Behavior of the Interphase Region of an Amphiphilic Polymer Conetwork Swollen in Polar and Nonpolar Solvent

Abstract

The most attractive property of amphiphilic polymer conetworks (APCNs) is their ability to swell in both polar and nonpolar solvents. Depending on the composition, their structure is phase separated on the nanometer scale possessing highly different morphologies. This special nanophase-separated structure provides numerous possible applications for heterogeneous chemical and biological processes. Although the interphase region can fundamentally influence the material transport between the different polarity phases, there has been no specific information regarding its nature. Recent work demonstrates that by selective labeling of the crosslinking molecules by deuterium, information on the mobility of the interphase region can be obtained by solid-state NMR techniques. The first results show that this interphase region behaves differently in dry state as well as when swollen in polar or nonpolar solvents. Although the cross-linker is a polar molecule, its mobility hardly changes upon swelling in water; however, its mobility increases drastically by swelling in heptane. Additionally, the amount of nonreacted, thus non-cross-linked, chain ends could be quantified by solid-state NMR methodologies.

Nanophasic morphologies as a function of the composition and molecular weight of the macromolecular cross-linker in poly(N-vinylimidazole)-l-poly(tetrahydrofuran) amphiphilic conetworks: bicontinuous domain structure in broad composition ranges

“…These novel polymeric systems belong to a rapidly emerging class of materials and have sparked enormous interest in the last few decades in both pure and applied sciences. 7,8,[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] APCNs possess several unique characteristics, such as the amphiphilic swelling properties and the improved mechanical characteristics compared to homopolymer hydrogels. Moreover, a special property of these materials is their phase behaviour.…”

“…These domains have various proportions over the composition range and the phase separation in the APCNs leads to average domain sizes in the nanometer scale. Diversity of techniques involving differential scanning calorimetry (DSC), 22,30 small angle X-ray scattering (SAXS), 20,24,27 small angle neutron scattering (SANS), 25,27 transmission electron microscopy (TEM), 17,19,27,30 atomic force microscopy (AFM) 17,19,30,32 and solidstate NMR 20,21 were used to conrm the formation of separated nanodomains in these materials. The systematic study of the compositionally asymmetrical morphology of APCNs is of major importance, when a stable, bicontinuous nanophase-separated structure is formed over a broad composition window of both constituent phases with large inner surface between the distinct phases.…”

An amphiphilic silicone-modified polysaccharide molecular hybrid with in situ forming of hierarchical superporous architecture upon swelling

“…Besides, unlike homopolymer gels, CAPNs are able to swell in both polar and nonpolar solvents due to their amphiphilic nature, which is advantageous for use in both hydrophilic and hydrophobic drug delivery. 13 In this work, we developed an unprecedented type of amphiphilic, zwitterionic, and strong polymer network, i.e. PDMScrosslinked-NOCC amphiphilic polymer networks (PMSC CAPNs), by esterification between cross-linked PDMS diol [bis(hydroxyalkyl) terminated polydimethylsiloxane, silicone] and NOCC (N,O-carboxymethyl chitosan).…”

Synthesis and Selective Loading of Polyhydroxyethyl Methacrylate-l-Polysulfone Amphiphilic Polymer Conetworks

“…NMR studies with a focus on the interphase region of poly­( N , N -dimethylaminoethyl methacrylate)- l -polyisobutylene APCNs swollen in polar and nonpolar solvents were performed with deuterium solid-state NMR on conetworks with selectively deuterium labeled cross-linking molecules. It was shown that the mobility of the cross-link points, despite being polar, hardly changes when the network is swollen in water, but tremendously increases when swollen in n -heptane …”