(1. 常州大學(xué) 材料科學(xué)與工程學(xué)院，常州 213164；
2. 常州大學(xué) 機(jī)械工程學(xué)院，常州 213164)
摘 要: 以無皂乳液聚合法制備的單分散聚苯乙烯(PS，經(jīng)二乙烯基苯交聯(lián)處理)微球為內(nèi)核，借助油/水兩相界面自組裝過程在PS內(nèi)核表面原位包覆樹枝狀介孔氧化硅(Dendritic mesoporous silica,D-mSiO2)，制備具有完整核殼包覆結(jié)構(gòu)的PS/D-mSiO2納米粒子。紅外光譜、X射線衍射、掃描電鏡、透射電鏡和氮氣吸附脫附等分析結(jié)果顯示：所制備納米粒子殼層中富含樹枝狀開放孔道，且基本垂直于內(nèi)核表面呈車輻放射狀；其平均孔徑在6.1~8.4 nm，但內(nèi)部孔道缺乏長程有序性。在本實驗條件下，隨反應(yīng)攪拌速率的增大，最終產(chǎn)物的粒徑尺寸(或包覆層厚度)呈先增大后減小的變化規(guī)律，且過快或過慢的攪拌速率均不利于所得產(chǎn)物包覆結(jié)構(gòu)完整性和孔徑均勻性的提高。這可能與剪切力對于界面乳化、自組裝以及動態(tài)漏斗式梯度生長過程的影響有關(guān)。
關(guān)鍵字: 介孔氧化硅；樹枝狀孔道；納米粒子；核殼結(jié)構(gòu)；油水兩相體系
（1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;
2. School of Mechanical Engineering, Changzhou University, Changzhou 213164, China）
Abstract:The monodispersed polystyrene (PS) spheres were obtained via a soap-free emulsion polymerization method using divinylbenzene as a crosslinker. The cross-linked PS cores were uniformly coated with dendritic mesoporous silica (D-mSiO2) shells via a developed St？ber method accompanied by the self-assembly of CTAB micelles with TEOS in terms of an oil-water biphase system, and the PS/DmSiO2nanoparticles with a well-defined core/shell structure were prepared. The obtained hybrids were characterized by Fourier transform infrared spectroscopy, low-angel X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy and nitrogen adsorption-desorption measurement. The results show that the silica shells are composed of abundant dendritic and three-dimensional mesopores, and the radial meso-channels (6.1-8.4 nm) are perpendicular to the surfaces of PS cores. As confirmed by low-angle XRD, the meso-channles in the silicashells are not in long-range order. For a given PS core, the particle size(or shell thickness) of composites increases firstly and then decreases as the stirring rate increasing. Under the experimental conditions, an appropriate stirring rate contributes to the improvement of the structural integrity and pore size uniformity of the final products. The possible formation mechanism involves the interfacial emulsion to form oil-water hemimicelles, exclusive composite micelles on the solid nuclei, funneling gradient assembly, and growth of the mesochannels.
Key words: mesoporous silica; dendritic mesopore; nanoparticle; core-shell structure; oil-water biphase system
