Theoretical kinetic study of the reaction between dimethyl disulfide and OH radicals

The potential energy profile of the reaction between dimethyl disulfide and OH^? radicals is explored by utilizing ab initio and hybrid meta density functional theory methods. Having the energies and structural data of the stationary points, statistical rate theories, such as transition state theory and variable reaction coordinate-transition state theory, are employed to compute the overall rate constants, and discuss the mechanism and product channels. On the basis of the calculations, the overall rate coefficient is predicted to be 2.49?×?10^?10?cm³?molecule^?1?s^?1 at 298?K. It is found that in the most favorable pathway, the reaction proceeds via formation of the relatively unstable intermediate CH₃S^?(OH)SCH₃ decomposing rapidly to yield CH₃S^?+CH₃SOH.     

聚苯硫醚复合涂层的耐磨性能

研究了用固体润滑石墨、碳化硅、二硫化钼等填料改性的聚苯硫醚 (PPS)涂层的耐磨性能。实验结果表明 ,聚苯硫醚复合涂层具有优良的耐磨性 ;加入适量 ( 3 0 % )的石墨、碳化硅等固体润滑剂 (石墨 :碳化硅 =2∶3 ) ,可以有效提高涂层的耐磨性能 ,而二硫化钼和三氧化二铬的减摩效果更佳     

Chemistry and Physics of Alkali Metals on MoS2 Surfaces

The interaction of alkali metal with surfaces has been of great interest to the community of catalysis since alkali metal can play an important role as a promoter. On alkali-doped MoS₂, such a promotion effect of alkali metal has been exemplified in the direct synthesis of linear alcohols from CO and H₂, where the alkali-doping switches the catalyst selectivity from methanation to alcohol synthesis. This paper reviews recent high-resolution X-ray photoelectron spectroscopy experiments that have provided direct observation of electron transfer from alkali metals to a model single crystal MoS₂ and the capture of the supra-valence electrons in the subsequent oxidation reactions.     

不同形貌MoS2电催化剂的制备及其析氢性能

为了提高二硫化钼催化水电解析氢的性能,采用钼酸铵和还原性磷钼酸铵(rPOM)两种不同的钼源,以硫代乙酰胺为硫源,制备片状和花球状两种形貌的MoS2电催化剂,并通过物理表征与电化学分析,考察了其水电解析氢的性能。结果表明:与片状MoS2相比,花球状MoS2具有较低的过电位(在交流密度为10 mA/cm2时的过电位为287 mV)和较小的Tafel斜率(96.2 mV/dec),经过2000圈循环后,花球状MoS2仅存在微小的电位衰减,展现出较好的稳定性和耐久性;而选用纳米尺度的rPOM作为模板得到的花球状MoS2,其尺寸小,易于暴露更多的终端硫原子,从而增加了催化剂活性位点数量,提高了本征催化性能。     

多级结构MoS2/C复合材料的储锂性能

利用二硫化钼和葡萄糖为原料,采用一锅乙醇/水复合溶剂热-后热处理法制备了绣球花状结构MoS₂/C复合材料。考查了乙醇/水复合溶剂的合理组成和MoS₂/C复合材料中碳的合理含量,分别采用SEM和TEM表征了MoS₂/C材料的形貌结构,通过TGA测试和计算了材料中的碳含量。采用循环伏安、恒流充放电和交流阻抗等测试了MoS₂/C复合电极的电化学性能。结果表明,MoS₂/C复合材料拥有多级花球状结构,缓解了MoS₂的团聚,使电极材料的利用率和电化学稳定性显著提高。当V（乙醇）：V（水）为1：2,碳含量为50%时,MoS₂/C复合电极在200 mA·g^-1的电流密度下,充放电循环100次后,可逆容量达到762 mA·h·g^-1。     

Perm-Inspired High-Performance Soy Protein Isolate and Chicken Feather Keratin-Based Wood Adhesive without External Crosslinker

Crosslinking modification can effectively improve the water resistance of soy protein isolate (SPI) adhesive, but it often depends on petroleum-based reagents, violating the concept of green environmental protection. Here, inspired by the breaking and recombination of the disulfide bond in the perm process, a high-performance wood adhesive is prepared by incorporation of SPI (modified by sodium sulfite to cleave the disulfide bonds of protein chains) and feather keratin (FK, extracted from waste chicken feathers by breaking the disulfide bond) without using any other crosslinkers. The crosslinking reaction occurs by disulfide bonds derived from the sulfhydryl group of FK and SPI. Thus the wet shear strength of the SPI/FK-20 adhesive is improved from 0.57 to 1.18 MPa, an increment of 107%. This study provides a green strategy to prepare high-performance protein-based adhesive from the waste products-chicken feathers, which will contribute to the development of the environmentally friendly wood adhesive industry.     

戒酒硫合成工艺改进研究

以二乙胺、二硫化碳、双氧水为原料,在硫酸的中和作用下合成戒酒硫,研究了各反应条件的影响。较佳工艺条件是:第一步,原料配比n(CS2):n(C4H11N)=1∶1,反应温度:90℃,反应时间:2 h;第二步氧化,滴加H2SO4和H2O2,物料配比n(H2SO4)∶n(H2O2)∶n(C4H11N)=1.2∶1.5∶1,反应温度:≤16℃,反应时间:12 h,得率为85%。     

Preparation and electrical conductivity of polyethers/WS2 layered nanocomposites

Utilizing the solvothermal synthesis technique, lithium intercalated tungsten disulfide Li_xWS₂ with x > 1 was obtained, which was allowed to react with water to the formation of single-molecule-layer suspension of tungsten disulfide. The layered nanocomposites PEG, PEO/WS₂, intercalating poly(ethylene glycol) (PEG, MW ≈ 1 × 10³, 6 × 10³, 1 × 10⁴) and poly(ethylene oxide) (PEO, MW ≈ 3 × 10⁵) into the tungsten disulfide host galleries, were prepared using the improved exfoliation-adsorption technique. It was revealed that the intercalated polymers within the host galleries are in a double-layer arrangement with an interlayer expansion of about 9 Å. Despite high conductivity of the host material, those of the PEG, PEO/WS₂ nanocomposites were found to be high in the order of 1 × 10⁻² to 10⁻³ S cm⁻¹ at ambient temperature, resulted from the guest-host charge transfers.     

角蛋白基药物载体的发展及应用探讨

从毛发中提取角蛋白，开发具有独特功能的角蛋白基药物载体材料，提高药物的活性和生物利用率，既能够增加毛发的利用价值，又能够实现节能减排，符合可持续发展战略要求。对毛发中提取角蛋白进行二硫键重建、自由基聚合、多糖改性和烷基化等改性处理，赋予角蛋白基药物载体优异地功能特性，进一步拓宽其作为角蛋白基药物载体的应用范围。角蛋白基药物载体可被加工成纳米粒子、纤维支架、水凝胶等各种形式用于药物的递送。作为一种高硫含量且具有良好细胞相容性的结构蛋白，角蛋白基药物载体在组织工程、再生医学等领域扮演着重要的角色。