十二烷基甜菜碱的界面活性及其体系的相态研究

合成了十二烷基甜菜碱（Ｃ１２ＢＥ），经提纯得到合格的样品，测定其等电为ｐＨ＝４．９，ｐＨ〈４．９，分子带正电，ｐＨ≥４．９，分子呈电中性，研究ｐＨ值对其界面活性的影响，同时还研究了醇的种类，浓度，水的盐度，ｐＨ值等因素对Ｃ１２ＢＥ／醇／水／油体系相态的影响，得到了中相微乳液的特性参数，其中有关ｐＨ对相态的影响的研究很有特点。     

杂质离子对有机共轭聚合物中极化子动力学性质的影响

基于一维紧束缚Su-Schrieffer-Heeger模型, 采用分子动力学方法, 讨论了杂质势的强度和杂质之间的距离对电子和空穴极化子动力学性质的影响. 研究结果表明: 1)当杂质势强度保持不变时, 两杂质离子之间的距离(d)在2-16个晶格常数变化时, 电子极化子的平均速度大于空穴极化子的平均速度, 这是由于电子、空穴极化子与杂质势的库仑作用不同而产生的差异, 同时极化子的平均速度随d的增加而增大; 若继续增加杂质离子之间的距离, 电子和空穴极化子的平均速度几乎保持不变, 仅有一些微小的振荡, 这是由于不同距离的杂质离子对电子和空穴极化子产生的势垒或势阱的叠加效果不同而引起的; 2)保持两杂质离子之间的距离不变时, 随着杂质势强度的增大, 电子和空穴极化子的平均速度均减小, 且空穴极化子的平均速度减小趋势更明显.     

非离子表面活性剂和β-环糊精协同诱导1-溴萘室温磷光的对比研究

对比研究了非离子表面活性剂聚氧乙烯辛基酚醚 (OPE 10 ,n =10 )及聚氧乙烯特辛基酚醚 (TritonX 10 0 ,n =10 )和 β 环糊精 (β CD)协同诱导 1 溴萘 (1 BrN)室温磷光光谱。根据分子大小和 β CD空腔尺寸分析阐述了 β CD与非离子表面活性剂形成 1∶1二元包络物 ,OPE 10和TritonX 10 0分子内的辛基和苯基团被包络在空腔内 ,驱除了空腔内的水分子 ,使空腔内微环境的极性更低 ,通过更强的疏水相互作用进一步和 1 BrN形成了结构紧密的稳定 1∶1∶1三元包络物。β CD/OPE 10 / 1 BrN和 β CD/TritonX 10 0 / 1 BrN包络物的表观稳定常数分别为 1 0 9× 10 5和 4 4 7× 10 5L2 ·mol- 2 。在 β CD空腔内 ,1 BrN的重原子对OPE 10和TritonX 10 0的荧光产生猝灭作用。对于更稳定的 β CD/TritonX 10 0 / 1 BrN三元体系 ,特辛基可更好地屏蔽溶液中的溶解氧和碘离子的猝灭作用 ,观察到了TritonX 10 0分子内苯基和受体 1 BrN之间的能量转移。     

表面活性剂含量对全息聚合物分散液晶光栅电光特性的影响

研究了含表面活性剂Actyflon-G04的全息聚合物分散液晶透射光栅的表面形貌和电光特性,通过理论分析得出驱动电压和膜的锚定能及表面自由能的关系.实验结果表明,在Actyflon-G04含量为4wt%-8wt%时光栅相分离程度高,相界面平滑,聚合物层的致密度增加.光栅的衍射效率达到96%,接近理想值.实现了在提高光栅衍射效率的同时降低驱动电压,使光栅的电光特性得到改善.     

溶剂对以PEIE为阴极修饰层的反型聚合物太阳能电池性能的影响

研究了乙氧基化聚乙烯亚胺(PEIE)作为反型太阳能电池阴极修饰层,其溶剂的选择对器件性能的影响.我们选择蒸馏水(DW)、异丙醇(IPA)、乙二醇甲醚(MEA)和乙氧基乙醇(EEA)作为PEIE的稀释溶剂来制备器件,并通过瞬态光电流的测量和低频电容-电压(C-V)曲线的测量分析了器件在1TO和PEIE修饰层之间的电荷积累程度和电极电荷收集效率,同时对不同溶液制成的PEIE层做了表面形貌分析.结果表明,MEA器件的光电转换效率(PCE)达到3.61％,相对于DW器件(2.66％)提高了24％,对于PEIE层选择不同的溶剂将导致表面形貌的差异,并影响器件界面的缺陷密度,进而影响器件性能.     

非热离子对非均匀碰撞热尘埃等离子体中三维孤波的影响

从理论上研究了非热离子、外部磁场、碰撞对非均匀热尘埃等离子体中三维非线性尘埃声孤波的影响。运用约化摄动法得到描述三维非线性尘埃声孤波的非标准的变系数Korteweg-de Vries(KdV)方程。然后把非标准KdV方程变为标准的变系数KdV方程,并且得到了标准的变系数KdV方程的近似解析解。由此解析解可以看出,非热离子的数目、碰撞、非均匀性、波的斜向传播、尘埃颗粒和非热离子的温度对三维非线性尘埃声孤波的振幅和宽度有很大的影响。外部磁场对三维非线性尘埃声孤波的宽度有影响,而对其振幅没有影响。此外,波的相速度与非热离子、波的斜向传播、尘埃颗粒的温度和非均匀性有关。     

非共轭聚合物PPV衍生物中烷氧基团对发光性质的影响

研究了3种非共轭PPV聚合物以及3种共轭PPV衍生物的吸收谱和发光光谱的特性.非共轭PPV聚合物上的侧链烷氧基团有着很强的供电子能力,对调节非共轭聚合物能带带隙有重要的影响,且离主链较近的碳原子对能带结构也有一定的影响.但当侧链上的碳原子数量很大,从7个小时一直变化到10小时,共轭PPV衍生物的吸收光谱和发光光谱变化较少,表明对能带结构影响小.     

Effect of temperature on the intrinsic viscosity of poly(ethylene glycol) in water/dimethyl sulfoxide solutions

In this work, the intrinsic viscosities of poly(ethylene glycol) with molar mass of 20 kg mol^− 1 were measured in water/dimethyl sulfoxide solutions from (298.15 to 318.15) K. The expansion factors of the polymer chains were calculated from the intrinsic viscosity data. The expansion factor were decreased by increasing temperature; therefore the chain of PEG shrinks and the end-to-end distance become smaller by increasing temperature. Perhaps the interactions of segment-segment are favored toward segment-solvent by increasing temperature; therefore the hydrodynamic volumes of the polymer coils become smaller by increasing temperature. The thermodynamic parameters (entropy of dilution parameter, the heat of dilution parameter, theta temperature and polymer-solvent interaction parameter) were derived by the temperature dependence of the polymer chain expansion factor. The thermodynamic parameters indicate that the interactions of segment-segment were increased by increasing temperature.     

Mn-CCA-CPC浊点萃取火焰原子吸收法测定水环境中锰

使用浊点萃取的方法分离富集水环境中痕量的锰离子,创新性地使用钙羧酸(CCA)与阳离子表面活性剂氯代十六烷基吡啶(CPC)为络合剂与锰离子形成更稳定的三元络合物,以TritonX-114为萃取剂浊点萃取分离富集水环境中的痕量锰,同时采用火焰原子吸收法进行测定,建立了测定水环境中痕量锰的新方法。对影响浊点萃取的主要因素如pH、TritonX-114的用量、CCA用量、CPC用量、NaCl用量、共存离子影响、加热温度、加热时间、离心时间、冰浴时间进行了优化。在优化的实验条件下,Mn2+-CCA-CPC体系分离富集锰有很好地效果,能够很好的克服基体干扰,浊点萃取体系在锰含量0.3～1.5 mg·L-1时呈现良好的线性关系。方法的灵敏度为1.939 mg·L-1,精密度为0.39%,检出限为(3σ)0.27 μg·L-1。测定自来水与井水中的锰含量的结果为33.5和64.5 μg·L-1,同时做加标回收实验,回收率在99.1%～101.5%之间。符合国际标准,因此该方法能够成功应用到水环境中的锰含量的测定,结果令人满意。     

Rheological Behaviors and Properties of Poly (Ether Ether Ketone) In-Situ Blends: Effect of Chemical Structure of Added Thermotropic Liquid Crystalline Polyarylates

Abstract

Two kinds of thermotropic liquid crystalline polyesters (TLCP) with different chemical structures were used as flow modifiers during the melt spinning of poly (ether ether ketone). One of TLCPs, named PAT-S, was a kind of aromatic polyester synthesized from 4-acetoxybenzoicacid and 6-hydroxy-naphthoic acid, and the other one named, PEEKAR, was a block copolymer based on poly (ether ether ketene) (PEEK) oligomers and PAT-S oligomers. The effects of the chemical structures of the prepared TLCPs on the rheological behavior of the TLCP/PEEK blends were measured by rheological measurements, and then the structure and properties of the TLCP/PEEK in-situ blend fibers were studied by a series of methods, including differential scanning calorimetry (DSC), wide angle X-ray diffraction (WRXD), optical microscopy (OM), scanning electron microscopy (SEM), orientation degree tests, mechanical properties tests, etc. The results showed that the melt viscosity of PEEK could be effectively reduced by nearly 20% by adding a small amount of PEEKAR or PAT-S with the viscosity reducing effect of PEEKAR on PEEK being greater than that of PAT-S; this was mainly caused by the better compatibility between PEEK and PEEKAR because of the similar segment structures. The crystallinity of the PEEK fibers increased by nearly 50% with addition of both TLCPs, indicating that both the PEEKAR and PAT-S could serve as nucleating agent as well. The results from the morphology analysis clearly proved that PEEKAR had a better compatibility with the PEEK resin compared with PAT-S. The tensile strength of the PEEK fibers could be improved to some extent by adding PEEKAR, while it was obviously reduced after adding PAT-S.     

Effect of relative humidity on the electrical transport properties of poly(thionaphtheneindole)

Poly(thionaphtheneindole) (pTNI) conducting polymer has previously been observed to undergo a large variation in the electrical conductivity as a function of relative humidity. In this paper the electrical characteristics of this material as a function of the adsorbed water are studied. Isothermal current-time and current-voltage plots can be understood in terms of an ionic charge transfer inside the polymer, controlled by a diffusion limited electrodic process. The charge transfer at the electrodes is probably due to proton reduction at the cathode and water oxidation at the anode.     

Effect of chemical etching on the Cu/Ni metallization of poly (ether ether ketone)/carbon fiber composites

Poly(ether ether ketone)/carbon fiber composites (PEEK/Cf) were chemical etched by Cr₂O₃/H₂SO₄ solution, electroless plated with copper and then electroplated with nickel. The effects of chemical etching time and temperature on the adhesive strength between PEEK/Cf and Cu/Ni layers were studied by thermal shock method. The electrical resistance of some samples was measured. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface composition and functional groups. Scanning electron microscopy (SEM) was performed to observe the surface morphology of the composite, the chemical etched sample, the plated sample and the peeled metal layer. The results indicated that CO bond increased after chemical etching. With the increasing of etching temperature and time, more and more cracks and partially exposed carbon fibers appeared at the surface of PEEK/Cf composites, and the adhesive strength increased consequently. When the composites were etched at 60 °C for 25 min and at 70-80 °C for more than 15 min, the Cu/Ni metallization layer could withstand four thermal shock cycles without bubbling, and the electrical resistivity of the metal layer of these samples increased with the increasing of etching temperature and time.     

用纳米压痕法分析溶剂对聚醚醚酮(PEEK)力学性能的影响

Poly (ether ether ketone)(PEEK) is a high-performance semi-crystalline thermoplastic polymer.Exposure of the polymeric surface to solvents can have a strong effect like softening/swelling of polymeric network or dissolution.In this study,nano-indentation analysis was performed to study the effect of acetone on the surface mechanical properties of PEEK using different exposure time.The experiments were performed with a constant loading rate (10 nm/s) to a maximum indentation displacement (1000 nm).A 30-second hold segment was included at the maximum load to account for any creep effects followed by an unloading segment to 80% unloading.The indentation hardness and the elastic modulus were computed as a continuous function of the penetration displacement in the continuous stiffness mode (CSM) indentation.The experimental data showed that the peak load decreased from ~5.2 mN to ~1.7 mN as exposure time in solvent environment increased from 0 to 18 days.The elastic modulus and the hardness of PEEK samples also displayed a decreasing trend as a function of exposure time in the solvent environment.Two empirical models were used to fit the experimental data of hardness as a function of exposure time which showed a good agreement with the experimental values.     

两性离子表面活性剂BS-12与DNA作用的共振光散射光谱

直接将两性离子表面活性剂用于DNA的共振光散射测定。在pH 9.3的缓冲液中,DNA与十二烷基二甲基甜菜碱(BS-12)在388 nm处有共振光散射增强,其强度与核酸的浓度呈线性关系,据此建立了一种测定DNA的共振光散射法。该方法具有操作简单、线性范围宽、检出限低的特点。fsDNA与ctDNA的线性范围分别为0.25～12.0 μg·mL-1和0.25～11.0 μg· mL-1,检测限分别为0.15和0.16 ng·mL-1。该法用于混合样品中DNA的测定,结果满意。     

Effect of melt viscosity and surface tension of polymers on the percolation threshold of conductive-particle-filled polymeric composites

The electrical conductivities of carbon-black-filled low-density polyethylene (LDPE), poly(methyl methacrylate) (PMMA), and poly(vinyl chloride)-vinyl acetate (PVC/ VAc) copolymer were measured as functions of carbon content and melt viscosity of the matrix at the temperatures at which the composites were prepared. Sharp breaks in the relationship between the carbon filler content and the conductivity of composites were observed in all specimens at some content of the carbon filler. The conductivity jumps as much as 10 orders of magnitude at the break point. This phenomenon has been known as the “percolation threshold”. The critical carbon content corresponding to the break point     

An experimental study on the effect of mesoporous silica addition on ion conductivity of poly(ethylene oxide) electrolytes

Solid polymer electrolyte (SPE) composites, which are composed of poly(ethylene oxide) (PEO), mesoporous silica (SBA-15), and lithium salt were prepared in order to investigate the influence of SBA-15 content on the ionic conductivity of the composites. The ionic conductivity of the SPE composites was monitored by frequency response analyzer (FRA), and the crystallinity of the SPE composites was evaluated by using XRD. As a result, the addition of SBA-15 to the polymer mixture inhibited the growth of PEO crystalline domain, due to the mesoporous structure of the SBA-15. Also, the PEO₁₆LiClO₄/SBA-15 composite electrolytes show an increased ion conductivity as a function of SBA-15 content up to 15 wt.%. These ion conductivity characteristics are dependent on crystallinity with SBA-15 content.     

Effect of dispersion state of carbon nanotube on the thermal conductivity of poly(dimethyl siloxane) composites

Herein, the effect of dispersion uniformity of multi-walled carbon nanotube (MWCNT) on the thermal conductivity of poly(dimethyl siloxane) (PDMS) composites was investigated by comparing experimentally obtained and calculated results based on simple models. Two different MWCNTs, i.e., raw and oxidized/masterbatched MWCNTs, were used and compared. For raw MWCNT, the dispersion in PDMS was poor, resulting in the significant reduction in the aspect ratio of MWCNT. However, for composites using masterbatched MWCNT, the thermal conductivity was always about 10% greater than those prepared with raw MWCNT and the aspect ratio calculated by the model equation was also 1.7 times greater. Above 1.5 phr masterbatched MWCNT concentrations, the aspect ratio of 430 was maintained. Finally, the results suggest that the thermal conductivity can be correlated with the degree of dispersion and aspect ratio obtained from the model equation used.