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1.
N—[1-(2-吡咯烷酮基)甲基]丙烯酰胺类的聚合及其水凝胶于淑艳,李福绵(北京大学化学系,北京,100871)关键词N-[1-(2-吡咯烷酮基)甲基]丙烯酸胺、氧化-还原引发体系、超高分子量、平衡吸水率N一【l一(2一毗咯烷酮基)甲基]丙烯酸胺(P...  相似文献   

2.
由含吡咯烷酮基丙烯酸酯类所得水凝胶的性质   总被引:1,自引:1,他引:1  
由含吡咯烷酮基丙烯酸酯类所得水凝胶的性质于淑艳,潘捷,李旺金,李福绵(北京大学化学系北京100871)关键词丙烯酸2-N-吡咯烷酮基乙酯,甲基丙烯酸2-N-吡咯烷酮基乙酯,水凝胶,平衡吸水率,释放行为水凝胶作为生物材料的一个重要分支而备受瞩目,尤其是...  相似文献   

3.
含吡咯烷酮基的衣康酸酯类聚合物不同酯基对其若干性质的影响潘怀忠阎雁唐莉吴志强李福绵(北京大学化学学院北京100871)关键词含吡咯烷酮基的衣康酸酯,折光指数,热性质,平衡吸水率吡咯烷酮基具有良好的亲水保湿性和生物相容性,将其引入聚合物具有其实际应用...  相似文献   

4.
以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)作引发剂引发交联聚乙烯醇(PVA)-戊二醛(GA)制备水凝胶聚合物电解质并组装成超级电容器.分别由红外光谱、交流阻抗、循环伏安与恒电流充放电曲线测定该凝胶聚合物电解质及超级电容器的电化学性能.结果表明,该聚合物电解质电导率可达1.23 mS/cm(室温).而且,以1.0 g AMPS引发0.05mL GA(5 %)与1.0 g PVA交联,制得的凝胶聚合物电解质超级电容器比电容可达139F/g,50次充放电后其值仍于80%以上.  相似文献   

5.
MgCO_3·3H_2O水热分解产物及其组成翟学良,周相廷,李美玲(河北师范大学化学系石家庄050016)关键词MgCO_3·3H_2O,Mg_5(CO_3)_4(OH)_2·8H_2O,Mg_5(CO_3)_4(OH)_2·5H_2O,水热分解,中间体MgCO_...  相似文献   

6.
聚乙烯吡咯烷酮存在时反相微乳液中水的状态    总被引:2,自引:0,他引:2  
运用傅立叶变换红外光谱(FTIR)研究不同分子量的聚乙烯吡咯烷酮(PVP)存在时,十二烷基甜菜碱(C12BE)/正庚烷/正戊醇/水(Ⅰ)及二(2-乙基)己基磺化琥珀酸钠(AOT)/正庚烷/水(Ⅱ)反相微乳液中水的存在状态.采用计算机分峰技术将微乳液中水分子的O-H伸缩振动进行曲线拟合,(Ⅰ)得到三个子峰,分别位于(3560±20)cm  相似文献   

7.
通过环氧氯丙烷活化(1,4) 2 氨基 2 脱氧 β D 葡萄糖(壳聚糖)制备免疫吸附剂,详细讨论了环氧氯丙烷活化过程的影响因素,确定了活化的最佳条件.活化(1,4) 2 氨基 2 脱氧β D 葡萄糖树脂对单克隆抗体的偶联率为176%,对含乙型肝炎表面抗原阳性血清的吸附实验表明,制备的免疫吸附剂能使阳性转为阴性,吸附率为44%.  相似文献   

8.
花尔并  杨频 《结构化学》1996,15(6):462-465
通过圆二色谱(CD)和吸收光谱研究了Cu(2+)对三螺旋poly(A:2I)的解旋行为,并从结构的角度分析了其解旋机理。结果表明:Cu(2+)通过与poly(A:2I)中的碱基的结合,破坏了Hoogsteen碱基对和Watson-Crick碱基对中的氢键,从而导致了三螺旋poly(A:2I)不可复性的解旋。  相似文献   

9.
2-乙基己基膦酸单(2-乙基己基)酯从盐酸溶液中萃取Ga(Ⅲ)的机理赵经贵,邢美君,刘宏(黑龙江大学化学系哈尔滨150080)关键词溶剂萃取,镓,乙基己基膦酸单(乙基己基)酯2-乙基己基膦酸单(2-乙基己基)酯(P507,EHP)在稀有元素、有色金属...  相似文献   

10.
利用一维和二维NMR技术,对含有手性膦配体的铂配合物cis-〔Pt(2-MBPAH)2Cl2〕(1),trans-〔Pt(2-MBPAH)2Cl2〕(2),cis-〔Pt(2-MBPA)2〕(3)和cis-〔Pt(2-MBPA)(2-MBPAH)Cl〕(4)进行1H和13CNMR谱分析,区分了化合物(3)和(4),归属了糖苷部分的1H和13CNMR谱线,并根据磷和铂及磷与磷的偶合常数确定化合物(3)和(4)是顺式构型  相似文献   

11.
Novel itaconates having a pyrrolidinonyl moiety, i. e. 4‐methyl 1‐(2‐pyrrolidonylethyl) itaconate (PyEMI) and 1‐methyl 4‐(2‐pyrrolidonylethyl) itaconate (MPyEI) were synthesized by the reaction of 2‐N‐hydroxyethyl‐pyrrolidinone (HEPy) with 4‐methyl or 1‐methyl itaconyl chloride in the presence of triethylamine. The polymerization of PyEMI and MPyEI were conducted in two ways. By photopolymerization using 2,2‐dimethoxy‐2‐phenylacetophenone as a photosensitizer, P(PyEMI)‐A and P(MPyEI) were obtained. By redox polymerization using N,N,N,N‐tetra‐methylethylenediamine – potassium persulfate as an initiating system, P(PyEMI)‐B was obtained. It was found that both polymers exhibit thermo‐responsive behavior in water. The thermo‐responsive behavior of P(MPyEI) is similar to that of P(PyEMI)‐A, however, P(PyEMI)‐B is more sensitive to a change in temperature than P(PyEMI)‐A. The fluid dynamic diameter of P(PyEMI)‐A and P(PyEMI)‐B in water were detected by a laser scattering method, and it was shown that the fluid dynamic diameter of the latter is about 5 times that of the former. Due to the difference in polymer chain size and shape, the thermo‐responsive behavior of P(PyEMI)‐B is more sensitive in the same mass concentration. The swelling ratios of PyEMI hydrogels with various amounts of cross‐linker at different temperature were determined. The thermo‐responsive behavior of the PyEMI hydrogel was compared with that of the P(PyEMI) aqueous solution.  相似文献   

12.
Novel thermosensitive nanocomposite (NC) hydrogels consisting of organic/inorganic networks are prepared via in situ free radical polymerization of 2‐(2‐methoxyethoxy) ethyl methacrylate (MEO2MA) and oligo(ethylene glycol) methacrylate (OEGMA) in the presence of inorganic cross‐linker clay in aqueous solution. The obtained clay/P(MEO2MA‐co‐OEGMA) hydrogels exhibit double volume phase transition temperatures, an upper critical solution temperature (UCST), and a lower critical solution temperature (LCST), which can be controlled between 5 and 85 °C by varying the fraction of OEGMA units and the weight percentage of cross‐linker clay. These new types of NC hydrogels with excellent reversible thermosensitivity are promising for temperature‐sensitive applications such as smart optical switches.

  相似文献   


13.
P(AMPS-co-BMA)水凝胶的电场敏感性及电刺激响应机理   总被引:3,自引:0,他引:3  
以离子型单体2-丙烯酰胺-2-甲基丙磺酸(AMPS)及非离子型单体甲基丙烯酸丁酯为原料, 偶氮二异丁腈为引发剂, N,N′-亚甲基双丙烯酰胺为交联剂, N,N-二甲基甲酰胺为溶剂, 通过自由基聚合合成了一系列聚离子浓度不同的聚(2-丙烯酰胺-2-甲基丙磺酸-co-甲基丙烯酸丁酯)电场敏感性水凝胶. 研究了其在去离子水及NaCl溶液中的溶胀行为. 结果表明, 该水凝胶在去离子水中的平衡溶胀度在236.4~298.5之间, 其溶胀速率随着AMPS用量的增加而增加; 并且随着凝胶内部聚离子浓度的增加, 凝胶在NaCl溶液中的消溶胀速率及消溶胀度逐渐减小. 凝胶的电刺激响应性能研究结果表明, 在电场存在下, 凝胶在NaCl溶液中的溶胀行为与凝胶内部聚离子浓度和溶液中NaCl浓度的相对大小有关, 当凝胶内部聚离子浓度大于溶液中NaCl浓度时, 凝胶溶胀, 反之则凝胶消溶胀; 而且, 凝胶在电场作用下的偏转行为同样与凝胶内部聚离子浓度和溶液中NaCl浓度的相对大小有关, 当凝胶内部聚离子浓度大于溶液中NaCl浓度时, 偏向阴极, 反之则凝胶偏向阳极. 另外, 在电场存在下, 凝胶在NaCl溶液中的电偏转速度与环境温度密切相关.  相似文献   

14.
疏水改性智能水凝胶P(NIPA-co-DiAB)的合成及其温敏行为   总被引:2,自引:0,他引:2  
耿同谋 《应用化学》2010,27(6):637-641
以N-异丙基丙烯酰胺(NIPA)和N,N-双烯丙基苄胺(DiAB)为共聚单体、N,N-亚甲基双丙烯酰胺(BIS)为交联剂、十二烷基硫酸钠(SDS)为表面活性剂、过硫酸铵(APS)-四甲基乙二胺(TMEDA)为氧化还原引发体系,采用自由胶束交联共聚法合成了疏水基团为芳香基的疏水改性温敏性智能水凝胶P(NIPA-co-DiAB)。研究了DiAB摩尔分数(x(DiAB))对水凝胶溶胀性能的影响。 在初始溶胀阶段,随着x(DiAB)由0增大至3%,P(NIPA-co-DiAB)水凝胶的溶胀行为由Fickian扩散转变为non-Fickian扩散。x(DiAB)分别为0、1%、2%和3%时,P(NIPA-co-DiAB)水凝胶的平衡溶胀率SR0在蒸馏水中分别为63.6、93.5、141.6和167.4,在0.01 mol/L SDS溶液中分别为63.1、71.0、59.0和77.5,在CTAB溶液中分别为37.6、42.2、44.1和60.0,在Triton X-100溶液中分别为30.9、49.4、68.5和88.3。 结果表明,P(NIPA-co-DiAB)水凝胶的(SR0)大于PNIPA水凝胶,且在蒸馏中比在0.01 mol/L表面活性剂溶液中要大。 加入0.01 mol/L Triton X-100、CTAB或SDS后,PNIPA水凝胶的体积相变温度或较低临界溶解温度(LCST)由32.5 ℃分别增加至35.4、45.6和80 ℃。P(NIPA-co-DiAB)水凝胶的LCST由32.0~32.5 ℃分别增加至34.7~35.6 ℃、45.8~46.2 ℃和80 ℃。 加入表面活性剂能增加P(NIPA-co-DiAB)水凝胶的体积相变温度,高的体积相变温度与DiAB含量无关。  相似文献   

15.
Samples of poly[1-(3-sulfopropyl)-2-vinyl-pyridinium-betaine] (PSPV) have been synthesized to high conversion by free radical polymerization in aqueous solution of the zwitterionic monomer SPV with several concentrations of the crosslinker N,N′-methylene-bis-acrylamide (MBA). The densities of the resultant xerogels increased regularly with the content of MBA. Hydrogels obtained by swelling them in water and aqueous KSCN solution were examined by gravimetric and dimensional analysis. The water contents increased with decreasing content of MBA, the value of 92.7 wt% at the lowest MBA content being higher than that for other zwitterionic hydrogels. Enhanced swelling occurred in 1 M aq. KSCN at each MBA content, the total swelling being 98.1 wt% at the lowest crosslinker content. Swelling increased with increasing temperature. An approximate procedure to formulating swelling equilibrium in term of the volume fraction of water in hydrogel, in conjunction with the van’t Hoff equation, yields a small positive value for the enthalpy of swelling. This is compared with values derived similarly for other hydrogels.  相似文献   

16.
In this study, swelling behavior and mechanical properties of polyelectrolyte cationic hydrogels of poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA), and poly((2-dimethylamino) ethyl methacrylate-co-butyl methacrylate) (P(DMAEMA-co-BMA)), were investigated. Hydrogels were prepared by free-radical solution copolymerization of DMAEMA and BMA using ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent. Compression-strain measurements were used to analyze the mechanical properties of the hydrogels. It was found that increasing the amount of BMA comonomer in the gel structure increases the compression modulus of the material. The results of mechanical measurements were used to characterize the network structure of the hydrogels, namely the effective crosslinking density (. It was found that exceeds the theoretical crosslinking density (νt) calculated from the initial amount of EGDMA used for hydrogel synthesis. These hydrogels demonstrated dual sensitivity to both pH and temperature. It was shown that the pH-sensitive or temperature-sensitive phase transition behavior of the gels can be changed by changing the temperature or pH of the swelling medium at constant hydrogel composition. Increasing the temperature decreased the transition pH of the pH-sensitive phase transition. On the other hand, increasing the pH of the surrounding medium decreased the transition temperature of the temperature-sensitive phase transition. Incorporation of BMA in the gel structure has a significant effect on the transition point of the gel. Increasing the BMA content reduced the transition pH and temperature of the pH- and temperature-sensitive phase transition, respectively. The similar effect of increasing temperature or BMA content can be explained by the role of hydrophobicity in the phase transition behavior of hydrogels. Finally, the results of equilibrium swelling and compression-strain measurements were used to calculate the polymer-solvent interaction parameters of these hydrogels using the Flory-Rehner equation of equilibrium swelling.  相似文献   

17.
The thermoresponsive poly(ionic liquid) of poly[1‐(4‐vinylbenzyl)‐3‐methylimidozolium tetrafluoroborate] trithiocarbonate (P[VBMI][BF4]‐TTC) showing the soluble‐to‐insoluble phase transition in the methanol/water mixture at the upper critical solution temperature (UCST) was synthesized by solution RAFT polymerization and the synthesized P[VBMI][BF4]‐TTC was employed as macro‐RAFT agent to mediate the RAFT polymerization under dispersion condition to afford the thermoresponsive diblock copolymer nanoparticles of poly[1‐(4‐vinylbenzyl)‐3‐methylimidozolium tetrafluoroborate]‐b‐polystyrene (P[VBMI][BF4]‐b‐PS). The controllable solution RAFT polymerization was achieved as indicated by the linearly increasing polymer molecular weight with the monomer conversion and the narrow molecular weight distribution. The P[VBMI][BF4]‐TTC macro‐RAFT agent mediated dispersion polymerization afforded the P[VBMI][BF4]‐b‐PS nanoparticles, the size of which was uncorrelated with the polymerization degree of the P[VBMI][BF4] block. Several parameters including the polymerization degree, the polymer concentration and the water content in the solvent of the methanol/water mixture were found to be correlated with the UCST of the poly(ionic liquid). The synthesized poly(ionic liquid) is believed to be a new thermos‐responsive polymer and will be useful in material science. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 945–954  相似文献   

18.
通过紫外引发聚合方法制备了无机交联的聚(N-异丙基丙烯酰胺)(PNIPAAm)/有机交联的聚丙烯酰胺(PAAm)互穿网络(IPN)水凝胶.利用FTIR和SEM分别表征了凝胶的化学结构和内部形态;测定了凝胶在高温(50℃)时的退溶胀性能;利用DMA和DSC分别研究了凝胶的储能模量随温度的变化及热相转变行为.研究表明,该IPN凝胶具有温度敏感性;与未互穿的无机交联PNIPAAm凝胶相比,IPN凝胶具有多孔的网络结构和超快的响应速率,如10min内失去90%的水;其储能模量增加了3~4倍,相转变行为变弱,而最低临界溶解温度(LCST)提高了1.4℃.  相似文献   

19.
快速响应的温敏性聚(N-异丙基丙烯酰胺)水凝胶的合成及表征;N-异丙基丙烯酰胺;水凝胶;温敏性;快速响应  相似文献   

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