聚苯胺/碳纳米管的原位复合

通过原位溶液聚合制备了聚苯胺/碳纳米管(PANI/CNT)复合材料。采用透射电子显微镜(TEM)、紫外-可见光光谱(UV-VIS)、傅立叶变换红外光谱(FTIR)、热失重分析(TGA)及差示扫描量热法(DSC)研究了PANI/CNT复合材料的结构与性能。研究表明,苯胺(ANI)的聚合倾向于在碳纳米管(CNT)表面进行,形成PANI包覆的CNT。CNT表面PANI层的厚度随溶液中ANI含量的增加而增加;当溶液中ANI含量较低时,CNT表面PANI层厚度均匀;当ANI含量过高时,CNT表面PANI层厚度不均匀,形成一些颗粒状附着物。PANI与CNT之间主要是物理吸附;PANI/CNT复合材料的电导率远高于PANI本身。同时,PANI/CNT复合材料的耐热性远高于PANI,并受PANI含量影响。     

化学法制备高容量导电聚苯胺

在室温下,采用化学原位聚合法制备得到超级电容器用导电聚苯胺(PANI),并采用扫描电子显微镜(SEM)和X-射线衍射(XRD)对其形貌和结构进行了表征.以制备的PANI为活性物质作为电极材料,1 mol/L Na2SO4水溶液为电解液组装成扣式超级电容器,通过循环伏安和恒电流充放电测试研究其电化学性能.结果表明,制备的...     

聚苯胺包覆酸处理螺旋碳纤维材料的制备和电化学性能

用原位聚合和乳液聚合两种方法制备聚苯胺(PANI)包覆螺旋碳纤维(CMCs)复合材料,使用红外光谱(FTIR),扫描电子显微镜(SEM),X射线衍射(XRD)等手段对其形貌和结构进行了表征。结果表明,用硝酸处理CMCs(表示为H-CMCs)为纤维表面提供含有羧基等含氧官能团。这为苯胺在H-CMCs表面的聚合提供基础,有助于PANI附着在H-CMCs的表面。用循环伏安、恒流充放电、交流阻抗等电化学方法测试了复合材料的电化学特性,结果表明:PANI包覆H-CMCs,其比电容值明显高于H-CMCs自身,表现出良好的大电容性能。原位聚合法更有益于PANI与H-CMCs的协同作用,使复合体的电容性能提高。     

聚苯胺/银复合薄膜的制备及其耐蚀性能

为了研究聚苯胺(PANI)/银复合薄膜对不锈钢的防腐蚀性能,采用循环伏安法在不锈钢表面沉积一层Ag后,再通过对苯胺的电化学聚合制备了PANI膜。利用阳极极化法和交流阻抗法研究了PANI/Ag复合膜的耐蚀性及其影响因素。结果表明:在0.1 mol/L NaC l溶液中,不锈钢覆盖复合膜后的自腐蚀电位比无膜时有所提高,其耐蚀性能得到增强;电化学聚合溶液浓度、扫描速率及扫描上限等因素对复合膜耐蚀性的影响情况为:电解液中苯胺和硫酸浓度过高或过低都会影响膜的致密度,从而影响复合膜的耐蚀性;电化学参数的变化会影响复合膜的聚合速率,使复合膜的抗腐蚀能力不同;当苯胺单体浓度为0.2 mol/L、硫酸浓度为1 mol/L、扫描电位上限为1 V、扫描次数为50次、扫描速率为50 mV/s时,采用循环伏安法聚合苯胺,可形成沉积致密度高、耐蚀性好的复合膜。     

柔性智能聚苯胺/聚氨酯导电纳米纤维的制备及性能

利用静电纺丝技术制备聚氨酯(PU)纳米纤维,采用原位聚合法在纤维表面聚合导电聚合物聚苯胺(PANI),得到具有优良导电性能的柔性PU/PANI复合纳米导电纤维。通过扫描电镜观察到表面均匀包覆聚苯胺的复合纳米纤维;红外光谱结果证明在聚氨酯纳米纤维表面成功合成了聚苯胺。通过实验可知,聚苯胺最佳聚合工艺为苯胺单体浓度为1.3 mol/L、聚合时间为120 min。导电性能测试发现,PU/PANI复合纳米纤维导电性能优良,电导率可达7.6×10-1S/cm,经聚合后力学性能较为稳定。将PU/PANI导电纳米纤维制成简易柔性传感器件,探究发现PU/PANI导电纳米纤维具有柔性应变电学性质,且反应灵敏。     

聚四氟乙烯膜表面的苯胺聚合沉积亲水改性研究

采用苯胺(An)分散聚合原位成膜的方法对等离子体预处理的聚四氟乙烯(PTFE)多孔膜进行亲水化改性,实验通过SEM、接触角测量等表征了PTFE膜的结构和表面亲水性质.试验结果表明,FTFE膜表面是内部留有孔道的纤维交织结构,有较强的疏水性;等离子体处理使聚合峰值提前,后期聚合速率增大,有利于An在PTFE膜的表面聚合沉积.接触角测试表明PANI/PTFE复合膜比原始膜的亲水性有了较好的改观.     

化学聚合条件对导电聚合物作阴极钽电解电容器性能的影响

研究了在多孔Ta/Ta2O5阳极表面原位聚合PEDT导电聚合物膜的制备方法,重点讨论了化学聚合的组成、聚合温度、驱溶温度等对所制电容器性能的影响.研究结果表明,所用氧化剂与单体EDT的比例保持在3～6范围内有益于提高电容器高频性能即降低ESR值;随着聚合温度的升高,对电容器的损耗有一定的影响;驱溶温度对被覆的薄膜导电性有较大影响,表现为电容器的ESR值变大.     

聚苯胺/聚丙烯复合微孔膜的研究

采用原位化学氧化聚合方法在聚丙烯(PP)微孔膜表面及膜孔内表面生长聚苯胺(PANI),得到PANI/PP复合微孔膜,从而提高聚丙烯微孔膜的亲水性、耐热性以及抗静电性能.结果表明,聚丙烯微孔膜经聚苯胺改性后,其亲水性、耐热性以及抗静电性都有明显改善.考察了盐酸用量、氧化剂过硫酸铵用量及聚合温度等反应条件对聚合反应的影响.     

GO@PANI分级异质核壳材料的可控制备研究

因具有多层次、多维度、多组分的耦合和协同效应,分级异质结构纳米材料的设计与制备已成人们关注的热点。利用氧化石墨烯(GO)的大比表面积片状结构的特点,通过原位低温聚合在其表面制备出聚苯胺(PANI)的纳米阵列,形成以GO为核层,PANI为壳层的GO@PANI微粒。分别研究反应时间、PANI添加量、掺杂酸浓度对GO@PNAI表面形貌的影响。在此基础上,探索GO@PNAI的生成机理,为GO@PNAI分级异质核壳材料的可控制备提供了理论依据。     

原位聚合法制备聚苯胺/多壁碳纳米管纳米复合材料及其热稳定性能

为合成树脂/聚苯胺(PANI)/多壁碳纳米管(MWCNTs)三元纳米复合电磁屏蔽材料的制备提供理论依据,在苯胺的盐酸溶液中,以过硫酸铵为氧化剂,采用原位聚合法制备PANI/MWCNTs纳米复合材料,并对PANI/MWCNTs纳米复合材料的结构、形貌以及热稳定性能进行研究。结果表明:PANI成功包覆在MWCNTs表面,且PANI和MWCNTs存在一定的相互作用;PANI在MWCNTs表面不均一性的有序生长,有效地改善了MWCNTs的分散性;PANI/MWCNTs纳米复合材料的热分解起始温度达到280℃,当温度为364℃时,热失重率为20%,说明PANI/MWCNTs纳米复合材料具有良好的热稳定性。     

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成，凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求，以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究，并介绍了其中某些方面和展望了可能的发展趋势。     

Development and challenges of planning and scheduling for petroleum and petrochemical production

Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.     

江澳两地高校文创设计的协同研究与商业实践

目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。     

Creation and motion of dislocations and fracture in metal and silicon crystals

By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.     

The Candela and Photometric and Radiometric Measurements

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.     

PSD和PWELCH函数的分析改进及应用

针对MATLAB中两个内建功率谱密度计算函数psd()和pwelch()计算结果迥异的现象,在功率谱密度估计理论的基础上,根据经典的周期图理论和Welch平均周期图方法,通过详细分析源程序,解析计算方法,发现psd()计算的并不是工程单边功率谱密度,而是采样信号双边谱,故与pwelch()结果迥异,另外pwelch()不能对分段信号数据进行预处理。就上述不足提出了相应的改进措施,比较验证表明改进措施行之有效。     

Density and viscosity of tetralin and trans-decalin

New measurements are reported for the density and viscosity of tetralin and trans-decalin. The density was determined from room temperature to 60°C for tetralin and to 95°C for trans-decalin. The kinematic viscosity was measured up to temperatures slightly above 100°C. Our results improve upon the values recommended by the American Petroleum Institute for these liquids.     

Miniature and MEMS-type vacuum sensors and pumps

In the paper, the observable trends of the actual research and development of selected types of miniature and MEMS-type vacuum sensors are presented. Some information about the new types of active vacuum gauges, which are offered by the leading manufacturers of the vacuum measurement instruments, is given. Next, the list of MEMS devices that need vacuum for proper operation is presented. Some aspects of vacuum-encapsulation of MEMS devices, on wafer level and package level are shown. The new conceptions of obtaining and maintenance of high and ultra-high vacuum in MEMS devices are described. They concern the conception of integration of a miniature orbitron pump on-chip with MEMS-type device or with vacuum part of the portable advanced instruments such as electron microscope, ion mass spectrometer, and free electron laser.