DNA薄膜的制备及性质研究进展

从化学的角度概述了近年来用分子组装技术对DNA分子的组装，DNA薄膜化及其性质研究的进展。     

纳米二苯甲酰甲烷铕配合物的制备和表征

以聚乙烯吡咯烷酮为表面活性剂,在无水乙醇中制备了纳米二苯甲酰甲烷铕配合物Eu(DBM)3,对其进行了红外光谱(IR)、透射电镜(TEM)、X-射线衍射(XRD)、荧光光谱(FS)等表征。结果表明,配合物在聚乙烯吡咯烷酮中呈纳米颗粒分散,分散尺度在5～30Nm之间,与普通二苯甲酰甲烷铕配合物相比,其主要荧光发射峰强度较高;后者在675．6、702．6、719．3、740．5nm处的小峰消失,612．9nm峰红移至611．8nm。     

保鲜膜的是与非

从媒体关注的保鲜膜安全问题入手,对保鲜膜的化学成分,聚氯乙烯（PVC）保鲜膜中增塑剂的危害以及危害成分的测定做一简要的介绍,以期使读者对保鲜膜有正确、全面的认识。     

Cd-Te薄膜的制备及表征

Cd-Te是一种重要的光电材料,它的禁带宽度为1·45eV,光吸收系数很大,厚度1μm的薄膜足以吸收能量大于CdTe禁带宽度的光所具有能量的99%[1],因此它是一种十分理想的太阳电池材料。Cd-Te薄膜制备的方法有喷涂法、电沉积法、丝网印刷法、分子束外延法、化学气相沉积法、近空间升华     

聚氯乙烯(PVC)的阻燃与抑烟研究进展

综述了无机阻燃剂对聚氯乙烯(PVC)阻燃和抑烟性能的影响,对阻燃剂和抑烟剂作了分类介绍。重点介绍了金属氢氧化物、锑系、硼系、锡系、红磷和含锌化合物等阻燃剂,对各体系进行了比较,指出各体系的阻燃机理、添加量、以及常用的改进方法。介绍了水滑石、沸石、蒙脱土等新型无机阻燃剂,这些阻燃剂在PVC的应用中具有潜在的优势,具有添加量少、阻燃效率高的优点。阻燃剂与抑烟剂的超细化、活性化、复合化是PVC阻燃与抑烟改性的发展方向。     

聚氯乙烯／热塑性弹性体共混增韧的研究进展

聚氯乙烯（PVC）是一种性能优良,价格低廉的通用树脂,但其脆性大、热稳定性差、加工性能不佳等,需要进行改性。通过用热塑性弹性体（TPE）对PVC进行共混增韧改性,可得到高性能的PVC复合材料。共混改性为PVC增韧改性的最简单易行的有效方法。本文概述了聚氯乙烯／热塑性弹性体共混体系的种类和制备方法,同时对影响热塑性弹性体...     

溶液电沉积法制备苝酰亚胺类化合物薄膜

溶液电沉积法是一种具有沉积时间短,可以常温沉积以及沉积物在基底上附着力高等优点的薄膜制备方法.本文用水合肼增溶苝酰亚胺类化合物(PTCDI)的方法制备了可用于溶液电沉积的苝酰亚胺类化合物溶液.用紫外-可见分光光度法(UV-Vis)对溶解的过程进行了表征,并用顺磁共振(ESR)验证了水合肼对PTCDI的增溶过程实质上是化学反应过程.在制备苝酰亚胺类化合物溶液的基础上,采用阳极电沉积法在ITO导电玻璃上沉积出了薄膜.采用UV-Vis,扫描电镜(SEM)和X射线衍射仪(XRD)对薄膜进行了表征,证实得到了表面较为平整、具有可控结晶结构和形貌的PTCDI薄膜以及具有较宽光谱吸收范围的复合薄膜.     

CMC系列高分子表面活性剂的胶束形态

高分子表面活性剂分子量高 ,分子中兼具亲水和疏水链段 ,在选择性溶剂水中同小分子表面活性剂一样 ,可形成疏水链段为核心、亲水链段为外壳的胶束结构 ,但高分子量又使其表现出许多不同于低分子表面活性剂的形态特征 ,如胶束的多种形态、尺寸分布多分散性等等 ,而这些形态特征对高分子表面活性剂的界面活性、增粘、乳化等性能有决定性的影响．结构规整的嵌段或接枝共聚物在选择性溶剂中的分子聚集形态已有研究 ［１,２］,亲水亲油性的高分子表面活性剂在水溶液中由于结构复杂、水溶液中氢键作用及静电作用力等因素造成的困难 ,因而研究较少…     

电荷转移配合物薄膜制备方法和结构表征的研究进展

回顾了与Langmuir-Blodgett(LB)技术有关的电荷转移配合物薄膜的各类制备方法、结构表征结果,并比较了制备方法对薄膜结构的影响.例如,将LB膜C18H37TCNQ(电子受体)插入到电子给体3,3’,5,5’-tetramethylbenzidine(四甲基联苯胺, TMB)的石油醚溶液中进行掺杂,制备了TMB•C18H37TCNQ电荷转移配合物薄膜.在这种薄膜中,给体和受体以面对面的方式堆积,两者的环平面与基片平面接近垂直.而采用硬脂酸和C18H37TCNQ的混合LB膜通过类似的掺杂路线制备的TMB•C18H37TCNQ薄膜的结构发生了一些变化,例如其长的烃链C18H37更加垂直于基片平面.通过比较以前的各种实验结果可以得出以下结论:电荷转移配合物的结构可以通过制备方法得到控制.     

Au/ZnO/TiO_2复合薄膜的制备及光电转换性质

以含有Au和ZnO纳米颗粒的氢氧化钛溶胶作为成膜液,通过浸渍-提拉及灼烧处理在导电玻璃表面制备Au/ZnO/TiO2复合薄膜.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)等方法对所得产物进行表征.结果表明,Au和ZnO纳米颗粒均匀地分布在多孔TiO2薄膜上,通过TiO2、ZnO和Au三组分的协同效应促进了光吸收和电荷分离,使Au/ZnO/TiO2复合薄膜具有较好的光电转换性质,可用作太阳能电池材料.     

Investigation at the chain segmental level of the miscibility of poly(vinyl chloride)/atactic poly(methyl methacrylate) blends

We employed high‐resolution ¹³C cross‐polarization/magic‐angle‐spinning/dipolar‐decoupling NMR spectroscopy to investigate the miscibility and phase behavior of poly(vinyl chloride) (PVC)/poly(methyl methacrylate) (PMMA) blends. The spin–lattice relaxation times of protons in both the laboratory and rotating frames [T₁(H) and T_1ρ(H), respectively] were indirectly measured through ¹³C resonances. The T₁(H) results indicate that the blends are homogeneous, at least on a scale of 200–300 Å, confirming the miscibility of the system from a differential scanning calorimetry study in terms of the replacement of the glass‐transition‐temperature feature. The single decay and composition‐dependent T_1ρ(H) values for each blend further demonstrate that the spin diffusion among all protons in the blends averages out the whole relaxation process; therefore, the blends are homogeneous on a scale of 18–20 Å. The microcrystallinity of PVC disappears upon blending with PMMA, indicating intimate mixing of the two polymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2390–2396, 2001     

Preparation and characterization of PVC/PANI conductive composite with extremely low percolation threshold

Aniline was polymerized in the presence of poly(vinyl chloride) (PVC) powders in hydrochloric acid to in situ prepare poly(vinyl chloride)/polyaniline (PVC/PANI) composite particles. UV‐vis spectra and FT‐IR spectra indicate PANI in PVC/PANI composite particles possessed a higher oxidation state with decreased aniline content in reactants. Both conductivity and impact strength of the dodecylbenzenesulfonic acid (DBSA) doped PANI composites (PVC/PANI‐DBSA), which were compression molded from the in situ prepared PVC/PANI particles, increase with the pressing temperature and decrease with the increase of DBSA doped PANI (PANI‐DBSA) loading. An excellent electric conductivity of 5.06 × 10^?2 S/cm and impact strength of 0.518 KJ/m² could be achieved for the in situ synthesized and subsequently compression molded composite. Copyright © 2004 John Wiley & Sons, Ltd.     

苯乙烯/聚氯乙烯接枝膜的热稳定性研究

用自由基悬浮聚合法合成了苯乙烯 /聚氯乙烯接枝膜 ,并对产物热处理 ,然后进行紫外 -可见光谱 ,红外光谱 ,热失重分析。结果表明接枝苯乙烯后的聚氯乙烯膜热稳定性得到了提高。同时 ,讨论了热稳定性机理。     

Effects of Epoxidation Content of ENR on Morphology and Mechanical Properties of Natural Rubber Blended PVC

This research work has concerned a study on toughness of PVC/natural rubber (NR) blends compatibilized with epoxidized natural rubber (ENR). The aim of this work was to investigate the effect of degree of epoxidation on morphology and mechanical properties of the blends. Epoxidized natural rubber with a variety of epoxidation contents were prepared by reacting the NR latex with formic acid and hydrogen peroxide at various chemical contents. Chemical structure and epoxidation content of epoxidized natural rubber were evaluated by FTIR and ¹H-NMR techniques. After that, three grades of ENR with epoxidation contents of 15, 25 and 42 % (by mole) were further used for blending with PVC and NR in an internal mixer at 60 rpm and at 170 °C. From tensile and impact tests, it was found that tensile elongation and impact strength of the materials remarkably increased with degree of epoxidation. On the other hand, tensile strength and modulus of the materials rarely changed with the epoxidation content. An increase in toughness of the blends with epoxidation content was related to a better molecular interaction between PVC and ENR as suggested by torque-time curves of the materials.     

Formation of crystalline inclusion compounds of poly (vinyl chloride) of different stereoregularity with γ-cyclodextrin

This work reports the formation and detailed characterization of the γ-cyclodextrin (γ-CD) inclusion compounds (ICs) formed with two poly (vinyl chloride) samples with different isotactic content. The ICs were characterized by X-ray diffraction, solid state ¹³C-NMR, solution ¹H-NMR, FT-infrared, differential scanning calorimetry, and thermogravimetric analysis. Experimental evidence of the inclusion of the guest polymer chains into the narrow channels created by the γ-CD crystalline host lattice has been obtained. Examination of coalesced poly (vinyl chlorides) (PVCs) obtained after the host γ-CD is removed reveals different characteristics specifically for the coalesced PVC sample with higher isotactic content. An increase in T_g was observed by DSC for this PVC. To the contrary, the T_g of the coalesced PVC sample with lower isotactic content is almost the same as that of the as-synthesized sample. Thermogravimetric analysis indicated that coalesced PVC with higher isotactic content acquires a degree of stabilization after modification by threading into and being extracted from its γ-CD IC. The results suggest that an irreversible conformational change takes place when PVC forms ICs with a solid host lattice like γ-CD. The PVC molecules extend and reorganize into a more stable conformation in the IC, consequently improving the properties of the coalesced sample. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2503–2513, 2007     

PVC硬脂酸轻稀土热稳定剂的复配与应用研究

为了进一步研发性价比高且"无铅化"的稀土复合热稳定剂,研究了系列硬脂酸轻稀土盐(镧/铈/镨/钕/钐/铕/混合)与其他常用PVC热稳定(助)剂的复配效果。通过刚果红试纸法、红外光谱分析(FT-IR)、转矩流变仪等探究了复合热稳定剂对PVC性能的影响。结果表明:复合热稳定剂配方为硬脂酸轻稀土盐0.7~1.0份、硬脂酸锌0.8~0.9份、β-二酮0.3~0.6份和季戊四醇0.8~0.9份。将3份复合热稳定剂添加到100份PVC树脂中,静态及动态热稳定时间延长至100和35 min左右;动态热稳定性能和力学性能优于市售钙锌热稳定剂,与市售铅盐较接近。红外光谱分析表明复合热稳定剂可在加热初期减缓PVC氧化降解,较好地抑制初期着色,对PVC性能影响顺序为:镧组钕组混合组铈组镨组钐组铕组。     

Molecular orientation behavior of poly(vinyl chloride) as influenced by the nanoparticles and plasticizer during uniaxial film stretching in the rubbery stage

The structural evolution during uniaxial stretching of poly(vinyl chloride) films was studied using our real time spectral birefringence stretching machine. The effect of clay loading and the amount of plasticizer as well as the rate effects on the birefringence development and true mechanical response are presented with a final model summarizing the molecular phenomena during stretching. Mechano‐optical studies revealed that birefringence correlated with mechanical response (stress, strain, work) nonlinearly. This was primarily attributed to the preexisting strong network of largely amorphous chains connected via small crystallites that act as physical crosslinking points. These crystallites are not easily destroyed during the high‐speed stretching process as evidenced from the birefringence–true strain curves along with the X‐ray crystallinity measurements. At high speeds, the amorphous chains do not have enough time to relax and hence attain higher orientation levels. The crystallites, however, orient more efficiently when stretched at slow speeds. Apparently, some relaxation of the surrounding amorphous chains helps rotate the crystallites in the stretching direction. Overall birefringence is higher at high stretching speeds for a given true strain value. When the nanoparticles are incorporated, the orientation levels are increased significantly for both the crystalline and amorphous phases. Nanoplatelets increase the continuity of the network because they have strong interaction with the amorphous chains and/or crystallites. This in turn helps transfer the local stresses to the attached chains and increase the orientation levels of the chains. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 724–742, 2005     

PVB存在下PVC化学法脱氯化氢的研究

ＰＶＢ存在下ＰＶＣ化学法脱氯化氢的研究刘恒＊李大成陈朝珍（四川联合大学化工学院成都６１００６５）关键词聚氯乙烯，脱氯化氢，聚乙烯醇缩丁醛１９９６－０９－０８收稿，１９９７－０５－２６修回国家教育委员会留学归国人员资助费资助课题近年来在ＰＶＣ脱氯化氢制...     

Poly(vinyl chloride) on the way from the 19th century to the 21st century

Despite all the technical and economic problems and the public discussions on the environmental dangers and hazards of chlorine chemistry, poly(vinyl chloride) (PVC) is the second most produced plastic (with a worldwide capacity of about 31 million tons), placing after polyolefins and before styrene polymers. Presently, PVC production worldwide is growing at a rate of more than 4% per year. The application of PVC was first described in a patent in 1913, but only after 1930 did a sustained interest in PVC arise in several industrial laboratories. The most remarkable milestones in PVC history and their importance to the development of macromolecular chemistry are briefly described, and some present PVC research and industrial applications, with respect to polymerization, stabilization, bulk property modification, and chemical and material recycling of PVC waste, are discussed. Some actual selected topics include the emulsion polymerization of vinyl chloride with polymeric surfactants and controlled free-radical polymerization with nitroxyls, whereas ionic and metal organic initiators have not found any technical applications. Chemical reactions offer many possibilities for the modification of PVC, but they have been not used on a technical scale yet. Much work has been done on stabilization with nontoxic or metal-free systems. The bulk properties of PVC can be influenced by impact modification through the addition of graft copolymers or by blending with other polymers. Also presented are some problems and recent developments in PVC recycling. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 578–586, 2004     

改性聚氯乙烯絮凝剂的合成及其性能的研究

采用乙醇胺为亲核试剂对聚氯乙烯进行改性,控制胺化反应条件可以得到不同氮含量的产物.确定了最佳反应条件：温度80℃,PVC结构单元与乙醇胺的摩尔比1/1,反应时间小于36h,反应压力2.8MPa;用红外光谱表征了产物的结构、用元素分析测定了产物中N、H、C、Cl的含量;以ω=0.03的硅藻土水悬浮液模拟污水,考察了产物的絮凝性能.