Dipyridine modified silica--a novel multi-interaction stationary phase for high performance liquid chromatography

A novel multi-interaction stationary phase based on 4,4'-dipyridine modified silica was synthesized and characterized, by infrared spectra, X-ray photoelectron spectroscopy and elemental analysis. Mechanism involved in the chromatographic separation is the multi-interaction including π-π, hydrophobic, hydrogen-bonding, electrostatic and anion-exchange interactions. Based on these interactions, polycyclic aromatic hydrocarbons and phenols were successfully separated respectively in reversed-phase chromatography; inorganic and organic anions were also separated individually in anion-exchange chromatography by using the same column. Furthermore, the simultaneous separation of neutral organics, inorganic and organic anions was obtained on this stationary phase with the appropriate mobile phase. Therefore, such stationary phase has the characteristics of multi-interaction mechanism and multi-modal separation, and has potential application on complex samples.     

炭黑填充顺丁橡胶(BR)复合材料中多重相互作用的研究

通过溶液浸泡及高速离心的方法分离了填料与聚合物间的强弱相互作用,研究了炭黑填充BR复合材料中多重相互作用与炭黑含量的关系,基于不同结合橡胶含量与储能模量的关系,提出了该多重相互作用随炭黑含量的演变模型.结果表明,存在于炭黑凝胶Ⅰ中的玻璃化转变温度和结晶熔融峰在炭黑凝胶Ⅱ中均完全消失,该现象意味着炭黑凝胶Ⅰ中测得的玻璃化转变及结晶行为只是与炭黑形成弱相互作用的那部分分子链段的贡献.在选用玻璃化转变温度考察炭黑-橡胶相互作用时应综合考虑样品特性以及测试方法.当炭黑含量不高于50 phr时,结合橡胶Ⅱ的含量随炭黑含量的增多呈线性增大,结合橡胶Ⅲ的含量则受炭黑含量的显著影响.炭黑填充橡胶复合材料中的多重相互作用可通过重叠模型进行描述,当炭黑含量分别为25~30phr,50~55 phr以及70~80 phr时,填充复合材料体系中分别存在结合橡胶Ⅲ的重叠层,结合橡胶Ⅲ和结合橡胶Ⅱ的重叠层,以及结合橡胶II的重叠层.