空心玻璃微珠偶联化学镀银的研究

使用氨丙基三乙氧基硅烷偶联剂改性空心玻璃微珠表面,然后直接实施化学镀银,借助红外光谱、扫描电镜和X-射线衍射测试手段对偶联改性效果、镀层表面形貌和结构进行了表征.测试结果表明,与胶体钯活化法和硝酸银活化法化学镀银相比,空心玻璃微珠偶联表面改性直接化学镀银的镀层更为致密、均匀,银利用率高,导电性好,结合力强.     

还原剂对涤纶织物化学镀银性能的影响

采用5种不同的还原剂对涤纶织物进行化学镀银.主要研究了还原剂对镀速的影响,测定了镀银织物的电磁波屏蔽、表面比电阻、耐磨性和结合力等性能,并借助扫描电镜、X射线衍射对镀层表面形貌和结构进行了分析.结果表明:不同还原荆镀银的镀速有所不同,镀层结构没有改变,晶粒大小有所不同;当增重率相同时,葡萄糖镀银织物的电磁波屏蔽性能最好...     

电磁屏蔽剂银/镍/玻璃微珠粉体的制备与性能

采用化学镀法在玻璃微珠表面先沉积镍镀层、再化学镀银,制备了Ag/Ni/玻璃微珠复合粉体。讨论了活化剂氯化钯和主盐硫酸镍的浓度、镀液pH对玻璃微珠表面化学镀镍层表面形貌的影响,得出了较佳的镀镍工艺条件:PdCl20.3g/L,NiSO4·6H2O30g/L,pH11。在此基础上化学镀银,采用扫描电镜和能谱分析对Ag/Ni/玻璃微珠结构进行了表征,测试了粉体的体积电阻率、介电常数、磁导率和磁性能。结果表明,镀镍玻璃微珠表面成功包覆一层银,Ag/Ni/玻璃微珠复合粉体的体积电阻率由Ni/玻璃微珠的2.28×104·cm降低至7.64×105·cm,导电性、介电损耗和磁损耗均提高;Ag/Ni/玻璃微珠粉体的饱和磁化强度为27.2emu/g,可以作为一种宽频电磁屏蔽材料的填料。     

玻璃微珠化学镀银

本文以40μm的实心玻璃微珠为原料,直接采用[Ag(NH3)2]OH溶液进行活化处理,在其表面镀覆了一层致密、均匀的银层。探讨了温度、pH、银含量以及镀液添加顺序等因素对化学镀银的影响。其压实电阻、表面形貌的测试结果表明,本实验制备的镀银玻璃微珠具有较好的导电性和表面形貌,在导电填料中可替代部分银粉;当银含量为9%~15%时,D50为40μm的镀银玻璃微珠镀层最为致密、均匀。     

粉煤灰微珠-Ag复合颗粒的制备工艺和分析

采用化学镀的方法,以银氨溶液为镀液,甲醛为还原剂,按照一定的工艺过程对粉煤灰微珠进行表面镀银处理,得到了粉煤灰微珠-Ag复合颗粒。同时借助激光粒径分析仪、X射线衍射仪、场发射扫描电子显微镜、X射线能谱仪等检测设备对复合颗粒的粒径分布、化学成分、镀层表面形貌和结构进行了分析。对复合微珠进行保温隔热性能测试,掺镀银微珠的涂料比原微珠的涂料温度低约4℃。结果表明,按照设定的工艺过程,可以成功制备出具有保温隔热低辐射功能的粉煤灰微珠-Ag复合颗粒,作为一种功能性骨料有望用于建筑物外围护结构表面的砂浆或涂料中以降低对远红外热的辐射能力。     

化学镀银间位芳纶织物制备及其性能研究

采用SEM、EDS和XRD测试方法对制备的化学镀银间位芳纶织物纤维表面形貌、镀层成分及物相组成进行分析,探讨了装载量对镀银件导电性的影响,并对镀层进行结合强度、耐腐蚀性和热稳定性测试。结果表明,合适的化学镀银装载量为80 cm~2/L,该条件下制备的镀银层连续致密与基体结合力强,表面方块电阻仅约20~30 m?/sq,导电性优良,并具有良好的耐腐蚀性及热稳定性。     

空心玻璃微珠化学镀银研究进展

综述了应用于电磁屏蔽涂料、导电填料等领域的镀银空心玻璃微珠化学镀制备工艺.按空心玻璃微珠化学镀银操作工艺的3个主要步骤,分别介绍了空心玻璃微珠表面前处理、施镀及镀后处理的各类方法.总结了不同表面前处理方法、镀液配方、操作工艺参数及微珠基体自身性质等因素对空心玻璃微珠化学镀银过程的影响.探讨了空心玻璃微珠化学镀银存在的问...     

玻璃微球表面化学镀银

研究了玻璃微球表面镀银过程中还原剂对镀层结合紧密程度、产品导电性的影响,并对银镀层的性能进行了测试。结果表明,用葡萄糖和酒石酸钾钠混合作还原剂改进了镀层的均匀度和结合强度。镀银玻璃微球有望用作高导电性聚合材料的导电填料。     

多巴胺改性空心玻璃微珠表面化学镀银工艺

先采用多巴胺溶液活化空心玻璃微珠(HGM),再化学镀银。研究了硝酸银质量浓度、葡萄糖质量浓度和装载量对银利用率和镀银HGM导电性的影响。采用扫描电镜(SEM)和能谱仪(EDS)分析了镀银HGM的形貌和表面成分。结果表明,经多巴胺活化后,HGM表面成功附着了一层聚多巴胺膜。当硝酸银质量浓度为15 g/L、葡萄糖质量浓度为30 g/L和装载量为4 g/L时,镀液中的银利用率达71.5%,镀银HGM的导电性良好(体积电阻率为34 mΩ·cm),表面银层均匀、致密。     

空心玻璃微珠无钯活化化学镀银的研究

基于银镜反应原理,不经过粗化和活化直接对空心玻璃微珠进行化学镀银。采用单因素分析法,研究了硝酸银、葡萄糖、装载量、氢氧化钠和无水乙醇对银的利用率以及镀层的增重率、导电性能和结合强度等的影响,并借助扫描电镜和X射线衍射仪对镀层的表面形貌和结构进行了分析。结果表明:与胶体钯活化工艺相比,无钯活化化学镀银工艺的银的利用率高,镀层均匀、致密,导电性好,结合强度高。     

TiO2纳米晶/空心玻璃微珠复合填料的制备与研究

采用化学沉积法使TiO2以纳米粒子的形式包覆于空心玻璃微珠表面,成功制备了TiO2纳米晶/空心玻璃微珠复合填料.分别用扫描电镜(SEM)及紫外可见近红外分光光度计对产物进行了晶体形貌观察及光反射性能测试.结果表明:TiO2在空心玻璃微珠表面包覆效果良好,且经过热处理后空心玻璃微珠破损率很低,二氧化钛纳米晶尺寸为5～50 nm,膜层厚度为50～500 nm;光谱分析表明:该复合粉体对可见光和近红外波段的太阳光辐射具有很高的反射率(＞95%).将改性空心微珠、空心玻璃微珠及国外较好的玻璃微珠分别作为填料制备隔热涂料,光谱分析表明:以改性微珠作为填料制备的涂料,漆膜对太阳光主要能最波段(500～1500 nm)的光反射性能得到显著提高,当涂料与改性微珠质量比为100:15时,漆膜的光反射效果最佳,平均光反射率高于85%,该性能指标优于空心玻璃微珠及国外同类产品.     

亚微米中空微球聚合物的制备及其形貌调控

采用乳液聚合协同碱渗透溶胀法，制备了亚微米中空微球聚合物。通过SEM、TEM、DLS分别对中空微球的形貌和粒径进行表征，并考察了中空微球聚合物的遮盖性能。研究了引发剂用量对核粒径的影响，中间层和壳层聚合物配比对微球形貌结构及其遮盖性能的影响。结果表明，在核制备过程中，核的粒径随引发剂用量的增加而减小；对于平均粒径为148 nm的核，当中间层甲基丙烯酸丁酯（BMA）用量为10 wt%、甲基丙烯酸（MAA）用量为3 wt%，甲基丙烯酸甲酯（MMA）用量为87 wt%，壳层苯乙烯（St）用量为97 wt%，交联剂用量为3 wt%时，可制备平均粒径414 nm，中空率为40.6 %的聚合物微球，且微球表面较为光滑，此时中空微球聚合物具有优异遮盖性能，遮盖度达到66 %。     

ZnO nanostructures decorated hollow glass microspheres as near infrared reflective pigment

Hollow glass microsphere/ZnO composite pigments were successfully prepared by a facile sol-gel method. ZnO coating layers composed of nanosheets, nanoplates, or nanoparticles were anchored at the surface of hollow glass microspheres by formation of Zn-O-Si bond. A reasonable growth mechanism for elucidating the formation of ZnO nanocoating was proposed. The results indicated that the near-infrared reflectance property of the composite pigments was strongly affected by the morphology of ZnO nanostructures. The nanoparticles structures exhibited higher near-infrared reflectance than that of nanosheets and nanoplates structures. The near-infrared solar reflectance of hollow glass microsphere/ZnO composite pigments was 95.7%, while the total solar reflectance of the composite pigment was as high as 97.2%. An approximately 11.1 °C decrease in outer surface temperature was obtained for the heat box coated with composite pigments. Therefore, hollow glass microsphere/ZnO composites are excellent near infrared reflective pigments for efficient solar reflective coatings designed for building facades and roofs.     

中空玻璃微球和增塑剂改性ACM的性能研究

采用物理共混的方法制备了中空玻璃微球填充的ACM复合材料,研究了硅烷偶联剂WD-40对中空玻璃微珠形态及复合材料性能的影响,考察了不同含量的中空玻珠微球和增塑剂DOP对复合材料性能的影响。结果表明:经过表面处理的中空玻璃微球与ACM的相容性显著提高,控制合适的中空玻璃微球和DOP添加量可获得力学性能最优的ACM复合材料。     

Controllable morphology and wettability of polymer microspheres prepared by nonsolvent assisted electrospraying

Polymethylmethacrylate (PMMA) microspheres with various morphologies are fabricated by nonsolvent assisted electrospraying. The morphology evolution is determined by nonsolvent properties including the solubility parameter, surface tension and viscosity, and nonsolvent induced phase separation is the main reason for the formation of the porous and/or hollow structures. It is found that nonsolvent possessing a high surface tension is beneficial to the formation of a hollow structure, while the large phase separation tendency between nonsolvent and the polymer can promote pore generation on the sphere surface. The nanosized pores, especially hierarchical pores, can enhance the hydrophobicity of the substrate surface coated with these microspheres. On the other hand, nonsolvent with a large viscosity could prevent the growth of the phase separated nuclei, leading to the presence of relatively small and discontinuous pores on the microsphere surface, which can finally cause the decrease of the contact angles. The surface pores of the electrosprayed microspheres are even eliminated if polymer additive, i.e., PVP, is incorporated into the polymer-solvent-nonsolvent solution. The addition of PVP renders the microsphere coated surface hydrophilic, which can be completely wetted by water droplets.     

Fracture surface morphology in thermosets modified with hollow microspheres

Fracture surface morphology in relation with toughening of thermosets modified with hollow microspheres was studied. Two different toughening methods were employed—one was with (MEH) and the other without (ME) compressive residual stresses around microspheres, respectively. The compressive residual stresses were to increase effective stress intensity factor. Various conditions arising from toughening method, properties of constituent materials, bonding between matrix and microspheres, relativity between bonding and microsphere strengths, and plane stress/strain were derived for part of generalization of fracture surface morphology. Mohr circle representations were employed for relative stress components analysis. New deformation mechanisms contributing to toughening were proposed. A major difference in toughening mechanism between ME and MEH methods was found to be in the location of plastic deformation under plane strain. The plastic deformation of ME was dominantly in matrix and appeared in the form of matrix cavitation. In the case of MEH, it was dominantly in microspheres. It was suggested that compressive residual stress promotes plastic deformation of microspheres caused by “extrusion” effect. The microsphere deformation in MEH was found also under plane stress although it was not as much as under plane strain. Matrix cavitation in ME under plane stress, however, was not found. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

磁性Fe3O4@SiO2@介孔SiO2空心微球的制备及漆酶固定化

磁性介孔二氧化硅复合材料作为酶固定化载体具有优异的酶固定化性能和良好的磁分离性能,受到国内外学术界广泛关注。本文在自制的β-FeOOH空心微球表面上包覆致密的SiO₂保护层,在酸性条件下以P123为模板剂,十六烷基三甲基溴化铵（CTAB）为辅助导向剂成功制备出了磁性β-FeOOH@SiO₂@介孔SiO₂空心复合微球,最后在还原气氛下煅烧得到Fe₃O₄@SiO₂@介孔SiO₂空心微球。结果表明,所制备的Fe₃O₄@SiO₂@介孔SiO₂微球空心结构未坍塌,具有规整的球形结构,介孔SiO₂壳层（平均厚度约为11nm）均匀地包覆在β-FeOOH@SiO₂中空微球表面。伴随着CTAB量的增加,微球的最可几孔径由4.30nm减小到3.19nm,比表面积从376m²/g升高到640m²/g,孔容从0.36cm³/g升高到0.56cm³/g。复合微球的饱和磁化强度为11.3emu/g,矫顽力为111.5Oe,外加磁场作用下可以实现样品的快速分离,且样品的再分散性良好。当介孔孔径为4.30nm时,Fe₃O₄@SiO₂@介孔SiO₂空心复合微球漆酶固定量高达234mg/g。固定化漆酶在不同pH、温度下的活性显著优于游离酶。     

酸碱渗透溶胀法制备微米/亚微米级中空聚合物微球

介绍了酸碱渗透溶胀法制备微米／亚微米级中空聚合物微球，以该方法制备中空聚合物微球的具体步骤为顺序，综述了现阶段该方法制备中空聚合物微球的研究现状，分析了该方法中有关微球中空形态及性质控制的影响因素，并对中空聚合物微球未来的研究方向和应用前景进行了展望。     

一种无磷化学镀镍制备聚苯乙烯/镍复合微球的方法

采用水合肼作为还原剂在聚苯乙烯微球表面进行化学镀镍,得到了聚苯乙烯/镍(PS/Ni)复合微球.考察了温度、主盐C4H604Ni?4H20浓度、配位剂EDTA-2Na浓度、还原剂N2H4?H2O浓度和装载量对微球表面形貌的影响,得到最优操作条件为:主盐0.12mol/L,配位剂0.11 mol/L,还原剂0.38 mol...     

生物模板法制备磁性中空微球的方法和应用

磁性中空微球在功能性吸附、酶固定化载体、物质的分离纯化、活性物质和药物的封装与控释、靶向给药、污染防治、食品和材料学等领域有突出的应用价值。文章综述了利用生物模板法制备磁性中空微球的制备原理和最新研究成果,并主要分析了软模板法和自模板法两种制备工艺。软模板法工艺主要通过吸附-高温炭化法除去生物模板材料获得固定外形的磁性中空微球。自模板法制备磁性中空微球可依据生物材料自身成分经水热碳化反应或在惰性气体氛围保护下的高温炭化反应生成具有特殊官能团结构的中空碳微球,并将磁性物质溶入或吸附到中空微球中,具体分为水热碳化法和浸渍-高温炭化法;也可将制备好的磁性物质吸附于经过特殊处理过的生物模板材料表面,如吸附-共沉淀法和高温炭化-共沉淀法。总之,生物模板法制备磁性中空微球条件较为温和、无污染,生物模板材料对人体无毒,特别适合于食品、医药等行业的应用,具有很好的生产应用前景。