Synthesis and characterization of side‐chain liquid‐crystalline polymers and study of their role in the crystallization of high‐density polyethylene

Side‐chain liquid‐crystalline polymers (SCLCPs) as nucleating agents for high‐density polyethylene (HDPE) were investigated. For this purpose, the molecular architectures of four different vinyl monomers with liquid‐crystalline properties were designed and prepared with 1‐butanol, 1‐pentanol, 4‐hydroxybenzoic acid, hydroquinone, and acryloyl chloride as the starting materials through alkylation and acylation reactions. The corresponding polymers were synthesized by homopolymerization in 1,4‐dioxane with benzoyl peroxide as the initiator at 60 °C. Both the monomers and the synthesized polymers were characterized with elemental analysis, Fourier transform infrared, and ¹H NMR measurements. Differential scanning calorimetry, thermogravimetric analysis, and hot stage polarized optical microscopy were employed to study the phase‐transition temperature, mesophase texture, and thermal stability of the liquid‐crystalline polymers. The results showed that all the polymers had thermotropic liquid‐crystalline features. Being used as nucleating agents, SCLCPs effectively increased both the crystallization temperature and rate and, at the same time, raised the crystallinity for HDPE. In comparison with common small‐molecule nucleating agents, such as 1,3:2,4‐dibenzylidenesorbitol, SCLCPs are more efficient and are indeed excellent nucleating agents for HDPE. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3067–3078, 2005     

Self‐assembly of amphiphilic tris(2,2′‐bipyridine)ruthenium‐cored star‐shaped polymers

Amphiphilic tris(2,2′‐bipyridine)ruthenium‐cored star‐shaped polymers consisting of one polystyrene block and two poly(N‐isopropylacrylamide) blocks were prepared by the “arm‐first” method in which RAFT polymerization and nonconvalent ligand–metal complexation were employed. The prepared amphiphilic star‐shaped metallopolymers are able to form micelles in water. The size and distribution of the micelles were studied by dynamic light scattering and transmission electron microscopy techniques. Preliminary studies indicate that the polymer concentration and the hydrophilic poly(N‐isopropylacrylamide) block length can affect the morphologies of the formed metal‐interfaced core–shell micelles in water. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4204–4210, 2007     

Self‐assembly phenomena of the brush‐like amphiphilic organopolysiloxanes in aqueous solution

A series of brush‐like amphiphilic organopolysiloxanes with varying hydrophilic side‐chains was prepared, and the assembly behavior of these promising polymers was investigated in aqueous solution using a combination method of surface tension, steady‐state fluorescence, dynamic light scattering, and transmission electron microscopy. An increasing number of side‐chains could lead a higher surface tension of the polymer solution. The polymers formed regular “micelle‐like” spherical multipolymer assemblies in aqueous solution with the size distributed from the scale of hundreds to that of tens of nanometer, and the polymers that possessed more of the side‐chains would form comparatively loose and swollen assemblies with slightly higher micropolarities and bigger dimensions. The interesting discovery in this report was that the visible clearness of the solution could be improved by increasing the hydrophilicity of the assemblies in the solution. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis and self‐assembly of amphiphilic dendronized conjugated polymers

Two kinds of amphiphilic dendronized conjugated polymers, polyfluorene (PF) and poly(binaphthyl‐alt‐fluorene) (PBF), were synthesized by Suzuki polycondensation of hydrophobic macromonomers with two nonpolar octyloxy chains and hydrophilic macromonomers with two polar oligo(ethylene oxide) chains. In these polymers, PF possesses a linear rod‐like backbone structure, and PBF adopts a folded rigid backbone structure. The different configurations in the conjugated main chains result in different supramolecular self‐assembly morphologies. The optical and thermal properties of PF and PBF were also studied. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 574–584, 2008     

Influence of crystalline peripheral chain length on the solid‐state assemblies of amphiphilic dendrons

We prepared third‐generation amphiphilic dendrons 3‐14 and 3‐18 consisting of a hydrophilic aliphatic polyether dendritic core and either tetradecyl or octadecyl peripheries, respectively. Their solid‐state self‐assembly behavior was investigated by comparison with 3‐22 having the same dendritic core and longer docosyl peripheries. In marked contrast to the lamellar assembly of 3‐22 , small‐angle X‐ray analysis suggested that 3‐14 and 3‐18 show oblique columnar structures with presumably elliptical cross sections. The observed results can be rationalized by dendron shape anisotropy, which is strongly associated with the degree of crystallization as a function of alkyl chain length. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4988–4994, 2007     

Polymersome‐forming amphiphilic glycosylated polymers: Synthesis and characterization

Copper‐catalyzed azide‐alkyne cycloaddition (CuAAC) was used to prepare glycosylated polyethylene (PE)–poly(ethylene glycol) (PEG) amphiphilic block copolymers. The synthetic approach involves preparation of alkyne‐terminated PE‐b‐PEG followed by CuAAC reaction with different azide functionalized sugars. The alkyne‐terminated PE‐b‐PEG was prepared by etherification reaction between hydroxyl‐terminated PE‐b‐PEG (M_n ～ 875 g mol^?1) and propargyl bromide and azidoethyl glycosides were prepared by glycosylation of 2‐azidoethanol. Atmospheric pressure solids analysis probe‐mass spectrometry was used as a novel solid state characterization tool to determine the outcome of the CuAAC click reaction and end‐capping of PE‐b‐PEG by the azidoethyl glycoside group. The aqueous solution self‐assembly behavior of these amphiphilic glycosylated polymers was explored by TEM and dye solubilization studies. Carbohydrate‐bearing spherical aggregates with the ability to solubilize a hydrophobic dye were observed. The potential of these amphiphilic glycosylated polymers to self‐assemble via electro‐formation into giant carbohydrate‐bearing polymersomes was also investigated using confocal fluorescence microscopy. An initial bioactivity study of the carbohydrate‐bearing aggregates is furthermore presented. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5184–5193     

The self‐assembly over nano‐ to submicro‐length scales in water of a fluorescent julolidine‐labeled amphiphilic random terpolymer

A novel fluorescent‐labeled amphiphilic random terpolymer is synthesized by controlled radical polymerization of a fluorescent molecular rotor monomer, 2‐cyano‐2‐[4‐vinyl(1,1′‐biphenyl)‐4′‐yl]vinyljulolidine, a hydrophilic monomer, poly (ethylene glycol) methyl ether methacrylate, and a hydrophobic monomer, perfluorohexylethyl acrylate. Combined dynamic light scattering and fluorescence emission spectroscopy measurements are used to investigate its self‐assembly in water solution. Self‐assembled nanostructures with a hydrodynamic diameter size D_h of 4 ± 1 nm are detected due to the single‐chain folding of the terpolymer in unimer micelles. The fluorescence emission intensity of the terpolymer in water solution is found to be one order of magnitude higher than that in organic solvents, as a result of the preferential encapsulation of the julolidine co‐units in hydrophobic compartments of the unimer micelles. The temperature dependence of the self‐associative behavior of the amphiphilic terpolymer is also investigated and a critical temperature is identified at which a transition between single‐chain unimer micelles and multi‐chain aggregates (D_h = 400 ± 40 nm) reversibly takes place on heating–cooling cycles. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 797–804     

Construction of nanostructures in aqueous solution from amphiphilic glucose‐derived polycarbonates

Carbohydrates are the fundamental building blocks of many natural polymers, their wide bioavailability, high chemical functionality, and stereochemical diversity make them attractive starting materials for the development of new synthetic polymers. In this work, one such carbohydrate, d ‐glucopyranoside, was utilized to produce a hydrophobic five‐membered cyclic carbonate monomer to afford sugar‐based amphiphilic copolymers and block copolymers via organocatalyzed ring‐opening polymerizations with 4‐methylbenzyl alcohol and methoxy poly(ethylene glycol) as initiator and macroinitiator, respectively. To modulate the amphiphilicities of these polymers acidic benzylidene cleavage reactions were performed to deprotect the sugar repeat units and present hydrophilic hydroxyl side chain groups. Assembly of the polymers under aqueous conditions revealed interesting morphological differences, based on the polymer molar mass and repeat unit composition. The initial polymers, prior to the removal of the benzylidenes, underwent a morphological change from micelles to vesicles as the sugar block length was increased, causing a decrease in the hydrophilic–hydrophobic ratio. Deprotection of the sugar block increased the hydrophilicity and gave micellar morphologies. This tunable polymeric platform holds promise for the production of advanced materials for implementation in a diverse range of applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 432–440     

Preparation of few‐layer two‐dimensional polymers by self‐assembly of bola‐amphiphilic small molecules

Two bola‐amphiphilic small molecules, based on the diphenylanthracene skeleton structure, namely, BASM‐1 and its functionalized small molecule BASM‐2 , were designed and synthesized. The self‐assembly behavior and mechanism of these two molecules in aqueous solution were studied. The supramolecular two‐dimensional (2D) layer and the covalent 2D polymers were, respectively, prepared by these two molecules. What is more, the transverse size of the covalent 2D polymer laminates increased with the extension of the polymerization time. Atomic force microscopy results showed that both free‐standing single‐layer 2D polymers and few layer laminates with two to three molecular layers were obtained. So our work provides a simple and efficient method for directly preparing independent both supramolecular 2D polymers and covalent 2D polymers in liquid phase which is of great significance. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1748–1755     

Synthesis of azobenzene‐containing polymers via RAFT polymerization and investigation on intense fluorescence from aggregates of azobenzene‐containing amphiphilic diblock copolymers

The well‐defined azobenzene‐containing homopolymers, poly{6‐(4‐phenylazophenoxy)hexyl methacrylate (AHMA)} (PAHMA), were synthesized via reversible addition fragmentation chain transfer polymerization (RAFT) in anisole solution using 2‐cyanoprop‐2‐yl 1‐dithionaphthalate (CPDN) as the RAFT agent and 2,2′‐azobisisobutyronitrile (AIBN) as the initiator. The first‐order kinetic plot of the polymerization and the linear dependence of molecular weights of the homopolymers with the relatively low polydispersity index values (PDIs ≤ 1.25) on the monomer conversions were observed. Furthermore, the amphiphilic diblock copolymer, poly{6‐(4‐phenylazophenoxy)hexyl methacrylate (AHMA)}‐b‐poly{2‐(dimethylamino)ethyl methacrylate (DMAEMA)} (PAHMA‐b‐PDMAEMA), was prepared with the obtained PAHMA as the macro‐RAFT agent. The structures and properties of the polymers were characterized by ¹H NMR and GPC, respectively. Interestingly, the amphiphilic diblock copolymers in chloroform (CHCl₃) solution (PAHMA₂₃‐b‐PDMAEMA₉₇ (4 × 10^?5 M, M_n(GPC) = 18,400 g/mol, PDI = 1.48) and PAHMA₂₈‐b‐PDMAEMA₁₁₇ (6 × 10^?5 M, M_n(GPC) = 19,300 g/mol, PDI = 1.51) exhibited the intense fluorescence emission at ambient temperature. Moreover, the fluorescent intensity of PAHMA‐b‐PDMAEMA in CHCl₃ was sensitive to the ultraviolet irradiation at 365 nm, which increased within the first 10 min and later decreased when irradiation time was prolonged to 30 min or longer. The well distributed, self‐assembled micelles composed of azobenzene‐containing amphiphilic diblock copolymers, (PAHMA‐b‐QPDMAEMA)s (QPDMAEMA is quaternized PDMAEMA), in the mixed N,N‐dimethyl formamide (DMF)/H₂O solutions were prepared. Their fluorescent intensities decreased with the increasing amount of water. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5652–5662, 2008     

Angle‐resolved XPS of fluorinated and semi‐fluorinated side‐chain polymers

Angle‐resolved XPS data (elemental quantification and high‐energy‐resolution C 1s) are presented for ten polymers with side‐chains of the form ? OCO(CF₂)_yF, ? COO(CH₂)₂OCO(CF₂)_yF (y = 1, 2, 3) and ? COO(CH₂)_x(CF₂)_yF (x = 1, y = 1, 2, 3; x = 2, y = 8). Particular attention was paid to charge compensation and speed of data acquisition, with co‐addition from multiple fresh samples to give spectra with good energy resolution and good signal‐to‐noise ratio free from the effects of x‐ray‐induced degradation. Water contact angles for the polymers are also reported. The XPS data demonstrate preferential surface segregation of fluorine‐containing groups for all but the shortest side‐chain polymer, where the ? OCOCF₃ side‐chain either does not surface segregate or is too short for surface segregation to be detectable by angle‐resolved XPS. In the other polymers studied the relative positions of functional groups in the side‐chains correlate with the angle‐resolved behaviour of the corresponding C 1s components. This shows that the surface side‐chains are oriented towards the polymer surface. For the ? COO(CH₂)₂OCO(CF₂)_yF (y = 1) side‐chain, the angle‐resolved C 1s data suggest reduced ordering and linearity compared with y = 2 and 3. For any particular series of polymers, e.g. ? COO(CH₂)_x(CF₂)_yF, the water contact angles increase with y, consistent with burying of the hydrophilic ester groups as y increases. For any particular value of y the sequence of water contact angles is ? COO(CH₂)_x(CF₂)_yF > ? OCO(CF₂)_yF ～ ? COO(CH₂)₂OCO(CF₂)_yF, suggesting greater ordering and density of fluorocarbon species at the surface of the ? COO(CH₂)_x(CF₂)_yF side‐chain polymers compared with the other polymers studied. For the ? COO(CH₂)₂(CF₂)₈F polymer a water contact angle of 124° is measured, which is greater than that of poly(tetrafluoroethene). The ? COO(CH₂)₂OCO(CF₂)F polymer is unusual in that it shows a particularly low water contact angle (83° ), suggesting that the probe fluid is able to sense both ester groups, consistent with the reduced ordering of the side‐chain detected by angle‐resolved XPS. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis and properties of mesogen‐jacketed liquid crystalline polymers containing bistolane mesogen

On the basis of the concept of mesogen‐jacketed liquid crystalline polymers, a series of new methacrylate monomers, (2,5‐bis[2‐(4′‐alkoxyphenyl) ethynyl] benzyl methacrylate (MACn, n = 4, 6, 8, 10, and 12) and 2,5‐bis[2‐(6′‐decanoxynaphthyl) ethynyl] benzyl methacrylate (MANC10), and their polymers, PMACn (n = 4, 6, 8, 10, and 12) and PMANC10 were synthesized. The bistolane mesogen with large π‐electron conjugation were side‐attached to the polymer backbone via short linkages. Various characterization techniques such as differential scanning calorimetry, wide‐angle X‐ray diffraction, and polarized light microscopy were used to study their mesomorphic phase behavior. The polymer PMACn with shorter flexible substituents (n = 4) forms the columnar nematic (?_N) phase, but other polymers with longer flexible tails (n = 6, 8, 10, and 12) can develop into a smetic A (S_A) phase instead of a ?_N phase. The PMANC10 containing naphthyl can also form a well‐defined S_A phase. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Free‐energy model of asymmetry in side‐chain liquid‐crystalline diblock copolymers

Side‐chain liquid‐crystalline‐b‐amorphous copolymers combine the thermotropic ordering of liquid crystals (LCs) with the physics of block copolymer phase segregation. In our earlier experiments, we observed that block copolymer order–order and order–disorder transitions could be induced by LC transitions. Here we report the development of a free‐energy model to understand the interplay between LC ordering and block copolymer morphology in an incompressible melt. The model considers the interaction between LC moieties, the stretching of amorphous chains from curved interfaces, interfacial surface contributions, and elastic deformation of the nematic phase. The LC block is modeled with Wang and Warner's theory, in which nematogens interact through mean‐field potentials, and the LC backbone is modeled as a wormlike chain. Free energy is estimated for various morphologies: homogeneous, lamellar, cylinder micelle, and spherical micelle. Phase diagrams were constructed by iteration over temperature and composition ranges. The resulting composition diagrams are highly asymmetric, and a variety of first‐order transitions are predicted to occur at the LC clearing temperature. Qualitatively, nematic deformation energies destabilize curved morphologies, especially when the LC block is in the center of the block copolymer micelle. The thermodynamics of diblocks with laterally attached, side‐on mesogens are also explored. Discussion focuses on how well the model captures experimental phenomena and how the predicted phase boundaries are affected by changes in polymer architecture. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2671–2691, 2001     

Synthesis and characterization of hyperbranched amphiphilic block copolymers prepared via self‐condensing RAFT polymerization

Four families of hyperbranched amphiphilic block copolymers of styrene (Sty, less polar monomer) and 2‐vinylpyridine (2VPy, one of the two more polar monomers) or 4‐vinylpyridine (4VPy, the other polar monomer) were prepared via self‐condensing vinyl reversible addition‐fragmentation chain transfer polymerization (SCVP‐RAFT). Two families contained 4VPy as the more polar monomer, one of which possessing a Sty‐b‐4VPy architecture, and the other possessing the reverse block architecture. The other two families bore 2VPy as the more polar monomer and had either a 2VPy‐b‐Sty or a Sty‐b‐2VPy architecture. Characterization of the hyperbranched block copolymers in terms of their molecular weights and compositions indicated better control when the VPy monomers were polymerized first. Control over the molecular weights of the hyperbranched copolymers was also confirmed with the aminolysis of the dithioester moiety at the branching points to produce linear polymers with number‐average molecular weights slightly greater than the theoretically expected ones, due to recombination of the resulting thiol‐terminated linear polymers. The amphiphilicity of the hyperbranched copolymers led to their self‐assembly in selective solvents, which was probed using atomic force microscopy and dynamic light scattering, which indicated the formation of large spherical micelles of uniform diameter. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1310–1319     

Light‐driven and aggregation‐induced emission from side‐chain azoindazole polymers

The well‐defined azoindazole‐containing homopolymer, poly(6‐{6‐[(4‐dimethylamino) phenylazo]‐indazole}‐hexyl methacrylate) (PDHMA), and amphiphilic diblock copolymer, poly({6‐[6‐(4‐dimethylamino)phenylazo]‐indazole}‐hexyl methacrylate)‐b‐poly(2‐(dimethylamino)ethylmethacrylate) (PDHMA_m‐b‐PDMAEMA_n), were successfully prepared via reversible addition‐fragmentation chain transfer polymerization technique. The homopolymer and amphiphilic diblock copolymer in CH₂Cl₂ exhibited intense fluorescence emission accompanied by trans–cis photoisomerization of azoindazole group under UV irradiation. The experiment results indicated that the intense fluorescence emission may be attributed to an inhibition of photoinduced electron transfer of the cis form of azoindazole. On the other hand, the intense fluorescence emission of amphiphilic diblock copolymers in water‐tetrahydrofuran mixture was observed, which increased with the volume ratio of water in the mixed solvent. The self‐aggregation behaviors of three amphiphilic diblock copolymers were examined by transmission electron microscopy, laser light scattering, and UV–vis spectra. The restriction of intramolecular rotation of the azoindazole groups in aggregates was considered as the main cause of aggregation‐induced fluorescence emission. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

Study of supramolecular side‐chain and cross‐linking polymers by complexation of various H‐donor acids with H‐acceptor copolymers containing pendent carbazole and fluorescent pyridyl units

Two H‐bonded acceptor (H‐acceptor) homopolymers 14 and 17 were successfully prepared by polymerization of fluorescent pyridyl monomers PBT and PBOT ( 12 and 13 ), which were synthesized via Sonogashira coupling and Wittig‐Horner reactions. To increase the glass transition temperatures as well as reduce the π‐π stacking of the photoluminescent (PL) H‐acceptor copolymers and their H‐bonded polymer complexes, fluorescent monomers 12 and 13 were copolymerized with N‐vinylcarbazole monomer CAZ (23) to produce H‐acceptor copolymers 15–16 and 18–19 . Supramolecular side‐chain and crosslinking polymers (i.e., H‐bonded polymer complexes) obtained by complexation of light‐emitting H‐acceptor polymers 14–19 with various proton donor (H‐donor) acids 20–22 were further characterized by DSC, POM, FTIR, XRD, and PL measurements. The mesomorphic properties can be tuned from the nematic phase in H‐acceptor homopolymers ( 14 and 17 ) to the tilted smectic C phase in their H‐bonded polymer complexes ( 14/20–21 and 17/20–22 ) by the introduction of H‐donor acids (20–22). Moreover, the PL properties of light‐emitting H‐acceptor polymers can be adjusted not only by the central structures of the conjugated pyridyl cores but also by their surrounding nonfluorescent H‐donor acids. In general, redder shifts of PL emissions in H‐bonded polymer complexes occurred when the light‐emitting H‐acceptor polymers were complexed with H‐donors having smaller pKa values. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2734–2753, 2009     

The preparation of amphiphilic core‐shell nanospheres by using water‐soluble macrophotoinitiator

The amphiphilic poly(AM‐co‐SA)‐ITXH macrophotoinitiator was synthesized by precipitation photopolymerization under UV irradiation with isopropylthioxanthone (ITX) as free radical photoinitiator. A novel method has been developed to prepare amphiphilic core‐shell polymer nanospheres via photopolymerization of methyl methacrylate (MMA) in aqueous media, with amphiphilic copolymer macrophotoinitiator poly(AM‐co‐SA)‐ITXH. During polymerization, the amphiphilic macroradicals underwent in situ self‐assembly to form polymeric micelles, which promoted the emulsion polymerization of the monomer. Thus, amphiphilic core‐shell nanospheres ranging from 70 to 140 nm in diameter were produced in the absence of surfactant. The conversion of the monomer, number average molecular weights (M_n), and particle size were found to be highly dependent on the macrophotoinitiator and monomer concentration. The macrophotoinitiator and amphiphilic particles were characterized by FTIR, UV‐vis, ¹H NMR, TEM, DSC, and contact angle measurements. The results showed the particles had well‐defined amphiphilic core‐shell structure. This new method is scientifically and technologically significant because it provides a commercially viable route to a wide variety of novel amphiphilic core‐shell nanospheres. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 936–942, 2010     

Synthesis of amphiphilic and thermosensitive graft copolymers with fluorescence P(St‐co‐(p‐CMS))‐g‐PNIPAAM by combination of NMP and RAFT methods

A three‐step process, combining nitroxide‐mediated polymerization (NMP) and reversible addition‐fragmentation chain transfer (RAFT) polymerization techniques, for synthesizing well‐defined amphiphilic and thermosensitive graft copolymers with fluorescence poly(styrene‐co‐(p‐chloromethylstyrene))‐g‐poly(N‐isopropylacrylamide) (P(St‐co‐(p‐CMS))‐g‐PNIPAAM), was conducted. Firstly, the NMP of styrene (St) and p‐chloromethylstyrene (p‐CMS) were carried out using benzoyl peroxide (BPO) as the initiator to obtain the random copolymers of P(St‐co‐(p‐CMS)). Secondly, the random copolymers were converted into macro‐RAFT agents with fluorescent carbazole as Z‐group through a simple method. Then the macro‐RAFT agents were used in the RAFT polymerization of N‐isopropylacrylamide (NIPAAM) to prepare fluorescent amphiphilic graft copolymers P(St‐co‐(p‐CMS))‐g‐PNIPAAM with controlled molecular weights and well‐defined structures. The copolymers obtained were characterized by gel permeation chromatography (GPC), ¹H nuclear magnetic resonance (NMR) spectroscopy, and FT‐IR spectroscopy. The size of self‐assembly micelles of the resulting graft copolymers in deionized water was studied by high performance particle sizer (HPPS), the results showed that the Z‐average size of the micelles increased with the increase of molecular weights of PNIPAAM in side chains. The aqueous solution of the micelles prepared from P(St‐co‐(p‐CMS))‐g‐PNIPAAM using a dialysis method showed a lower critical solution temperature (LCST) at ～ 27.5 °C, which was below the value of NIPAAM homopolymer (32 °C). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5318–5328, 2007     

Synthesis of triblock and multiblock methacrylate polymers and self‐assembly of stimuli responsive triblock polymers

Multisegmented poly(methacrylate)s were synthesized using one pot reversible addition fragmentation chain transfer polymerization. Initially, a series of triblock copolymers were synthesized with different ratios of trimethylsilyl methacrylate, di(ethylene oxide) methacrylate, and oligo(ethylene oxide) methacrylate, and different total polymer molecular weights. Additionally, a polymer containing seven distinct blocks of methacrylic monomers was synthesized in one pot. For the triblock copolymers, the trimethylsilyl group was subsequently hydrolyzed, and the self‐assembly of the triblock copolymer was studied in water, under different pH and thermal conditions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2548–2555     

Crystallization‐Driven Self‐Assembly of Rod–Coil–Rod Pseudopolyrotaxanes into Spherical Micelles,Nanorods, and Nanorings in Aqueous Solutions

A novel rod‐containing block copolymer is constructed by supramacromolecular self‐assembly of α‐cyclodextrin and a triblock copolymer with methoxy polyethylene glycol as the flanking chains and the midterm block alternately connected by 2,2‐dimethylolbutyric acid and isophorone diisocyanate. The assembled rod‐containing block copolymer shows an exciting phenomenon of concentration‐ and pH‐dependent morphological switching of well‐defined nanostructures. In the solutions at pH 9.2, spherical micelles, rod‐like micelles, and hydrogel are observed successively with an increase of the concentration. Notably, the rod‐like micelles are composed of spherical segments due to the combination of the crystalline cores of the spherical micelles. In addition, 1D nanostructures with different curvatures from linear rod‐like micelles (pH 9.2) to ring‐shaped micelles (pH 7.5) can be obtained by controlling the pH values of the assembled systems.