高等学校化学学报
高等學校化學學報
고등학교화학학보
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES
2014年
4期
689-694
,共6页
介孔分子筛%微孔分子筛%纳米绝热材料%热导
介孔分子篩%微孔分子篩%納米絕熱材料%熱導
개공분자사%미공분자사%납미절열재료%열도
Mesoporous molecular sieve%Microporous molecular sieve%Nano thermal insulation material%Thermal conductivity
在水热体系中合成了具有规则孔道结构的微孔分子筛 ZSM-5和介孔分子筛 MCM-41, SBA-15, MAS-5,通过改变材料表面的电性对介孔材料进行了化学修饰.采用X射线衍射( XRD)和扫描电子显微镜( SEM)对样品的结构、形貌进行了表征；通过氮气吸附-脱附测试了产物的比表面积,采用BJH法计算孔分布和孔容；将制得的样品压制成绝热材料后,进行导热性质测定.常温(25℃)常压下,有序介孔分子筛MCM-41的导热系数为0.038 W · m-1· K-1,具有少量微孔结构的 MAS-5的导热系数为0.035 W·m-1·K-1,二者均为超级绝热材料.材料经改性后,绝热性能有所提高：MCM-41的导热系数降至0.028 W·m-1·K-1, MAS-5的导热系数降至0.017 W·m-1·K-1.结合纳米介孔材料导热理论模型进行分析,发现纳米孔绝热材料的孔径越小,孔隙率越大,绝热性能好；介孔分子筛的导热系数与其孔壁厚度、孔径大小以及孔隙率有关.
在水熱體繫中閤成瞭具有規則孔道結構的微孔分子篩 ZSM-5和介孔分子篩 MCM-41, SBA-15, MAS-5,通過改變材料錶麵的電性對介孔材料進行瞭化學脩飾.採用X射線衍射( XRD)和掃描電子顯微鏡( SEM)對樣品的結構、形貌進行瞭錶徵；通過氮氣吸附-脫附測試瞭產物的比錶麵積,採用BJH法計算孔分佈和孔容；將製得的樣品壓製成絕熱材料後,進行導熱性質測定.常溫(25℃)常壓下,有序介孔分子篩MCM-41的導熱繫數為0.038 W · m-1· K-1,具有少量微孔結構的 MAS-5的導熱繫數為0.035 W·m-1·K-1,二者均為超級絕熱材料.材料經改性後,絕熱性能有所提高：MCM-41的導熱繫數降至0.028 W·m-1·K-1, MAS-5的導熱繫數降至0.017 W·m-1·K-1.結閤納米介孔材料導熱理論模型進行分析,髮現納米孔絕熱材料的孔徑越小,孔隙率越大,絕熱性能好；介孔分子篩的導熱繫數與其孔壁厚度、孔徑大小以及孔隙率有關.
재수열체계중합성료구유규칙공도결구적미공분자사 ZSM-5화개공분자사 MCM-41, SBA-15, MAS-5,통과개변재료표면적전성대개공재료진행료화학수식.채용X사선연사( XRD)화소묘전자현미경( SEM)대양품적결구、형모진행료표정；통과담기흡부-탈부측시료산물적비표면적,채용BJH법계산공분포화공용；장제득적양품압제성절열재료후,진행도열성질측정.상온(25℃)상압하,유서개공분자사MCM-41적도열계수위0.038 W · m-1· K-1,구유소량미공결구적 MAS-5적도열계수위0.035 W·m-1·K-1,이자균위초급절열재료.재료경개성후,절열성능유소제고：MCM-41적도열계수강지0.028 W·m-1·K-1, MAS-5적도열계수강지0.017 W·m-1·K-1.결합납미개공재료도열이론모형진행분석,발현납미공절열재료적공경월소,공극솔월대,절열성능호；개공분자사적도열계수여기공벽후도、공경대소이급공극솔유관.
Microporous aluminosilicates ZSM-5 , ordered mesostructured materials MCM-41 , SBA-15 , MAS-5 were synthesized in hydrothermal system. Then, these nanoparticles were electrostatically modified with linear cationic polymer agent. The as-synthesized samples were characterized by X-ray diffraction( XRD) , scanning electron microscopy( SEM) and N2 adsorption-desorption isotherms. Surface area was determined by Brunauer-Emmett-Teller( BET ) equation; pore size distribution and pore volume were measured by Barrett-Joyner-Halonda( BJH) method. Samples for thermal conductivity measurements were prepared by pressing powders into disks. The thermal conductivity of well-ordered mesoporous MCM-41 is as low as 0.038 W·m-1 ·K-1 . The thermal conductivity of MAS-5 is 0.035 W·m-1 ·K-1 . The thermal conductivities of modified MCM-41 and MAS-5 deereased to 0.028 and 0.017 W·m-1 ·K-1 respectively. Theoretical analysis and experimental results simultaneously explain that materials with smaller pore size or higher porosity demonstrate better proper-ties of thermal insulation;thermal conductivities of ordered mesoporous materials associate with wall thickness, pore size and porosity.
