间接原子吸收光度法测定微量S^2—

研究了用间接原子吸收分光光度法测定微量S~(2-).在pH=4.5的含S~(2-)溶液中,加入定量过量的Cu~(2+),使其形成CuS沉淀,多余的Cu~(2+)用戊黄原酸钾配合,然后用甲基异丁基甲酮(MlBK)溶剂萃取配合物.不需分离,直接喷雾有机相溶液测定配合铜.S~(2-)的灵敏度为0.01μg/mL/1％,变动系数2.7％.     

pH值对于表面硼改性纳米二氧化钛交联剂交联性能的影响

传统有机硼交联羟丙基瓜胶 （HPG）冻胶压裂液体系具有稠化剂用量大,压裂施工成本高,压裂残渣多,裂缝导流能力差等诸多缺点。为了达到降低压裂液稠化剂用量、提高压裂施工效果的目的, 采用“两步法”制备了一种表面硼改性的纳米二氧化钛颗粒 （NCC）作为HPG压裂液交联剂。研究了pH值对于NCC交联HPG冻胶耐温性能的影响,结果表明随着pH值的增加,NCC冻胶压裂液的耐温性能先增大后减小。所形成的冻胶压裂液在pH=12时耐温性能最佳。与传统有机硼交联剂相比,NCC可大大减小稠化剂用量,NCC交联的0.3 wt.% HPG冻胶在pH值为8~14的范围内均能保持良好的耐温性能。利用扫描电镜表征了NCC冻胶在不同pH值条件下的交联形貌及交联结构,结果表明,在pH值为12时,NCC冻胶微观形貌最致密。     

Preparation of PVDF/TiO_2 Electrospun Membranes and its Application as Separators for Lithium-ion Batteries

1 Results Microporous PVDF-based membranes could be used as polymer matrix due to its good ionic conductivity and high electrochemical stability in the organic electrolyte[1,2].Fig.1 SEM image of PVDF/TiO2 membraneIt was reported that the ionic conductivity of microporous PVDF-based membranes could be improved by filling with Al2O3 nanoparticles[3].In this paper,electrospinning was employed to prepare microporous PVDF/TiO2 membranes and tetrabutyl titanate was used as original source of TiO2 to improve...     

微凝胶模板法制备表面图案化CuS有机-无机复合微球

采用反相悬浮聚合法合成了PNIPAM和P(NIPAM-co-MAA)微凝胶,以这2种微凝胶为模板,制得了具有表面图案化结构的PNIPAM/CuS和P(NIPAM-co-MAA)/CuS有机—无机复合微球。结果表明:复合微球的表面形貌取决于微凝胶模板的性质和金属无机物的相对沉积量。微凝胶模板法为制备具有复杂形貌的有机-无机复合微球材料提供了一种新的途径。     

单源前驱物溶剂热分解过程控制合成硫化铜纳米晶

文章提出了通过简单的单源前驱物溶剂热分解过程,在150℃或180℃温度下,制备不同物相和形貌的硫化铜纳米晶.改变乙二胺的量,单源前驱物Cu(S2CNC(2H5)22)能分解得到蓝铜矿结构的CuS和辉铜矿结构Cu1.8S.在不同的溶剂中,制备了蓝铜矿结构CuS的不同相貌产物(像棒状、球状、片状).探讨了温度和溶剂对产物物相和形貌的影响.用X-射线粉末衍射仪(XRD)和透射电子显微镜(TEM)对样品的组成和形貌进行了表征,产物的光学性能用紫外-可见光谱仪(UV-vis)进行了表征。     

Detection of TNT by a molecularly imprinted polymer film-based surface plasmon resonance sensor

A surface plasmon resonance(SPR) sensor using a molecularly imprinted polymer(MIP) film as a recognition element for detection of 2,4,6-trinitrotoluene(TNT) was developed.The TNT-imprinted polymer film was prepared by thermo initiated polymerization on the bare Au surface of an SPR sensor chip.Template TNT molecules were quickly removed with an organic solution of acetonitrile/acetic acid(9:1,v/v),causing a shift of 0.7° in SPR angle.The limit of detection for TNT was demonstrated to be as low as 1×10-8 mol/L.In the concentration range of 1×10-8-1×10-5 mol/L,the change of SPR angle was linear with the negative logarithm of TNT concentration,Selectivity studies showed that the SPR sensor had no response to TNT analogues 2,4,5-trinitrotoluene and 1,3,5-trinitrohexahydro-1,3,5-triazine at a concentration of 1×10-4 mol/L.The results suggest that the SPR sensor combined with a MIP film has the advantages of high sensitivity and selectivity,and long-term stability toward the analyte TNT.     

Electronic Structure and Electron-transport Properties of Peanut-shaped C60 Polymers with a Negative Gauss Curvature

1 Results When a C60 film was irradiated with electron-beam (EB) with an incident energy of 3 kV, a peanut-shaped C60 polymer with metallic properties was formed[1], as shown in Fig.1. To elucidate the origin of the metallic properties of the peanut-shaped polymer, we examined the valence photoelectron spectra of the polymer using in situ high-resolution photoelectron spectroscopy and found that the electronic states of the polymer came across the Fermi level (EF)[2]. Interestingly, the spectral shape i...     

低固相阳离子聚合物钻井液体系的研究

介绍了一种由聚季铵盐型有机阳离子聚合物（ＣＯＰ）、硝基腐殖酸（ＮＨｍ）、聚乙烯醇．（ＰＶＡ）、膨润土等配制的低国相阳离子聚合物钻井液体系．评价了该钻井液体系的粘度、切力、滤失性能、抑制性能以及抗盐、抗温能力，考察了该钻井液体系的抑制剂—有机阳离子聚合物与常用钻井液处理剂的配伍性能．含１０％ＮａＣｌ的低国相阳离子聚合物钻井液在１２０℃滚动１２ｈ后的性能如下：（１）密度为１．０８～１．０９ｇ／ｃｍ３；（２）ＰＨ值为６．５～７；（３）切力为１～４Ｐａ；（４）表观粘度为９～２４ｍＰａ·ｓ；（５）在常温０．７ＭＰａ下的ＡＰＩ滤失量为７．０～１３．４ｍｌ，在１２０℃、３．５ＭＰａ下的ＡＰＩ滤失量为２８～４３ｍｌ．页岩在１０％ＮａＣｌ水溶液、０．１％ＣＯＰ水溶液及该钻井液体系中的回收率分别为６５％～６８％，９１％，８７％～９１％．车铵盐型有机阳离子聚合物与阳离子型及非离子型钻井添加剂相配伍，但与复合离子型及阴离子型钻井液添加剂不配伍．该钻井液体系完善后可用作防塌钻井液     

Topological Polymer Chemistry for Designing New Macromolecular Architectures

1 Introduction The precise control in polymer architectures has been an ongoing challenge in synthetic polymer chemistry, since new polymer topologies will realize unprecedented properties and functions in polymeric materials. In particular, topologically unique macromolecules comprising single cyclic and multicyclic polymer units have gained growing interests due to their distinctive behaviors from linear and branched counterparts~([1-4]).See Fig.1.1IntroductionThe precise control in polymer…     

高分子载体四氯化锡复合物催化剂Ⅲ.苯乙烯、乙烯基咔唑共聚物-四氯化锡复合物

合成了苯乙烯-N-乙烯基咔唑交联聚合物。此聚合物在氯仿中能同四氯化锡生成稳定的含氯量为20.8％的复合物(相当于1.47mmol SnCl_2/g)。此复合物对许多有机反应如,酯化、缩醛、缩酮及醚化等有良好的催化活性。     

顺1,4-聚丁二烯凝胶的制备及溶胀特性研究

采用溶液聚合工艺，以未经硫化的顺丁橡胶为高分子骨架进行接枝交联制备了1，4—聚丁二烯凝胶。研究了反应条件，如溶剂用量、引发剂用量、交联剂用量及4—叔丁基苯乙烯(tBS)对有机凝胶的平衡溶胀率的影响。实验表明，该凝胶在二甲苯、环己烷中最大溶胀率(Qe)分别为51．35g／g和29．41g／g。研究了该凝胶在二甲苯中的溶胀特性，得到一个与实验结果相吻合的溶胀动力学方程：Q=Qe—[kt 1/Qe-Qo]^-1，同时也发现二甲苯在凝胶中的扩散行为可用Fickian定律来描述。     

Ultrafast holographic nanopatterning of biocatalytically formed silica

Diatoms are of interest to the materials research community because of their ability to create highly complex and intricate silica structures under physiological conditions: what these single-cell organisms accomplish so elegantly in nature requires extreme laboratory conditions to duplicate-this is true for even the simplest of structures. Following the identification of polycationic peptides from the diatom Cylindrotheca fusiformis, simple silica nanospheres can now be synthesized in vitro from silanes at nearly neutral pH and at ambient temperatures and pressures. Here we describe a method for creating a hybrid organic/inorganic ordered nanostructure of silica spheres through the incorporation of a polycationic peptide (derived from the C. fusiformis silaffin-1 protein) into a polymer hologram created by two-photon-induced photopolymerization. When these peptide nanopatterned holographic structures are exposed to a silicic acid, an ordered array of silica nanospheres is deposited onto the clear polymer substrate. These structures exhibit a nearly fifty-fold increase in diffraction efficiency over a comparable polymer hologram without silica. This approach, combining the ease of processability of an organic polymer with the improved mechanical and optical properties of an inorganic material, could be of practical use for the fabrication of photonic devices.     

Synthesis of CuS nanoparticles decorated Ti_3C_2T_x MXene with enhanced microwave absorption performance

MXene,a novel two-dimensional (2D) multi-layer material,has drawn unusual interest as the microwave absorbers for electromagnetic energy attenuation.Synthetic MXene-based heterostructure composites via optimizing structure is an effective strategy to endow MXene materials with high-performance microwave absorption.This study reports the fabrication and investigation of the microwave absorption performance of a sandwich-like CuS/Ti_3C_2T_xMXene composites prepared by loading CuS nanoparticles onto 2D Ti_3C_2T_xvia a solvothermal method.The morphology and electromagnetic absorption properties of this composite were investigated and the results demonstrated that the CuS/Ti_3C_2T_xcomposite with a heterolayered architecture displayed superior microwave absorption ability.With a 35 wt%filler loading in the paraffin matrix,the minimum reflection loss value reached-45.3 dB at a frequency of 7.3 GHz and the effective absorption bandwidth achieved a value as high as 5.2 GHz with a thickness of 2.0 mm.The enhanced microwave absorption performances can be ascribed to the cooperation of the conductive network,interface polarization,dipole polarization,multiple reflection and scattering.Therefore,the synthesized CuS/Ti_3C_2T_xMXene composites offer an efficient foundation for the design and utilization of other lightweight microwave absorbers.     

Thermoreversible Thickening and Self-assembly Behaviors of pH/Temperature Dually Responsive Microgels with Interpenetrating Polymer Network Structure

The pH /temperature dually responsive microgels of interpenetrating polymer network（ IPN） structure composed of poly（ N-isopropylacrylamide）（ PNIPAM） network and poly（ acrylic acid）（ PAA） network（ PNIPAM /PAA IPN microgels） were synthesized by seed emulsion polymerization. The results obtained by dynamic laser light scattering（ DLLS） show that the microgels have good pH /temperature dual sensitivities. The temperature sensitive component and the pH sensitive component inside the microgels have little interference with each other. The rheological properties of the concentrated PNIPAM /PAA IPN microgel dispersions as a function of temperature at pH 4. 0 or 7. 0 were investigated by viscometer,and the results displayed that only at pH 7. 0 the dispersions presented thermoreversible thickening behavior. Then the PNIPAM /PAA fibers were prepared by self-assembly of the PNIPAM /PAA IPN microgels in the ice-crystal templates formed by unidirectional liquid nitrogen freezing method. Field emission scanning electron microscopy（ FESEM） images indicate that the PNIPAM /PAA fibers are rounded,randomly orientated and interweaved.     

Reversible phase transitions in polymer gels induced by radiation forces

Many polymer gels undergo reversible, discontinuous volume changes in response to changes in the balance between repulsive intermolecular forces that act to expand the polymer network and attractive forces that act to shrink it. Repulsive forces are usually electrostatic or hydrophobic in nature, whereas attraction is mediated by hydrogen bonding or van der Waals interactions. The competition between these counteracting forces, and hence the gel volume, can thus be controlled by subtle changes in parameters such as pH (ref. 4), temperature, solvent composition or gel composition. Here we describe a more direct influence on this balance of forces, by showing that the radiation force generated by a focused laser beam induces reversible shrinkage in polymer gels. Control experiments confirm that the laser-induced volume phase transitions are due to radiation forces, rather than local heating, modifying the weak interactions in the gels, in agreement with previous observations of light-induced chain association in polymer solutions. We find that, owing to shear-relaxation processes, gel shrinkage occurs up to several tens of micrometres away from the irradiation spot, raising the prospect that the combination of stimuli-responsive polymer gels and laser light might lead to new gel-based systems for applications such as actuating or sensing.     

Synthesis of Cu–TiO2/CuS p-n heterojunction via in situ sulfidation for highly efficient photocatalytic NO removal

Cu doped TiO₂/CuS (Cu–TiO₂/CuS) p-n heterojunction was synthesized via in situ sulfidation method for efficient photocatalytic removal of NO at ppb-level. The results show that optimized Cu–TiO₂/CuS heterojunction possessed a maximum efficiency of 85% for the removal of NO under visible light irradiation, which was approximately 8.5, 4.3 and 1.2 times that of CuS, TiO₂ and Cu–TiO₂, respectively. The improved photocatalytic performance is attributed to the enhancement of visible light absorption and charge carrier separation induced by the construction of p-n heterojunction. Meanwhile, the p-n heterojunction charge transfer mechanism of Cu–TiO₂/CuS was verified by systematic investigations. The appropriate band structures of the two components and the internal electric field formed at the interface of the heterojunction were two factors for this charge transfer mechanism. Furthermore, the role of active species in NO removal was explored, and the corresponding mechanism for NO removal of the heterojunction was proposed. This work provides a promising approach for the synthesis of heterojunction photocatalysts and facilitates the application of photocatalysts in sustainable and efficient pollutant removal.     

四磺基铜酞菁共振光散射法测定人血清白蛋白

研究了四磺基铜酞菁与人血清白蛋白作用的共振光散射光谱，pH=1.0～3.0的范围内，人血清白蛋白的加入导致四磺基铜酞菁共振散射的增强，在407nm处存在一共振光散射强峰，其强度增加值与人血清白蛋白的浓度呈线性关系，据此建立了一种用共振光散射光谱测定人血清白蛋白的方法，该方法的线性范围为0～17mg/L，检出限为0.050mg/L(n=6，RSD为1.8%）。     

新型的二维铅配位聚合物Pb(dpq)(bdic)的合成、晶体结构及荧光性质

利用水热法合成了一种新型二维配位聚合物Pb(dpq)(bdic)(dpq=二-吡啶-(3,2-d:2′,3′-f)-二氮萘,H_2bdic=丁二酸).通过元素分析、IR、单晶X射线衍射对配合物的结构进行了表征.结果表明:该配合物属于三斜晶系,P-1空间群;晶胞参数a=0.697 8(5) nm,b=0.868 9(6) nm,c=1.395 0(10) nm,α=100.995(8)°,β=100.164(8)°,γ=101.649(8)°,Z=2,V=0.792 6(10) nm~3,R_1=0.084 5,wR_2=0.210 1.标题配合物有较好的热稳定性.此外,该固态配合物在室温下表现出绿色的荧光性质.     

有机包覆对磁性聚乳酸复合材料力学和介电性能的影响

合成了磁性纳米Fe_3O_4粒子,并通过有机包覆制备了磁性复合微球,进而分别以铁粒子和微球为填充相制备了两种磁性聚乳酸复合材料,研究比较了不同复合材料的力学性能、结晶,性能及介电性能,探讨了有机包覆对复合材料微观相态及界面特征的影响.结果发现,有机包覆可提高无机铁粒子与聚合物基体的相容性,使得复合材料的韧性大幅提高,同时有机包覆使得无机粒子与聚乳酸分子之间存在强相互作用,从而减少了界面缺陷,改善了复合材料的介电性能.     

Construction of Supramolecular Architectures via Self-assembly

1 Results In this paper we report supramolecular polymeric nano networks formed by the molecular-recognition-directed self-assembly between a calix[5]arene and C60[1]. Covalently-linked double-calix[5]arenes take up C60 into their cavities[2]. This complementary interaction creates a strong non-covalent bonding; thus,the iterative self-assembly between dumbbell fullerene 1 and ditopic host 2 can produce the supramolecular polymer networks (See Fig.1).