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In this contribution, a series of well‐defined amphiphilic di‐block copolymers poly(ethylene oxide)‐b‐polystyrene (PEO43‐b‐PSx) with different PS segment lengths of x = 41, 78, and 130 units were synthesized through activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The as‐prepared block copolymers successfully stabilized the water‐in‐oil (W/O) high internal phase emulsions (HIPEs) containing pH responsive monomers 2‐(dimethylamino)ethyl methacrylate (DMAEMA) and 2‐(diethylamino)ethyl methacrylate (DEAEMA). The effect of macro‐surfactant loading, PS segment length, and DMAEMA/DEAEMA content on the stability of HIPEs and the corresponding polyHIPE structure were investigated. Results show that the average void size of polyHIPE decreases with the increase of surfactant concentration. Macroporous morphologies with closed‐cell or open‐cell can be manipulated by surfactant loading as well. The openness of polyHIPE decreases as the increase in hydrophobic PS segment length. Compared to DMAEMA containing HIPE systems, stable DEAEMA containing HIPEs are more easily obtained by using the as‐prepared macro‐surfactant. Stable HIPE with a relatively large amount of DEAEMA, up to 70 vol% of oil‐phase has been achieved. The obtained PDEAEMA‐co‐PS polyHIPEs derived from 0.116 mol% PEO43‐b‐PS41 stabilized emulsion templates show pH responsiveness towards water absorption and the highest acidic water uptake capacity can be up to 6.6 times its weight at equilibrium state. This work paves the way for the preparation of hydrophilic macroporous monolith from stable W/O HIPE template, and confirms the strength of macro‐surfactant in such an approach. [ABSTRACT FROM AUTHOR]

Successful fabrication of mussel-inspired V-shaped copolymer based materials for pH controllable oil/water separation was reported. Triblock copolymer, polydimethylsiloxane-block-poly(2-hydroxyethyl methacrylate)-block-poly(2-(dimethylamino)ethyl methacrylate) (PDMS- b -PHEMA- b -PDMAEMA) was designed and synthesized through copper(0)-mediated reversible-deactivation radical polymerization (RDRP). Hydroxyl-containing PHEMA block enabled the covalent reaction to occur between polymer and polydopamine (PDA) functionalized substrates. The mixed polymer brushes of oleophilic/hydrophobic PDMS and pH-responsive PDMAEMA endowed the substrates with good pH responsive oil/water wettability and stability. As a proof of concept, the functionalized mesh can separate a range of different immiscible oil/water mixtures with high separation efficiency over 98.5% and high oil flux of 8800–9500 L h −1 m −2 and water flux of 7400–7800 L h −1 m −2 . Additionally, the functionalized sponge realized reversible oil capture and release in aqueous media. Because dopamine through self-polymerization can form strong adhesive films on inorganic and organic substrates in alkalescence solution, the method used in current contribution would be also suitable for producing polymer brush functionalized intelligent materials based on other common substrates. [ABSTRACT FROM AUTHOR]

The increasing environmental burdenin human society calls forthe development of more environmentally benign technologies and sustainableapplications. Wastewater contaminated by oil or organic solvents hasbecome a serious environmental issue nowadays. Herein, a well-definedthermosensitive block copolymer was designed and used for controllablewater/oil separation. The functional material poly(2,2,3,4,4,4-hexafluorobutylmethacrylate)-block-poly(N-isopropylacrylamide)was synthesized through a new environmentally benign “living”radical polymerization technique [i.e., photoinitiated atom-transferradical polymerization (photoATRP)]. The synthesized functional copolymerwas considered as a modifier for fabricating a smart surface withthermal-responsive wettability. The switchable mechanism, surfacecomposition, and morphology of the as-fabricated surface were investigatedby water contact-angle measurement, X-ray photoelectron spectroscopy,and atomic force microscopy. Results showed that the as-fabricatedsurface can reversibly switch between the hydrophilicity and hydrophobicity,which results from the synergistic effect of surface chemical composition,reorientation of the functional groups, and roughness in responseto the temperature. On the basis of mechanism understanding, a smartseparation device was constructed and used for separating water/oilmixtures. The separation of a water/hexane layered mixture has highpenetration fluxes of 2.50 L s–1m–2for water and 2.78 L s–1m–2for hexane, while exhibiting a good efficiency of over 98%. [ABSTRACT FROM AUTHOR]

Poly(methyl methacrylate)- block-poly(4-vinylpyridine), polystyrene- block-poly(4-vinyl pyridine), and poly(ethylene glycol)- block-poly(4-vinylpyridine) block copolymers are synthesized by successive atom transfer radical polymerization (ATRP), single-electron-transfer nitroxide-radical-coupling (SET-NRC) and nitroxide-mediated polymerization (NMP). This paper demonstrates that this new approach offers an efficient method for the preparation of 4-vinylpyridine-containing copolymers. [ABSTRACT FROM AUTHOR]

A series of thermal-responsive blockcopolymers, i.e., poly(methylmethacrylate)-block-poly(N-isopropylacrylamide)(PMMA-b-PNIPAAm), were successfully synthesized viasuccessive copper(0)-mediated reversible-deactivation radical polymerizationtechnology. Thermal properties of block copolymers with differentPNIPAAm chain lengths were investigated by differential scanning calorimetery(DSC) and thermogravimetric analysis (TGA). The well-separated glasstransition temperature values shown in DSC results indicate that twochemically different blocks, PNIPAAm and PMMA, are incompatible andphase-segregated. The thermal degradation results show that the thermalstability of these copolymers was improved through incorporating thePNIPAAm segments. The PMMA120-b-PNIPAAm86and PMMA120-b-PNIPAAm130maintain stability and undergo one-stage degradation when the temperatureincreases above 360 °C. Because of the synergistic effect ofcopolymer composition and copolymer film roughness, the obtained reversiblethermal-responsive wettability for the resulting copolymer-modifiedsurfaces is different, which is enhanced by incorporating more functionalNIPAAm units. Specifically, the variations of the static water contactangle for the surfaces fabricated by PMMA120-b-PNIPAAm40, PMMA120-b-PNIPAAm54, PMMA120-b-PNIPAAm86, and PMMA120-b-PNIPAAm130are 18.7, 20.4, 26.8, and 34.3°, respectively. In addition,all as-prepared surfaces present a stable reversible thermal-responsivewettability, which can be applied to coatings with temperature-controllablewettability as well as manipulation of liquids in microfluidic devices. [ABSTRACT FROM AUTHOR]

A “schizophrenic” blockcopolymer (poly[1′-(2-methacryloxyethyl)-3′,3′-dimethyl-6-nitrospiro-(2H-1-benzopyran-2,2′-indoline)]-b-poly(acrylic acid) (PSPMA-b-PAA)) was synthesizedby sequential copper(0)-mediated living radical polymerization (Cu(0)-mediatedLRP) at 30 °C in an oxygen-tolerant system followed by hydrolysisof the resulting polymer. The solvatechromic behaviors of the PSPMA10-b-poly(t-butyl acrylate)40(PSPMA10-b-PtBA40) and PSPMA10-b-PAA40block copolymers in organic solvents were investigated byUV–vis spectroscopy. The PSPMA10-b-PtBA40stabilizes the nonpolar photoisomerand is not sensitive to the polarity of the solvent, while the PSPMA10-b-PAA40stabilizes the planarzwitterionic form without irradiation. Furthermore, light-inducedisomerization of spiropyran (Sp) moieties from Sp to merocyanine (Mc)was demonstrated. Finally, the “schizophrenic” micellizationbehavior of as-prepared copolymer in aqueous solution regulated bylight and pH stimuli was vividly demonstrated, and the reversibilityof micellization processes performed in this study was also examined.The large compound micelles can bring out a gradually extended andeven transformed conformation with increasing deprotonation degreeat pH > pKa. [ABSTRACT FROM AUTHOR]

Highlights: [•] PDMS-b-PHFBMA is a novel fluorosilicone double-hydrophobic block copolymer. [•] The micellization of PDMS-b-PHFBMA in organic solvent was investigated in detail. [•] Different factors were employed to induce the morphology transition. [•] Abundant morphologies for micelles were found in this system. [•] A classical thermodynamic model was applied to describe the mechanism of aggregation. [ABSTRACT FROM AUTHOR]

Abstract: Well-defined poly(dimethylsiloxane)-b-poly(2,2,3,3,4,4,4-heptafluorobutylmethacryl-ate-b-poly(styrene) (PDMS-b-PHFBMA-b-PS) triblock copolymers were prepared by two-step reversible addition–fragmentation chain transfer (RAFT) polymerization. A comprehensive mathematical model for the two-step RAFT polymerization in a batch reactor was presented using the method of moments. The model described molecular weight, monomer conversion and polydispersity index as a function of polymerization time. Good agreements in the polymerization kinetics were achieved for fitting the kinetic profiles with the suggested model. In addition, the model was used to predict the effects of initiator concentration, chain transfer agent concentration and monomer concentration on the two-step RAFT polymerization kinetics. The simulated results showed that for the two-step RAFT polymerizations, the effects initiator concentration, chain transfer agent concentration and monomer concentration are identical and the influence degrees are different yet. [Copyright &y& Elsevier]