有机介观体系相行为的量热学研究

项目名称： 有机介观体系相行为的量热学研究

项目编号： No.21273138

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 兰孝征

作者单位： 山东农业大学

项目金额： 82万元

中文摘要： 多孔材料孔道内的介观尺度有机液体的相行为，受到尺寸及界面作用的显著影响。孔内液体的存在状态、相变温度及相变焓，随尺寸及孔壁作用的变化规律，是理解介观尺度有机液体热力学性质的关键。用系列孔径的纯硅基（SBA-15）、有机硅(PMOs)、碳质孔壁C/SBA-15有序介孔材料及可控孔径玻璃（CPGs）为吸附剂，使孔壁与有机分子之间形成弱、中等及强相互作用模式。以低温DSC量热法为基本手段，研究3-30nm有序介孔内单、双组分液体熔点、凝固点及相变焓随吸附量、孔径、孔壁组成的变化规律，结合XRD分析，推断接触层相厚度、可冻结液体晶型，确定各种界面作用下熔点、凝固点及其焓变与尺寸关系模型；研究常规完全互溶、低共熔物吸附于3nm-1微米孔道中的有机介观体系相行为，考察各种尺寸及界面作用下,介观二元相图演化至常规相图的规律。研究为理解低维液体性质，及催化、纳米摩擦学、纳米材料制备等研究提供热力学基础。

中文关键词： 纳米限域；尺寸效应；界面作用力；量热线；相行为

英文摘要： Phase behavior of mesoscopic scale organic liquids confined in porous materials is significantly influenced by the pore size and interface interaction. The existing state, phase change temperature and enthalpy of pure and binary mixtures under different size and interface interaction are the key points of understanding the thermodynamic properties of the confined organic liquids. Ordered mesoporous silicates(SBA-15), periodic mesoporous organic silicas(PMOs), carbon-walled silicates(C/SBA-15) and controlled porous glasses (CPGs) with different pore sizes act as the media for adsorbing orgnanic liquids,thereby the gradient interface interactions can be formed between pore wall and the organic molecules in weak, moderate and strong strength. For pure organic liquids and the representative mixture, the melting and freezing temperatures and the enthalpies during the transitions will be measured confined in pores of 3-30nm at different pore fillingness and interaction modes by low temperature DSC method. Combined with XRD diffraciton patterns for the frozen pore liquids, the thickness of contact layer phase, crystlline structure of freezing layer may be deduced. The global phase diagram of pure liquids can be obtained in respect to different size and interface interactions. For binary organic liquids of 3nm to micro

英文关键词： nanoconfinement；size effect；interface interactions；calorimetry；phase behavior