Synthesis and properties of novel fluoroalkyl end‐capped oligomers containing phosphorus segments

New fluoroalkyl end‐capped oligomers containing pendant phosphoric acid groups wereprepared by the reactions of the corresponding monomer with fluoroalkanoyl peroxides. It was demonstrated that not only strong aggregations of fluoroalkyl segments but also hydrogen bonding could interact synergistically to form the highly viscoelastic fluids (gel‐like fluids) in aqueous solutions of these new fluoroalkyl end‐capped oligomers containing pendant phosphoric acid groups. Furthermore, these oligomers were able to reduce the surface tension of water effectively to exhibit a clear breakpoint resembling a CMC, and the modified stainless‐steel surface treated with these oligomers was shown to possess an excellent property imparted by fluorine. More interestingly, these oligomers were found to be potent and selective inhibitors against HIV‐1 replication in vitro. New fluoroalkyl end‐capped phosphonic acid and phosphonate oligomers were also prepared by the reactions of the corresponding phosphonic acid and phosphonate monomers, respectively, by the use of fluoroalkanoyl peroxides. These new fluoroalkyl end‐capped phosphonic acid and phosphonate oligomers were found to have a higher solubility in not only water but also in common organic solvents than that of the corresponding fluorinated oligomers containing pendant phosphoric acid groups, and these new oligomers were able to reduce the surface tension of these solvents quite effectively. Thus, these oligomers are expected to develop as new fluorinated oligosurfactants. Moreover, the modified poly(methyl methacrylate) surface treated with these phosphonate oligomers was clarified to exhibit a good oil‐repellency imparted by fluorine. In addition, fluoroalkyl end‐capped phosphonate homo‐ and cooligomers were found to form monomolecular films at the air–water interface. Therefore, these fluorinated oligomers are suggested to have high potential for new functional materials through not only their excellent properties imparted by both fluorine and phosphorus, but also through their biological properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 228–245, 2001     

Synthesis and gelation of novel fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide copolymers containing triol segments—Interaction of these fluorinated gels with various hydrophilic compounds

Fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide (DOBAA) copolymers containing triol segments were prepared by the reactions of fluoroalkanoyl peroxide with the corresponding monomer and N‐tris(hydroxymethyl)methylacrylamide (NAT). These obtained fluorinated copolymers [R_F‐(DOBAA)_x‐(NAT)_y‐R_F] were found to cause gelation in water, dimethyl sulfoxide, and N,N‐dimethylformamide under the non‐crosslinked conditions, although the corresponding nonfluorinated DOBAA–NAT copolymer [‐(DOBAA)_x‐(NAT)_y‐] could cause no gelation in these solvents. This gelation is governed by the synergistic interaction of strong aggregations of end‐capped fluoroalkyl segments and intermolecular hydrogen bonding between triol segments. We also studied the uptake and release of a variety of hydrophilic compounds such as methylene blue, methyl orange, 4‐hydroxyazobenzene‐4′‐sulfonic acid sodium salt, 2,4‐dihydroxyazobenzene‐4′‐sulfonic acid sodium salt, acriflavine hydrochloride, acridine hydrochloride, lucigenin, and fluorescein by this fluorinated copolymer gel and fluoroalkyl end‐capped NAT homopolymer gel [R_F‐(NAT)_n‐RF] for comparison. It was demonstrated that the uptake and release ratios of these hydrophilic compounds by R_F‐(DOBAA)_x‐(NAT)_y‐R_F gel become generally lower than those of R_F‐(NAT)_n‐R_F gel. Interestingly, R_F‐(DOBAA)_x‐(NAT)_y‐R_F gel has no releasing power toward methylene blue, acridine hydrochloride, lucigenin, and fluorescein, although R_F‐(NAT)_n‐R_F gel has a good releasing power toward these compounds. Additionally, R_F‐(DOBAA)_x‐(NAT)_y‐R_F gel was applied to the controlled release of anticancer drugs such as methotrexate (MTX), and the releasing ratios of MTX became higher with increasing pH values (from pH 4.3 to 9.1). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88:3212–3217, 2003     

Facile preparation and characterization of novel fluoroalkyl end‐capped oligomer/zinc oxide nanocomposites

BACKGROUND: The aim of the present work was to prepare novel fluoroalkyl end‐capped oligomer/zinc oxide nanocomposites by the use of fluoroalkyl end‐capped oligomers as key intermediates. In addition, it was intended to clarify the unique properties of these fluorinated nanocomposites. RESULTS: A variety of fluoroalkyl end‐capped oligomer/zinc oxide nanocomposites were prepared by the interaction of the corresponding oligomers with zinc oxide particles, which were obtained by the reaction of zinc acetate dihydrate with sodium hydroxide in ethanol solution at room temperature. In contrast, fluoroalkyl end‐capped 2‐methacryolyoxyethanesulfonic acid oligomer was found to afford the corresponding fluorinated amorphous zinc oxide composites under similar conditions. CONCLUSION: These fluorinated zinc oxide composites thus obtained are nanometer size‐controlled very fine particles, and they exhibit a good dispersibility and stability in water and traditional organic media. These fluorinated nanocomposites were also applied for the surface modification of poly(methyl methacrylate) (PMMA) films, which gave not only a good surface‐active property imparted by fluorine but also unique characteristics related to the presence of zinc oxide nanoparticles on the modified PMMA film surface. Copyright © 2008 Society of Chemical Industry     

Synthesis and properties of fluoroalkyl end‐capped sulfobetaine polymers

A variety of fluoroalkyl end‐capped 3‐[N‐(3‐acrylamido)propyl‐N,N‐dimethylammonio]propanesulfonate polymers [R_F–(APDAPS)_n–R_F] were prepared by the reactions of fluoroalkanoyl peroxides with the corresponding monomer under very mild conditions. Similarly, fluoroalkyl end‐capped 2‐vinylpyridinio propane sulfonate polymer was obtained by the use of fluoroalkanoyl peroxide. These fluoroalkyl end‐capped sulfobetaine polymers exhibited a good solubility in water; however, these polymers have a poor solubility in other solvents. In particular, R_F–(APDAPS)_n–R_F polymers caused gelation in methanol, although R_F–(VPPA)_n–R_F polymer showed no gelation in methanol. R_F–(APDAPS)_n–R_F polymers were found to form the self‐assembled molecular aggregates with the aggregations of the end‐capped fluoroalkyl segments and the ionic interactions between sulfobetaine segments in aqueous solutions. On the other hand, it was suggested that R_F–2‐vinylpyridinio propane sulfonate (VPPS)_n–R_F polymer is not likely to form the self‐assemblies in aqueous solutions because of the steric hindrance of pyridiniopropyl betaine units in polymer. We also studied the surfactant properties of R_F–(APDAPS)_n–R_F and R_F–(VPPS)_n–R_F polymers compared with those of other fluoroalkyl end‐capped betaine‐type polymers such as 2‐acrylamido‐2‐methylpropanesulfonic acid polymers and 2‐(3‐acrylamidopropyldimethylammonio) ethanoate polymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1144–1153, 2004     

Synthesis of fluoroalkyl end‐capped preoligomers containing succinimidyl segments—Application to novel fluorinated oligomers possessing surface antibacterial activity

Fluoroalkyl end‐capped N‐acryloxysuccinimide (ASuI) cooligomers were prepared under very mild conditions by the cooligomerizations of fluoroalkanoyl peroxides with ASuI and comonomers such as N,N‐dimethylacrylamide (DMAA) and acryloylmorpholine (ACMO). These fluorinated ASuI cooligomers thus obtained were in general easily soluble in water and common organic solvents. These fluorinated ASuI cooligomers were also able to reduce the surface tension of water quite effectively to around 20 mN/m with a clear break point resembling a critical micelle concentration (CMC), although the corresponding nonfluorinated ASuI cooligomers were not effective for reducing the surface tension of water. Fluorinated ASuI cooligomers were applicable to new fluorinated precooligomers, and these precooligomers could react with several amino compounds such as aniline, cytosine, and cyclohexylamine to afford fluorinated cooligomer‐bound aromatic and cyclohexyl segments under mild conditions. Of particular interest, these fluorinated precooligomers were able to react with low molecular weight biocides such as sulfathiazole (STZ) and 3‐amino‐5‐hydroxypyrazole (AHP) to give the corresponding fluorinated cooligomers containing antibacterial segments under similar conditions. These cooligomers were shown to have not only a good oleophobicity imparted by fluorine but also surface antibacterial activity against Staphylococcus aureus. Therefore, our present fluorinated cooligomers containing antibacterial segments are suggested to have high potential for new fluorinated functional materials through their surface active property and surface antibacterial activity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3874–3880, 2004     

Synthesis and properties of novel fluoroalkyl end‐capped oligomers containing silsesquioxane segments

Fluoroalkyl end‐capped homo‐ and co‐ oligomers containing silsesquioxane segments were prepared by the reactions of fluoroalkanoyl peroxides with the corresponding methacrylate monomer‐bearing silsesquioxane unit (Si‐MMA) and comonomers such as N,N‐dimethylacrylamide (DMAA) and acrylic acid (ACA). These new fluorinated Si‐MMA oligomers were easily soluble in various organic solvents and were able to reduce the surface tension of m‐xylene effectively. The modified poly(methyl methacrylate) [PMMA] and glass surface treated with fluorinated Si‐MMA homo‐oligomers exhibited a strong oleophobicity, although these fluorinated oligomers possess high oleophilic silsesquioxane segments. In contrast, the modified PMMA surface treated with fluorinated Si‐MMA–DMAA cooligomers exhibited a good hydrophilicity with a strong oleophobicity. In a series of fluorinated Si‐MMA oligomers, fluorinated Si‐MMA homo‐oligomers had a relatively high thermal stability. Therefore, these fluoroalkyl end‐capped Si‐MMA oligomers are suggested to have high potential for new functional materials through their unique properties such as a high solubility and surface active properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3486–3493, 2002     

Epoxidized poly(N‐isopropyl acrylamide)‐b‐epoHTPB‐b‐poly(N‐isopropyl acrylamide) triblock copolymer micelle nanoparticles for 10‐hydroxycamptothecin drug release

Thermoresponsive poly(N‐isopropyl acrylamide) (PNIPAM)‐block‐hydroxy‐terminated polybutadine‐block‐PNIPAM triblock copolymers were synthesized by atom transfer radical polymerization; this was followed by the in situ epoxidation reaction of peracetic acid. The copolymers were characterized by ¹H‐NMR, Fourier transform infrared spectroscopy, and size exclusion chromatography measurements, and their physicochemical properties in aqueous solution were investigated by surface tension measurement, fluorescent spectrometry, ultraviolet–visible transmittance, transmission electron microscopy observations, dynamic light scattering, and so on. The experimental results indicate that the epoxidized copolymer micelle aggregates retained a spherical core–shell micelle structure similar to the control sample. However, they possessed a decreased critical aggregate concentration (CAC), increased hydrodynamic diameters, and a high aggregation number and cloud point because of the incorporation of epoxy groups and so on. In particular, the epoxidized copolymer micelles assumed an improved loading capacity and entrapment efficiency of the drug, a preferable drug‐release profiles without an initial burst release, and a low cytotoxicity. Therefore, they were more suitable for the loading and delivery of the hydrophobic drug as a controlled release drug carrier. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41877.     

Formation of honeycomb films based on a soluble polyimide synthesized from 2,2′‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride and 3,3′‐dimethyl‐4,4′‐diaminodiphenylmethane

A soluble polyimide was synthesized from 2,2′‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) and 3,3′‐dimethyl‐4,4′‐diaminodiphenylmethane (DMMDA) by a two‐step method, and it had good solubility both in strong bipolar solvents and in common low‐boiling‐point solvents. The BPADA–DMMDA polyimide was dissolved in chloroform (CHCl₃) and cast onto a glass substrate in a humid atmosphere. The BPADA–DMMDA/CHCl₃ solution easily formed honeycomb films. Some affecting factors, such as the polymer solution concentration, atmospheric humidity, and solvent volatility, were tested. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermosensitive self‐assembly micelles from A2BA2‐type poly(N‐isopropyl acrylamide)2‐b‐Poly(lactic acid)‐b‐Poly(N‐isopropyl acrylamide)2 four‐armed star block copolymers and their applications as drug carriers

A novel A₂BA₂‐type thermosensitive four‐armed star block copolymer, poly(N‐isopropyl acrylamide)₂‐b‐poly(lactic acid)‐b‐poly(N‐isopropyl acrylamide)₂, was synthesized by atom transfer radical polymerization and characterized by ¹H‐NMR, Fourier transform infrared spectroscopy, and size exclusion chromatography. The copolymers can self‐assemble into nanoscale spherical core–shell micelles. Dynamic light scattering, surface tension, and ultraviolet–visible determination revealed that the micelles had hydrodynamic diameters (D_h) below 200 nm, critical micelle concentrations from 50 to 55 mg/L, ζ potentials from ?7 to ?19 mV, and cloud points (CPs) of 34–36°C, depending on the [Monomer]/[Macroinitiator] ratios. The CPs and ζ potential absolute values were slightly decreased in simulated physiological media, whereas D_h increased somewhat. The hydrophobic camptothecin (CPT) was entrapped in polymer micelles to investigate the thermo‐induced drug release. The stability of the CPT‐loaded micelles was evaluated by changes in the CPT contents loaded in the micelles and micellar sizes. The MTT cell viability was used to validate the biocompatibility of the developed copolymer micelle aggregates. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4137–4146, 2013     

Amphiphilic star‐shaped poly(ε‐caprolactone)‐block‐poly(l‐lysine) copolymers with porphyrin core: Synthesis,self‐assembly,and cell viability assay

Star‐shaped copolymers poly(ε‐caprolactone)‐bolck‐poly(ε‐benzyloxycarbonyl‐l ‐lysine) (SPPCL‐b‐PZLLs) with porphyrin core were synthesized by a sequential ring‐opening polymerization (ROP) of CL and Nε‐Benzyloxycarbonyl‐l ‐lysine N‐Carboxyanhydride. After the deprotection of benzyloxycarbonyl groups in polylysine blocks, the star‐shaped amphiphilic copolymers SPPCL‐b‐PLLs were obtained. These amphiphilic copolymers can self‐assemble into micelles or aggregates in aqueous solution. Investigation shows that the morphology of micelles/aggregates varied according to the change of pH values of media, indicating the pH‐responsive property of SPPCL‐b‐PLL copolymers. Furthermore, associated with conjugated porphyrin cores, the SPPCL‐b‐PLL copolymers micelles showed a certain degree of Photodynamic Therapy (PDT) effects on tumor cells, suggesting its potential application as carrier for hydrophobic drug with additional therapeutic ability of inherent porphyrin segments. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40097.     

Synthesis and gelation of fluoroalkyl end‐capped copolymers containing glucosyl segments: Application to new fluorinated conductive polymer electrolytes

Fluoroalkyl end‐capped copolymers containing glucosyl segments were prepared by the copolymerizations of fluoroalkanoyl peroxides with 2‐glucosyoxyethyl methacrylate (GEMA) and comonomers such as acrylic acid (ACA) and methacrylate monomer‐containing poly(oxyethylene) units (PME). Under the non‐cross‐linked conditions, fluoroalkyl end‐capped GEMA–ACA and GEMA–PME copolymers were found to cause a gelation in dimethyl sulfoxide (DMSO), where the aggregations of end‐capped fluoroalkyl segments and the hydrogen‐bonding interaction between hydroxyl segments are involved in establishing a physical gel network, although the corresponding nonfluorinated GEMA copolymers could cause no gelation in DMSO. More interestingly, it was demonstrated that these fluorinated polymeric gelling electrolytes containing lithium salts exhibit a considerably high ionic conductivity of 10^?3 S/cm level at room temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2833–2838, 2002     

Novel and Mild Route to Phthalocyanines and 3‐Iminoisoindolin‐1‐ones via N,N‐Diethylhydroxylamine‐Promoted Conversion of Phthalonitriles and a Dramatic Solvent‐Dependence of the Reaction

Refluxing a mixture of phthalonitrile C₆R¹R²R³R⁴(CN)₂ 1 (R¹–R⁴=H), or its substituted derivatives 2 (R¹, R³, R⁴=H, R²=Me), or 3 (R¹, R⁴=H, R², R³=Cl) (1 equiv.) and N,N‐diethylhydroxylamine, Et₂NOH, (4 equivs.) in methanol for 4 h results ( Route A ) in precipitation of the symmetrical ( 6 and 8 ) and an isomeric mixture of unsymmetrical ( 7 ) phthalocyanines, isolated in good (55–65 %) yields. The reaction of phthalonitriles 1 , 2 , or 4 (R¹, R³, R⁴=H, R²=NO₂) (4 equivs.) with Et₂NOH (8 equivs.) in the presence of a metal salt MCl₂ (M=Zn, Cd, Co, Ni) (1 equiv.) in n‐BuOH or without solvent results in the formation of metallated phthalocyanine species ( 9 – 17 ). Upon refluxing in freshly distilled dry chloroform, phthalonitrile 1 or its substituted analogues 2 , 3 or 5 (R¹–R⁴=F) (1 equiv.) react with N,N‐diethylhydroxylamine (2 equivs.) affording 3‐iminoisoindolin‐1‐ones 18 – 21 ( Route B ) isolated in good yields (55–80 %). All the prepared compounds were characterized with C, H, and N elemental analyses, ESI‐MS, IR, and compounds 18 – 21 also by 1D (¹H, ¹³C{¹H}), and 2D (¹H,¹⁵N‐HMBC and ¹H,¹³C‐HMQC, ¹H,¹³C‐HMBC) NMR spectroscopy.     

Synthesis and tunable thermoresponsive solution morphologies of 2,2‐bis‐methylolpropionic acid dendron–azobenzene–poly(N‐isopropyl acrylamide) copolymers

Amphiphilic temperature‐ and photoresponsive linear–dendritic block copolymers comprising second‐generation acetonide‐2,2‐bis‐methylolpropionic acid‐based polyester dendron and linear poly(N‐isopropyl acrylamide) (PNIPAM) linked by an azobenzene unit were synthesized using atom transfer radical polymerization (ATRP) followed by click chemistry. Linear PNIPAM precursor was prepared from an azide‐functionalized azobenzene containing ATRP initiator. Two polymers obtained by varying the chain length of the PNIPAM block showed different morphologies and lower critical solution temperature (LCST) values in aqueous solution. Complete change in morphology of the two polymers into large spherical aggregates and nanotubes, respectively, was observed upon heating the micellar solution above LCST. The azobenzene unit was found to undergo trans–cis photoisomerization in the assemblies and caused a change in the microenvironment of an encapsulated hydrophobic dye without any release. Acetonide groups on the dendron were deprotected to afford hydroxylated polymer that showed well‐defined morphologies above the LCST and after heating–cooling cycle while significant dye encapsulation was seen only above the LCST. © 2017 Society of Chemical Industry     

Organosoluble,low‐dielectric‐constant fluorinated polyimides based on 9,9‐bis[4‐(4‐amino‐2‐trifluoromethyl‐ phenoxy)phenyl]xanthene

A new trifluoromethylated bis(ether amine) monomer, 9,9‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]xanthene (BATFPX), was prepared through the nucleophilic aromatic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 9,9‐bis(4‐hydroxyphenyl)xanthene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of novel fluorinated polyimides were synthesized from BATFPX with various commercially available aromatic tetracarboxylic dianhydrides by one‐step polycondensation in m‐cresol. The resulting polyimides were readily soluble in many organic solvents such as N,N‐dimethylacetamide and tetrahydrofuran, and afforded transparent, flexible and strong films with low moisture absorption (0.28–0.51%), low dielectric constant (2.85–3.26 at 1 MHz) and good optical transparency with UV‐visible absorption cut‐off wavelengths at 352–410 nm. All the polyimides were amorphous and exhibited high thermal stability, with glass transition temperatures of 282–330 °C, 5% weight loss temperatures above 520 °C in nitrogen or air and char yields higher than 55% at 800 °C in nitrogen. Also, these polyimides had good mechanical properties with tensile strengths of 93–118 MPa, elongations at break of 9–16% and initial moduli of 2.07–2.58 GPa. Copyright © 2011 Society of Chemical Industry     

Monomers and polymers of 4‐(N,N‐diallylamino)pyridine functions

4‐(N,N‐Diallylamino)pyridine (DAAP), N,N‐diallylaminobenzene (DAAB), N,N,N′,N′‐tetrallyl‐4,4′‐diaminobenzidine (AAB), N,N,N′,N′‐tetrallyl‐4,4′‐diaminodiphenyl sulfone (AABS), and N,N,N′,N′‐tetrallyl‐4,4′‐diaminodiphenyl ether (AABE) were prepared by sodium substitution and N‐allylation. Moreover, linear polyDAAP, poly(DAAP‐co‐DAAB), and network poly(DAAP‐co‐AAB), poly(DAAP‐co‐AABS), and poly(DAAP‐co‐AABE), all being polymers containing supernucleophilic groups, were synthesized in the cyclopolymerization. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 363–367, 2000     

Amphiphilic block copolymer poly(lactic acid)‐block‐(glycidylazide polymer)‐block‐polystyrene: synthesis and self‐assembly

The triblock energetic copolymer poly(lactic acid)‐block‐(glycidylazide polymer)‐block‐polystyrene (PLA‐b‐GAP‐b‐PS) was synthesized successfully through atom‐transfer radical polymerization (ATRP) of styrene and ring‐opening polymerization of d,l ‐lactide. The energetic macroinitiator GAP‐Br, which was made from reacting equimolar GAP with α‐bromoisobutyryl bromide, firstly triggered the ATRP of styrene with its bromide group, and then the hydroxyl group on the GAP end of the resulting diblock copolymer participated in the polymerization of lactide in the presence of stannous octoate. The triblock copolymer PLA‐b‐GAP‐b‐PS had a narrow distribution of molecular weight. In the copolymer, the PS block was solvophilic in toluene and improved the stability of the structure, the PLA block was solvophobic in toluene and served as the sacrificial component for the preparation of porous materials, and GAP was the basic and energetic material. The three blocks of the copolymer were fundamentally thermodynamically immiscible, which led to the self‐assembly of the block copolymer in solution. Further studies showed that the concentration and solubility of the copolymer and the polarity of the solvent affected the morphology and size of the micelles generated from the self‐assembly of PLA‐b‐GAP‐b‐PS. The micelles generated in organic solvents at 10 mg mL^?1 copolymer concentration were spherical but became irregular when water was used as a co‐solvent. The spherical micelles self‐assembled in toluene had three distinct layers, with the diameter of the micelles increasing from 60 to 250 nm as the concentration of the copolymer increased from 5 to 15 mg L^?1. © 2017 Society of Chemical Industry     

Biocatalyic synthesis of unusually photoluminescent oligomers and electrically conducting polymers of 4‐(3‐pyrrolyl)butyric acid

Unusually photoluminescent undoped oligomers and doped electrically conducting polymers of 4‐(3‐Pyrrolyl)butyric acid have been enzymatically synthesized using the oxidoreductase soybean peroxidase as a catalyst. This biocatalytic approach provides a direct route to a fluorescent‐undoped oligomer of pyrrole that requires no protection/deprotection chemistry. The synthesis is carried out in aqueous media that requires only monomer, enzyme, and hydrogen peroxide. The undoped oligomer exhibits stable emission properties and is highly sensitive to the presence of environmentally important metal ions, such as Co(II), Hg(II), and Cu(II) in solution. Electrically conducting polymers can also be obtained by adding a dopant to a buffered reaction solution prior to initiating the polymerization. Polymers doped with camphor‐10‐sulfonic acid exhibit conductivity values as high as 10^?2 S/cm. Additionally, polymers synthesized in the presence of a biobased cationic template, N,N,N‐trimethylchitosan chloride, exhibit conductivity values that are an order of magnitude greater than polymers synthesized with the anionic polymeric template, poly(styrene sulfonic acid)‐sodium salt. The biobased synthetic strategy described here is the first report of directly obtaining an undoped, fluorescent conjugated oligomer of a pyrrole in aqueous solution. Unlike conventional chemical catalysts, the enzyme does not dope the oligomer and therefore provides the opportunity to directly obtain fluorescent conjugated species. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41035.     

α‐cyclodextrin assisted self‐assembly of poly(ethylene glycol)‐block‐poly(N‐isopropylacrylamide) in aqueous media

Poly(ethylene glycol)‐block‐poly(N‐isopropylacrylamide) (PEG‐b‐PNIPAM) block copolymers were synthesized by atom transfer radical polymerization, and the α‐cyclodextrin (α‐CD) induced self‐assembly characteristics of the system were elucidated. Below the lower critical solution temperature (LCST) of PNIPAM, CD threaded onto the PEG segments and induced micellization to form rod‐shaped nanostructures comprising of a PEG/α‐CD condensed phase and a PNIPAM shell. Increasing the temperature of system above the LCST caused the PNIPAM segments to collapse, which resulted in the dethreading of the CD. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Vesicular and micellar self‐assembly of stimuli‐responsive poly(N‐isopropyl acrylamide‐b‐9‐anthracene methyl methacrylate) amphiphilic diblock copolymers

Dually responsive amphiphilic diblock copolymers consisting of hydrophilic poly(N‐isopropyl acrylamide) [poly(NIPAAm)] and hydrophobic poly(9‐anthracene methyl methacrylate) were synthesized by reversible addition fragmentation chain‐transfer (RAFT) polymerization with 3‐(benzyl sulfanyl thiocarbonyl sulfanyl) propionic acid as a chain‐transfer agent. In the first step, the poly(NIPAAm) chain was grown to make a macro‐RAFT agent, and in the second step, the chain was extended by hydrophobic 9‐anthryl methyl methacrylate to yield amphiphilic poly(N‐isopropyl acrylamide‐b‐9‐anthracene methyl methacrylate) block copolymers. The formation of copolymers with three different hydrophobic block lengths and a fixed hydrophilic block was confirmed from their molecular weights. The self‐assembly of these copolymers was studied through the determination of the lower critical solution temperature and critical micelle concentration of the copolymers in aqueous solution. The self‐assembled block copolymers displayed vesicular morphology in the case of the small hydrophobic chain, but the morphology gradually turned into a micellar type when the hydrophobic chain length was increased. The variations in the length and chemical composition of the blocks allowed the tuning of the block copolymer responsiveness toward both the pH and temperature. The resulting self‐assembled structures underwent thermally induced and pH‐induced morphological transitions from vesicles to micelles and vice versa in aqueous solution. These dually responsive amphiphilic diblock copolymers have potential applications in the encapsulation of both hydrophobic and hydrophilic drug molecules, as evidenced from the dye encapsulation studies. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46474.