Swelling and Exchange Behavior of Poly(sulfobetaine)-Based Block Copolymer Thin Films

Abstract

The humidity-induced swelling and exchange behavior of a block copolymer thin film, which consists of a zwitterionic poly­(sulfobetaine) [poly­(N,N-dimethyl-N-(3-(methacrylamido)­propyl)­ammoniopropanesulfonate) (PSPP)] block and a nonionic poly­(N-isopropylacrylamide) (PNIPAM) block, are investigated by time-of-flight neutron reflectometry (TOF-NR). We monitor in situ the swelling in the H2O atmosphere, followed by an exchange with D2O. In the reverse experiment, swelling in the D2O atmosphere and the subsequent exchange with H2O are studied. Both, static and kinetic TOF-NR measurements indicate significant differences in the interactions between the PSPP80-b-PNIPAM130 thin film and H2O or D2O, which we attribute to the different H- and D-bonds between water and the polymer. Changes in the chain conformation and hydrogen bonding are probed with Fourier transform infrared spectroscopy during the kinetics of the swelling and exchange processes, which reveals the key roles of the ionic SO3 – group in the PSPP block and of the polar amide groups of both blocks during water uptake and exchange.

Internal Structure of Thermoresponsive Physically Crosslinked Nanogel of Poly[N-(2-hydroxypropyl)methacrylamide]-Block-Poly[N-(2,2-difluoroethyl)acrylamide], Prominent 19F MRI Tracer

“…The PBS measurements were performed to investigate the characteristics of the HF polymer self-assemblies in an environment with a similar ionic strength to the biological environment, since the ionic strength can have an impact on the thermoresponsive behaviour and the lower critical solution temperature (LCST). The measurements in D 2 O were performed to compare the results collected by SANS, which required measurement in D 2 O, while the results with H 2 O were used in lieu of D 2 O measurements to ensure compatibility with the NMR measurements [ 48 , 49 , 50 , 51 ].…”

“…The thermoresponsive behaviour of our copolymer shows a moderate variation between the solvents used. Obtaining this data is therefore important to conduct a reliable comparison of results from experimental methods carried out in different environments [ 48 , 49 , 50 , 51 ].…”

Flexible Sample Environment for the Investigation of Soft Matter at the European Spallation Source: Part II—The GISANS Setup

“…It is crucial for the sample environment to provide stable control over temperature and humidity because various soft matter systems are highly sensitive to these parameters [25][26][27][28][29]. There is a wide range of humidity chambers used for controlling the vapor composition around a sample during neutron scattering experiments [30][31][32].…”

Self-Assembly of Linear Amphiphilic Pentablock Terpolymer PAAx-PS48-PEO46-PS48-PAAxin Dilute Aqueous Solution

“…Amphiphilic block copolymers, with hydrophilic and hydrophobic segments connected by covalent bonds, can self-assemble into micelles with various morphologies and structures in selective solvents [ 1 , 2 , 3 , 4 ]. Because of the unique physical and chemical properties, block copolymer micelles have been used in many technical fields, including drug delivery [ 5 , 6 ], templates [ 7 , 8 , 9 ], hydrogels [ 10 , 11 ], and membranes [ 12 , 13 , 14 ]. In past decades, the self-assembly of block copolymers in selective solvents has been extensively studied experimentally [ 15 , 16 ] and theoretically [ 17 , 18 , 19 , 20 ].…”