碳笼烯的高分子化──苯乙烯－烯丙基胺共聚物与C_（60）的反应

碳笼烯的高分子化──苯乙烯－烯丙基胺共聚物与Ｃ＿（６０）的反应田慧洁，周锡煌，李福绵（北京大学化学系北京１００８７１）关键词碳笼烯的高分子化，Ｃ＿（６０），苯乙烯－烯两基胺共聚物碳笼烯（ｆｕｌｌｅｒｅｎｅ）是因其具有特殊的功能性质ｍ而颇受青睐的球簇分...     

碳笼烯-60对Ziegler-Nata催化剂催化苯乙烯聚合的影响

碳笼烯 ６０对Ｚｉｅｇｌｅｒ Ｎａｔａ催化剂催化苯乙烯聚合的影响洪瀚周锡煌李福绵（北京大学化学学院北京１００８７１）关键词碳笼烯 ６０（Ｃ６０），Ｚｉｅｇｌｅｒ Ｎａｔａ催化剂，配位聚合，等规聚苯乙烯Ｃ６０独特的球笼形空间结构和电子结构决定了其有许...     

碳笼烯(C60)在高分子领域中的研究进展

综述了碳笼烯（Ｃ６０）在高分子领域中的研究进展,包括碳笼烯的高分子化、与聚合物形成电荷转移复合物以及作为催化聚合反应的催化剂。     

球笼烯（C_（60）／C_（70）载体钕系催化丁二烯聚合的研究

球笼烯（Ｃ_（６０）／Ｃ_（７０）载体钕系催化丁二烯聚合的研究赵春英，陈滇宝，仲崇祺，董文寰，徐玲，唐学明（青岛化工学院高分子材料系青岛２６６０４２）杨海滨，李明辉，邹广田（吉林大学超硬材料国家重点实验室长春１３００２３）关键词球碳载体钕系催化剂，聚丁...     

球笼烯（C_（60）／C_（70）载体钕系催化丁二烯聚合的研究

球笼烯（Ｃ_（６０）／Ｃ_（７０）载体钕系催化丁二烯聚合的研究赵春英，陈滇宝，仲崇祺，董文寰，徐玲，唐学明（青岛化工学院高分子材料系青岛２６６０４２）杨海滨，李明辉，邹广田（吉林大学超硬材料国家重点实验室长春１３００２３）关键词球碳载体钕系催化剂，聚丁...     

碳笼烯(C_(60)/C_(70))载体钕系催化异戊二烯聚合

较系统地研究了Ｎｄ（ｎａｐｈ）３ Ｃ６０Ｘ Ａｌ（ｉ Ｂｕ）３碳笼烯钕系催化异戊二烯配位聚合的反应规律，并测定了聚合物分子量、分子量分布和微观结构．碳笼烯钕系为一均相体系．Ａｌ／Ｎｄ及Ｃｌ／Ｎｄ摩尔比对催化体系的活性、聚合物分子量都有较大的影响，活性中心的形成有很好的时间和温度的稳定性．ＰＩｐ的特性粘数［η］在２左右，分子量分布ＭＷ／Ｍｎ在３左右，均小于传统钕催化体系．ＰＩｐ的顺式含量大于９７％．     

碳笼烯C32和碳笼烷C32H32的量子化学研究

用量子化学计算方法ＭＮＤＯ和ＡＭ１研究了具有Ｏｈ对称性的碳笼烯Ｃ３２和碳笼烷Ｃ３２Ｈ３２的几何结构和电子结构及其稳定性，ＡＭ１水平下，评论Ｃ３２的基态性质和分子振动。     

金属碳笼

概要地综述了碳笼物理化学的新进展：金属碳笼（Ｍｅｔａｌｌｏ－Ｃａｒｂｏｈｅｄｒｅｎｅｓ），包括金属碳笼在实验上的发现、结构和稳定性、生长机理、化学反应性质等。     

水溶性铑－膦配合物催化1－十二碳烯常压氢甲酰化反应研究

本文研究了水溶性铑配合物ＲｈＣｌ（ＣＯ）（ＴＰＰＴＳ）２在常压（ＣＯ：Ｈ２＝１：１）条件下对１－十二碳烯氢甲酰化反应的催化性能，并对催化剂浓度、表面活性剂浓度、溶液ｐＨ值、膦铑比、溶剂等因素的变化对催化活性的影响作了考察．结果表明，表面活性剂（ＣＴＡＢ）的加入，可以在反应体系中形成胶束．加速有机相和水相间的传质速度，从而提高催化转化速度．在反应温度（８０℃）下，ＣＴＡＢ的临界胶束浓度（ＣＭＣ）较室温下高．达到最佳催化活性的ｐＨ范围为７～９，［Ｐ］／［Ｒｈ］比为１６，而有机溶剂的加入则使转化数降低．     

碳笼（C_（60）／C_（70））载体钕系催化聚合丁二烯的研究 Ⅱ．聚合物分子量及其微观结构

碳笼（Ｃ_（６０）／Ｃ_（７０））载体钕系催化聚合丁二烯的研究Ⅱ．聚合物分子量及其微观结构赵春英，陈滇宝，仲崇祺，柳润平，徐玲，唐学明（青岛化工学院高分子材料系青岛２６６０４２）关键词球笼钕催化剂，聚丁二烯，分子量及其分布，微观结构目前，稀土催化双烯烃...     

氯化钠相转变 K-型卡拉胶/聚 N-异丙基丙烯酰胺共混凝胶的辐射合成及性质研究

用γ辐射技术合成了K 型卡拉胶 (KC)与聚N 异丙基丙烯酰胺共混凝胶 (Blendgels) .合成产物透明 ,有弹性和较好的力学强度 .对不同条件下共混凝胶性能的测定结果表明 ,所形成的共混凝胶有明显的氯化钠相转变性质 ,也保持了聚N 异丙基丙烯酰胺 (PNIPAM)特有的温度敏感性 (LCST为 34℃ )     

New Route to Smart Core‐Shell Polymeric Microgels: Synthesis and Properties

Summary: A new method has been developed to prepare smart polymeric microgels that consist of well‐defined temperature‐sensitive cores with pH‐sensitive shells. The microgels were obtained directly from aqueous graft copolymerizations of N‐isopropylacrylamide and N,N‐methylenebisacrylamide from water‐soluble polymers containing amino groups such as poly(ethyleneimine) and chitosan. The gel diameters ranged from 300 to 400 nm. The unique core‐shell nanostructures, which had narrow size distributions, exhibited tuneable responses to pH and temperature.

Transmission electron micrograph of the poly(N‐isopropylacrylamide)/chitosan core‐shell microgels.     

Thermal actuation of hydrogels from PNIPAm,alginate, and carbon nanofibres

Composite ionic‐covalent entanglement (ICE) hydrogel networks were prepared from poly(N‐isopropylacrylamide), alginate, and carbon nanofibres. An optimised triple network hydrogel with 86% water content exhibited a compressive strength of 3.0 ± 0.1 MPa and 66 ± 13 mS/cm electrical conductivity. Thermal actuation was shown to have a shorter response time for gels containing nanofibres, compared to those which did not and hydrogel samples more than halved in volume within 1 minute when placed in a 60 °C water bath. Controlled dye release was demonstrated as a potential application and used to further quantify thermal actuation over short times. Joule heating techniques were used to electronically actuate the hydrogel samples, removing the traditional requirements for immersion in a temperature controlled liquid. It is expected that devices based on these materials will find potential applications in soft robotics and micro fluidics. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 46–52     

温度及pH敏感N-异丙基丙烯酰胺/β-环糊精水凝胶的合成与性能研究

用顺丁烯二酸酐 (MAH)对具有分子包结能力的 β 环糊精 (β CD)进行化学改性 ,合成出了丁烯二酸单酯化 β CD单体 (MAH β CD) .通过氧化还原自由基引发MAH β CD与N 异丙基丙烯酰胺 (NIPA)聚合 ,合成出含 β CD结构单元的新型水凝胶 .用核磁共振、红外光谱及元素分析对MAH β CD单体及共聚物的结构和组成进行了表征 .溶胀研究结果表明 ,该水凝胶具有较好的pH、温度及离子强度敏感性 ;并且水凝胶在较高羧基(—COOH)含量和弱碱环境中 ,仍能表现出明显的温敏性     

Synthesis and swelling behavior of comb‐type grafted hydrogels by reversible addition–fragmentation chain transfer polymerization

The comb‐type grafted hydrogels poly(N‐isopropylacrylamide)‐g‐poly(N‐isopropylacrylamide) (PNIPAM‐g‐PNIPAM) and poly(acrylic acid)‐g‐poly(N‐isopropylacrylamide) (PAAc‐g‐PNIPAM) were prepared by reversible addition–fragmentation chain transfer polymerization. A macromolecular chain‐transfer agent was prepared first. Then, hydrogels were obtained by a reaction with a comonomer (N‐isopropylacrylamide or acrylic acid) in the presence of N,N‐methylenebisacrylamide as a crosslinker. The equilibrium swelling ratios and the swelling and deswelling kinetics of PNIPAM‐g‐PNIPAM were measured. The effects of the chain length and amount on the swelling behavior were investigated. The deswelling mechanism was illustrated. Meanwhile, the PAAc‐g‐PNIPAM hydrogel was used to confirm the versatility of this novel method. It was prepared in an alcoholic medium, whereas hydrogen‐bonding complexes formed in 1,4‐dioxane, which was chosen as the reaction medium for the PNIPAM‐g‐PNIPAM hydrogel. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2615–2624, 2005     

Recognition‐Mediated Hydrogel Swelling Controlled by Interaction with a Negative Thermoresponsive LCST Polymer

Most polymeric thermoresponsive hydrogels contract upon heating beyond the lower critical solution temperature (LCST) of the polymers used. Herein, we report a supramolecular hydrogel system that shows the opposite temperature dependence. When the non‐thermosesponsive hydrogel NaphtGel, containing dialkoxynaphthalene guest molecules, becomes complexed with the tetra cationic macrocyclic host CBPQT⁴⁺, swelling occurred as a result of host–guest complex formation leading to charge repulsion between the host units, as well as an osmotic contribution of chloride counter‐ions embedded in the network. The immersion of NaphtGel in a solution of poly(N‐isopropylacrylamide) with tetrathiafulvalene (TTF) end groups complexed with CBPQT⁴⁺ induced positive thermoresponsive behaviour. The LCST‐induced dethreading of the polymer‐based pseudorotaxane upon heating led to transfer of the CBPQT⁴⁺ host and a concomitant swelling of NaphtGel. Subsequent cooling led to reformation of the TTF‐based host–guest complexes in solution and contraction of the hydrogel.     

Positron annihilation studies on radiation‐crosslinked poly(N‐isopropylacrylamide) hydrogels

The temperature‐sensitive poly(N‐isopropylacrylamide) hydrogels, prepared by γ and electron‐beam (EB) irradiation, were studied using positron annihilation lifetime spectroscopy (PALS). The effect of water content in the hydrogel on the ortho‐positronium (o‐Ps) lifetime and intensity was investigated. The observed positronium lifetime suggests microstructural differences between γ‐ and EB‐synthesized hydrogels. The distribution in positronium lifetime indicates nonhomogeneity in the distribution of free‐volume holes in EB‐synthesized hydrogels. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3462–3466, 2000     

温度敏感聚(N-异丙基丙烯酰胺)/聚(乙烯醇)水凝胶的制备及性能研究

聚 (N -异丙基丙烯酰胺 ) (PNIPA)水凝胶具有温度敏感性 ,其在 33℃左右有一个相转变温度或较低临界溶解温度 (L CST) [1,2 ] .当外界温度低于 LCST时 ,PNIPA水凝胶吸水溶胀 ;而当外界温度高于L CST时 ,PNIPA水凝胶剧烈收缩失水 ,发生相分离 .这种相分离特性应用于药物的控制释放 [3] .固定化酶[4 ] 和循环吸收剂 [5] 等领域 .然而 ,通常的 PNIPA水凝胶是通过化学键交联而成的三维网络聚合物 ,很难发生解体或进行生物降解 ,其在某些特定场合 (如药物的体内释放等 )受到一定限制 .聚乙烯醇 (PVA)的亲水性和生物相容性较好 ,是…     

Doubly photoresponsive and water‐soluble block copolymers: Synthesis and thermosensitivity

We report the synthesis and investigation of a new type of photoresponsive block copolymers (BCPs). They were designed to comprise two water‐soluble polymers containing two different photoisomerizable moieties (either azobenzene and spiropyran or two different azobenzenes), with the two constituting blocks that, when separated, exhibit a lower critical solution temperature (LCST) in water and can shift their LCST in opposite directions upon photoisomerization (decrease of LCST for one polymer and increase for the other). A variety of such doubly photoresponsive BCPs were synthesized using either azobenzene‐ or spiropyran‐containing poly(N,N‐dimethylacrylamide) (PDMA), poly(N‐isopropylacrylamide) (PNIPAM) and poly[methoxydi(ethylene glycol) methacrylate] (PDEGMMA). Their thermal phase transition behaviors in aqueous solution before and after simultaneous photoreactions on the two blocks were investigated in comparison with their constituting blocks, by means of solution transmittance (turbidity) and variable‐temperature ¹H NMR measurements. The results show that BCPs displayed a single LCST whose shift upon two photoisomerizations appeared to be determined by the competing and opposing photoinduced effects on the two blocks. Moreover, optically controlling the relative photoisomerization degrees of trans azobenzene‐to‐cis azobenzene and spiropyran‐to‐merocyanine could be used to tune the LCST of BCP solution. This study demonstrates the potential of exploring a more complex photoreaction scheme to optically control the solution properties of water‐soluble thermosensitive BCPs. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4055–4066, 2010     

Synthesis,characterization, and evaluation of enzymatically degradable poly(N‐isopropylacrylamide‐co‐acrylic acid) hydrogels for colon‐specific drug delivery

The enzymatically degradable poly(N‐isopropylacrylamide‐co‐acrylic acid) hydrogels were prepared using 4,4^′‐bis(methacryloylamino)azobenzene (BMAAB) as the crosslinker. It was found that the incorporated N‐isopropylacrylamide (NIPAAm) monomer did not change the enzymatic degradation of hydrogel, but remarkably enhanced the loading of protein drug. The hydrogels exhibited a phase transition temperature between 4°C (refrigerator temperature) and 37°C (human body temperature). Bovine serum albumin (BSA) as a model drug was loaded into the hydrogels by soaking the gels in a pH 7.4 buffer solution at 4°C, where the hydrogel was in a swollen status. The high swelling of hydrogels at 4°C enhanced the loading of BSA (loading capability, ca. 144.5 mg BSA/g gel). The drug was released gradually in the pH 7.4 buffer solution at 37°C, where the hydrogel was in a shrunken state. In contrast, the enzymatic degradation of hydrogels resulted in complete release of BSA in pH 7.4 buffer solution containing the cecal suspension at 37°C (cumulative release: ca. 100 mg BSA/g gel after 4 days). Copyright © 2008 John Wiley & Sons, Ltd.