Star block copolymer electrolytes with a lithium-ion conducting phase are investigated in the present work to assess the influence of this complex architecture compared to that of the linear one, on both, bulk morphology and ionic conductivity. For that purpose, the controlled synthesis of a series of poly(styrene--benzyl methacrylate)--poly[oligo(ethylene glycol) methyl ether acrylate] [P(S--BzMA)--POEGA] block copolymers (BCPs) by reversible addition-fragmentation transfer polymerization was performed from either a monofunctional or a tetrafunctional chain transfer agent containing trithiocarbonate groups. We emphasized how a small amount of styrene (6 mol %) drastically improved the control of the RAFT polymerization of benzyl methacrylate mediated by the tetrafunctional chain transfer agent.
View Article and Find Full Text PDF, an abundant yet unexploited species of swimming crab, was investigated as a potential source of α-chitin and calcium lactate using deep eutectic solvents (DES) as extracting solvents. Choline chloride-malonic acid (CCMA) and choline chloride-lactic acid (CCLA) were used to obtain high purity α-chitin from ball-milled exoskeleton in 2 h at 120 °C, with yields of 12.05 ± 2.
View Article and Find Full Text PDFNowadays, a challenge in the preparation of hierarchically ordered materials is the control of concomitant and interacting self-organization processes occurring in time at different length scales. In the present paper, the breath figure process is combined with block copolymer nano-phase segregation to elaborate hierarchically structured honeycomb porous films. Copolymer ordering, at the nanometer length scale, is observed and described in detail with respect to the array of pores of micrometer dimension, hence pointing out the structural interplays between both length-scales.
View Article and Find Full Text PDFIn the present manuscript, we have demonstrated that hierarchically structured smart porous polymer films based on honeycomb-patterned surface can be elaborated from PS-b-P4VP pH-responsive block copolymer using the breath figure process. Despite the fast film formation by a bottom-up process, the copolymer nanostructuration was observed inside the walls of the honeycomb porous film. Atomic force microscopy (AFM), small angle X-ray and neutron scattering (SAXS and SANS) measurements were used to reveal both the hexagonal arrays formed by the pores at the micrometer length scale and the hexagonal copolymer self-assembly at the nanometer length scale.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
March 2011
We report the results of an experimental study of the microstructure of dispersions of Carbopol ETD 2050, a model yield-stress fluid. Using two different light scattering instruments, measurements were made over three decades in scattering wave vector, from 0.02 to 25 μm⁻¹.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
April 2006
The small-scale rheology of Carbopol ETD 2050, a polymer gel with a yield stress, is studied as a function of polymer concentration by measuring the diffusion of submicron-sized spherical fluorescent particles suspended in gel. Dynamic light scattering is used to determine the mean-squared displacement