私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

當前位置:> 首頁 > 論文著作 > 正文
Preparation of silica/polymer hybrid microspheres and the corresponding hollow polymer microspheres with functional groups
作者:Guangyu Liu, Longyu Li, Xinlin Yang,* Zhao Dai
關鍵字:inorganic–organic hybrid; functional hollow microspheres; distillation precipitation polymerization; core–shell microspheres
論文來源:期刊
具體來源:Polym. Adv. Technol., 19 (12), 1922-1930 (2008). DOI: 10.1002/pat.1233
發(fā)表時間:2008年
Monodisperse functional silica/polymer core–shell hybrid microspheres were prepared by a two-stage reaction with silica grafting of 3-(methacryloxy)propyl trimethoxysiliane (MPS) as core and polymer as shell having various functional groups such as chloromethyl, pyridyl, carboxylic acid, hydroxyl, and ester. MPS-modified silica core was synthesized by the Sto¨ber method and subsequently grafted with MPS as the first-stage reaction. The functional polymer shell was then encapsulated over the MPS-modified silica by distillation precipitation copolymerization of divinylbenzene (DVB) as a crosslinker and comonomers with different functional groups, including chloromethylstyrene (CMSt), vinyl pyridine (VPy), methacrylic acid (MAA), 2-hydroxyethylmethacrylate (HEMA), ethyl methacrylate (EMA), ethyleneglycol dimethacrylate (EGDMA), and trimethylol propanetrimethacrylate (Trim), in neat acetonitrile with 2,2(-azobisisobutyronitrile (AIBN) as an initiator. The encapsulation of the functional polymer shell onto the MPS-modified silica core particles was driven by the capture of oligomer radicals the vinyl groups on the surface of the MPS modified silica cores during the second-stage distillation precipitation copolymerization in the absence of any stabilizer or surfactant. The functionality and the shell thickness of the inorganic/polymer core–shell hybrid particles were controlled by the amount of DVB crosslinker and the functional comonomers during the copolymerization. The corresponding hollow polymer microspheres with various functional groups, including chloromethyl, pyridyl, carboxylic acid, and ester groups were further developed after the selective removal of silica core with hydrofluoric acid. The functional core–shell silica/polymer hybrid microspheres and the corresponding functional hollow polymer microspheres were characterized with transmission electron microscopy (TEM) and Fourier transform infrared spectra (FT-IR).
主站蜘蛛池模板: 林周县| 罗定市| 万载县| 太仆寺旗| 湛江市| 鹤峰县| 南康市| 崇信县| 邓州市| 乐山市| 木里| 广南县| 绍兴市| 马山县| 顺义区| 彭泽县| 昭平县| 古丈县| 双流县| 洛川县| 辽中县| 勐海县| 芜湖县| 施甸县| 驻马店市| 兰溪市| 宁武县| 石景山区| 韶山市| 武穴市| 河池市| 玉环县| 成安县| 宝丰县| 县级市| 岳池县| 上高县| 海晏县| 那坡县| 巴彦淖尔市| 平凉市|