多重交联水凝胶的制备与性能研究

以过硫酸钾和亚硫酸氢钠为引发体系,丙烯酰胺(AM)、丙烯酸(AA)为亲水单体,甲基丙烯酸十八烷基酯(SMA)为疏水单体,十二烷基硫酸钠(SDS)为表面活性剂,N,N’-亚甲基双丙烯酰胺(MBAA)为化学交联剂,聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)和聚乙烯醇(PVA)为聚合物基质,通过自由基聚合制备了微晶-共价-离子-疏水缔合-氢键多重交联水凝胶。通过改变PDMC、AM和MBAA的量,制备出了结构不同的多重交联水凝胶。采用电子万能试验机对多重交联水凝胶的拉伸性能进行了测试,结果表明:1. 73 g PDMC、5 g AM、15 mg MBAA体系制备的多重交联水凝胶的力学性能最好,拉伸强度为0. 71 MPa,断裂伸长率为419. 0%。通过吸水性能的测试,表明所制备的多重交联水凝胶吸水性均较好,其中8. 75 g AM、15 mg MBAA体系制备的水凝胶的吸水率最高,为1612. 0%。     

可注射型海藻酸/磷酸化壳聚糖复合水凝胶的制备及其生物相容性

将N-亚甲基磷酸化壳聚糖(NMPC)引入海藻酸钙水凝胶体系,制备了力学强度和稳定性均优于海藻酸钙和海藻酸/壳聚糖复合水凝胶的可注射型材料.通过正交实验,根据材料的力学性能、浸提液pH值和凝胶化时间的对比分析,确定了各组分质量分数为:海藻酸钠1.50%、碳酸钙0.30%、N-亚甲基磷酸化壳聚糖1.00%、柠檬酸0.30%.细胞培养和肌内植入试验表明,海藻酸/磷酸化壳聚糖(Alg/NMPC)复合水凝胶具有良好的生物相容性.     

高强度物理-化学混杂双网络水凝胶的制备及性质

以聚乙烯醇（polyvinyl alcohol, PVA）和丙烯酰胺（acrylamide, AM）为原料, 采用“一锅煮”及紫外辐照结合冷冻 解冻两步聚合法制备聚乙烯醇/聚丙烯酰胺(PVA/PAM)混杂双网络水凝胶, 并对水凝胶的力学性能、 溶胀性能、 失水性能以及自愈合性进行测试和分析. 结果表明, PVA/PAM混杂双网络水凝胶具有较高的力学强度, 其拉伸强度为428 kPa, 失水速率和单网络水凝胶相比较慢, 具有一定的自愈合性.     

智能海藻酸钙/PNIPAAm互穿网络水凝胶微囊制备研究

以海藻酸钙凝胶为聚合模板，过硫酸铵/偏重亚硫酸钠氧化还原引发剂体系、自由基水溶液法聚合制备了温度敏感和pH敏感的海藻酸钙/聚N异丙基丙烯酰胺（CA/PNIPAAm）互穿网络水凝胶微囊。并研究了引发剂用量、单体量、单体/海藻酸钠配比、缓冲液pH值等因素对该互穿智能水凝胶温度敏感和pH敏感性的影响。结果表明：该互穿凝胶微囊对pH/温度具有敏感溶胀性，可望作为口服药物缓释制剂的载体。     

PP纤维接枝聚丙烯酰胺/海藻酸钙蛋白质印迹水凝胶的制备

以PP纤维为载体,牛血清白蛋白(BSA)为模板,丙烯酰胺为单体,N,N′-亚甲基双丙烯酰胺为交联剂,在海藻酸钠的存在下,采用紫外辐射引发,制备了PP纤维接枝BSA印迹聚丙烯酰胺/海藻酸钙水凝胶(PP-g-PAM/CA MIP)。研究了单体浓度、交联剂浓度和海藻酸钠浓度对BSA吸附量和印迹效率的影响,结果表明,单体质量分数为10%,交联剂质量分数为3%,海藻酸钠质量分数为0.5%时,PP接枝的印迹水凝胶对BSA有最大吸附量。     

ICPA水凝胶的电致溶胀/溶蚀行为研究

以2-丙烯酰胺-2-甲基丙磺酸(AMPS)和甲基丙烯酸二乙胺基乙酯(DEAEM)形成的离子复合物,通过自由基共聚反应制备了新型离子交联聚两性电解质(ICPA),并获得ICPA水凝胶.ICPA水凝胶在电场作用下具有溶胀/溶蚀的双重响应行为,该行为受电压、电解质种类和浓度等多种因素影响.扫描电镜表征在溶胀阶段,凝胶网络保持完整,不发生溶蚀;而在溶蚀阶段,凝胶的网络结构解体.实验结果表明:凝胶的溶蚀行为与溶胀行为响应程度呈同一变化趋势,凝胶网络的紧密程度(即交联的密度和强度)是其溶胀/溶蚀行为的主要决定因素.     

HEMA/AM/clay纳米复合水凝胶的制备及性能

以无机黏土为物理交联剂,通过原位自由基聚合制备甲基丙烯酸羟基乙酯/丙烯酰胺/黏土(HEMA/AM/clay)纳米复合水凝胶.通过傅里叶红外光谱(FT-IR)分析,证明制备的纳米复合水凝胶具有预期的化学组成;通过差示扫描量热仪(DSC)分析了水凝胶中水的存在状态.研究结果表明,凝胶的溶胀度随AM投料量的增加而增大,且随着AM投料量的增加,凝胶的力学性能随之提高,在溶胀度为350％时,水凝胶的断裂伸长率和抗拉强度分别达到400％和0.5 MPa.     

新型高强度荧光水凝胶探针制备及铁离子检测

为制备具有优异力学性能的荧光水凝胶,以丙烯酰胺(AM)、聚乙二醇(PEG)和双丙烯酰氧基荧光素(BAcF)为原料,N,N'-亚甲基双丙烯酰胺、过硫酸铵-四甲基乙二胺(APS-TEMED)为氧化还原引发体系,通过自由基聚合制备P(BAcF-AM)/PEG水凝胶.对单体和凝胶的结构进行红外、核磁表征,考察AM浓度、PEG添加量对水凝胶力学性质的影响.结果 表明,PEG的加入明显提高了水凝胶的力学性能,当PEG的添加量为AM质量的8％时,水凝胶的拉伸强度达到0.45 MPa,应变达到1190％.同时,该水凝胶在365 nm紫外灯下显现明亮的绿色荧光,并且对水中的一定浓度范围内的Fe3+具有显著的荧光猝灭响应,可以作为潜在的便携式荧光探针材料,检测水中金属离子的浓度.     

海藻酸钙纤维基本性能的研究与表征

对海藻酸钙纤维的表观结构、吸湿性能、基本力学性能、成凝胶性能、耐热性进行研究与表征.研究发现:海藻酸钙纤维表面有沟槽,且沟槽形状多样、均匀性较差;海藻酸钙纤维吸湿能力很强;纤维力学性能较差,是一种低强低伸纤维,但其初始模量较大,纤维较硬脆;海藻酸钙纤维的耐热性较差,处理温度达到90℃后,纤维力学性能急速下降;纤维经生理盐水作用成凝胶后,形成独特的类似"皮芯"的结构,纤维力学性能明显下降.     

海藻酸钠的提纯及海藻酸钙多孔支架的制备

采用丙酮沉淀法对海藻酸钠原料进行了提纯,对纯化后的海藻酸钠进行了红外光谱测试和凝胶渗透色谱测试,并测定了提纯前后海藻酸钠样品中剩余蛋白质的含量.此外,通过CaCl2-海藻酸钠、CaSO4/GDL-海藻酸钠和Ca-EDTA/GDL-海藻酸钠3种交联体系制备了多种海藻酸钙三维多孔支架材料.研究结果表明:由质量分数为2.5%～3.0%的海藻酸钠所制得的Ca-EDTA/GDL-海藻酸钙三维多孔支架材料中微孔分布均匀,比表面积较大,且具有较好的力学性能,该支架有可能用作组织工程和细胞工程中培养细胞的培养基.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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