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1.
偶氮聚电解质的静电逐层自组装是实现偶氮聚合物功能性的重要手段,是制备诸如光存储材料、光开关材料和非线性光学材料等的新途径.因此,光响应性偶氮聚电解质的静电逐层自组装已引起了人们的广泛关注.静电逐层自组装通常在水溶液中进行,即通过基材在在水溶液中的交替浸渍和逐层  相似文献   

2.
研究了一种光响应偶氮聚电解质(PEAPE)在不同pH值条件下的自组装,重点讨论了pH值对静电逐层自组装以及对光响应性能的影响.研究表明,在所研究的pH范围内,pH值越低,越有利于生成吸光度高的自组装膜,对应的自组装膜厚度也越大.红外光谱分析表明,偶氮聚电解质在不同pH溶液中存在不同的电离情况.pH值越低,用于自组装的溶液中的聚合物链上的电荷数越少,链构象越卷曲.解释了不同pH值条件下自组装膜吸光度和厚度差别的原因.  相似文献   

3.
聚电解质层层自组装纳滤膜*   总被引:2,自引:0,他引:2  
层层自组装技术能够方便地对膜的微观结构和组成进行调控,已在制备复合型纳滤膜方面取得了迅速的发展。本文综述了近年来用于聚电解质层层自组装纳滤膜的制备方法,种类以及影响因素。介绍了静态层层交替沉积、压力驱动自组装和电场强化自组装等三种制备方法;归纳了均聚型、共聚型和有机/无机杂化型等三类用于层层自组装纳滤膜的聚电解质的特点;讨论了聚电解质的荷电性、电荷密度和电离程度等因素对其自组装膜分离性能的影响。总结了聚电解质自组装纳滤膜在水处理和有机溶剂中物质的分离等方面的应用。同时,对提高聚电解质自组装纳滤膜的组装效率,分离性能和发展方向提出了设想和建议。  相似文献   

4.
扼要论述了聚电解质自组装膜制备过程中电荷密度、驱动力及增长方式等对膜厚和膜结构影响的基本规律,着重介绍了近年来聚电解质自组装渗透气化膜和离子分离膜研究概况。对聚电解质自组装分离膜今后的研究工作提出了建议。  相似文献   

5.
扼要论述了聚电解质自组装膜制备过程中电荷密度、驱动力及增长方式等对膜厚和膜结构影响的基本规律,着重介绍了近年来聚电解质自组装渗透气化膜和离子分离膜研究概况。对聚电解质自组装分离膜今后的研究工作提出了建议。  相似文献   

6.
扼要论述了聚电解质自组装膜制备过程中电荷密度、驱动力及增长方式等对膜厚和膜结构影响的基本规律,着重介绍了近年来聚电解质自组装渗透气化膜和离子分离膜研究概况.对聚电解质自组装分离膜今后的研究工作提出了建议.  相似文献   

7.
用偏振紫外光谱研究了 4种带有不同端基的侧链型偶氮聚电解质静电逐层自组装膜中偶氮生色团的初始取向 .讨论了不同的端基对偶氮生色团在自组装膜中初始取向的影响 .进一步探讨了偶氮聚电解质自组装膜的结构特点 .研究表明 ,侧链型偶氮聚电解质自组装膜中偶氮生色团普遍存在一定程度的沿面取向 .偶氮生色团所带端基的类型对其在自组装膜中的取向程度有较大的影响 ,这主要取决于偶氮生色团与聚阳离子基底的电荷相互作用和极性相互作用等 .对偶氮生色团在水溶液中能形成H 聚集体的自组装膜来说 ,H 聚集体对生色团取向也有一定的影响 .结果表明 ,在制备需控制生色团取向性的自组装膜时 ,要考虑生色团上的不同端基对取向的影响  相似文献   

8.
带相反电荷的聚电解质的自组装,由于方法简单,对环境无污染,近年来备受重视[1~8]。以重氮树脂为聚正离子的聚电解质复合物,由于光照时重氮基分解,致使复合物的离子键转为共价键,溶解性发生重大改变,从而以重氮树脂为聚正离子的聚电解质复合物是一种新的光成像体系[9,10]。张希等用重氮树脂与聚苯乙烯磺酸钠成功地制备了对极性溶剂稳定的自组装超薄膜[11]。本文用羧基负离子聚电解质与重氮树脂进行自组装,并研究该自组装膜的光,热反应。羧基负离子聚电解质与重氮树脂的自组装超薄膜,文献上报道较少。1 聚丙烯酸钠…  相似文献   

9.
智能响应与自修复的层层组装聚合物膜   总被引:2,自引:0,他引:2  
陈栋栋  马莹  孙俊奇 《高分子学报》2012,(10):1047-1054
具有刺激响应性和自修复功能的复合膜是重要的仿生功能膜材料.层层组装是一种基于物质交替沉积而制备复合膜的方法,可以实现膜的结构和组成的精确调控.通过结构与组成的精确调控,基于层层组装制备的微米厚度的聚电解质厚膜可以对外界刺激产生快速有效的响应,因而在制备智能仿生膜材料方面具有重要的价值.本文以作者的研究结果为基础,阐明了基于层层组装的聚电解质膜可以成功用于制备湿度和温度响应的双结构自支持膜和高效的促动器及行走机器,以及自修复超疏水和划痕修复聚电解质膜.  相似文献   

10.
多孔聚电解质材料协同结合了静电与高比表面积双重特点,在能源、环境、生物医药等领域具有重要的应用前景,近年来发展迅速。由于其荷电性与亲水性,多孔聚电解质的制备方法与传统中性多孔高分子有所不同,也表现出独特的应用属性。本文概括总结了层层组装、聚电解质嵌段聚合物自组装、反离子交换、劣溶剂静电络合等制备多孔聚电解质材料的方法,介绍了多孔聚电解质在绿色环境、清洁能源、生物医药和催化剂等领域的应用,并简单展望了未来的研究机遇。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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