聚合物包覆二氧化硅及其环氧树脂固化物的研究

使用合有氨基的硅烷偶联剂对纳米二氧化硅进行表面修饰,然后再与含有羧基的甲基丙烯酸甲酯共聚物反应,得到聚合物包覆二氧化硅微粒子。使用FT-IR及粒径分布仪对该微粒子进行了鉴定与观察,证实了聚合物通过化学键结合包覆在二氧化硅表面。研究了舍有该微粒子的环氧树脂固化物的力学性能。当微粒子的添加量为2wt％时,其抗拉强度、冲击强度及硬度都得到了一定的提高,有较明显的增韧效果。     

反应性二氧化硅／聚甲基丙烯酸甲酯复合微粒子的合成

在有效的表面活性剂的存在下，经乙烯基三乙氧基硅烷处理过的SiO2水性分散液中，进行甲基丙烯酸甲酯乳液聚合，在反应末期加入终止剂4-羟基-2，2，6，6-四甲基氧化哌啶醇（HTEMPO），使高分子末端生成具有HTEMPO残基结构的无机／有机复合微粒子。该微粒子具有核-壳结构，SiO2表面包覆的长链高分子可直接与树脂分子缠绕，能提高复合材料的力学性能。该复合微粒子在较高温度下可发生HTEMPO-聚合物结构的解离，生成活性自由基聚合物链，因而能够与特定官能团进行反应，实现复合微粒子的功能化。     

含有受阻胺构造的光稳定性复合微粒子的合成

为了制备大分子型受阻胺光稳定剂,利用1,2,2,6,6-五甲基-4-哌啶醇与酸酐在甲苯中进行反应,生成了含有酯基的三级胺盐,用FT-IR及1H-NMR对该胺盐的化学结构进行了鉴定,并利用TG-DTA技术考察其热性质.用该胺盐在甲苯-乙醇混合溶媒中与经胺基类硅烷偶联剂处理过的二氧化硅粉反应,通过共沸蒸馏及在130℃真空干燥得到了含有受阻胺构造的光稳定性复合微粒子,探讨了受阻胺光稳定复合微粒子的合成路径,推测了其反应机理.     

Pickering乳液聚合制备草莓型PSt/SiO2有机-无机复合微球

在纳米硅溶胶分散介质中,以苯乙烯(St)为单体,偶氮二异丁脒盐酸盐(AIBA)为引发剂,不添加任何辅助单体,通过Pickering乳液聚合,成功制备了PSt/SiO2有机-无机复合微球,透射电镜研究显示,复合微球具有草莓型形态。所得复合微球粒径在190 nm-300 nm之间,二氧化硅吸附量介于28%-44%之间。研究了初始硅溶胶用量、AIBA用量和反应温度等因素对复合微球粒子粒径和二氧化硅吸附量的影响。结果发现,初始硅溶胶用量增大,复合微球粒径减小、二氧化硅吸附量增大;引发剂用量增加,二氧化硅吸附量增大;反应温度升高,复合微球粒径增大,但对二氧化硅吸附量影响较小。     

二氧化硅/聚苯胺复合粒子的制备与性能

在化学氧化聚合的反应介质中分散二氧化硅粒子,苯胺(ANI)优先在二氧化硅粒子表面聚合,形成聚苯胺(PANI)包覆的二氧化硅复合粒子(SD/PANI).扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察表明,ANI用量较小时,在二氧化硅粒子表面形成均匀的PANI层,其厚度在10～60nm之间;ANI用量较大时,二氧化硅粒子表面有颗粒状PANI形成.紫外-可见光光谱(UV-VIS)和X射线光电子能谱(XPS)分析表明,复合粒子表面PANI的氧化程度随ANI用量的减小有所下降.复合粒子表面的PANI对二氧化硅结合牢固,这种复合粒子能像纯PANI颗粒一样使冷轧钢(CRS)表面钝化,可以作为廉价的缓蚀剂用于防腐涂料.     

催化臭氧氧化处理丙烯腈废水的研究

进行了碱、双氧水、二氧化锰、氧化铜、五氧化二钒和一种复合催化剂催化臭氧氧化降低丙烯腈废水COD的研究，考察了药剂用量、反应时间对COD去除率的影响，分析了复合催化剂具有较好催化效果的原因。碱用量对臭氧氧化丙烯腈废水的COD去除率影响很大，当碱用量小时，COD去除率很低，但碱用量增大到3.20 g/L以上时，COD去除率达到了62%以上；在使用氢氧化钠条件下，CuO催化剂有较好的催化能力，而MnO2和钒催化剂的催化能力较弱；复合催化剂具有催化、消除羟基自由基抑制剂和絮凝等作用，对催化臭氧丙烯腈废水具有非常好的COD去除能力，在复合催化剂用量为6.65 g/L，进气量为1.5 L/min，气体臭氧浓度为90 mg/L，通气90 min时，COD去除率达到了97.7%。     

蓖麻油-SiO2复合改性AZ91镁合金环氧有机涂层防腐性能研究

采用化学浸渍法在AZ91镁合金表面制备磷酸盐转化膜,继而进行环氧有机涂层制备,在环氧涂层中,分别添加了不同用量的纳米二氧化硅(SiO_2)和蓖麻油。并对制得的蓖麻油-二氧化硅复合改性AZ91镁合金环氧有机涂层进行表征,考察了蓖麻油和纳米SiO_2加入量及两者共同改性对复合有机涂层防腐性能的影响。结果表明,在蓖麻油添加量为3%(wt,质量分数),纳米SiO_2用量为1%(wt,质量分数)条件下,两者共同改性的复合环氧有机涂层的腐蚀电位达到-0.732V,阻抗可达到220.5MΩ,对基底具有较好的防护作用。     

Fe_3O_4@SiO_2与PAC、PAM联合去除污水中磷的研究

采用共沉淀法制备四氧化三铁(Fe_3O_4)磁性纳米球,并采用St9ber溶胶-凝胶法制备四氧化三铁@二氧化硅(Fe_3O_4@SiO_2)纳米复合粒子,Fe_3O_4@SiO_2具有超顺磁性,可在外加磁场作用下实现从水中快速分离。并对Fe_3O_4@SiO_2进行了表征,同时系统研究了不同pH和不同浓度的Fe_3O_4@SiO_2与聚合氯化铝(PAC)、聚丙烯酰胺(PAM)联合使用时对污水中磷酸盐的吸附行为,结果表明Fe_3O_4@SiO_2用量为5mg/L,PAC用量为3mg/L,PAM用量为0.413mg/L,pH=9的条件下,Fe_3O_4@SiO_2对磷的去除率达到86.441%,采用Fe_3O_4@SiO_2与PAC和PAM联合除磷效果较好。     

TiO_2/SiO_2/石墨烯复合光催化剂的合成

以钛酸四正丁酯(TBOT)、氧化石墨烯、正硅酸四乙酯(TEOS)为原料,采用水热法合成了一系列二氧化钛(TiO_2)/二氧化硅(SiO_2)/石墨烯复合光催化剂,并对TiO_2/SiO_2/石墨烯复合光催化剂进行了表征。研究结果表明,随着SiO_2用量的增大,TiO_2/SiO_2/石墨烯复合光催化剂的比表面积及气孔直径增大,在石墨烯用量为1%(wt,质量分数),SiO_2用量为30%(摩尔百分数),10mg TiO_2/SiO_2/石墨烯复合光催化剂在80min内对亚甲基蓝(MB)溶液(10mg/L,40mL)的光催化降解率达到99.2%。     

原位合成法二氧化硅/硅钨酸改性聚乙烯醇质子交换膜的研制

以聚乙烯醇(PVA)为基体,利用原位合成法制备了二氧化硅(SiO2)和硅钨酸(SiWA)微粒在PVA基质中均匀分布的二氧化硅/硅钨酸改性聚乙烯醇(SiO2/SiWA-m-PVA)质子交换膜,利用扫描电镜(SEM)和热重分析仪(TG)分别对膜的形貌及热稳定性进行了表征,四氯化硅与钨酸钠摩尔比对SiO2/SiWA-m-PVA质子交换膜的质子导电性能、阻醇性能的影响.结果表明,四氯化硅与钨酸钠摩尔比为1∶1时,原位合成的二氧化硅和硅钨酸在质子交换膜中分散均匀,在温度低于100℃时SiO2/SiWA-m-PVA膜保水性能好;室温质子电导率为1.48×10-2 S/cm,甲醇渗透率为1.37×10-7 cm2/s,比相同条件下Nafion117膜甲醇渗透率低一个数量级,应用于直接甲醇燃料电池单电池能量密度可达11.82 mW/cm2.     

含Si-O-P键的减反膜结构及性能影响因素研究

采用SiO₂水溶胶(ACS)为硅源, H₃PO₄为桥联剂, H₂O₂为活化剂在玻璃表面成功制备了一种性能优异的新型减反膜。利用FTIR、XRD、FESEM、TEM、AFM对薄膜结构、形成机理及性能进行了研究, 结果表明, 在成胶过程中, H₂O₂的导入有效修复了SiO₂胶粒的表面羟基, 提高了SiO₂的反应活性; 而在焙烧过程中, H₃PO₄通过其自身脱水形成的偏磷酸链状体分别与SiO₂胶粒及玻璃基底表面的Si-OH进行了脱羟基缩聚, 构架了坚固的Si-O-P网络交联, 最终形成了稳定的磷硅酸盐凝胶网络结构, 提高了成膜质量。当n(H₃PO₄) : n(H₂O₂) : n(EtOH) : n(SiO₂)= 0.49: 0.52: 30: 1时, 制备的SiO₂减反膜在可见光区平均透光率高达98%, 硬度可达6H。     

导电聚苯胺/二氧化锰复合材料原位化学合成制备及表征

通过合理选择二氧化锰加入苯胺/过硫酸铵/酸水反应体系的时间,制备了各种含量的聚苯胺/二氧化锰复合材料(PANI/MnO₂)。用FTIR、UV-VIS、XRD和SEM对原位制备的PANI/MnO₂进行了表征。XRD证明了原位合成的复合材料中聚苯胺组分为无定型,MnO₂的晶型在反应前后未发生变化。SEM证明了反应中形成的聚苯胺倾向于在MnO₂颗粒表面沉积,得到一种包裹型的PANI/MnO₂复合材料。用苯胺的盐酸溶液在静止状态下处理复合材料,可得到一种树状珊瑚形貌的聚苯胺,这种形貌的聚苯胺不同于酸水体系中常见的颗粒状聚苯胺。     

化学氧化法合成聚苯胺的导电性与产率研究

以过硫酸铵((NH4)2S2O4)为氧化剂,盐酸作为质子酸掺杂,采用化学氧化聚合法合成了导电聚苯胺,研究了氧化剂用量、掺杂质子酸浓度、反应温度和反应时间对聚苯胺导电性及产率的影响,用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶红外变换光谱(FTIR)、紫外-可见光谱(UV-Vis)分析研究了聚苯胺的结构和形貌特征。结果表明,制备导电性好、产率高的掺杂态聚苯胺最佳实验条件为:n((NH4)2S2O4)/n(An)为1︰1,盐酸浓度为1 mol/L,反应温度为5℃,反应时间6 h。在此条件下,制备得到的聚苯胺电导率大于27 S/cm,产率在95%以上,颗粒表现出一定的结晶性。     

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。     

纳米镍/聚苯胺复合粒子的制备与表征

采用对氨基苯甲酸（ABA）处理纳米镍粉,然后在ABA-nano-Ni（ABA处理的纳米镍粉）的存在下苯胺（An）原位化学氧化聚合,形成纳米镍/聚苯胺（PANi/nano-Ni）复合粒子.IR和TGA分析表明ABA通过化学键与纳米镍粒子结合,颗粒表面引入了-NH2基团;采用IR、UV、DSC、TEM等分析手段对复合粒子PANi/nano-Ni进行了分析表征.结果表明苯胺在ABA-nano-Ni表面进行聚合,纳米镍粉表面的NH2基团参与了聚合反应,形成了具有核壳结构的复合粒子.     

Folic acid-functionalized magnetic ZnFe2O4 hollow microsphere core/mesoporous silica shell composite particles: Synthesis and application in drug release

A drug delivery system was designed by deliberately combining the useful functions into one entity, which was composed of magnetic ZnFe₂O₄ hollow microsphere as the core, and mesoporous silica with folic acid molecules as the outer shell. Amine groups coated magnetic ZnFe₂O₄ hollow microsphere core/mesoporous silica shell (MZHM-MSS-NH₂) composite particles were first synthesized by a one-pot direct co-condensation method. Subsequently a novel kind of folic acid-functionalized magnetic ZnFe₂O₄ hollow microsphere core/mesoporous silica shell (MZHM-MSS-NHFA) composite particles were synthesized by conjugating folic acid as targeted molecule to MZHM-MSS-NH₂. Ibuprofen, a well-known antiphlogistic drug, was used as a model drug to assess the loading and releasing behavior of the composite microspheres. The results show that the MZHM-MSS-NHFA system has the higher capacity of drug storage and good sustained drug-release property.     

可控粒径mTiO2/mSiO2及其中空结构mSiO2微球制备

近年来,mTiO_2/mSiO_2复合材料和中空结构介孔二氧化硅在生物催化、药物控释等领域展现出良好的应用前景。在乙醇体系下,以十六胺为模板剂,运用自组装原理制备出介孔氧化钛;并运用晶种法,通过改变TEOS量、模板剂用量、异丙醇和水的用量制备出一种粒径大小在0.80~1.92μm范围内可控的mTiO_2/mSiO_2复合材料;最后在乙醇体系中加入盐酸冷凝回流制备出中空结构介孔二氧化硅微球。通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射(XRD)对合成的产物进行表征。     

Poly(vinyl alcohol)/silica hybrid nanocomposites by sol-gel technique: Synthesis and properties

Poly(vinyl alcohol)/silica organic inorganic hybrid composites were prepared by using sol-gel technique. Tetraethoxysilane was used as the precursor for silica. The reaction was carried out in an aqueous medium having a pH of 1.5 with concentrated hydrochloric acid, used as the catalyst. All the composites were optically clear. Interaction at organic-inorganic interfaces due to hydrogen bonds was speculated from infrared spectroscopic analysis of the hybrid composites. Transmission electron microscopic studies revealed the existence of silica nanoparticles, uniformly dispersed in the organic matrix, which were found to grow in size with increase in tetraethoxysilane loading in the composites. Uniform dispersion of silica particles within the hybrid nanocomposites was also supported from the energy dispersive X-ray mapping of silicon. Dynamic mechanical properties exhibited substantial mechanical reinforcements due to the dispersion of nanosilica particles in the matrix. The results were further supported by significant improvements in the Young's modulus and the tensile strengths of the samples. All the hybrid composites demonstrated excellent water resistance.     

Adsorption and recognizing ability of molecular imprinted polymer MIP-PEI/SiO(2) towards phenol

Firstly, functional macromolecule polyethyleneimine (PEI) was grafted onto the surfaces of silica gel particles via the coupling grafting method, the adsorption material PEI/SiO(2) was formed. Secondly, the molecular imprinting was carried out towards the macromolecule PEI grafted on the surface of silica particles using phenol as a template and diepoxyalkyl (669) as a crosslinking agent. Finally, imprinted polymer MIP-PEI/SiO(2) with high affinity, specific recognition ability and excellent selectivity for phenol was prepared. The adsorption and recognition ability of MIP-PEI/SiO(2) for phenol were researched by static methods. The experimental results show that MIP-PEI/SiO(2) possesses very strong adsorption and recognition ability for phenol. The saturated adsorption capacity could reach to 46.6 mg g(-1). The selectivity coefficients relative to resorcin and p-nitrophenol are 35.41 and 37.40, respectively. The empirical Freundlich isotherm was found to describe well the equilibrium adsorption data. pH and temperature have great influence on the adsorption capacity. Diluted hydrochloric acid solution is used as eluent, and the adsorbed phenol is eluted easily from MIP-PEI/SiO(2).     

Polyacrylamide and poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid)-silica composite nanogels through in situ microemulsion polymerisation

Nanosize monodisperse composite particles of polyacrylamide (PAM) and poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid)-silica [Poly(AM-co-AMPSA)-SiO₂] were prepared by water-in-oil in situ microemulsion polymerisation without surface treatment of silica. The synthesised composite particles were produced with controllable sizes ranging from 44 to 77 nm in diameter. Presence of silica filler in the nanoreactors facilitates the formation of well-defined discrete particles. The prepared nanocomposites were characterised by dynamic light scattering, transmission electron microscope, Fourier transform infrared spectrophotometer, thermogravimetric analyzer, differential scanning calorimeter, scanning electron microscope and X-ray diffraction. The spectroscopic result shows strong interactions of silica nanoparticles with sulphonic groups of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA). The onset degradation temperature is increased from 227 to 262 °C in copolymer–silica composite as compared to polyacrylamide–silica (PAM–SiO₂) which indicates improved thermal stability. The shifting of glass transition temperature from 194 to 203 °C in copolymeric composite nanogels further confirms the existence of strong interactions of silica filler with poly(acrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid) [Poly(AM-co-AMPSA)] chains. Also the chemical composition of polymeric chains and the affinity of polymer chains and silica influenced the morphology of nanogels.