Chain Dynamics of Water-Saturated Hydrogen-Bonded Polymer Complexes and Multilayers

Abstract

The chain mobility of a series of hydrogen-bonded polymer complexes and multilayers were compared by variable temperature wide-line deuterium NMR spectroscopy. Poly-(methacrylic acid), deuterated at the methyl group, PMAA-d 3 , was complexed with five different hydrogen bond acceptor polymers-poly(ethylene oxide) (PEO), poly(acrylamide) (PAAM), poly(vinyl methyl ether) (PVME), poly(vinylpyrrolidone) (PVPon), and poly(vinylcaprolactam) (PVCL)-as well as with chitosan, where the interaction should be primarily ion pairing. The overall chain mobility of PMAA in its water-saturated complexes was observed to increase in the following order: PVCL < PVPon < chitosan < PVME < PAAM < PEO. For these polymer pairs, the same trend in chain mobility was also confirmed for the first few layers deposited on colloidal silica. The observed chain dynamics correlate well with the reported variation of the critical pH, bilayer thickness, and the permeability for multilayer films of the same polymers. In addition, the extent of chain interpenetration was demonstrated through the effect of a stabilizing primer layer on the chain mobility of the subsequently deposited weaker hydrogen-bonded multilayers.

Solid state NMR study of hydrogen bonding, miscibility, and dynamics in multiphase polymer systems

“…Hydrogen bonding plays a fundamental role in structure, function and dynamics of multiphase polymer materials for its directionality, specificity, strength and selectivity [62][63][64]. Thus, a variety of methods were used to obtain the information about hydrogen bonding in polymer systems, such as IR [65][66][67] spectroscopy, Raman spectroscopy [66,68,69], NMR [70][71][72] spectroscopy, neutron diffraction [73,74], single-crystal X-ray diffraction [75] and so on.…”

“…However, 2 H NMR techniques allow us to monitor rotational motions over a wide range of characteristic frequencies, including the fast (200-10 7 kHz), intermediate , and slow (0.4-10 kHz) motions. The chain mobility of a series of hydrogen-bonded polymer complexes and multilayers were compared by variable temperature wideline deuterium NMR spectroscopy by Reven's group [161]. Wherein, the series of water saturated complexes took form from deuterium labeled poly (methacrylic acid), PMAA-d3 and a range of hydrogen accepting polymers that have been used to produce pH responsive multilayer films and capsules.…”

“…Variable temperature 2 H NMR of~40 wt% PMAA-d 3 complexes saturated with acidic deuterium depleted water, with the exception of the chitosan complex which was saturated with untreated deuterium depleted water [161].…”

Dynamics and Self-Healing of Layer-by-Layer Hydrogen-Bonded Films of Linear Synthetic Polyphenols

“…Studies of dynamics in hydrogen-bonded systems so far have been limited to the application of wide-line 2 H NMR spectroscopy to films composed of weak poly(carboxylic acids) with neutral polymer acceptors, such as PVP and PEO. 50 In this work, we use a combination of in situ ellipsometry, NR, and AFM techniques to explore the dynamics of polymer chains and self-healing in hydrogen-bonded assemblies. These studies are performed with linear synthetic polyphenol (lPPh) polymers rather than with the previously studied films of poly(carboxylic acids).…”

Fractional complexation in a miscible polymer blend. Calorimetry and size exclusion chromatography

“…Macromolecular complexes continue to attract the interest of researchers as they have found important technological and biomedical applications, such as in chemical engines, actuators, biosensors, drug delivery, surface multilayers, colloid stability, design of composites and biocompatible materials, etc …”