【作者】 王斌；

【导师】 郭朝霞；

【作者基本信息】 清华大学 ， 材料科学与工程， 2005， 硕士

【摘要】 本论文主要研究无机纳米粒子(纳米氧化硅、氧化铝和氧化钛)的表面接枝改性。所使用的表面改性剂包括有机小分子(二异氰酸酯,氨基硅烷偶联剂,硬脂酸等)和高分子化合物(聚乙二醇,聚醚型树枝状高分子)。在催化剂二月桂酸二丁基锡(DBTDL)存在的条件下,采用一步加料法实现了甲苯二异氰酸酯(TDI)偶合聚乙二醇(PEG)接枝改性纳米氧化硅表面。研究了不同反应温度下的接枝机理。与通常使用的二异氰酸酯偶合高分子二元醇接枝改性纳米粒子表面的两步加料法和两步反应法相比较,这种一步加料法具有简单、高效等优点。利用二环己基碳二酰亚胺(DCC)催化酰胺化反应,在二氯甲烷等溶剂中,成功地将含羧基的有机小分子模拟物(硬脂酸、苯甲酸、苯乙酸)接枝到经过氨基硅烷偶联剂预处理的纳米氧化铝表面。考察了羧酸用量、溶剂种类、羧酸种类等因素对接枝的影响。在此基础上,考察了聚醚型树枝状高分子接枝改性纳米氧化铝表面的情况,使用了第一代(G1),第二代(G2)和第三代(G3)树枝状高分子。研究表明,端基为羧基的聚醚型树枝状高分子也能通过酰胺化反应接枝到纳米氧化铝表面。本研究为纳米氧化铝表面的有机化改性提供了一种通用的方法。使用小分子改性剂甲苯二异氰酸酯(TDI)和己二异氰酸酯(HDI),对金红石相纳米氧化钛和锐钛矿相纳米氧化钛的表面性质和反应活性进行了研究。在此基础上,进一步研究了HDI接枝锐钛矿相纳米氧化钛,考察了HDI用量,反应时间,反应温度对接枝的影响。此外还初步研究了催化剂DBTDL存在的条件下,HDI偶合PEG接枝改性锐钛矿相纳米氧化钛表面的一步加料法。本工作为深入研究纳米氧化钛的表面改性打下了基础。更多还原

【Abstract】 This dissertation deals with surface modification of inorganic nano-particles(nanometer silica, alumina and titania). The surface modifiers used include smallorganic molecules (diisocyanate, silane coupling agent, stearic acid,etc.) andpolymers (polyethylene glycol and polyether dendrimer).Polyethylene glycol (PEG) is successfully grafted onto nano-silica surface usingtoluene diisocyanate (TDI) as the coupling agent through a one-step procedure, underthe presence of catalyst dibutyltin dilaurate (DBTDL). The grafting mechanismsunder different reaction temperatures are also investigated. Compared with thosecommon used two-step procedures to graft polymer alcohol onto nano-particle surfacethrough diisocyanate coupling, this kind of one-step procedure is more simple andeffective.Small organic molecule carboxyl acids (stearic acid, benzoic acid and phenylacetic acid) are successfully grafted onto nano-alumina surface pretreated with3-aminopropyltriethoxysilane, through N, N’-dicyclohexylcarbodiimide (DCC)mediated amidation reaction in dichloromethane and other solvents. Furthermore, theeffects of carboxyl acid amount, carboxyl acid type and solvent type on the graftingare investigated. On that basis, polyether dendrimers with carboxyl group as the endgroup are used to graft nano-alumina surface. The results indicate that first generation(G1), second generation(G2) and third generation(G3)polyether dendrimers canall be grafted onto nano-alumina surface. This research may offer a general methodfor surface modification of nano-alumina.Two types of titania (rutile and anatase) are treated with toluene diisocyanate (TDI)and hexamethylene diisocyanate (HDI) respectively, and the surface property andreactivity of the titanias are analyzed. On that basis, the treatment of anatasenano-titania by HDI was further studied, the effects of HDI amount, reaction time andreaction temperature on grafting are investigated. Furthermore, anatase nano-titaniawas grafted with PEG using HDI as the coupling agent through a one-step procedure,under the effect of catalyst DBTDL. This work may serve as the basis for furtherstudy on surface modification of nano-titania.更多还原