纳米材料的表面修饰与应用

综述了纳米材料表面修饰的研究概况，介绍了纳米粒子的表面特性及表面修饰的目的和方法，阐述了表面修饰在制备半导体纳米材料、稀土化合物纳米材料、氧化物和金属纳米材料等方面的应用，并对表面修饰技术的发展进行了展望。     

Preparation of SiO2 Nanoparticles by Silicon and Their Dispersion Stability

Silicon dioxide sol was synthesized by silicon tn the presence of alkali catalyst. ,SiO2 nanoparticles (size in 8- 15nm) aqueous dispersion was prepared by using dispersion and surface modification in situ. The effects of reaction time, temperature, medium pH value, dispersant and surface-modifier on their diameters, sizes distribution and dispersion stability were also studied. The experimental results show that the preparation method can effectively resolve the dispersion stability of SiO2 nanoparticles in water.     

高岭土干法有机改性及效果评价

本实验采用干法改性工艺,选用十二胺、十八胺、硬脂酸、硅油和铝钛复合偶联荆(OL-ATl618)五种不同的改性剂对云南临沧高岭土进行表面改性.对改性高岭土进行活化指数和有效活化指数测定,并对其进行红外光谱分析以确定最佳改性剂.最后选效果最好的改性高岭土作为橡胶填料进行力学性能检测.实验结果表明,对云南临沧高岭土进行表面有机改性.以十八胺为改性剂,加八量为1.2%.改性时间为30min改性高岭土的有效活化指数最高,改性效果最佳.有效活化指教越高,对橡胶的补强效果越好.     

短切芳纶纤维增强复合材料的研究进展

综述了短切芳纶纤维增强环氧树脂、热塑性聚氨酯、尼龙、聚乙烯、聚苯硫醚、间规聚苯乙烯等复合材料的研究进展.芳纶纤维的加入影响了基体树脂的力学性能.纤维表面经过改性后,复合材料的力学性能得到了改善.     

油酸钠表面改性纳米氢氧化镁阻燃HDPE

通过油酸钠湿法表面处理纳米氢氧化镁(MH)共混改性阻燃HDPE.研究油酸钠表面改性机理及其用量对体系阻燃性、力学性能及流变性能的影响.得出结论:油酸钠可在MH表面形成包覆层,且改性后MH仍保持了纳米级粒径.油酸钠湿法改性MH可提高体系的阻燃性能和力学性能.在HDPE:MH=100:60时使用5%MH的油酸钠.体系拉伸强度、断裂伸长率和冲击强度分别提高约12%、10.5%和8%,而氧指数提高12.5%达到29.9%,垂直燃烧等级达FV-1级.MH加入将导致体系加工性恶化,表观黏度剧烈降低,油酸钠表面改性可一定程度改善流变性.     

Flame retardancy effect of surface-modified metal hydroxides on linear low density polyethylene

Metal hydroxides （MAH） consisting of magnesium hydroxide and aluminum hydroxide with a mass ratio of 1：2 were surface-modified by y-diethoxyphosphorous ester propyldiethoxymethylsilane, boric acid and diphenylsilanediol in xylene under dibutyl tin dilaurate catalyst at 140 ℃. Phosphorus, silicon and boron elements covalently bonded to metal hydroxide particles were detected by X-ray photoelectron spectroscopy. The degradation behavior of the surface-modified MAH was characterized by thermogravimetric analysis. The results show that linear low density polyethylene （LLDPE） composite, filled with 50% （mass fraction） of MAH modified by 5.0% （mass fraction） of modifiers, passes the V-0 rating of UL-94 test and shows the limited oxygen index of 34%, and its heat release rate and average effective heat combustion in a cone calorimeter measurement decrease obviously; The mechanical properties of MAH can be improved by surface-modification. The uniform dispersion of particles and strong interfacial bonding between particles and matrix are obtained.     

重晶石提纯及表面改性研究

重晶石是一种重要的含钡工业矿物，正日益受到人们的关注。对湖北某地重晶石矿粉用CRD、DTATG、粒度分析和化学分析等手段进行原矿性质表征研究。用酸浸、氧化-还原漂白、煅烧等方法使杂质溶解、除掉有机质、制备出高纯度和高白度的重晶石。用硅烷偶联剂、硬脂酸对重晶石进行表面改性。结果表明，提纯后BaSO4由95．44％提高到98．55％，白度由84．10％提高到93．50％。经有机偶联剂改性后重晶石矿物表面疏水性明显提高。     

乙烯基聚硅氧烷包覆改性聚磷酸铵及其在环氧树脂中的阻燃应用

以正硅酸乙酯（ＴＥＯＳ）与乙烯基三乙氧基硅烷（ＶＴＯＳ）为前驱物,采用溶胶凝胶工艺将乙烯基引入聚磷酸铵（ＡＰＰ）的表面,以期对ＡＰＰ进行二次接枝改性。对ＶＴＯＳ改性ＡＰＰ（ＶＭＡＰＰ）进行了研究,并研究了其对环氧树脂（ＥＰ）阻燃性能的影响。结果表明,包覆膜材料中存在乙烯基;经含有乙烯基的聚硅氧烷对ＡＰＰ进行包覆改性后,在ＡＰＰ表面生成一层致密的保护膜,表面Ｐ、Ｎ 元素含量明显降低,Ｃ元素含量明显增加,出现Ｓｉ元素的吸收峰;ＶＭＡＰＰ的疏水性及耐水性均得到改善;ＶＭＡＰＰ能够促使ＥＰ生成更为致密和稳定的炭层,促进ＥＰ阻燃性能的改善。     

非金属矿物粉体表面改性技术进展

表面改性是非金属矿深加工的主要技术之一,对提高非金属矿产品的应用性能和应用价值至关重要。本文从粉体表面改性方法、工艺、设备、表面改性剂及其配方等方面综述了非金属矿物粉体表面改性技术现状;从表面改性工艺与设备、改性剂及其配方、层状硅酸盐矿物的插层以及表面无机复合改性等方面综述了非金属矿物表面改性技术的最新进展;并对发展前景和发展趋势进行了展望。     

Nanospike surface-modified bionic porous titanium implant and in vitro osteogenic performance

This work aimed to prepare the nanospike surface-modified bionic porous titanium implants that feature favorable osteointegration performance and anti-bacterial functions. The implant was prepared using freeze casting, and nanospike surface-modification of the implant was performed using thermal oxidation. The pore morphology and size, mechanical properties, and osteogenic performance of the implants were analyzed and discussed. The results showed that when the volume ratio of titanium powder in slurry was set to be 10%, the porosity, pore diameter, compressive strength, and elastic modulus of the porous samples were (58.32±1.08)%, (126.17±18.64) μm, (58.51±20.38) MPa and (1.70±0.52) GPa, respectively. When the porous sample was sintered at a temperature of 1200 °C for 1 h, these values were (58.24±1.50)%, (124.16±13.64) μm, (54.77±27.55) MPa and (1.63±0.30) GPa, respectively. The nanospike surface-modified bionic porous titanium implants had favorable pore morphology and size, mechanical properties and osteointegration performance through technology optimization, and showed significant clinical application prospect.