【作者】 葛治伸；

【导师】 刘世勇；

【作者基本信息】 中国科学技术大学 ， 高分子化学与物理， 2009， 博士

【摘要】 通过非共价键相互作用而自发进行的小分子以及大分子的超分子自组装对材料科学、生命科学、信息科学以及纳米科学与技术等众多的科学领域的发展都产生了重大的影响,已经成为21世纪最重要的科学问题之一。本论文,主要集中在环境响应性超分子聚合物组装体的构筑和结构调控。在论文的前半部分,基于环境敏感水溶性高分子设计合成了一系列具有不同结构（AB,AB₄及A₄BA₄型杂臂星形聚合物,树枝形/线性嵌段共共聚聚合物,环形）的两亲和全亲水性嵌段聚合物。在水溶液中,研究了聚合物链构造以及不同的条件（温度、pH）对超分子组装体的影响,另外,对AB两嵌段在可控催化和可视化靶向治疗上的应用进行了初步的探索。论文的后半部分,主要基于冠醚和环糊精的主客体相互作用以及三联吡啶的金属配体络合作用构筑了不同结构的环境响应性高分子,并且在不同的条件下研究了它们的组装行为以及可逆超分子凝胶的形成。具体来说,本论文的工作包括以下几个方面:1.通过可逆加成-断裂链转移/黄酸盐交换的大分子设计（RAFT/MADIX）技术在可控条件下成功制备了全亲水性两嵌段聚合物聚（N-异丙基丙烯酰胺）-b-聚（N-乙烯基咪唑）（PNIPAM-b-PVim）。这也是首次得到基于PVim的嵌段聚合物。PVim是常用的酯水解反应的催化剂。含咪唑基团的嵌段聚合物,PNIPAM-b-PVim,在低温下可以分子溶解于水。但是在高于嵌段聚合物最低临界溶解温度（LCST）下或者适当的甲醇/水混合溶液中,PNIAPM嵌段变得不溶于水,嵌段聚合物形成以PNIPAM为核PVim为壳的胶束。在不同的温度以及不同比例甲醇/水的混合溶剂中,PNIPAM-b-PVim以及相应的PVim均聚物对乙酸对硝基苯酚酯（NPA）水解的催化活性进行了比较。在Arrhenius坐标中,对均聚物来说,log（V）～T¹（V为催化反应速率）呈直线关系;然而对含咪唑基团的嵌段聚合物来说,在温度高于PNIPAM嵌段的临界胶束化温度（CMT）,嵌段聚合物发生胶束化,催化反应的log（V）～T¹曲线的曲率增加。在不同比例甲醇/水的混合溶剂中,PVim均聚物催化反应的速率保持恒定。然而对于嵌段聚合物PNIPAM-b-PVim,催化活性在甲醇体积分数为0.3-0.5的范围内,催化反应的速率有明显提高,表现出了最大值。我们第一次观察了全亲水性嵌段聚合物胶束作为自催化的纳米反应器,更重要的是,催化反应的活性可以通过外界温度和溶剂成分来调控。然后,结合原子转移自由基聚合物（ATRP）、开环聚合（ROP）、click反应成功地合成了生物相容的两亲性嵌段聚合物聚（ε-己内酯）-b-聚（寡聚环氧乙烷甲基丙烯酸酯-co-叠氮丙基甲基丙烯酸酯）（PCL-b-P（OEGMA-co-AzPMA））。通过点击化学反应,将含炔基的具有肿瘤靶向功能的叶酸以及含炔基的MRI增强对比剂（DOTA）Gd分别接到聚合物链上制备得到PCL-b-P（OEGMA-co-folate）以及PCL-b-P（OEGMA-co-（DOTA）Gd）。在水溶液中,通过自组装的方法制备了同时含有肿瘤靶向分子叶酸以及MRI增强对比试剂（DOTA）Gd的PCL-b-P（OEGMA-co-folate）和PCL-b-P（OEGMA-co-（DOTA）Gd）（1:1,w/w）混合胶束。在初步的大白兔的体内MRI增强对比实验中,以混合胶束作为增强对比剂,对肝脏显示了良好的对比增强效果;同时混合胶束对疏水性抗癌药物紫杉醇的负载能力和释放情况与具有类似组成的的聚合物PCL-b-POEGMA相似。这些都表明我们得到的多功能化生物相容的混合胶束在肿瘤靶向以及可视化治疗上有着很大潜在应用价值。2.基于第二代或者第三代Fr（?）chet型树枝形聚合物聚苄基醚[G-2]或[G-3],设计制备了RAFT试剂,以此进行NIPAM的RAFT聚合,分别制备了树枝形/线性两亲性两嵌段共聚物[G-2]-PNIPAM或者[G-3]-PNIPAM。在水溶液中,两亲性嵌段聚合物可以自组装形成含有疏水的致密聚苄基醚核和亲水的具有温度敏感性的PNIPAM壳的胶束。研究证明了胶束壳上的PNIPAM随着温度的升高呈二阶塌缩行为。第一个阶段的塌缩发生在20-29℃的温度范围内,第二个阶段的塌缩发生在29-31℃很窄的温度范围内。然后,基于[G-3]合成了结构新颖的两端分别含有[G-3]的三硫代碳酸酯,以此为RAFT试剂,RAFT聚得到了两端含有[G-3]的树枝形/线性/树枝形三嵌段聚合物[G-3]-PNIPAM-[G-3]。同样地,在水溶液中,该三嵌段聚合物也可以自组装形成以[G-3]为核,温敏的PNIPAM为壳的球形胶束。3.对于星形聚合物的合成,基于四官能团PNIPAM大分子ATRP引发剂引发聚合N,N-二乙基胺乙基甲基丙烯酸酯（DEA）得到了AB₄型杂臂星形聚合物,PNIPAM-b-（PDEA）₄。为了比较聚合物链结构对其胶束化行为的影响,与以上聚合物具有可比的链长度和组成的线性两嵌段聚合物,PNIPAM-b-PDEA通过RAFT聚合得到。在水溶液中,PNIPAM₆₅-b-(PDEA₆₃)₄和PNIPAM₆₅-b-PDEA₂₆₀表现出了pH和温度响应多重胶束化行为。在酸性溶液中和较高的温度下,得到了以PNIPAM为核,PDEA为壳的胶束;在碱性以及室温下,可以得到以PDEA为核的胶束。其中,PNIPAM₆₅-b-(PDEA₆₃)₄以PDEA为核的胶束远小于PNIPAM₆₅-b-PDEA₂₆₀。以上两个嵌段聚合物在pH值从4跃迁到10的过程中的胶束化动力学,它们的胶束化动力学曲线都可以通过二次拟合得到一个快的（τ₁）和一个慢的（τ₂）弛豫过程。对两个聚合物来说,得到的τ₁值都随着聚合物浓度的增加而增加。由PNIPAM₆₅-b-(PDEA₆₃)₄得到的τ₂几乎没有浓度依赖性,表明慢过程主要通过单分子链的插入/解离机理完成的;由PNIPAM₇₀-b-PDEA₂₆₀得到的τ₂随聚合物浓度增加而降低,表明慢过程主要通过胶束融合/分裂机理完成的。基于相似的方法,我们合成了H-型A₂BA₂以及星形/线性/星形A₄BA₄杂臂星形聚合物,观察了它们在水溶液中的多重响应性自组装行为。然后,通过ATRP使用“in-out”方法合成了以聚（二乙烯基苯）微凝胶核为交联点,以聚甲基丙烯酸（PMAA）和聚环氧乙烷（PEO）的为臂的全亲水性杂臂星形聚合物（PEO）_n-PDVB-（PMAA）_n。所得全亲水性杂臂星形聚合物表现出了pH依赖的水溶性。在高pH值下,（PEO）_n-PDVB-（PMAA）_n在水中可溶;在低pH值下,由于PEO和PMAA的氢键络合作用,该星形聚合物不溶于水。然而,随着两嵌段聚合物PEO₁₁₃-b-PQDMA₄₈(PQDMA为碘甲烷季铵化的聚（N,N-二甲基胺乙基甲基丙烯酸酯）的加入,混合溶液在整个pH值范围内稳定存在。在高pH值下,PQDMA嵌段和离子化的PMAA形成不溶性的静电络合物,此时的胶体粒子是由（PEO）_n-PDVB-（PMAA）_n和PEO₁₁₃-b-PQDMA₄₈上的PEO链段稳定的。在低pH值下,质子化的PMAA和PEO之间形成氢键络合物,此时形成的稳定的胶体粒子含有疏水的PDVB核,内层PMAA/PEO氢键络合物以及起稳定作用的PQDMA外壳。4.以含有炔基的ATRP引发剂进行ATRP聚合以及亲核取代反应得到了α-炔,ω-叠氮且在水溶液中温度敏感的两嵌段聚合物linear-PMEO₂MA-b-POEGMA-N₃（MEO₂MA为甲基丙烯酸2-（2-甲基氧乙基）氧乙基酯）。首先,通过在相同的聚合条件下,以2-溴异丁酸苄酯为ATRP引发剂进行ATRP聚合以及与叠氮化钠亲核取代反应后与1-（2-炔丙基氧基）苯进行click反应,通过¹H NMR谱图,证明了linear-PMEO₂MA-b-POEGMA-N₃含有较高的端基叠氮官能化率（＞90%）。在40℃水中时,linear-PMEO₂MA-b-POEGMA-N₃超分子自组装成胶束,炔基和叠氮会分别置于胶束的表面和内核,而同时体系中存在浓度极低的单链分子,通过click反应成功实现了在较高浓度下进行线型前体聚合物的分子内关环反应,同时抑制前体分子间的偶合反应,从而达到了在高浓度下制备环型嵌段聚合物的目的。另外,环形嵌段聚合物在水溶液中自组装所得的胶束与其对应的线性聚合物前体相比较有很大的不同,有着更高的临界胶束化浓度（CMC）,较小的流体力学半径（<R_n>）以及较低的平均聚集数(N_agg)。5.结合ROP和click反应,制备出结构明确的端基二苯并24-冠-8（DB24C8）官能化的四臂星形PCL（4-arm star PCL-DB24C8）以及两端二苄胺离子（DBAS）官能化的PCL（2-arm PCL-DBAS）。基于这些结构清晰的高分子前体并利用它们链端的冠醚基团和胺基之间的准轮烷连接作用,在非极性溶剂中较高的浓度下,环境响应性的超分子凝胶被成功构建。这些超分子凝胶表现出完全可逆的温度和pH响应的凝胶-溶液相变行为。然后,通过ATRP以及click化学反应制备了端基DB24C8功能化的聚苯乙烯（PS-DB24C8）,结合以上的2-arm PCL-DBAS,通过DB24C8和DBAS之间的主客体相互作用在非极性溶剂中构筑了超分子ABA三嵌段聚合物。通过改变PCL链的长度可以得到具有不同络合常数的三嵌段聚合物,基本的规律是随着PCL链的不断增长,空间位阻增大导致超分子自组装得到三嵌段超分子聚合物的络合常数逐渐降低。另外,所得到的超分子ABA三嵌段在选择性溶剂（40℃,环己烷）中可以自组装得到以PCL为核,PS为壳的核壳结构超分子胶束。胶束的核和壳之间通过冠醚和铵离子的主客体相互作用连接。6.通过以含金刚烷基团（AD）的ATRP引发剂引发聚合NIPAM,再通过端基叠氮化以及与大大过量的含三炔基团的小分子点击化学反应后,得到端基双炔官能化的AD-PNIPAM-（Alkynyl）₂。再与单叠氮基团官能化的β-环糊精（β-CD）进行点击化学反应成功制备了一端含一个AD和另一端两β-CD的聚合物,AD-PNIPAM-（β-CD）₂。在水溶液中,相对较高的浓度下,该AB₂型聚合物可以形成高分子量的超分子高分子超支化聚合物在,这可以通过二维NOESY谱图和粘度测试得到证明。7.通过RAFT聚合以基于PMEO₂MA的大分子RAFT试剂,成功合成了其中一个嵌段含三联吡啶基团的全亲水性两嵌段聚合物PMEO₂MA-b-P（DEA-co-TpyMA）。在合适的条件(较高的反应聚合物浓度,较高的反应温度,通过N-乙基吗啉还原Ru³⁺)下,该嵌段聚合物可以通过自交联得到金属络合超分子核交联（CCL）胶束。该CCL胶束的内核在水溶液中表现出了pH值敏感性,外壳表现出了温度敏感性,并且随着与Ru²⁺有着更高络合常数的配体羟乙基乙二胺三乙酸（HEEDTA）的加入,胶束可以成功解离得到单分子的嵌段聚合物。然后,基于两端三联吡啶功能化的PPO-PEO-PPO（tpy-PPO-PEO-PPO-tpy,PPO为聚环氧丙烷）,分别在较高（1g/mL）和较低（0.46 mg/mL）的络合反应浓度下,通过三联吡啶和Ru²⁺的金属配体络合作用构筑了金属超分子多嵌段聚合物以及环形聚合物。其中金属超分子多嵌段含有～6个重复单元。更多还原

【Abstract】 The supramolecular self-assembly of small molecular and polymeric building blocks via noncovalent interactions have exhibited important roles in developing novel biomaterials,smart devices,information science,and nanotechnology,which renders this interdiscipilary research subject as one of the key scientific issues in the 21st century.This dissertation mainly focuses on the fabrication and structural tuning of stimuli-responsive supramolecular polymeric assemblies.A series of amphiphilic and double hydrophilic block copolymers with varying chain topologies including AB diblock,AB₄ and A₄BA₄-type miktoarm star copolymers,dendritic-linear and macrocyclic block copolymers were synthesized.In aqueous solution, chain architectural effects on thier self-assembling properties under varying solution conditions were investigated.Moreover,their relevant applications in the field of catalysis,drug delivery,and clinical diaglosis（MRI） have ben explored. Stimuli-responsive supramolecular polymers with varying chain architectures were constructed via crown ether and cyclodextrin-based molecular recognition or terpyridine-based metal-ligand complexation,and their self-assembling properties in dilute solution and reversible gel formation at high concentrations were investigated. This dissertation can be further categorized into seven main parts as described below:1.Double hydrophilic block copolymers,poly（N-isopropylacrylamide）-b-poly（N-vinylimidazole ）（PNIPAM-b-PVim）,were successfully prepared with good control via reversible addition-fragmentation chain transfer（RAFT） using PNIPAM-based macromolecular xanthate agents（i.e.,MADIX,macromolecular design via the interchange of xanthates）.This represents the first preparation of well-defined block copolymers based on N-vinylimidazole,which has been well-known to be able to catalyze esterolysis reactions.The imidazole-containing diblock copolymers molecularly dissolve at low temperatures in water.Above the phase transition temperatures of PNIPAM or in a proper mixture of methanol/water（cononsolvency）,the PNIPAM block becomes hydrophobic and stable micelles form with a dense core consisting of a hydrophobic PNIPAM block and a polar PVim shell.The catalytic activities of PNIPAM-b-PVim toward the hydrolysis of p-nitrophenyl acetate（NPA） at different temperatures or methanol/water compositions were then determined and compared to that of PVim homopolymer.The Arrhenius plot for the PVim-based diblock copolymers exhibited a pronounced upward curvature above the critical micellization temperature（CMT）.Moreover,in the methanol/water mixture,the catalytic activities of PNIPAM-b-PVim diblock copolymers evolved discontinuously as a function of solvent composition and exhibited a maximum in the range of volume fraction of methanol,φ_methanol,between 0.3 and 0.5,corresponding to the solvent composition range where cononsolvency-induced micellization took place.For the first time,double hydrophilic block copolymer micelles of PNIPAM-b-PVim can serve as self-catalyzing nanoreactors.Most importantly, the catalytic activities can be well-tuned with external temperature or solvent compositions.In terms of potential applications of polymeric assemblies in clinical diagnosis（magnetic resonance imaging,MRI）,amphiphilic block copolymers,poly（ε-caprolactone）-b-poly（oligo（ethylene glycol） methacrylate -co-3-azidopropyl methacrylate）,PCL-b-P（OEGMA-co-AzPMA）,were synthesized via a combination of atom transfer radical polymerization（ATRP） and ring-open polymerization（ROP）.The subsequent click conjugation of PCL-b-P（OEGMA-co-AzPMA） with alkynyl-containing targeting moieties, alkynyl-folate,and MRI contrast agent,alkynyl-（DOTA）Gd afforded amphiphilic block copolymers,PCL-b-P（OEGMA-co-DOTA）Gd and PCL-b-P（OEGMA-co-folate ）.In aqueous solution,mixed micelles of PCL-b-P（OEGMA-co-DOTA）Gd and PCL-b-P（OEGMA-co-folate）（1:1 w/w） were obtained via self-assembly using ethanol as the cosolvent.In vivo MRI experiments in rabbits revealed mixed micelles can serve as excellent contrast agents to the liver organs. Moreover,the dug-loading capacity and controlled release profiles were also investigated.All the results augur well for potential applications of this novel type of biocompatible hybrid micelles beating targeting and MRI contrasting moieties for combined anti-cancer treatment and in-situ therapeutic monitoring.2.Amphiphilic dendritic-linear diblock copolymers,[G-2]-PNIPAM and [G-3]-PNIPAM,were prepared by reversible addition-fragmentation transfer （RAFT） polymerizations of N-isopropylacrylamide（NIPAM） by employing [G-2]- and[G-3]-based RAFT agents,respectively.Transmission electron microscopy results indicate the presence of spherical micelles in aqueous solutions.The thermo-responsive conformational changes of PNIPAM chains located at the micellar coronas have been thoroughly investigated with a combination of laser light scattering and excimer fluorescence of pyrene.The thermo-responsive collapse of the PNIPAM shell is a two-stage process;the first one occurs gradually in the temperature range of 20-29℃,which is much lower than the lower critical solution temperature（LCST） of linear PNIPAM homopolymer,followed by the second process,in which the main collapse of PNIPAM chains takes place in the narrow temperature range of 29-31℃.In terms of dumbbell-shaped dendritic-linear-dendritic triblock copolymers, [G-3]-PNIPAM-[G-3]was facilely synthesized via RAFT polymerization for the first time using novel[G-3]-based trithiocarbonate-containing RAFT agent, [G-3]-CH₂SCSSCH₂-[G-3],which was prepared from third-generation dendritic poly（benzyl ether） bromide,[G-3]-CH₂Br.The amphiphilic dumbbell-shaped triblock copolymer contains a thermo-responsive PNIPAM middle block.In aqueous solution,it self-assembles into spherical nanoparticles with the core consisting of hydrophobic[G-3]dendritic block and coronas of PNIPAM central blocks,which form loops surrounding the insoluble core.3.Well-defined double hydrophilic miktoarm AB₄ star copolymer, PNIPAM-b-（PDEA）₄,was synthesized by polymerizing 2-（diethylamino） ethyl methacrylate（DEA） via ATRP using PNIPAM-based tetrafunctional ATRP macroinitiator.For comparison,PNIPAM-b-PDEA linear diblock copolymer with comparable molecular weight and composition to that of PNIPAM-b-（PDEA）₄ was also prepared via RAFT polymerization.The chain architectural effects on pH- and thermo-responsive ’schizophrenic’ micellization behavior of the obtained PNIPAM₆₅-b-(PDEA₆₃)₄ and PNIPAM₇₀-b-PDEA₂₆₀ were investigated.In acidic solution and elevated temperatures,PNIPAM-core micelles were formed;whereas at slightly alkaline conditions and room temperature,structurally inverted PDEA-core micelles were formed.The size of the PDEA-core micelles of PNIPAM₆₅-b-(PDEA₆₃)₄ is much smaller than that of PNIPAM₇₀-b-PDEA₂₆₀.Furthermore,the pH-induced micellization kinetics of the AB₄ miktoarm star and AB block copolymers were investigated upon a pH jump from 4 to 10.Typical kinetic traces for the micellization of both types of copolymers can be well fitted with double-exponential functions,yielding a fast （τ₁） and a slow（τ₂） relaxation processes.τ₁ for both copolymers decreased with increasing polymer concentration.τ₂ was independent of polymer concentration for PNIPAM₆₅-b-(PDEA₆₃)₄,whereas it decreased with increasing polymer concentration for PNIPAM₇₀-b-PDEA₂₆₀.Following similar protocols,H-shaped A₂BA₂-type and A₄BA₄-type star copolymers possessing pH-responsive and thermoresponsive arms,（PDEA）₂-PNIPAM-b-（PDEA）₂ and（PDEA）₄-PNIPAM -b-（PDEA）₄,were also synthesized and their multi-responsive supramolecular self-assembly in aqueous solution were investigated.In another example,double hydrophilic heteroarm star copolymers of poly（methacrylic acid） （PMAA） and poly（ethylene oxide）（PEO） possessing a cross-linked microgel core of poly（divinylbenzene）（PDVB） were synthesized via ATRP using the "in-out" method.This novel type of double hydrophilic heteroarm star copolymer can be considered as unimolecular micelles with hybrid coronas.The star copolymers exhibited pH-dependent solubility in water,being soluble at high pH and insoluble at low pH,due to the formation of hydrogen-bonded complexes between the PEO and PMAA arms.A mixed solution of the heteroarm star copolymer and a PEO-b-PQDMA diblock copolymer,where PQDMA is poly（2-（dimethylamino） ethyl methacrylate） fully quatemized with methyl iodide, remained stable in the whole pH range,and exhibited an intriguing pH-switchable complexation behavior accompanied with structural rearrangement.At high pH,the PQDMA block and ionized PMAA arms formed insoluble polyelectrolyte complexes,which were co-stabilized by PEO chains from both the PEO-b-PQDMA and the（PEO）_n-PDVB-（PMAA）_n.At low pH,the neutral PMAA arms and PEO formed hydrogen-bonded complexes,and the colloidal particles again possessed a hydrophobic PDVB core,an inner layer of PMAA/PEO hydrogen-bonded complexes,and a stabilizing PQDMA outer corona.4.α-Alkynyl-ω-azidoheterodifunctional linear-PMEO₂MA-b-POEGMA-N₃ was synthesized via the azidation of alkynyl-terminated PMEO₂MA-b-POEGMA-Br prepared via successive ATRP,where PMEO₂M was poly（2-（2-methoxy-ethoxy）-ethylmethacrylate ）.High end group functionality of linear precursors is crucial to achieve successful cyclization reaction and confirming the strategy of high-efficiency cyclization under micellar conditions.Firstly,the evolution of chain-end functionality during the preparation of heterodifunctional linear diblock copolymer was determined by ATRP of MEO₂MA using benzyl 2-bromoisobutyrate（BBIB） as the initiator under the same conditions,after its transformation into benzyl-PMEO₂MA-N₃ and the subsequent click reaction with an excess of 1-（2-propynyloxy）benzene,the end group functionality of benzyl-PMEO₂MAA -N₃ was determined to be 96%.Following similar procedures,the end group functionality of benzyl-PMEO₂MA-b-POEGMA-N₃ was also determined to be very high（＞90%）.Thus,the end functionality of linear-PMEO₂MA-b-POEGMA-N₃ can be determined to be＞90%.Then,the high-efficiency synthesis of water-soluble cyclic diblock copolymers, cyclic-PMEO₂MA-b-POEGMA,was achieved via "selective" click reaction in aqueous micellar solutions ofα,ω-heterodifunctional linear precursors at a relatively high concentration（10 g/L）,which relies on controlling the spatial accessibility between terminal reactive groups within micellar entities and the "tadpole" conformation of unimers.Moreover,it was found that macrocyclic diblock copolymers,possess higher CMC values,smaller <R_h>,and lower average aggregation numbers(N_agg) in self-assembled micelles,as compared to their linear precursors5.DB24C8-terminated four-arm star PCL（4-arm star PCL-DB24C8） and DBAS-terminated two-arm PCL（2-arm PCL-DBAS） were synthesized by a combination of ROP and click reaction.Based on these well-defined precursors, stimuli-responsive supramolecular gels were constructed,taking advantage of the formation of pseudorotaxane linkages between terminal crown ether and ammonium moieties.The resultant supramolecular gels underwent thermo- and pH-induced reversible gel-sol transitions.Moreover,the obtained multiresponsive supramolecular networks contain cavities,the size of which are expected to be facilely adjusted by changes in the arm lengths of 4-arm star PCL-DB24C8 and 2-arm PCL-DBAS.This augurs well for their applications as smart nanocarriers for guest molecules and complicated molecular devices. Supramolecular ABA triblock copolymers based on crown ether-based molecular recognition were also fabricated.DB24C8-terminated polystyrene（PS-DB24C8） was synthesized via the ATRP of styrene and subsequent click reaction.The mixed solution of PS₂₄-DB24C8 and DBAS-PCL-DBAS form reversible supramolecular ABA triblock copolymers via peseudorotaxane formation.With the increase of molecular weights of DBAS-PCL-DBAS,the average association constants between PS₂₄-DB24C8 and DBAS-PCL-DBAS decreased rapidly due to the steric effect of the PCL coils with higher molecular weights.Supramolecular ABA triblock copolymer,PS₂₄-PCL₃₆-PS₂₄,self-assembles into micelles in the selective solvent of PS outer blocks（cyclohexane,40℃）.6.Supramolecular hybranched polymers were constructed via cyclodextrin （CD）-based molecular recognition.AB₂ type macromonomer containing one adamantyl（AD） and twoβ-CD moieties,AD-PNIPAM₁₁-（β-CD）₂,was synthesized via atom transfer radical polymerization（ATRP） and consecutive "click" reactions.General synthetic routes employed for the preparation of AD-PNIPAM₁₁-（β-CD）₂ are as follows.AD-PNIPAM₁₁-N₃ was prepared via ATRP using AD-Cl as the initiator and the subsequent nucleophilic substitution reaction with NaN₃.The ’click’ reaction between AD-PNIPAM₁₁-N₃ and an excess of trialkynyl-containing small molecule afforded dialkynyl-terminated polymer,AD-PNIPAM₁₁-（Alkynyl）₂.The target product,AD-PNIPAM₁₁-（β-CD）₂, was prepared via click coupling reaction between AD-PNIPAM₁₁-（Alkynyl）₂ andβ-CD-N₃.In aqueous solution,AD-PNIPAM₁₁-（β-CD）₂ can self-organize into supramolecular hyperbranched polymer at relatively higher concentrations, which have been evidenced by 2D NOESY spectrum and viscosity measurements.7.Terpyridine-containing double hydrophilic diblock copolymer,PMEO₂MA-b-P （DEA-co-TpyMA）,was successfully prepared with good control via RAFT polymerization by employing PMEO₂MA-based macromolecular RAFT agent. Structurally stable core cross-linked（CCL） nanoparticles were prepared in ethanol upon addition of ruthenium（Ⅲ） and N-ethylmorpholine via the formation of bis（2,2’:6’,2"-terpyridine） ruthenium（Ⅱ） complexes.In aqueous solution,the nanoparticles exhibit pH-responsive core swelling/collapse and thermoresponsive corona swelling/collapse.Interestingly,the obtained metallo-supramolecular CCL nanoparticles can be disintegrated into unimers upon addition of N-（2-hydroxyethyl）ethylenediaminetriacetic acid（HEEDTA）. Furthermore,metallo-supramolecular multiblock and cyclic block copolymers were fabricated from terpyridine-terminated PPO-PEO-PPO（tpy-PPO-PEO-PPO -tpy） via the formation of bis（2,2’:6’,2"-terpyridine）-ruthenium（Ⅱ） complexes at relatively high concentration（1 g/mL） and low concentration（0.46 mg/mL）,where PPO is polyprpylene oxide.The number of repeating sequences of metallo- supramolecular multiblock copolymer was estimated to be～6 from GPC results.更多还原