López-Barrón, Carlos R.; Eberle, Aaron P. R.; Yakovlev, Sergey; Bons, Anton-Jan
Structural origins of mechanical properties and hysteresis in SIS triblock copolymers/polystyrene blends with spherical morphology
The mechanical response and the corresponding microstructure of polymer blends composed of styrene-isoprene-styrene block copolymer and deuterated polystyrene are studied via in situ small-angle neutron scattering (SANS) measurements during intermittent uniaxial extension. The initial blend morphologies consist of spherical PS glassy domains arranged in body-centered cubic (BCC) lattices. The…
Poly(alkyl methacrylate)-grafted silica nanoparticles in polyethylene nanocomposites
Khani, Mohammad M.; Woo, Dongjin; Mumpower, Edward L.; Benicewicz, Brian C.
Surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization has been widely used to synthesize various polymers grafted from nanoparticles (NPs) for incorporation into polymer nanocomposites. It is believed that these grafted polymer brushes, with a similar chemistry as the matrix polymer, can be employed to improve NP dispersion by reducing unfavorable…
P3HT/graphene composites synthesized using In situ GRIM methods
Presto, Dillon; Song, Vivian; Boucher, David
Poly(3-hexylthiophene)/graphene (P3HT/G) materials are synthesized using an in situ Grignard metathesis approach. The structural properties and spectroscopy of the materials are studied using NMR, FTIR, and UV–vis absorption spectroscopies, wide-angle X-ray scattering, atomic force microscopy and cyclic voltammetry. P3HT regioregularities ≥90% are observed in composites with approximate graphene…
Self-assembly of PS-b-PNIPAM-b-PS block copolymer thin films via selective solvent annealing
Cetintas, Merve; Kamperman, Marleen
Block copolymer (BCP) thin films are interesting material systems for nanofabrication since they can form well-defined periodic nanostructures by microphase separation. However, attaining a specific morphology with the required orientation can be challenging. In this study, we investigated the morphological behavior of polystyrene-b-poly(N-isopropylacrylamide)-b-polystyrene (PS-b-PNIPAM-b-PS) BCP…
Single-step electrospinning of multi walled carbon nanotubes – Poly(3-octylthiophene) hybrid nano-fibers
Bounioux, Céline; Avrahami, Ron; Vasilyev, Gleb; Patil, Nilesh; Zussman, Eyal; Yerushalmi – Rozen, Rachel
Single-step electrospinning of micro-fibers from native solutions of poly(3-octyl thiophene) (P3OT) presents a simplified processes as compared to previously reported host-guest or core–shell strategies for production of conjugated-polymers fibers. Furthermore, as P3OT is a good dispersing agent for Multi-Walled Carbon Nanotubes (MWNT) the process is extended to spinning of MWNT-P3OT…
The rational design of biomimetic skin barrier lipid formulations using biophysical methods
Bulsara, P. A.; Varlashkin, P.; Dickens, J.; Moore, D. J.; Rawlings, A. V.; Clarke, M. J.
Objective The focus of this communication was to study phospholipid-structured emulsions whose phase behaviour is modified with monoalkyl fatty amphiphiles. Ideally, these systems would mimic key physical and structural attributes observed in human stratum corneum (SC) so that they better alleviate xerotic skin conditions. Methods Phosphatidylcholine-structured emulsions were prepared, and…
Influence of diurnal photosynthetic activity on the morphology, structure, and thermal properties of normal and waxy barley starch
Goldstein, Avi; Annor, George; Vamadevan, Varatharajan; Tetlow, Ian; Kirkensgaard, Jacob J. K.; Mortensen, Kell; Blennow, Andreas; Hebelstrup, Kim H.; Bertoft, Eric
This study investigated the influence of diurnal photosynthetic activity on the morphology, molecular composition, crystallinity, and gelatinization properties of normal barley starch (NBS) and waxy barley starch (WBS) granules from plants cultivated in a greenhouse under normal diurnal (16 h light) or constant light photosynthetic conditions. Growth rings were observed…
High Molecular Mobility and Viscoelasticity of Microphase-Separated Bottlebrush Diblock Copolymer Melts
Yavitt, Benjamin M.; Gai, Yue; Song, Dong-Po; Winter, H. Henning; Watkins, James J.
Macromolecules, 2016, vol 50, 1, pp. 396–405DOI:Visit the full articleBack to the overview
Effects of chain configuration on the crystallization behavior of polypropylene based copolymers
Wamuo, Onyenkachi; Wu, Ying; Hsu, Shaw Ling; Paul, Charles W.; Eodice, Andrea; Huang, Kuan-Yeh; Chen, Meng-Hsin; Chang, Yih-Her; Lin, Jen-Lien
The effects of sequence distribution of two types of poly(propylene-ethylene) (PP-PE) copolymers, with propylene being the dominant component, on the associated crystallization behavior have been analyzed. The average sequence lengths of the crystallizable propylene sequences in these copolymers are different, although the ethylene content was virtually identical. In one case…
Concentration-Induced Association in a Protein System Caused by a Highly Directional Patch Attraction
Li, Weimin; Persson, Björn A.; Lund, Mikael; Bergenholtz, Johan; Zackrisson Oskolkova, Malin
Self-association of the protein lactoferrin is studied in solution using small-angle X-ray scattering techniques. Effective static structure factors have been shown to exhibit either a monotonic or a nonmonotonic dependence on protein concentration in the small wavevector limit, depending on salt concentration. The behavior correlates with a nonmonotonic dependence of…