静电喷涂高附着力疏水涂层及其性能

目的提高静电喷涂疏水涂层的附着力。方法采用硅烷偶联剂和聚二甲基硅氧烷制备了表面改性疏水二氧化硅粉末。将一定比例的聚偏氟乙烯粉末、超高分子量聚乙烯粉末与疏水二氧化硅粉末混合,制备了复合型疏水粉末。使用环氧树脂、固化剂、活性剂等配制了导电环氧树脂。通过静电喷涂工艺将复合疏水粉末喷涂到已用导电环氧树脂覆盖的铝基板表面,经过中温固化,制得了铝合金疏水复合涂层。采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)、接触角测量仪(CA)、百格刀附着力测试仪等,对疏水复合涂层进行测试表征。结果 SEM结果表明涂层表面构建了微米-纳米的阶层粗糙结构,经CA测试,该表面具有较好的疏水性。当混合粉末中聚二甲基硅氧烷改性二氧化硅的比例占到20%时,环氧基疏水涂层的接触角最高可达到140°,滚动角最低可达5°,附着力的等级为0级,同时疏水涂层的耐磨性和耐腐蚀性良好。结论采用简单、易于工业化的静电喷涂工艺制备了高附着力的疏水涂层,具有广泛的应用前景。     

乙二醇纳米硅溶胶的制备及应用

将由离子交换法制备的SiO2水溶胶进行溶剂置换,得到了乙二醇纳米硅溶胶。借助纳米粒度分析仪、TGA-DSC、FT-IR对溶胶中粒子的粒度分布、溶胶的热稳定性和化学结构分别进行了表征。结果表明:所制乙二醇纳米硅溶胶的平均粒径为30nm,热稳定性非常好,化学结构为无定形的水合二氧化硅。另外,其含水量低于0.8%,稳定期超过一年半。添加该溶胶到铝电解电容器的工作电解液中,电解液的闪火电压提高了约50V,电导率提高了约90×10–6S/cm。     

有机硅及纳米二氧化硅改性聚丙烯酸酯无皂乳液的合成和性能

采用无皂乳液聚合技术和溶胶凝胶技术,合成了有机硅及纳米二氧化硅改性聚丙烯酸酯无皂乳液,并采用红外光谱和透射电子显微镜对其结构进行表征。研究结果表明,当w(烷基乙烯基磺酸盐)=3.5%,w(乙烯基硅油)=8%,w(KH-570)=9%,w(正硅酸乙酯)=6%时,乳液和膜的综合性能最优。随着乙烯基硅油用量和KH-570用量增加,膜的耐水性增大。当w(正硅酸乙酯)=6%时,膜的抗张强度为5.98 N/mm2。     

纳米SiO_2表面引发接枝PA6的制备

以己内酰胺钠为引发剂,使纳米SiO_2(nano-SiO_2)表面羟基与过量2,4-甲苯二异氰酸酯反应,再用己内酰胺(CL)封端制备CL接枝nano-SiO_2(nano-SiO_2-g-CL);以其产物为活化剂,使CL在nano-SiO_2表面引发阴离子聚合,制备nano-SiO_2接枝聚酰胺(PA)6(PA 6-g-nano-SiO_2)。相比于水解聚合,表面引发的阴离子聚合能在较低的温度(170℃)下进行。研究表明,nano-SiO_2颗粒均匀地分散在PA 6基体中,并影响PA 6-g-nano-SiO_2的结晶性而导致熔点降低,且其热稳定性提高。     

Long-term Aging Properties of Bitumen With Expanded Vermiculite and Different Inorganic Nanoparticles

The authors evaluate a novel bitumen modification by using the expanded vermiculite (EVMt) and three inorganic nanoparticles. The effect of EVMt and inorganic nanoparticles on physical and long-term aging properties of bitumen was investigated. The results show that the physical properties of bitumen are slightly influenced by with the introduction of nanomaterials. As a result of pressurized aging vessel, ultraviolet (UV) radiation aging, the viscosity aging index of bitumen is decreased obviously by adding the nanomaterials. It indicates that nanomaterials can improve the thermal and UV aging resistance of bitumen simultaneously. Furthermore, this improvement depends on the inorganic nanoparticle types. Compared with nano-silica and nano-titanium dioxide modified bitumens, bitumen with 1% EVMt and 3% nano-zinc oxide shows the lower viscosity aging index values, indicating its good long-term aging resistance.     

Adjusted pH for the Selective Separation of Cadmium from Lead by Nano-Active Silica-Functionalized-[Bmim+Tf2 N−] Ionic Liquid

A method is described for the selective separation and extraction of cadmium-lead from aqueous solutions by tuning the pH value between 1.0 and 7.0. A modified nano-active silica sorbent was loaded with 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide hydrophobic ionic liquid, [Bmim⁺Tf₂N^?] and used in this work. The pH value was found to play a significant role in the sorption capacity of Cd(II) and Pb(II). In pH 1.0, the metal capacity values were characterized as 1.40 and 0.30 mmol g^?1 for Cd(II) and Pb(II), respectively. In pH 7.0, Cd(II) and Pb(II) switched their capacity values to 0.65 and 1.00 mmol g^?1, respectively. An anion exchange mechanism was proposed in solution with pH 1.0 for exchange of chloroanionic cadmium species by [Tf₂N^?]. The sorptive separation processes of Cd(II) and Pb(II) were studied and evaluated under the influence of various controlling factors. The potential applications of modified nano-silica sorbent for selective sorptive removal and separation of Cd(II) from Pb(II) in water samples was successfully accomplished by adjusting the pH value of the contact solution between 1.0 and 7.0. The results of this study indicated an efficient extraction behavior of the two examined metal ions.     

改性纳米二氧化硅制备及FTIR分析初探

以正硅酸乙酯为硅源,乙醇为溶剂．氨水为催化剂,Stober溶胶．凝胶法合成纳米二氧化硅。KH－550硅烷偶联荆改性纳米二氧化硅。改性轴米二氧化硅的宏观形貌呈白色粉末状。傅里叶交换红外（FTlR）分析结果表明改性纳米二氧化硅并未政变纳米二氧化硅的体相成分和晶体结构,只是使其表面的部分羟基与硅烷偶联剂作用生成Si－0键,疏水性增强。     

一步法制备纳米SiO_2/环氧树脂杂化材料的研究

以正硅酸乙酯(TEOS)为无机前驱体、三乙烯四胺(TETA)为固化剂和γ-氨丙基三乙氧基硅烷(KH-550)为硅烷偶联剂,采用溶胶-凝胶一步法制备SiO2/EP(环氧树脂)杂化材料。研究了TEOS和丙酮含量对杂化材料的力学性能、热性能等影响,并对杂化材料的微观相态结构和性能进行了表征和分析。结果表明:当w(TEOS)=3%(相对于改性EP质量而言)时,不加丙酮的杂化材料具有相对最好的综合性能,其断面形貌呈韧性断裂,热变形温度和玻璃化转变温度均高于纯EP体系,生成的SiO2粒径为20 nm左右且分布较均匀;加入丙酮后的杂化材料透明性变好,但其力学强度和热性能均随丙酮含量增加而降低。     

对羟基苯甲醛改性纳米二氧化硅的抗菌性能研究

采用硅烷偶联剂3-氨丙基三乙氧基硅烷(APTES)将对羟基苯甲醛接枝在纳米二氧化硅上。用红外光谱对产物结构进行了表征,并用抑菌圈法测试了其抗菌防霉性能。结果表明:对羟基苯甲醛可通过硅烷偶联剂成功接枝在纳米二氧化硅表面,并得到相应的含希夫碱(C=N)官能团有机无机杂化材料。这种杂化材料对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、青霉和黑曲霉都具有较强的抗菌性能,对研究有机无机抗菌杂化材料具有实际意义。     

低粒径纳米白炭黑的制备研究

为了制取极低粒径纳米白炭黑以满足工业应用的要求,采用沉淀法,以稻壳灰为原料,研究白炭黑生成过程中水玻璃浓度和10%硫酸溶液的滴加速度对白炭黑粒径的影响。结果表明,水玻璃浓度为11.8%,10%硫酸溶液滴加速度为14.5mL/min时,产品的粒径为30nm,达到纳米尺寸;红外分析和X射线衍射分析表明,产品为白炭黑;透射电镜分析表明,产品呈颗粒状的单层排列,因而具有较好的分散性。