Chau, Mokit; De France, Kevin J.; Kopera, Bernd; Machado, Vanessa R.; Rosenfeldt, Sabine; Reyes, Laura; Chan, Katelyn J. W.; Förster, Stephan; Cranston, Emily D.; Hoare, Todd; Kumacheva, Eugenia
Composite Hydrogels with Tunable Anisotropic Morphologies and Mechanical Properties
Fabrication of anisotropic hydrogels exhibiting direction-dependent structure and properties has attracted great interest in biomimicking, tissue engineering, and bioseparation. Herein, we report a freeze-casting-based fabrication of structurally and mechanically anisotropic aerogels and hydrogels composed of hydrazone cross-linked poly(oligoethylene glycol methacrylate) (POEGMA) and cellulose…
Amphiphilic single and double networks: a small-angle X-ray scattering investigation
Zhang, Xiaohan; Kyriakos, Konstantinos; Rikkou-Kalourkoti, Maria; Kitiri, Elina N.; Patrickios, Costas S.; Papadakis, Christine M.
We investigated the microphase-separated morphologies of water-swollen amphiphilic single and double polymer networks using small-angle X-ray scattering (SAXS). The networks consist of (i) a first conetwork containing hydrophobic blocks from either 2-ethylhexyl methacrylate (EHMA) or lauryl methacylate (LauMA) and hydrophilic blocks from 2-(dimethylamino)ethyl methacrylate (DMAEMA) and (ii) a…
Complexes of PEO-PPO-PEO triblock copolymer P123 and bile salt sodium glycodeoxycholate in aqueous solution: A small angle X-ray and neutron scattering investigation
Bayati, Solmaz; Galantini, Luciano; Knudsen, Kenneth D.; Schillén, Karin
Small angle X-ray (SAXS) and neutron scattering techniques were combined to study mixed complexes formed between micelles of the nonionic amphiphilic PEO-PPO-PEO copolymer (P123) and the anionic bile salt (NaGDC) in aqueous solution. The purpose was to investigate the structural parameters of the charged complexes, such as size and internal…
Small-Angle X-ray Scattering Demonstrates Similar Nanostructure in Cortical Bone from Young Adult Animals of Different Species
Kaspersen, Jørn Døvling; Turunen, Mikael Juhani; Mathavan, Neashan; Lages, Sebastian; Pedersen, Jan Skov; Olsson, Ulf; Isaksson, Hanna
Despite the vast amount of studies focusing on bone nanostructure that have been performed for several decades, doubts regarding the detailed structure of the constituting hydroxyapatite crystal still exist. Different experimental techniques report somewhat different sizes and locations, possibly due to different requirements for the sample preparation. In this study,…
Adsorption of sodium dodecylsulfate on single-walled carbon nanotubes characterised using small-angle neutron scattering
Kastrisianaki-Guyton, E. S.; Chen, L.; Rogers, S. E.; Cosgrove, T.; van Duijneveldt, J. S.
Aqueous dispersions of single-walled carbon nanotubes are often made using sodium dodecylsulfate (SDS), which adsorbs to the nanotube surface to stabilise them. Despite SDS being commonly used with single-walled carbon nanotubes, there is no consensus on the structure of the adsorbed layer. Small-angle neutron and X-ray scattering results reported here…
On the dissolution state of cellulose in aqueous tetrabutylammonium hydroxide solutions
Behrens, M. A.; Holdaway, J. A.; Nosrati, P.; Olsson, U.
We have characterized the dissolution state of microcrystalline cellulose (MCC) in aqueous 40 wt% tetrabutylammonium hydroxide (TBAH) using a combination of light and small angle X-ray scattering, up to 0.1 g cm−3. In dilute solutions, cellulose–cellulose interactions are repulsive, as seen by a positive second virial coefficient. Above 0.04 g…
Monodisperse Cylindrical Micelles of Controlled Length with a Liquid-Crystalline Perfluorinated Core by 1D “Self-Seeding”
Li, Xiaoyu; Jin, Bixin; Gao, Yang; Hayward, Dominic W.; Winnik, Mitchell A.; Luo, Yunjun; Manners, Ian
Precise control over the morphology and dimensions of block copolymer (BCP) micelles has attracted interest due to the potential of this approach to generate functional nanostructures. Incorporation of liquid crystalline (LC) block can provide additional ways to vary micellar morphologies, but the formation of uniform micelles with controllable dimensions from…
Sequence distribution and elastic properties of propylene-based elastomers
Tsou, Andy H.; Norman, Alexander I.; Lu, Yonglai; Throckmorton, Joseph A.; Hsiao, Benjamin S.
Three iso-specific organometallic catalysts for ethylene and propylene copolymerization with varying r1r2 parameters, i.e., the products of ethylene and propylene reactivity ratios, were utilized to synthesize equal-molecular-weight propylene-based elastomers (PBEs) of alternating, random, and blocky backbone sequences. To compensate for the variations in catalyst iso-specificity and thus to…
Ferroelectric switching and electrochemistry of pyrrole substituted trialkylbenzene-1,3,5-tricarboxamides
Meng, Xiao; Gorbunov, Andrey V.; Christian Roelofs, W. S.; Meskers, Stefan C. J.; Janssen, René A. J.; Kemerink, Martijn; Sijbesma, Rint P.
We explore a new approach to organic ferroelectric diodes using a benzene-tricarboxamide (BTA) core connected with C10 alkyl chains to pyrrole groups, which can be polymerized to provide a semiconducting ferroelectric material. The compound possesses a columnar hexagonal liquid crystalline (LC) phase and exhibits ferroelectric switching. At low switching frequencies,…
Morphology and tensile properties of model thermoplastic polyurethanes with MDI/butanediol based monodisperse hard segments
Ren, Li; Shah, Priyank N.; Faust, Rudolf
Morphology and tensile properties of model thermoplastic polyurethanes (TPUs) containing polyisobutylene (PIB) or poly(tetramethylene oxide) (PTMO) based soft segment and 4,4-methylene bis(phenyl isocyanate) (MDI) and 1,4-butanediol (BDO) based monodisperse hard segments (HSs), consisting of exactly two to four MDI units extended by BDO, were investigated. Using FT-IR spectroscopy, increased…