PDLLA/CS/CHS多层膜的制备及影响因素研究

利用静电自组装技术制备聚乳酸/硫酸软骨素/壳聚糖(PDLLA/CS/CHS)多层膜,并对组装影响因素进行研究.用紫外-可见吸收光谱对PDLLA/CS/CHS多层膜在组装过程中的时间、温度、溶液浓度和pH值等影响因素进行分析研究.结果表明自组装复合材料制备的最佳条件为:CS的浓度为2 mg/mL、CHS的浓度为1%(g/mL),组装时间为30 min,温度为30 ℃,溶液pH值为3.8.根据紫外光谱拟定的最佳组装条件组装了多层膜,用扫描电镜观察了多层膜的表面形貌,结果表明自组装膜是一种具有多孔结构的不对称复合膜.     

静电自组装法制备镧/铈掺杂锶铁氧体纳米复合多层膜

为制备具有良好吸波性能的锶铁氧体纳米薄膜,确定了静电自组装法制备掺杂态铁氧体与聚苯乙烯磺酸钠(PSS)多层复合膜的基片处理方法和单层膜的组装时间.用紫外-可见分光光度计、XRD、AFM、矢量网络分析仪对纳米薄膜的结构与性能进行研究.研究表明:所制得薄膜为非晶态,薄膜表面由球状颗粒组成,其平均粒径约150nm.通过SrLa0.4Fe11.6O19/PSS纳米复合多层薄膜的电磁参数分析,发现随层数的增加,薄膜的吸波性能增强;在9.21GHz和10.5GHz左右,且组装层数一定时,复合多层膜的吸波性能排序为SrCe0.2Fe11.8O19/PSS> SrLa0.2Fe11.8O19/PSS>Sr.Fe12O19/PSS.     

吖啶橙修饰金纳米自组装膜制备及其性能研究

采用水相硅烷化方法,将γ-氨基丙基三乙氧基硅烷[H2N(CH2)3Si(OC2H5)3](APES)组装在石英表面,在基底表面修饰上氨基为末端的单层膜,并进一步在这种功能化的单层膜基底上组装金纳米粒子得到金纳米粒子/APES/石英的纳米复合结构。以制备的金纳米粒子自组装膜修饰石英为基底、半胱胺酸为中介,利用吖啶橙(AO)和半胱胺酸的化学吸附作用,将吖啶橙间接组装在金纳米粒子自组装膜修饰石英基底表面,制备出具有荧光特性的超分子自组装膜AO/Cys/AuNP/APES/Quartz。文章着重研究了吖啶橙修饰金纳米粒子自组装膜的制备和组装条件,以及用原子力显微镜、紫外吸收光谱、荧光光谱对膜进行表征。基于膜具有的荧光性质,有望发展一种新型的荧光传感器。     

PVDF/PDDA静电自组装超薄膜的制备与表征

提出了一种制备纳米量级铁电聚合物PVDF/PDDA超薄膜的新方法。聚二烯丙基二甲基氯化铵(PDDA)和极化处理后的聚偏氟乙烯(PVDF)复合超薄膜是通过层与层的静电自组装(LbL-SA)方法制备的,厚度约30~150 nm,每层膜厚度约为9 nm。PVDF/PDDA多层膜通过石英晶振微天平(QCM)、红外频谱仪、原子力显微镜(AFM)进行了测试与表征。QCM表征结果表明,PVDF与PDDA超薄膜能较好地交替组装;AFM表明PVDF/PDDA聚合物超薄膜的表面均匀、薄膜致密。与PVDF厚膜的电阻性能相比,PVDF/PDDA复合超薄膜的电阻性能有了很大提高。     

聚多巴胺诱导层层自组装抗紫外聚丙烯无纺布

为提高聚丙烯(PP)无纺布的抗紫外性能,用浸涂法在PP无纺布表面涂覆聚多巴胺(PDA)层,再将壳聚糖(CS)接枝在PDA表面使无纺布表面带正电;利用CS和氧化石墨烯(GO)的静电吸附作用制备不同自组装层数的抗紫外PP无纺布.通过FTIR、TEM、SEM和UPF等测试方法对所制备的无纺布进行表征分析.结果表明:GO与CS成功组装在PP无纺布表面,且自组装10层GO/CS后样品UPF值提高近500倍,达到2 000,UVA和UVB的透过率仅为0.05%.     

结构色纤维的制备及应用进展

结构色纤维无需染料、色彩鲜艳、永不褪色的特点符合当前绿色、环保纤维纺织技术的发展新要求，有广阔的发展前景。概述了结构色纤维显色原理、制备及其应用，重点探讨了结构色纤维的制备方法，介绍了目前研究报道的微加工法、多层膜组装法、胶体晶体静电纺丝法、胶体组装法以及湿法纺丝等，讨论了这些方法的优缺点。     

C60自组装单层与多层膜的制备及其光致发光

利用Ｃ６０与乙二胺改性的玻璃表面进行加成反应,得到一种新的Ｃ６０自组装单层膜,在Ｃ６０自组装单层膜的基础上,将Ｃ６０与乙二胺反应制备自组装双层和多层膜,并对其光致发光性质进行了研究,Ｘ射拇光电子能谱,激光解吸电离飞行时间质谱的测试结果表明,在乙二胺改性的玻璃表面上存在以化学键键合的Ｃ６０自组装单层和多层膜,并且随着膜的层数增加,Ｃ６０与乙二胺的键合由一维线形结构向三维网状结构转变,光致发光研究表明     

静电层层组装纳米粒子多层膜修饰电极及其应用

通过静电层层组装技术,得到了纳米粒子二硫化锡(SnS2)、单壁碳纳米管(SWCNTs)多层膜修饰电极.用电化学循环伏安法(CV)、电化学阻抗(EIS)法对该多层膜修饰电极进行表征,证明了其多层膜修饰电极具有很好的稳定性、重复性、有序性、均一性.并且该多层膜修饰电极对多巴胺(DA)具有良好的电催化效果,在pH=7.0磷酸...     

界面自组装法制备高性能氧化石墨烯膜

为制备可靠、精确的分子筛氧化石墨烯(GO)膜,克服基于厚度调控的抽滤自组装GO膜分离性能提升和通量减小之间的矛盾关系,采用界面自组装法,制备了具有更加紧密层间结构的GO膜,并对其性能进行了表征。实验结果表明:与抽滤自组装法制备GO膜相比,界面自组装法可以实现更加紧密的层间结构;在化学环境相似的条件下,界面自组装膜的层间距可达0.75 nm,较抽滤自组装膜减小了0.10 nm左右;成膜机理和速率是GO膜层间结构的主要影响因素。将该膜用于金属离子水溶液的截留实验,结果表明:界面自组装GO膜对Mg~(2+)的截留率可达70%左右,是抽滤自组装膜的1.3倍。     

锗掺杂二氧化硅膜的紫外光致折变

研究了用火焰水解法制备的掺锗二氧化硅膜在KrF紫外激光下曝光后的结构和光学性质的变化。经过10 m in的照射后,在1550 nm处的折射率变化大约为3.41×10-3。采用原子力显微镜分析了曝光过程及膜的表面形貌。结果表明:随着曝光时间的延长,膜的致密性增加,表面粗糙度下降,折射率增大。     

CrAlN/TiAlN 纳米多层膜的微结构及其性能研究

采用磁控反应溅射法制备了不同调制周期的CrAlN/TiAlN纳米多层膜,并通过X射线衍射仪 、显微硬度计、扫描电镜分析了调制周期对多层膜的微结构、力学性能和高温抗氧化性能的影响。结果表明：CrAlN/TiAlN纳米多层膜共格外延生长,呈现CrAlN（或TiAlN）面心立方结构,且呈（111）择优取向;CrAlN/TiAlN纳米多层膜在某些调制周期出现硬度异常升高的超硬度效应;CrAlN/TiAlN纳米多层膜比CrAlN, TiAlN单层膜具有更好的高温稳定性,高温时仍具有较高的硬度。     

Fiber Optic Humidity Sensor Based on Self-Assembled Polyelectrolyte

Polyelectrolyte multilayers were self-assembled onto planar glasssubstrates and multimode optic fibers. The multilayer thin films deposited on glass substrates were characterized by using UV-vis spectroscopy and X-ray photoelectron spectroscopy. The multilayer thin films containing hydrophilic side-groups possessed are affinity for water molecules. The adsorption and desorption of free water vapor gave rise to the changes in the refractive index and in the reflectance of the thin films. A multilayer thin film based fiber optic humidity sensor with an LED light source of 0.85 μm was designed. Under certain conditions, the reflected light intensity of the thin film sensor was a function of the humidity of air. About 30 bilayers was optimal for the multilayer thin film sensor working at wavelength of 0.85 μm. This sensor can work over almost the whole relative humidity range with very good sensitivity.     

CrAIN／TiAIN纳米多层膜的微结构及其性能研究

采用磁控反应溅射法制备了不同调制周期的CrAIN／TiAIN纳米多层膜,并通过x射线衍射仪、显微硬度计、扫描电镜分析了调制周期对多层膜的微结构、力学性能和高温抗氧化性能的影响。结果表明：CrAIN／TiAIN纳米多层膜共格外延生长,呈现CrAIN（或TiAIN）面心立方结构,且呈（111）择优取向;CrAIN／TiAIN纳米多层膜在某些调制周期出现硬度异常升高的超硬度效应;CrAIN／TiAIN纳米多层膜比CrAIN,TiAIN单层膜具有更好的高温稳定性,高温时仍具有较高的硬度。     

多孔 PTFE/FEP复合驻极体材料的电荷动态特性

采用高温熔融复合和负电晕充电方法制备了多孔聚四氟乙烯（PTFE）氟代乙烯丙烯共聚物（FEP）的复合驻极体膜，通过等温及热刺激表面电位测量等方法研究了复合驻极体膜的电荷储存和衰减的动态行为。结果表明：当从不同的面对复合膜材料进行充电时，复合膜系统呈现不同的驻极体特性；与单一的聚合物膜相比，PTFE面充电复合膜的电荷稳定性显著增加，而FEP面充电时复合膜的电荷稳定性则变差。     

铜合金表面Ti/TiN多层膜的制备、结构及其性能

为了研究多层膜的腐蚀性能,促进多层膜在生产中的应用,采用电弧离子镀技术,通过调整环境N₂和Ar气的时间比例在铜衬底上成功制备了不同调制周期的Ti/TiN多层膜.利用x 射线衍射谱和交流阻抗谱研究了该多层膜的结构和腐蚀性能.表面形貌显示,沉积的Ti/TiN多层膜具有明显的周期性,环境中N2和Ar气的时间比例决定了多层膜的调制周期,N₂气时间越长,多层膜中TiN相层越厚.腐蚀性能测定表明,多层膜的调制周期影响其耐蚀性,当调制周期为550nm时,沉积膜的耐腐蚀性最好.     

Gold Nanoparticulate Thin Films Fabricated by the Electrostatic Self—Assembly Process

Gold colloids were prepared by citrate-induced reduction of hydrogen tetrachlorourate, and gold nanoparticles were electrostatically self-assembled with poly (diallyldimethylammonium chloride) into multilayer thin films on silicon and quartz substrates. The particulate thin films were characterized by UV-vis spectroscopy, surface enhanced Raman scattering, atomic force microscopy and resistivity measurements. Due to the interparticle coupling between individual gold particles, an obvious collective particle plasmon resonance was observed on UV-vis spectra, and the particulate thin films exhibited a strong SERS effect. For multilayer thin films with a high particle coverage on substrates, resistivity of the order of 10⁻⁴Ω·cm was yielded. Yu Hai-hu This research was financially supported by China Scholarship Council and the Natural Science Foundation of Hubei Province (Project 2000J002)     

多维电极法去除水中溶解态腐殖酸的机理探讨

腐殖酸被认为是氯消毒副产物（DBPs)的主要前驱物,为了寻求有效、经济的控制DBPs的手段,采用了活性碳多维电极法,讨论了溶液pH,Ca^2 浓度和外电压影响去除效果的机理,并对多维电极吸附与单纯活性碳吸附进行了比较。研究结果表明,多维电极对腐殖酸的吸附过程符合修正的Freundlich模型：x/m＝Kf(C/D)^1/n,模型中的常数Kf和1／n均小于单纯活性碳吸附时的相应常数。联系到pH,C^2 浓度和外电动对去除效果的影响,可以认为静电引力是强化活性碳多维电极吸附溶解态腐殖酸的主要作用力。电子显微镜检测显示,在运行同样时间后,作为多维电极的活性碳的微观结构较单纯吸附时的活性碳疏松,说明该方法有可能延长活性碳的使用寿命。     

Effect of Ag addition on the microstructure and magnetic properties of FePt thin films

FePt thin films and [FePt/Ag]n multilayer thin films were prepared by magnetron sputtering technique and subsequent annealing process. By comparing the microstructure and magnetic properties of these two kinds of thin films, effects of Ag addition on the structure and properties of FePt thin films were investigated. Proper Ag addition was found helpful for FePt phase transition at lower annealing temperature. With Ag addition, the magnetic domain pattern of FePt thin film changed from maze-like pattern to more discrete island-like domain pattern in [FePt/Ag]n multilayer thin films. In addition, introducing nonmagnetic Ag hindered FePt grains from growing larger. The in-depth defects in FePt films and [FePt/Ag]n multilayer films verify that Ag addition is attributed to a large number of pinning site defects in [FePt/Ag]n film and therefore has effects on its magnetic properties and microstructure.     

Effects of LaNiO_3 Interlayer on the Microstructures and Electrical Properties of Ba_(0.9)Sr_(0.1)Ti_(0.99)Mn_(0.01)O_3 Multilayer

The aim of this work was to investigate the effects of low-resistivity interlayer on the physical properties of periodic Ba_(0.9)Sr_(0.1)Ti_(0.99)Mn_(0.01)O_3(BSTM) multilayers prepared by a chemical solution deposition method. A LaNiO_3(LNO) layer was inserted into the periodic BSTM multilayer artificially to form a sandwiched configuration of BSTM/LNO/BSTM. The capacitances at low frequencies(100 k Hz) of the sandwiched multilayer are significantly enhanced compared to that of the pure BSTM multilayer. The space charge accumulated at the LNO layer was proposed to explain the enhancement based on Maxwell-Wagner(M-W) model. However, LNO interlayer leads to an increase in the leakage current. A non-Ohmic conduction region is observed for BSTM/LNO/BSTM multilayer when the electric field exceeds 100 k V/cm. The results offer a new approach to achieve dielectric films with high dielectric constant.