【作者】 黄晓玲；

【导师】 谭业邦； 周其凤；

【作者基本信息】 山东大学 ， 高分子化学与物理， 2008， 博士

【摘要】 聚电解质具有非常重要的地位,所以对聚电解质的研究一直受到人们的关注。葫芦脲[6]（CB[6]）是由六个甘脲通过亚甲基桥连接成的六元环,CB[6]具有一个疏水的空腔,两端各具有6个端羰基。CB[6]的疏水空腔及两端的羰基使其很容易与一些小分子,比如质子化的烷基胺,形成非常稳定的主.客体配合物。CB[6]还可以同聚电解质发生相互作用,形成新的配合物。这些配合物往往会具有与聚电解质和CB[6]本身所不同的一些特殊的性质。论文首先综述了课题在国内外的相关研究背景,概括了葫芦脲及其在聚电解质方面应用的研究成果,从而阐明了论文选题的科学意义。并围绕聚电解质与CB[6]的超分子相互作用进行了一系列理论与应用方面的研究。（1）通过甲基丙烯酸丁铵与CB[6]进行自组装,合成了一类侧链型配合准轮烷单体CB[6]/甲基丙烯酸丁铵（BAMACB）;将准轮烷单体BAMACB与丙烯酰胺（AM）通过4,4’-偶氮二（4-氰基戊酸）引发,进行水溶液共聚,合成了一系列的共聚物。通过¹H NMR、FT-IR、元素分析、TGA、DSC等手段对这一系列共聚物进行测试分析,由核磁和元素分析结果表明,我们此系列共聚物中,BAMACB/AM结构单元的摩尔比分别为1/32.9,1/52.9,1/82.8以及1/87.8;由TGA结果我们得到,由于BAMACB大的空间位阻,破坏了酰胺基的氢键作用,而使酰胺基的降解温度降低;从DSC的结果可知,共聚物PAM/BAMACB的玻璃化转变温度T_g较不含CB[6]的共聚物明显提高,这是由于BAMACB的刚性和大的空间位阻所致。通过动态光散射研究了聚合物在不同溶液中的聚集行为,在水溶液中聚合物PAM/BAMACB分子间的相互作用占主导地位;在0.1 mol/L NaCl溶液中,存在着分子内相互作用与分子间相互作用的平衡过程,在聚合物浓度较小时,分子内收缩占主导地位,当浓度增加时,分子间聚集变得比较明显;当NaCl浓度增加到一定值时,盐的存在很大程度的抑制了聚合物发生明显的聚集。（2）研究了海藻酸钠（Alg）与CB[6]的相互作用,研究发现将CB[6]引入到海藻酸钠溶液中后,海藻酸钠与CB[6]可以发生很明显的相互作用。首先通过荧光、圆二色谱、透射电镜、动态光散射等方法研究了海藻酸钠稀溶液与CB[6]的相互作用。结果表明,海藻酸钠稀溶液与CB[6]相互作用后,可以形成一种类胶束结构的Alg/CB[6]纳米聚集体,这种聚集体的结构是以CB[6]进行物理交联的区域为核,电离的羧酸根离子为壳。当海藻酸钠的浓度为0.05 wt%时,可以得到粒径比较均一的纳米聚集体。通过动态光散射和透射电镜结果可知,海藻酸钠与CB[6]形成的配合物溶液中,单个纳米粒子与纳米粒子形成的聚集簇共存。当CB[6]的浓度较低时,溶液中主要存在的是单个纳米粒子,随着CB[6]浓度的增加,这些纳米粒子会变得更紧密,表面电荷会减少;而当CB[6]的浓度增加到一定程度时,纳米粒子聚集成的聚集簇的数量明显增加。对于海藻酸钠浓溶液,CB[6]可以与海藻酸钠发生配合,形成物理交联的Alg/CB[6]凝胶粒子。流变结果表明,CB[6]的量直接关系到凝胶的形成情况,只有CB[6]的量达到一定程度时,才可以形成凝胶状的弹性固体。本文通过数码相机记录了Alg/CB[6]凝胶粒子的形成过程,发现,凝胶粒子的形成过程是一个CB[6]由外向内的扩散过程。Alg/CB[6]干凝胶粒子的红外、TGA、DSC和XRD等分析结果表明,CB[6]主要是通过与海藻酸钠的羧基相互作用而形成凝胶,同时也存在着氢键等其他相互作用,由于海藻酸钠分子链G-G结构的存在,易于形成“egg-box”式的特殊结构,使得Alg/CB[6]凝胶粒子比较稳定。本论文采用5-氟脲嘧啶（5-Fu）作为模型药物,将这种凝胶粒子进行药物释放的初步研究。载药量不同的Alg/CB[6]载药凝胶粒子的释放结果表明,5-Fu载药量为5.94 wt%的Alg/CB[6]载药凝胶粒子的缓释效果较好。（3）通过荧光、动态光散射、透射电镜及zeta电位等多种手段,研究了羧甲基纤维素钠（CMC-Na）与CB[6]在溶液中的相互作用情况。研究结果表明,羧甲基纤维素钠的浓度、CB[6]的量、外加小分子无机盐及pH值均会对CMC-Na/CB[6]配合体系产生影响。由于CMC-Na不能与CB[6]形成类似Alg/CB[6]配合体系的“egg-box”结构,所以CB[6]与CMC-Na的结合力较海藻酸钠弱一些。在CMC-Na/CB[6]配合体系中,CMC-Na与CB[6]聚集的纳米粒子形成较慢,需要经过放置才可以形成一些不太规整的球形纳米粒子;CMC-Na的浓溶液与CB[6]相互作用后,CB[6]对CMC-Na分子链的架桥作用要弱一些,在我们的实验条件下也没有象海藻酸钠浓溶液那样,形成球形凝胶粒子,将CMC-Na/CB[6]浓溶液配合体系在室温放置后,体系会出现许多絮状结构的聚集体。（4）采用荧光、共振光散射、紫外吸收波谱、动态光散射等表征手段,系统研究了CB[6]与丁胺盐酸盐配合形成的准轮烷离子（CB[6]/BA）与两性聚电解质O-羧甲基壳聚糖（O-CMCS）的相互作用。分别改变pH值、盐浓度、CB[6]/BA浓度等各个条件,考察了CB[6]/BA-O-CMCS配合体系的聚集情况。结果表明在水溶液中,pH值为2.32时,CB[6]/BA只能使O-CMCS分子链发生扩张,没有使O-CMCS分子链发生进一步聚集。对于pH值为7.05和8.35的体系,CB[6]/BA充当了一个交联桥的作用,可以同时与羧基和胺基或铵离子配位,从而使O-CMCS聚集行为发生变化,当CB[6]/BA的浓度较低时,CB[6]/BA首先通过与胺基和羧基发生聚集体内的配位,使得O-CMCS聚集体收缩,当CB[6]/BA的浓度足够大时,聚集体间易团聚,从而形成更大的聚集体簇。在0.1 mol/L NaCl溶液中,CB[6]/BA准轮烷离子主要以⁺NH₃CB[6]/BANa⁺的形式存在。⁺NH₃CB[6]/BANa⁺复合离子相当于一个大环状二价阳离子,可以与两个-COO^-配位,形成一种（-COO^-）⁺NH₃CB[6]/BANa⁺（-COO^-）形式的配位桥,这种配位效果可以影响整个聚合物在溶液中的聚集形态。在0.1 mol/L NaCl溶液中,O-CMCS与CB[6]/BA发生配位时,存在着聚集体内部配合与聚集体间配合的竞争,当CB[6]/BA浓度较低时,容易发生聚集体内的配位,而当CB[6]/BA浓度较高时,易于发生聚集体间的配位而导致团聚,会引起O-CMCS进一步聚集成聚集体簇。更多还原

【Abstract】 Because of fundamental importance of polyelectrolytes,polyelectrolytes have been the object of a continued interest since the early days of polymer science. Cucurbit[6]uril（CB[6]）,which is a macrocycle comprising six glycoluril units interconnected with twelve methylene bridges,has a hydrophobic cavity that is accessible through two identical carbonyl-fringed portals.The polar carbonyl groups at the portals and a hydrophobic cavity allow CB[6]to form stable host-guest complex with small molecules such as protonated aminoalkanes,diaminoalkanes.Moreover, CB[6]and polyelectrolyte can interact with each other to form complex,they usually display intriguing and fascinating features,which are different from polyelectrolyte or CB[6].In this doctoral dissertation,the detailed supermolecule interaction between CB[6]and polyelectrolytes has been investigated.Brief research background of this work is introduced,in which the history and recent progress in cucurbituril and polyelectrolyte as well as the application of CB[6]in polyelectrolyte are reviewed from a worldwide angle of view.The objective and the scientific significance of this doctoral dissertation are also pointed out.（1） A novel complex pseudorotaxane monomer（BAMACB） by the self-assembly of the host molecule of CB[6]and guest molecule of butyl ammonium methacrylate （BAMA） was synthesized.A series of copolymers of acrylamide（AM） with complex pseudorotaxane monomer BAMACB were synthesized via conventional free radical polymerization in aqueous media using 4,4 ’-azobis（4-cyanopentanoic acid） as initiator. The copolymers（PAM/BAMACB） were characterized extensively via ¹H NMR, Elementary Analysis,Fourier Transform Infrared（FT-IR）,Thermogravimetric Analysis （TGA） and Differential Scanning Calorimetry（DSC）.Compositional analysis by ¹H NMR spectroscopy and Elementary Analysis revealed that copolymers with the mole ratio of BAMACB/AM 1/32.9,1/52.9,1/82.8 and 1/87.8 were achieved.The results showed that the bulky steric hindrance of CB[6]can damage the hydrogen bond of the amide groups,leading to the decrease of decomposition temperature of amide groups. However,the T_g of PAM/BAMACB increased,which was the results of the enhanced rigidity and the bulky steric hindrance of side chain of PAM/BAMACB.The results of Dynamic Light Scattering（DLS） showed that the aggregation of PAM/BAMACB occured.In aqueous solutions,intermolecular aggregation is dominant;transition between the intrachain and interchain association appear in 0.1 mol/L NaCl solutions. The copolymer chains first undergo the intrachain complexation at low copolymer concentration;while in the case of a high polymer concentration,the interchain complexation becomes dominant and apparent.At higher NaCl concentration, aggregation can be suppressed by the added NaCl.（2） The interaction between alginate and CB[6]was investigated.The interaction between polysaccharide alginate dilute solution and CB[6]has been investigated by Static Fluorescence Spectroscopy,DLS,Transmission Electron Microscopy（TEM）, Circular Dichroism（CD） and Zeta Potential.Results showed that the interactions between alginate and CB[6]lead to the formation of micelle-like nanometer-sized aggregates due to electrostatic interaction and ion-dipole interaction.Micelle-like core-shell aggregates with physical cross-link segments as core and dissociated carboxyl in alginate as shell were obtained.In our experiment,when the concentration of sodium alginate was 0.05 wt%,the uniform micelle-like aggregates were achieved.DLS and TEM results both showed that isolated and clusters coexist in the blend solutions of CB[6]and alginate.Isolated micelle-like aggregates prevailed at low CB[6] concentration and clusters were predominant with increasing CB[6]concentration due to the decrease of charges at surface of micelle-like aggregates.A novel CB[6]mediated alginate physical hydrogel bead was prepared for the first time,which is based on the electrostatic attraction and ion-dipole interaction between concentrated sodium alginate solution and CB[6].These alginate/CB[6]gel beads are useful in controlled drug delivery and other biomedical applications.The rheological results show that the gel can be obtained at given CB[6]concentration.At lower CB[6]concentration,the gel is impossible.The process of the formation of alginate/CB[6]gel beads was recorded by Digital Cameras,which suggested that the process of gellation is controlled by the diffusion of CB[6].CB[6]diffused through outer thin film into the center of the beads. The structure and thermal stability of alginate/CB[6]gel beads were studied by FT-IR, X-Ray Powder Diffraction（XRD）,and TGA.The results showed that alginate/CB[6] gel beads were formed through the interaction between CB[6]and G-G chains of alginate in the form of "egg-box".The potential of alginate/CB[6]gel beads as carrier for 5-Fluorouracil（5-Fu） was studied in this paper.It was found that the optimum alginate/CB[6]gel beads of drug loading is 5.94 wt%.（3） The interaction between sodium carboxymethylcellulose（CMC-Na） and CB[6] was investigated by Fluorescence Spectroscopy,DLS,TEM,and Zeta Potential.The results showed that the concentration of CMC-Na,the amount of CB[6],the added salt and pH values have effect on the aggregation of CMC-Na/CB[6]systems.Because it is impossible to form the structure of "egg-box" in CMC-Na/CB[6]system,the binding force between CMC-Na and CB[6]is smaller than the system of alginate/CB[6].The formation of nano aggregates between CMC-Na and CB[6]is slow in CMC-Na/CB[6] system.Irregular nano aggregates were obtained after a long time placement.The interaction between concentrated CMC-Na solution and CB[6]could not induce the formation of gel bead.In concentrated CMC-Na solution,floccule was separated out from CMC-Na/CB[6]system and visible with naked eyes after placement.（4） CB[6]can complex with butyl ammonium hydrochloride（BA） to form stable pseudorotaxane（CB[6]/BA）.The interaction between CB[6]-based pseudorotaxane （CB[6]/BA） and O-carboxymethyl chitosan（O-CMCS） in aqueous solution was investigated by Steady-State Fluorescence,Resonance Light Scattering（RLS）, Ultraviolet Absorption Spectra（UV） and DLS.The interaction between CB[6]/BA and O-CMCS depended on pH values,the concentration of CB[6]/BA and the added salt.In aqueous solution,when pH value was 2.32,the conformations of polymer chains expanded.In the mixtted solution of O-CMCS and CB[6]/BA at pH value of 7.05 and 8.35,CB[6]/BA act as "stickers" to interact with the O-CMCS chains.At low CB[6]/BA concentration,the intra-aggregate complexation was expected to be dominant, CB[6]/BA first undergo the intra-aggregate complexation through the -NH₂ or -NH₃⁺ and carboxylic groups,which might make the aggregates of O-CMCS form more compact structure.In the case of a high CB[6]/BA concentration,the inter-aggregate complexation became dominant and apparent.The inter-aggregate complex points result in the further aggregation of the O-CMCS chains,leading to larger clusters.In 0.1 mol/L NaC1 solution,Na⁺ may complex with bare carbonyl of CB[6]/BA by ion-dipole interaction,leading to the appearance of ⁺NH₃CB[6]/BANa⁺.⁺NH₃CB[6]/BANa⁺ tended to complex with two -COO^- to form（-COO^-）⁺NH₃CB[6]/BANa⁺（^-OOC-） complex point and formation of bridges.The interaction between -COO^- and ⁺NH₃CB[6]/BANa⁺ can lead to the distinct conformational change of polymer chains.In 0.1 mol/L NaCl solution,interaction between O-CMCS and CB[6]/BA was dominated by either the intra-aggregate or inter-aggregate complexation.At low CB[6]/BA concentration,the intra-aggregate complexation was expected to be apparent,while in the case of high CB[6]/BA concentration,the inter-aggregate complexation became dominant and apparent.The inter-aggregate complex points resulted in the further aggregation of the O-CMCS chains.The larger clusters were obtained.更多还原