无机溶胶粒子的有机高分子胶囊化研究EI

采用一种水溶性聚合物—羟丙基甲基纤维素(HPMC)处理硅溶胶粒子(SiO_2);并以这样的粒子作核,制得了SiO_2/PMMA复合胶囊化粒子;通过电泳实验对其胶囊化效果进行了表征。     

溶胶凝胶法制备二氧化钛微粉体

对二氧化钛微粉体的溶胶 凝胶法最佳制备工艺条件进行了探讨,其中溶液温度和ｐＨ 值对二氧化钛水溶胶的形成和稳定性具有较大影响,研究了二氧化钛微粉体的表面性质,ＳＥＭ 分析和孔径分布测定表明,本方法制备的二氧化钛微粉体粒子外观呈球形,其粒径以７０ ～９０Ａ 为主     

均匀分散纳米二氧化钛的制备及其紫外线屏蔽性能

以TiCl4、三乙醇胺为原料配位形成可溶性配合物，将此配合物先驱液滴加到氨水中，得到锐钛矿型二氧化钛超细粒子溶胶。研究了先驱液的加入量对二氧化钛纳米粒子的粒径及紫外线透过率的影响。将丙烯酸树脂乳液加入到均匀分散的纳米二氧化钛粒子溶胶中，通过原位聚合的方法获得了纳米TiO2高度分散的丙烯酸树脂复合薄膜。结合纯丙烯酸树脂薄膜的紫外线透过率曲线分析了TiO2的紫外线屏蔽性能。该分散均匀的锐钛矿型TiO2对紫外线具有十分优异的屏蔽作用。     

二氧化钛空心微球的制备及表征

采用模板法制备了可控制球壳厚度的亚微米二氧化钛空心微球.首先利用钛酸四丁酯乙醇溶液和聚苯乙烯粒子制备了二氧化钛/聚苯乙烯复合粒子,在空气中经500℃煅烧除去苯乙烯模板后得到锐钛矿二氧化钛空心微球.透射电镜和扫描电镜观察表明,二氧化钛/聚苯乙烯复合粒子煅烧后体积发生了急剧的收缩,形成具有空心结构二氧化钛微球.电子衍射和X射线衍射分析可知空心微球的二氧化钛球壳为锐钛矿.实验发现当钛酸四丁酯与乙醇的体积比从120提高到110时,二氧化钛空心微球的球壳厚度从20～25 nm增加到45～50nm;以不同粒径的聚苯乙烯粒子作模板,可以得到不同内孔直径的二氧化钛空心微球,其内孔直径比聚苯乙烯模板直径小15%～20%.     

PMMA-CI复合磁流变粒子的制备及影响因素研究

通过自由基聚合法制备PMMA-CI复合磁流变粒子，并对PMMA-CI复合磁流变粒子的形态和结构进行表征。考察了制备过程中的聚合温度、MMA与CI的质量配比、引发剂用量等因素对复合磁流变粒子的粒度、密度和高分子包覆量的影响。结果表明：MMA在CI表面聚合，形成了以CI为核，PMMA为壳的复合磁流变粒子；提高聚合温度以及降低MMA与CI的配比都会使粒子平均粒度和高分子包覆量减少，密度提高；引发剂用量的增加，会使粒子粒度和密度减小，高分子包覆量增加。     

St/BA/MAA复合胶乳粒子大小及羧基分布的研究

以十二烷基硫酸钠（ＳＤＳ）和平平加ＯＳ－１５为复合乳化剂,分别采用批量法、种子法、全滴加法和分步法制备了一系列的苯乙烯（Ｓｔ）／丙烯酸丁酯（ＢＡ）／甲基丙烯酸（ＭＡＡ）复合胶乳。对复合胶乳的粒子大小及形态结构、羧基分布和碱增稠性能等进行测试;考察了复合乳化剂浓度和聚合方式对复合胶乳性能的影响。     

PT／TiO2复合粒子光催化降解有机污染物的性能

在CHCl3中以FeCl3为氧化剂通过原位化学氧化方法制备了聚噻吩/二氧化钛(PT/TiO2)复合粒子。通过X射线光电子能谱(XPS)和紫外可见漫反射光谱(DRS)分析,分别研究了PT/TiO2复合粒子的结构和光响应特性。结果表明,复合粒子是由PT包裹在TiO2粒子表面而形成的具有核-壳结构的粒子;复合粒子能吸收200 nm~800 nm波长的光。分别以甲基橙和苯酚为目标污染物,研究了PT/TiO2复合粒子光催化降解污染物的性能。结果表明,具有一定含量聚噻吩的复合粒子光催化降解污染物的性能优于TiO2。     

基于原子转移自由基聚合的无机纳米粒子表面接枝改性方法研究进展

综述了原子转移自由基聚合法、反向原子转移自由基聚合法、电子转移生成催化剂原子转移自由基聚合法、电子转移活化再生催化剂原子转移自由基聚合法在无机纳米粒子表面接枝聚合物的研究进展,介绍了聚合物接枝改性过程中不同催化体系的特点。采用上述方法在无机纳米粒子表面接枝改性,均能有效控制纳米复合粒子的粒径及其分布,提高纳米粒子的分散性、耐久性和相容性且反应条件简单、可控性强,是前景广阔的聚合方法。     

硅烷偶联剂对聚苯胺/钛酸钡复合粒子的结构影响

采用不同类型的硅烷偶联剂对钛酸钡进行表面修饰,实施接枝聚合,制备聚苯胺/钛酸钡核壳结构的复合粒子.借助SEM、XRD和TG等分析方法对复合粒子的表观形貌和结构进行表征,应用Gaussian 03软件对硅烷偶联剂分子在钛酸钡表面接枝的几何构型进行计算.理论计算与实验结果表明,采用硅烷偶联剂后,在钛酸钡表面有效地实施了接枝聚合,硅烷偶联剂的类型对包覆量和复合粒子的密度有着显著的影响,反应型的硅烷偶联剂能够更好地作用于钛酸钡的表面,形成稳定核壳结构的复合粒子.     

纳米镍粒子表面接枝聚合甲基丙烯酸甲酯

采用丙烯酸(AA)和盐酸(HC l)处理纳米镍粉,通过乳液聚合方法,在纳米镍粉存在下甲基丙烯酸甲酯(MM A)原位聚合,形成纳米镍/聚甲基丙烯酸甲酯(nanoN i/PMM A)复合粒子。IR分析表明,AA通过化学键与纳米镍粒子结合,颗粒表面引入了C=C基团;采用XRD,IR,TGA,DSC,TEM等分析手段分别对含有盐酸处理的纳米镍粉的复合粒子(HC l-nanoN i/PMM A)及含有AA处理的纳米镍粉的复合粒子(AA-nanoN i/PMM A)进行了分析表征。结果表明,MM A在AA-nanoN i表面接枝聚合,纳米镍粉表面的双键参与了聚合反应,形成了具有核壳结构的复合粒子。     

乳液聚合法制备TiO2/PS复合粒子及其性能研究

采用乳液聚合法制备了以纳米二氧化钛(TiO2)为核,聚苯乙烯(PS)为壳的复合粒子.利用正交实验研究了引发剂用量、单体用量、表面活性剂浓度对复合粒子包覆效率的影响;通过透光率和亲水亲油实验,检验复合粒子的分散性,并采用透射电镜(TEM),红外光谱(FTIR)表征了复合粒子的形貌和结构.     

Preparation of carboxylic magnetic polymeric composite particles by miniemulsion polymerization in the absence of hydrophobe

Carboxylic magnetic polymeric composite particles (C-MPCPs) were prepared by miniemulsion polymerization in the absence of hydrophobe using styrene (St) as monomer, methacrylic acid (MAA) as comonomer, sodium dodecyl sulfate (SDS) as emulsifier, and azodiisobutyronitrile (AIBN) as initiator in the presence of hydrophobic magnetite particles. For comparison, non-carboxylic magnetic polymeric composite particles (N-MPCPs) were also prepared under the same conditions as C-MPCPs but without MAA as comonomer. Microscopic morphology of resulting C-MPCPs and N-MPCPs was observed by Transmission Electron Microscopy (TEM). Magnetic properties of C-MPCPs in dry condition were investigated by vibrating sample magnetometer (VSM). The results showed that the encapsulation of magnetite to prepare C-MPCPs by miniemulsion in the absence of hydrophobe was successful but not totally successful in the preparation of N-MPCPs, and the resultant C-MPCPs exhibited a broad practical size distribution, superparamagnetism and a certain level of magnetic response. The mechanism of miniemulsion polymerization to encapsulate magnetite particles successfully in the absence of hydrophobes was hypothesized that the hydrophobic magnetite particles could act as a hydrophobe and MAA could enhance the hydrophobicity of magnetite particles by ensuring oleic acid adsorption on magnetite particles' surface in acid form instead of salt form.     

绢云母-TiO_2复合颗粒的制备与应用

为制备具有钛白粉性能的矿物基体复合颜料,并发挥绢云母的协同效应,采用机械力化学包覆方法制备绢云母-TiO2复合颗粒,对制备工艺因素的影响、复合颗粒的结构与颜料性能进行研究。结果表明:绢云母研磨粒度、复合时间、球料质量比和TiO2用量对绢云母-TiO2复合颗粒性能影响显著,该复合颗粒的遮盖力为钛白粉的90%,吸油量和紫外线吸收性与钛白粉相同。在建筑涂料中填加绢云母-TiO2复合颗粒,其对比率显著高于单一填加钛白涂料;复合颗粒形貌观测显示,TiO2在绢云母表面形成了有效包覆。     

POSS/PMMA纳米复合粒子的制备与表征

以十二烷基硫酸钠为乳化剂,过硫酸钾为引发剂,用乳液聚合方法,合成出以笼型聚倍半硅氧烷(POSS)为核,聚甲基丙烯酸甲酯(PMMA)为壳的核壳型POSS/PMMA复合粒子。通过FT-IR红外光谱仪和XPS光电子能谱证实复合粒子的合成,激光粒度仪测量复合粒子粒径(大小在50nm左右)及其分布,透射电子显微镜(TEM)观察复合粒子的形态,其单分散性较好。     

疏水性光催化剂的制备及其催化动力学

采用十二烷基硫酸钠(SDS)为改性剂对TiO₂进行了疏水改性, FTIR表征表明催化剂表面具有CC和CH烷基疏水基团. 同时采用CuO对催化剂进行了可见光响应改性, UV-Vis表征表明催化剂具有良好的可见光响应性能, 吸收边红移至830nm以上. 三维荧光扫描发现随着CuO和SDS的加入,催化剂的空穴电子分离效果迅速提高. 以硝基苯为处理对象, 考察了体系pH值、污染物初始浓度、催化剂用量和光照强度对光催化反应过程的影响, 建立了动力学模型. 低浓度条件下, 通过模型计算的动力学常数相对误差范围为-16.5％～-4.5％; 高浓度条件下为-11.3％～4.6％.     

Preparation and properties of composite particles made by nano zinc oxide coated with titanium dioxide

In this paper, composite particles of nano zinc oxide coated with titanium dioxide were prepared and characterized by TEM, XRD, XPS and FT-IR, and the properties of the composite particles for photo catalysis and light absorption were studied. Tetrabutyl titanate (TBT) was hydrolyzed in an alcoholic suspension of nano zinc oxide with diethanolamine (DEA) as an additive, resulting in a film with a thickness of 20–30 nm being coated on the surface of nano zinc oxide, and the composite particles contained ZnTiO₃ after drying and calcination. Photocatalysis capabilities of the composite particles for the degradation of phenol in an aqueous solution were greatly improved as compared with nano zinc oxide particles before coating, with pure nano ZnO and nano TiO₂ with similar average sizes, or with the mixture of nano ZnO and TiO₂ with the similar composition as the composite particles. The light absorption scope of the composite particles was enlarged when compared to nano titanium dioxide with same average size.     

TiO_2包覆无机矿物粉体的制备

选用无机矿物粉体为基料,官能化金红石型TiO_2浆液为成膜物质,KM-10为官能化助刺,制备了无机矿物粉体/TiO_2复合粒子.采用正交设计实验法,探讨了不同组分的配比及无机矿物粉体的种类对合成包覆产物遮盖力的影响,最佳组分的重量配比为:m(TiO_2浆液):m(KM-10):m(硅酸铝)=0.25:0.05:1,包覆产物的遮盖力可达59.9g/cm~2.产物FTIR结构分析表明,TiO_2是通过化学键包覆在无机矿物粉体表面;经TEM分析表明,产物呈球形结构,分散性良好,平均粒径约为1.0μm.     

高分子材料在微胶囊电泳显示技术中的应用

介绍了微胶囊电泳显示技术的原理、微胶囊电泳显示器件的制备。阐述了高分子材料在制备微胶囊电泳显示材料和器件过程中的应用．重点说明了在这种新型的显示技术中颜料一聚合物复合粒子、微胶囊和塑料晶体管的应用。     

Preparation of magnetic polymeric composite nanoparticles by seeded emulsion polymerization

Seeded emulsion polymerization was used to prepare magnetic polymeric composite nanoparticles (MPCNPs) with the aim to successfully encapsulate magnetite particles and to improve particle size distribution (PSD). Microscopical morphology and number-average diameter of hydrophilic magnetite particles (HMPs), magnetic seed latex nanoparticles (MSLNPs) and MPCNPs were observed and analyzed by transmission electron microscope (TEM). Weight-average diameter and PSD of MSLNPs and MPCNPs were also analyzed by TEM. Magnetic properties of MPCNPs were investigated by Vibrating Sample Magnetometry (VSM). The results showed that the encapsulation of magnetite particles was not complete by conventional emulsion polymerization but very successful by seeded emulsion polymerization, the resulted MPCNPs were nanoparticles with much narrower PSD than that of MSLNPs, and exhibited superparamagnetism and possessed a certain level of magnetic response.