The phase behavior and related morphological evolution of thin films of lengthy alkyl substituted core-tetrachlorinated perylene bisimide (C18-4ClPBI), a large ?-conjugated molecule, have been studied. It is found that the C18-4ClPBI can exist in two different crystalline phases depending on temperature, which transform reversibly in heating and cooling processes. The…
sergio.rodrigues@xenocs.com27 January 2020
Promoting the transformation from Form II to Form I in polybutene-1 (PB-1) is deemed to be crucial and demanded for commercial applications. The mechanism of phase transition is previously described in terms of thermal or mechanical stress applied between the crystalline and amorphous regions. Here, we find that the structural…
sergio.rodrigues@xenocs.com27 January 2020
The influence of a backbone microstructure on the side chain crystallization of a comb-like polymer is analyzed systematically using a tailor-made random versus block siloxane copolymer system. While the side alkyl chains of the random siloxane undergo a stepwise orderdisorder (OD) transition to form well-ordered orthorhombic structure at low temperature,…
sergio.rodrigues@xenocs.com27 January 2020
The microstructure and molecular orientation distribution over both the length and the thickness of microinjection-molded linear low-density polyethylene with a weld line were characterized as a function of processing parameters using small-angle X-ray scattering and wide-angle X-ray diffraction techniques. The weld line was introduced via recombination of two separated melt…
sergio.rodrigues@xenocs.com27 January 2020
Biomacromolecular antifreezes distinguish ice from water, function by binding to specific planes of ice, and could have many applications from cryobiology to aerospace where ice is a problem. In biology, antifreeze protein (AFP) activity is regulated by protein expression levels via temperature and light-regulated expression systems, but in the laboratory…
sergio.rodrigues@xenocs.com27 January 2020
In this work, the effects of orientated crystal morphology of polypropylene (PP) induced by tensile stretching on the subsequent crystallization behavior of polybutene-1 (PB-1) in the incompatible PP/PB-1 (50/50) blends were studied. When the PP/PB-1 blends were stretched at a temperature above melting temperature (Tm) of PB-1 but below the…
sergio.rodrigues@xenocs.com27 January 2020
Microporous ceria thin films having nanocrystallites network were synthesized by evaporation-induced self-assembly process, using P123 amphiphilic copolymer as structure-directing agent. The impact of key experimental parameters, i.e., the sol ageing, the relative humidity (RH), the thermal treatment, on the thin layer elaboration were investigated. The results show that the organization…
sergio.rodrigues@xenocs.com27 January 2020
Two types of imidazolium-based ionic liquids (ILs) and and their mixtures were blended with poly(ethylene oxide) (PEO) matrix to tune the strength of intermolecular hydrogen bonding in the system. With the addition of ILs, particularly increasing ratio, significantly reduced overall crystallization kinetics in the order of pure
sergio.rodrigues@xenocs.com27 January 2020
Fluorinated electroactive polymers (FEPs) are among the most interesting insulating materials for the production of organic electronic devices. Their ability to tune their response to an applied electric field makes them appropriate for vastly different applications in electronics. However, due to the chemical inertness of such polymers and the rather…
sergio.rodrigues@xenocs.com27 January 2020
A series of polyethylene-like ionomers with periodic sulfonate groups were synthesized by polyesterification of octatetracontane-1,48-diol and tetrabutylammonium dimethyl sulfosuccinate. Optional cation exchange in aqueous dispersions replaced the NBu4+ counterions for Na+ or Cs+. The defined periodic microstructure of the polymers leads to the formation of layered structures in bulk and…
sergio.rodrigues@xenocs.com27 January 2020