Mushroom-shaped Morphology Formed in Thin Films of Cylinder-forming Block Copolymer

The morphology of the film of polystyrene-block-poly(methyl methacrylate)(PS-b-PMMA) block copolymer having polystyrene(PS) cylinder forming composition spin-coated on a neutral brush modified silicon substrate has been investigated in this report. A mushroom-shaped morphology formed in the film with one period to two periods(L0―2L0) in thickness, which was spin-coated under a low humidity condition(RH ca.13%) and then thermally annealed at an extreme high temperature(230 °C). The results suggest that the s...     

HCl对有序介孔氧化硅结构与形貌的影响

以三嵌段共聚物P123为有机模板导向剂、正硅酸乙酯TEOS为无机硅源, 在HCl存在的强酸性环境下, 采用水热法合成了有序介孔分子筛SBA-15. 采用XRD、SEM、TEM、N2吸附-脱附等手段对产物的结构与形貌进行了分析, 考察了HCl用量对有序介孔材料结构及形貌的影响. 结果表明, 在合成有序介孔氧化硅时, HCl发挥了催化和中间离子的双重作用, 促使棒状胶束形成六方有序排列, 降低SBA-15中微孔的数量, 而且对合成有序介孔氧化硅SBA-15的形貌有显著影响. 适宜的HCl用量对形成“珍珠链状”形貌的、热稳定性优良的SBA-15介孔材料具有重要作用.     

聚苯乙烯-聚(4-乙烯基吡啶)嵌段共聚物LB膜结构形态的研究

采用氯仿作为铺展溶剂,将嵌段共聚物聚苯乙烯-聚(4-乙烯基吡啶)(PS-b-P4VP)稀溶液铺展于空气与水界面上,利用Langmuir-Blodgett(LB)膜技术转移至固体基底.研究了不同的嵌段比、表面压和小分子1-芘丁酸(PBA)的加入对嵌段共聚物气液界面聚集组装的影响.研究发现随着亲水段(P4VP)的增加,聚集组装结构由纳米片状、带状转变成纳米条状、纳米点状结构.表面压对纯PS-b-P4VP聚集组装产生影响,表面压增大,组装体排列紧密;随着表面压的继续增大,单层聚集结构遭到破坏,发生堆叠.加入PBA小分子后,PBA与PS-b-P4VP形成氢键,形态发生明显变化,原来的片状结构转变为条状或点状结构.     

Silver Chloride Loaded Mesoporous Silica Particles and Their Application in the Antibacterial Coatings on Denture Base

Thiol-functionalized MCM-41 type mesoporous silica particles（MSPs） were prepared and loaded with silver chloride to act as antibacterial agents. The antibacterial activity of the silver chloride loaded MSPs（AgCI-MSPs） was evaluated by the minimum bactericidal concentration（MBC） against Candida albieans（ATCC 10231）. The AgC1-MSPs with the highest antibacterial activity were then dispersed in hybrid coatings with different mass ratios to fabricate antibacterial coatings. The antibacterial activity of the coatings was tested against Candida albicans{ATCC 10231） and Streptococcus mutans（ATCC 25175）. The resulting antibacterial coatings exhibited high antibacterial activity, good adhesion to the substrate and high hardness.     

嵌段共聚物组成对薄膜形貌影响的多体耗散粒子动力学研究

利用多体耗散粒子动力学(Multibody Dissipative Particle Dynamics, Multibody DPD)方法研究了在溶剂蒸发条件下, 嵌段共聚物在表面自组装形成薄膜的过程, 分别考虑了两嵌段共聚物和三嵌段共聚物及不同组成对薄膜形貌的影响. 模拟得到了无序状薄膜和层状薄膜, 并计算了这些薄膜的序参量和薄膜厚度随时间的演化. 结果表明, 嵌段共聚物的组成对薄膜厚度几乎没有影响, 当某种组分的链段很短时, 只能形成序参量较小的无序薄膜, 相反, 则可以得到序参量较大的层状薄膜.     

嵌段共聚物/均聚物共混体系的结晶行为 I. 非球状共聚物胶束的作用

将Leibler, Whitmore和Mayes等近期关于非晶嵌段共聚物“稀固体溶液”的理论应用于嵌段聚共聚物结晶型“稀固体溶液”结晶行为的研究。发现球状共聚物胶束既可起成核剂作用, 也可起抑制成核作用。报导了当共聚物胶束由球形变为非球形时, 共聚物胶束的上述作用都会发生较大的变化, 并根据Leibler和Mayes分别提出的球形和非球形胶束理论解释了这一实验现象。     

溶剂去除速度对于溶剂退火薄膜相形貌的影响

以聚苯乙烯-聚4-乙烯基吡啶(PS-b-P4VP)嵌段共聚物作为研究对象,采用DMF作为退火溶剂,以原子力显微镜(AFM)和透射电子显微镜(TEM)为表征手段,研究了溶剂退火后期溶胀薄膜中溶剂的去除速度对于薄膜相形貌的影响,发现通过改变溶剂去除速度可以有效的调控薄膜中的形貌.当薄膜厚度为35 nm时,DMF的快速挥发会导致薄膜中形成以PS为分散相的反转柱状相结构,当降低溶剂的挥发速度时,薄膜中形成了以PS为分散相的环状形貌,当进一步减缓挥发速度时,薄膜中将形成台阶状的片层结构;然而当薄膜厚度为55 nm时,溶剂退火后期薄膜中形成的是以P4VP为分散相的正常柱状相结构,在相同溶剂去除速度条件下薄膜相形貌变化较小.     

Temperature Dependence in the Synthesis of SBA-16-Type Mesoporous Silica with Pluronic F68 Block Copolymer

By adjusting the local effective surfactant packing parameter through synthesis temperature, highly ordered SBA-16-type mesoporous silica materials have been synthesized by templating with a nonionic triblock copolymer Pluronic F68 in strongly acidic conditions at temperature 30～40°C with the addition of K₂SO₄. The prepared SBA-16-type mesoporous silica materials having Im3m cubic mesostructure were proved by the well-defined x-ray diffraction patterns combined with transmission electron microscopy. Scanning electron microscopy indicated that a transformation from faced-sphere to faced-polyhedron shape morphologies could be induced with increasing of the synthesis temperature. The nitrogen adsorption–desorption analysis revealed that the mean pore size (5.50～6.13 nm) of the prepared materials increased with increasing synthesis temperature. However, when the synthesis temperature exceeded 46°C, only disordered mesoporous silca was obtained. Our synthesis strategies by adjusting the local effective surfactant packing parameter through synthesis condition, even in a narrow range, would be used not only to optimize the synthesis conditions of reported mesoporous silca, but also to fabricate new mesoporous silica materials with well-ordered channel and anticipated morphologies.     

酸诱导介观相转变硅基介孔材料的合成机理及其改性

采用两步法以三嵌段共聚物P104(PEO27-PPO61-PEO27)为模板剂合成介孔材料, 研究了介孔材料结构随体系pH 值的变化, 探讨了体系中介观相转变的机理. 研究表明,随着pH 的升高, 发现体系中无机物种和模板剂所组成的介观相发生了转变,由P6mm 的SBA-15(pH=1.51-2.67)2D六角孔道结构转变为3D 蠕虫状孔道的MSU-X(pH=3.93-4.56)结构. 对所得的两种不同种类的硅基材料以γ-胺丙基三乙氧基硅烷(APTES: NH2(CH2)3Si(C2H5O)3)进行表面烷基化改性结果表明, 在同样的条件下, 经过改性后MSU-X类介孔材料孔壁上接枝的烷基数目要远超过SBA-15 类介孔材料.     

Engineering the Morphologies of Block Copolymer Particles from the Confined Self-assembly within Emulsion Droplets†

Block copolymers (BCPs) can automatically assemble into various regulated nanoparticles when they are confined within the emulsion droplet because of the structural frustration of polymer chains and the soft template effect of the oil/water interface. In the past few years, great efforts have been made to regulate the morphologies of the resulting BCP particles. In this review article, various strategies for tuning oil/water interfacial properties to engineer the as-formed BCP particles were summarized. Then, the comprehensive scenarios of the applications of the resulting BCP particles were discussed. Finally, the future tendency and challenge of the self-assembly of BCPs confined in emulsion droplet were suggested.     

嵌段共聚物熔体流变行为研究进展

微相分离的结构特点赋予了嵌段共聚物很多优异的性能,使其广泛应用于汽车部件及工具手柄、电线电缆包皮或绝缘带、医疗制品及食品容器、密封胶、粘合剂、涂料以及聚合物共混改性等领域。聚合物流变特性直接关系到材料加工参数的选择以及产品最终性能,是聚合物结构设计、材料加工参数优化选择及拓展产品应用领域的理论基础。本文对嵌段共聚物的熔体流变行为进行了综述,着重介绍了与嵌段共聚物特殊结构相对应的流变特性,以及流变特性与相行为之间的关联,并提出了嵌段共聚物熔体流变行为研究的前沿与重点。     

Effects of Morphology and Structural Characteristics of Ordered SBA-15 Mesoporous Silica on Release of Ibuprofen

Three kinds of highly ordered SBA-15 mesoporous materials with different pore sizes and morphologies denoted as LPS-SBA-15 (stick-like with pore size 7.28 nm), CPS-SBA-15 (stick-like with pore size 5.96 nm) and T-SBA-15 (tablet-like with pore size 4.64 nm) have been prepared, characterized and employed as carrier materials. The release behaviors of the ibuprofen in a simulated body fluid from these mesoporous silica materials were studied. The influences of pore size and exterior morphologies of mesoporous silica on the release behaviors of ibuprofen have been investigated. It has been found that the release becomes fast with increasing of pore size and slow with extending of transport pathway, and that the release rate of ibuprofen from the three kinds of SBA-15 is LPS-SBA-15 > T-SBA-15 > CPS-SBA-15. The results show that the inner structure as well as the exterior morphologies of SBA-15 mesoporous silica can seriously affect the release behaviors of ibuprofen.     

介孔材料MCFs的合成及组装青霉素酰化酶的性质研究

介孔材料由于具有纳米级规则孔道和巨大的比表面积而在催化、吸附及分离等方面存在较大的应用价值．近年来,由介孔分子筛如MCM-41和SBA-15州等组装功能性材料已成为研究的热点．酶作为高效催化剂有许多优点,但在溶液中易失活,使用后无法回收,有的酶在溶液中还存在自水解问题：将酶组装在介孔材料中制成固定化酶则可解决上述问题．目前已成功地将辣根过氧化物酶     

双亲嵌段共聚物P103对牛血清白蛋白构象的影响

利用傅立叶变换红外光谱和傅立叶变换拉曼光谱研究了牛血清白蛋白(BSA)与双亲嵌段共聚物P103作用过程中蛋白质构象的变化规律。研究表明,当P103浓度较低时,BSA二级结构变化不大,当P103浓度为16 g/L或以上时,α-螺旋结构由45.9%降至40%以下,β-折叠结构升高,由6.1%增至17%左右,同时无规结构略微下降。P103的加入主要改变BSA分子内部氢键的结合方式,使α-螺旋结构转变为β-折叠结构;P103的加入还影响BSA中氨基酸侧链的微环境变化和蛋白质二硫键的构象变化。     

嵌段共聚物增容剂对不相容均聚物共混体系相行为和界面性质的影响

聚合物共混体系(又称聚合物合金)兼具其相应组分的均聚物和共聚物的多种特征,甚至具有新的理想性能,从而成为了一种具有极高经济价值的新材料.该材料的研发极大地丰富了高分子物理学、高分子化学和材料学的研究内容,拓宽了聚合物材料在现代工业中的应用,同时把聚合物材料研究推向了交叉科学的前沿.均聚物/嵌段共聚物/均聚物体系作为经典的三元聚合物共混体系,对其进行深入地研究,不仅可以促进人们对高分子科学中重要问题的理解,而且可为新型嵌段共聚物增容剂的改良和设计提供理论依据.近年来,有关聚合物共混体系的实验、理论和计算机模拟工作很多,并且取得了较大的进展,但是相关综述较少.本文以均聚物/嵌段共聚物/均聚物体系为例,综述该领域的基本概念和发展历史,并着重介绍两嵌段共聚物增容剂对该三元共混体系相行为和界面性质的影响.此外,还介绍了这一领域的关键科学问题、发展前景和研究方向.     

原子力显微镜与透射电镜对比研究嵌段共聚物微相分离形态

嵌段共聚物微观相分离形态结构由于其理论与应用中的重要性一直是人们研究的热点 [1] .本文研究的聚苯乙烯 -聚乙烯 /聚丁烯 -聚苯乙烯三嵌段共聚物 (SEBS)为聚苯乙烯 -聚丁二烯 -聚苯乙烯 (SBS)饱和加氢后的产物 .由于中间嵌段中的双键大多已加氢饱和 ,过去一直没有合适的染色剂进行染色 ,所以在 2 0世纪 80年代中期以前 ,SEBS形态结构未见文献报道 [1] .近年来 ,由于新型染色剂 Ru O4 的应用 ,使得用透射电镜 (TEM)观察其微相分离形态成为可能 .　　随着对嵌段共聚物形态结构认识程度深入 ,人们迫切希望能有新的手段提供更加丰富的…     

Influence of Block Copolymer on Formation and Acid Resistant Properties of Hybrid CaCO_3 Particles

Block copolymer polystyrene-b-poly(acrylic acid)(PS-b-PAA) was used as structural template for the synthesis of CaCO3 microparticles. Through this procedure, acid resistant hybrid CaCO3 micro-spheres were obtained. Acid resistant properties of this type of hybrid CaCO3 were studied. Size mea-surement shows that the acid resistant properties of the hybrid particles are different in different solutions, such as HCI, EDTA, and H2SO4 solutions.     

Effect of Epoxidation of Diene Component of SBS Block Copolymer on Morphology and Mechanical Properties

In this work, the polybutadiene (PB) block of an asymmetric lamellae forming polystyrene/polybutadiene based triblock copolymer was epoxidized to different extent in order to study its effect on morphology and mechanical behaviour of the copolymer. The products were analyzed by means of different microscopic techniques, Fourier transform infrared (FTIR) spectroscopy and microhardness measurements. It was found that the microphase separation behavior and hence the mechanical properties of the materials were drastically altered through epoxidation of the diene block of the styrene/diene triblock copolymer. With the increase in the extent of epoxidation the lamellar structure changed to distorted lamellae and then to disordered domains. Consequently, inhomogeneous mechanical performance of the samples was observed at higher degree of chemical modification.     

利用TDGL方法模拟嵌段共聚物链长和浓度对A/B/A-B三组分体系相形态演化的影响

从Flory-Huggins自由能出发,得到了适合TDGL模拟的自由能泛函.在自由能中保留了各序参量的耦合项,并且还保留了链长的信息.利用自由能中的链长的信息,模拟了不同嵌段共聚物链长以及不同浓度下体系的形态变化,在均聚物的链长和浓度确定的条件下,存在一个使体系的相区尺寸最小的最佳嵌段共聚物链长.同时,在嵌段共聚物和均聚物的链长都一定的情况下,研究了不同量的嵌段共聚物对体系相行为的影响,发现嵌段共聚物的浓度不同,体系的结构存在很大的区别.此外,如果均聚物A和B的浓度不同,其相区的结构也不同.