超细硼粉的HTPB包覆

采用表面直接反应包覆及物理包覆法研究了硼粉的端羟基聚丁二烯(HTPB)的包覆技术,经过研究发现:经表面直接反应包覆法的包覆效果较好。研究了包覆方法和反应时间对包覆效果的影响。经过红外光谱、X-光电子能谱、透射电镜等对包覆效果进行了表征。结果表明,以苯为溶剂,于80℃经14 h的酯化反应后,以TDI为固化剂,于70～80℃固化处理后,可以成功地实现HTPB对硼粉的包覆。经透射电镜观察,包覆的硼粒子表面变得规整。     

PDA包覆铝粉及其在HTPB中的分散稳定性

通过原位多巴胺(DA)聚合法在铝粉表面包覆聚多巴胺(PDA),制备了Al@PDA复合颗粒;采用SEM表征不同DA质量浓度下Al@PDA的表面形貌。用XRD测试铝粉包覆前后的晶型;采用XPS分析Al@PDA的表面元素组成;通过沉降法研究了铝粉和Al@PDA在HTPB中的分散稳定性;通过制备固化胶并切片取样观察固体颗粒在HTPB中的分散情况。结果表明,当DA质量浓度为3.5g/L时对铝粉的包覆效果最好,在铝粉表面形成牢固的PDA薄膜;包覆前后Al的晶型没有改变;XPS在Al@PDA表面检测到的C-OH、C=O组分和π-π共轭结构证实了PDA包覆层的存在。沉降24h后Al-HTPB体系出现分层,而Al@PDA-HTPB体系仍然颜色均一,表明Al@PDA在HTPB中的分散稳定性明显优于原料铝粉。     

原位聚合包覆HMX的研究

为探索制备PBX的新方法,利用原位聚合反应,直接在HMX表面包覆一层热塑性高聚物,获得了分别以端羟基聚丁二烯(HTPB),聚叠氮缩水甘油醚(GAP)、3,3-双(叠氮甲基)环氧丁烷-四氢呋喃共聚醚(BAMO-THF)3种黏结剂包覆的PBX.通过光学显微镜、显微-红外、光电子能谱(XPS)、元素分析和机械感度测定对包覆效果进行表征.结果表明,HMX表面较均匀地包覆上了一层聚合物,黏结剂的质量分数约为4%～5%,包覆HTPB的HMX机械感度明显下降,而包覆GAP和BAMO-THF的HMX机械感度略有降低.     

氟化物包覆纳米铝粉对HTPB燃料燃烧性能的影响

为研究氟化物包覆纳米铝粉对端羟基聚丁二烯(HTPB)燃料燃烧性能的影响,采用真空浇注法制备了含氟化物包覆纳米铝粉和不含添加物的两种HTPB燃料,并测试了在氧气流中的燃烧性能。利用NASA-CEA程序计算了两种燃料的理论比冲和绝热火焰温度。结果表明,两种燃料的退移速率都随着氧气质量密流的增加而增大,两种燃料的退移速率与氧气的质量密流关系均满足幂函数,幂函数指数分别为0.704±0.003和0.688±0.002;氟化物包覆纳米铝粉对燃料的退移速率有一定的促进作用,且这种作用不随氧化剂质量密流的变化而变化;在氧化剂质量密流研究范围内,含氟化物包覆纳米铝粉燃料的退移速率比不含添加物的燃料的退移速率高13%左右。氧气与燃料的质量比为2.0时,两种燃料在真空中的理论比冲和绝热火焰温度都达到最大值;氧气与燃料的质量比为0.4~8时,铝粉未能显著提高真空中HTPB燃料的比冲。     

煅烧高岭土与钛白粉的湿法研磨复合工艺研究

采用湿法超细研磨方法对煅烧高岭土与钛白粉进行机械物理复合,通过正交试验和单因素试验研究了研磨复合工艺条件对煅烧高岭土/钛白粉复合粉体材料白度、遮盖力等物理性能的影响.结果表明,复合配比、研磨时间、pH和悬浮液质量分数是影响包覆效果的主要因素;在煅烧高岭土/钛白粉复合质量配比50:50、研磨时间10 min、pH=5、悬浮液高岭土质量分数50%条件下,制得的复合粉体在主要物理性能指标上接近钛白粉,可作为钛白粉的代用材料.     

端羟基聚丁二烯基聚氨酯的溶胀试验研究

以HTPB(端羟基聚丁二烯)基PU(聚氨酯)作为RDX(黑索金)/AP(高氯酸铵)含能材料包覆用黏合剂,在废弃复合推进剂的回收过程中,比较了7种溶剂对HTPB基PU溶胀效果的影响;采用红外光谱(FT-IR)法对RDX、AP在三氯甲烷中浸泡前后的结构进行了表征,并采用分子动力学模拟计算了溶剂与HTPB基PU的结合能、溶剂在其中的扩散系数。研究结果表明:三氯甲烷对HTPB基PU的溶胀率相对最高(700%),7种溶剂对HTPB基PU的溶胀率依次为三氯甲烷甲苯苯二氯甲烷环己烷乙酸乙酯丙酮;温度对溶胀率没有明显的影响,仅仅缩短了溶胀平衡所需的时间;浸泡前后RDX和AP的特征峰没有发生变化,说明两者与三氯甲烷未发生反应;分子动力学模拟计算而得的结合能、扩散系数判定的溶胀效果排序与溶胀率大小排序基本吻合。     

端羟基聚丁二烯/聚己内酯型聚氨酯弹性体的研究

采用预聚法合成了以端羟基聚丁二烯(HTPB)和聚己内酯二醇(CAPA2200)为软段、2,4-甲苯二异氰酸酯(TDI-100)和3,5-二甲硫基甲苯二胺(DADMT)为硬段的聚氨酯弹性体。研究了预聚体中HTPB与CAPA2200的质量比、NCO含量、扩链系数等因素对聚氨酯弹性体力学性能的影响。结果表明,当NCO质量分数为3.8%、HTPB与CAPA2200质量比为25∶75、扩链系数为0.90时,弹性体的生热较小,综合性能较好。     

FR-NP阻燃母粒的研制

采用熔融指数为10的EBA和PA6作为阻燃剂粉末的包覆载体,研究了以EBA,PA6为载体的FR-NP阻燃母粒的制备,讨论了用量、加工温度等因素对包覆效果的影响。研究表明：EBA的质量分数为20%或PA6的质量分数为25%时,能制备性能良好的FR-NP阻燃母粒。     

超声空化-表面活性剂水溶法提取RDX/Al/AP/HTPB炸药中的AP

为了对RDX/Al/AP/HTPB炸药的有效成分进行分离回收,研究了以超声空化-表面活性剂水溶法提取RDX/Al/AP/HTPB炸药中高氯酸铵(AP)的分离工艺,探讨了各工艺参数对AP提取率的影响。结果表明,表面活性剂浓度、提取时间和超声频率是影响AP提取率的主要因素,表面活性剂种类为次要因素,料液质量比和提取次数对AP提取率的影响很小。最佳工艺条件为:室温,提取时间40min,料液质量比1∶3,提取次数1次,超声功率3.0kW,表面活性剂为吐温80(质量分数2.0%)。     

端羟基聚丁二烯包覆多壁碳纳米管的制备及其对顺丁橡胶的补强研究

研究端羟基聚丁二烯包覆多壁碳纳米管(MWNTs)的制备及其对顺丁橡胶(BR)的补强效果。结果表明:将MWNTs与HTPB研磨,可使聚合物包覆在MWNTs表面,显著提高MWNTs在甲苯等溶剂中的溶解性;对MWNTs进行羧酸化处理可进一步改善HTPB对MWNTs的包覆效果,提高MWNTs在BR中的分散性,增强MWNTs与BR的界面粘合力,使其在BR基体中表现出更好的补强效果。     

烷基糖苷的直接苷化法研究

采用直接苷化法合成了十二烷基葡糖苷。通过正交试验,考察了原料配比、催化剂用量和反应温度等因素对产率的影响。得到了最佳反应条件：十二醇与葡萄糖的摩尔比为3．0：1,催化剂与葡萄糖的质量比为0．01：1,反应温度为120℃。结果表明：影响产率的主要因素为催化剂和葡萄糖的配料比。     

MA-AMPS-AMPP共聚物的合成及其阻垢效果

以水为溶剂,过氧化物为引发剂,马来酸酐（ＭＡ）、２－丙烯酰胺－２－甲基丙基磺酸（ＡＭＰＳ）、２－丙烯酰胺－２－甲基丙基膦酸（ＡＭＰＰ）为单体合成了三元共聚物。探讨了该共聚物的阻垢效果及以聚合率与单体配比、引发剂用量和组成、反应温度、时间等之间的关系,并考察了水质条件变化对共聚物阻垢性能的影响。结果表明,该共聚物具有很好的阻ＣａＣＯ３垢和Ｃａ３（ＰＯ４）２垢能力。     

耐磨胶粘涂层及其磨损机理分析

对耐磨胶粘涂层的组成、影响涂层性能的因素进行了研究，并通过扫描电镜对涂层的结构形貌、涂层磨损失效机理进行了分析，认为涂层磨损失效，主要是由于强度（或刚性）不足而造成的变形磨损，以及韧性不足造成的脆性破坏，并提出了提高涂层性能的途径和见解。     

Coating Mass Dependence of Soot Aggregate Restructuring due to Coatings of Oleic Acid and Dioctyl Sebacate

Soot particles in the atmosphere can be coated with organic or nonorganic material, which may affect particle morphology and optical properties. The effect of the mass of coating on the morphology of soot particles was studied using oleic acid and dioctyl sebacate (DOS) coatings. A wide range of coatings were used, with up to 10 times as much coating as the mass of the soot. It is shown that as the coating mass increases the degree of collapsing increases until the coating is so large that the soot particle becomes completely contained within a spherical droplet of the coating material. Higher amounts of coating will not cause further collapse of the particle. The degree of collapse is also a function of the initial size of the soot particle but was independent of the coating materials tested, which have similar surface tensions. A model is presented to predict the change in mobility diameter as a function of coating mass ratio. The effect of coating mass on effective density, shape factor, and fractal dimension is also reported.

Copyright 2013 American Association for Aerosol Research     

Surface,microstructure and optical properties of copper-doped diamond-like carbon coating deposited in pulsed cathodic arc plasma

Diamond-like carbon (DLC) coating doped with copper has been deposited on silicon substrate by pulsed cathodic arc plasma using a composite cathode made of graphite with inserted copper rods. The surface morphology, microstructure and distribution patterns of elements in the coating and substrate have been studied by atomic force microscopy, scanning electron microcopy, Raman spectroscopy and energy dispersive spectroscopy. The results show that the studied coating is very well-adhered to the silicon substrate, with no microcracks, microvoids, localized delaminations or other defects being observed at the coating/substrate interface. It is also shown that the studied coating has layered microstructure and its surface is very smooth, however containing a few of nano-sized particle-like projections of copper oxide that seems to be a specific feature of all the pulsed methods used for deposition of DLC coatings doped with metals. The distribution patterns of elements in the microstructure of the studied coating are discussed. The relationship between refractive index of the coatings, and the intensity ratio of D and G peaks in the Raman spectrum has been established.     

Fabrication and characterization of polyaniline coated carbon nanofiber for supercapacitor

Polyaniline coated carbon nanofiber was fabricated using one-step vapor deposition polymerization technique. Fourier transform infrared (FT-IR) spectra and transmission electron microscope (TEM) images indicated that uniform and ultrathin conducting polymer layers were formed on the carbon nanofiber surfaces regardless of the coating thickness. It was also confirmed that the thickness of polyaniline layer could be conveniently tuned by the feeding amount of monomer. The coating thickness was dependent on initiator/monomer ratio, the vacuum pressure of reaction chamber and polymerization temperature. Among them, the vacuum pressure was a major factor to control the coating thickness of polyaniline onto the carbon nanofiber surface. In addition, the electrochemical analysis demonstrated that polyaniline coated carbon nanofiber showed an improved performance as supercapacitor. The specific capacitance of polyaniline coated carbon nanofiber exhibited a maximum value of 264 F/g when the thickness of polyaniline layer was ca. 20 nm.     

Si3N4粉末表面的非均质成核法包覆及其浆料流变性的研究

在研究Ｓｉ３Ｎ４粉末表面包覆工艺及各因素影响规律的基础上,确定了非均质成核法对Ｓｉ３Ｎ４粉末表面包覆改性的最佳工艺范围。利用透射电镜,Ｘ射线粒度分布仪,粘度测定仪、ｚｅｔａ电位测定仪对包覆前后Ｓｉ３Ｎ４浆料进行了分析。结果表明：在最佳包覆工艺范围内,Ｓｉ３Ｎ４粉末表面均匀包覆一层Ａｌ（ＯＨ）３,并包覆后Ｓｉ３Ｎ４浆料的ｚｅｔａ电位发生明显变化,粒度分布更加均匀,流变性能得到明显改善。     

改性海泡石除氟影响因素分析及机理探讨

对海泡石除氟条件及机理进行了实验探讨。结果表明,海泡石经过活化改性后,具有降低水中氟离子含量的作用。活化海泡石与含氟溶液的作用时间、海泡石用量、水中氟离子沈度以及酸度等因素都会影响除氟效果。活化海泡石除氟机理是由于活化过程,靠离子交换作用吸附了一定量的铝离子,而铝离子又与水中的氟离子结合从而达到除氟目的。     

Effect of doping in hydroxyapatite as coating material on biomedical implants by plasma spraying method: A review

Hydroxyapatite (HAp) is still one of the most widely used bioactive coating material to metallic implant in orthopedic fields because of its good biocompatibility, chemical and structural resemblance to natural bone, osteo-conductivity, coupled with quicker implant fixation and strong bonding between living bone with implants. Many techniques are used to deposit HAp as coating material on metallic implants among which plasma spray coating stands out as this process is cost effective, reliable, and protects surface of metal from wear and corrosion. Although, HAp is a smart choice as implant coating material, however, its medical application has been restricted because of the unfavorable mechanical properties like brittleness, weak fracture toughness and poor tensile strength. Further, HAp coated implants suffer from longer time period for remodeling, slow osseointegration rate and lack of antimicrobial effects/properties. Different methodologies have been adopted as surface modification techniques to increase mechanical as well as biological properties of HAp. Among those approaches use of dopants in HAp is a very efficient way for modification of properties. Therefore, aim of this review paper is to assemble information related to HAp coating by plasma spray technique on implants and discuss their advantages and limitations. The article also reports how addition of various doping ions into HAp can overcome these limitations by effecting structural, compositional, mechanical properties of HAp. Finally, it reports how the single, binary and multi ion dopants incorporation in the HAp structure can affect the properties which ultimately affect implant functionality when coated by plasma spraying method.     

水性环氧涂料制备及性能

采用环氧树脂乳液和固化剂作为水性环氧涂料的成膜物质,考察环氧值与胺氢值物质的量比、涂料固含、消泡剂用量、固化时间等对涂膜性能的影响。结果表明：当环氧值与胺氢值物质的量比为1.6：1.0,涂料固含为32.5%、消泡剂用量为0.1%、固化时间为7 d时涂膜的综合性能达到最佳。