波等离子体化学气相沉积法制备的新型纳米片状碳膜

在甲烷和氢气的混合系统中,利用石英管型微波等离子体化学气相沉积方法,在硅片上制备了新型的纳米片状碳膜．利用场发射扫描电子显微镜和拉曼光谱仪对碳膜的结构进行了表征,结果表明碳膜是由长1μm、宽100nm的纳米碳片相互缠绕而成．最后简单讨论了新型碳纳米片的形成机理．     

Electrochemical determination of sulfite and phenol using a carbon paste electrode modified with ionic liquids and graphene nanosheets: Application to determination of sulfite and phenol in real samples

Benzoylferrocene was used to construct a modified-graphene paste electrode. Also, hydrophilic ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate) was used as a binder to prepare the modified electrode. The electro-oxidation of sulfite at the surface of the modified electrode was studied using electrochemical approaches. This modified electrode offers a considerable improvement in voltammetric sensitivity toward sulfite, compared to the bare electrode. Square wave voltammetry (SWV) exhibits a linear dynamic range from 5.0 × 10⁻⁸ to 2.5 × 10⁻⁴ M and a detection limit of 20.0 nM for sulfite. The diffusion coefficient and kinetic parameters (such as electron transfer coefficient and the heterogeneous rate constant) for sulfite oxidation were also determined. The prepared modified electrode exhibits a very good resolution between the voltammetric peaks of sulfite and phenol that makes it suitable for the detection of sulfite in the presence of phenol in real samples.     

Removal of methylene blue from aqueous solution with silica nano-sheets derived from vermiculite

The adsorption kinetics of a cationic dye, methylene blue (MB), onto the silica nano-sheets derived from vermiculite via acid leaching was investigated in aqueous solution in a batch system with respect to contact time, initial dye concentration, pH, and temperature. Experimental results have shown that increasing initial dye concentration favors the adsorption while the acidic pH and temperature go against the adsorption. Experimental data related to the adsorption of MB on the silica nano-sheets under different conditions were applied to the pseudo-first-order equation, the pseudo-second-order equation and the intraparticle diffusion equation, and the rate constants of first-order adsorption (k(1)), the rate constants of second-order adsorption (k(2)) and intraparticle diffusion rate constants (k(int)) were calculated, respectively. The experimental data fitted very well the pseudo-second-order kinetic model. The activation energy of system (E(a)) was calculated as 3.42 kJ/mol. The thermodynamics parameters of activation such as Gibbs free energy, enthalpy, entropy were also evaluated and found that DeltaG*, DeltaH*, and DeltaS* are 65.95 (71.63, 77.45)kJ/mol, 0.984 (0.776, 0.568)kJ/mol, and -0.222 (-0.223, -0.224)kJ/(Kmol) at 20 (45, 70) degrees C, respectively. The desorption of the dye on the silica nano-sheets using ethanol was also investigated primarily.     

三元乙丙橡胶/石墨功能复合材料的制备与性能分析

以超声波处理膨胀石墨得到的石墨纳米薄片为原料,采用熔融插层复合方法制备密封用三元乙丙橡胶/石墨功能复合材料,利用SEM与XRD分析石墨及其复合材料微观结构、利用透气仪分析复合材料气体阻隔性能。结果表明:三元乙丙橡胶与石墨形成插层型功能复合材料,其气体阻隔性能显著提高,有望成为气密性优异的新型橡胶密封材料。