Thermally activated diffusion in reversibly associating polymers

Li, Jiahui; Sullivan, Kelley D.; Brown, Edward B.; Anthamatten, Mitchell

doi:10.1039/b909662k

Cited by 14 publications

(16 citation statements)

References 20 publications

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“…Similarly, by studying both macroscopic shear behavior and the microscopic diffusion of a low molecular weight dye in polymer melts that consist of chains with self-complementary, reversibly associating UPy side groups, Anthamatten et al 212 showed that the macroscopic sample viscosity is determined by the UPy dissociation rate, whereas the transport of the dye through the network is dominated by the equilibrium constant of the UPy association and dissociation. The authors explain this result by considering that the fragments of a broken UPy associate are immediately torn away from each other under shear, such that recombination is likely to occur with a different broken associate, as shown in Fig.…”

Section: Dynamicsmentioning

confidence: 99%

Physical chemistry of supramolecular polymer networks

2012

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Supramolecular polymer networks are three-dimensional structures of crosslinked macromolecules connected by transient, non-covalent bonds; they are a fascinating class of soft materials, exhibiting properties such as stimuli-responsiveness, self-healing, and shape-memory. This critical review summarizes the current state of the art in the physical-chemical characterization of supramolecular networks and relates this knowledge to that about classical, covalently jointed and crosslinked networks. We present a separate focus on the formation, the structure, the dynamics, and the mechanics of both permanent chemical and transient supramolecular networks. Particular emphasis is placed on features such as the formation and the effect of network inhomogeneities, the manifestation of the crosslink relaxation dynamics in the macroscopic sample behavior, and the applicability of concepts developed for classical polymer melts, solutions, and networks such as the reptation model and the principle of time-temperature superposition (263 references).

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Section: Dynamicsmentioning

confidence: 99%

Physical chemistry of supramolecular polymer networks

2012

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“…For example, our group and others have previously shown that viscous relaxation in hydrophobic polymers bearing UPy side-groups is limited by the H-bonding dissociation rate. 18,28 For samples bearing UPy side-groups, swelling is signicantly slower and the thermal activation barrier is higher. Higher temperatures correspond to faster side-group rearrangement thereby hastening viscous relaxation, and, consequently, swelling.…”

Section: Water Swelling Behaviormentioning

confidence: 99%

“…We have recently investigated the viscoelastic properties of low glass transition temperature polymers and elastomers that contain UPy-terminated side-groups. [17][18][19] The combination of covalent and non-covalent crosslinks gives rise to a broad dynamic viscoelastic transition, forming the basis for novel shape memory elastomers.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, swelling behavior, and viscoelastic properties of functional poly(hydroxyethyl methacrylate) with ureidopyrimidinone side-groups

Lewis

Anthamatten

2013

Soft Matter

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In this report the swelling and linear viscoelastic behavior of a hydrophilic polymer containing reversibly associating hydrogen bonding side-groups will be examined. Ureidopyrimidinone (UPy) moieties selfassociate to form hydrogen-bonded dimers (DDAA) in non-polar media; however, UPy behavior in water-swollen hydrogel environments is unclear. A series of technologically important, poly(hydroxyethyl methacrylate) (poly(HEMA)) polymers, with varying UPy side-group content, were prepared using a reversible addition-fragmentation chain transfer (RAFT) polymerization. Water swelling experiments revealed that UPy side-groups retard early time (<24 h) Fickian-like swelling and lead to two-stage, temperature-dependent, water sorption. At longer times UPy side-groups promote water swelling. Rheological studies show that the material's viscosity and viscous relaxation time both increase with increasing UPy-content. The activation energy of the shear-induced flow scales linearly with UPy-content, suggesting cooperative dynamics. These results are similar to observations made for hydrophobic polymers bearing hydrogen-bonding side-groups and suggest some UPy hydrogenbonding occurs in hydrated poly(HEMA), despite competitive H-bonding with water. Experimental observations can be explained by reversible association of UPy side-groups within water-excluded domains of poly(HEMA)'s secondary structure.

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“…The original “spot” FRAP technique has undergone a variety of modifications to accommodate different photobleaching methods, including patterned (Abney et al 1992), continuous (Wedekind et al 1996), line (Braeckmans et al 2007), and disc-shaped (Mazza et al 2008) photobleaching. Modifications to the recovery analysis have also expanded FRAP as a tool to analyze binding kinetics (Kaufmann and Jain 1991; Berk et al 1997; Schulmeister et al 2008), to quantify the connectivity of compartments (Majewska et al 2000; Cardarelli et al 2007), and to investigate polymer structure-property relationships (Li et al Submitted). …”

Section: Introductionmentioning

confidence: 99%

Single- and Two-Photon Fluorescence Recovery after Photobleaching

Sullivan¹,

Majewska²,

Brown³

2015

Cold Spring Harb Protoc

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Fluorescence recovery after photobleaching (FRAP) is a microscopy technique for measuring the kinetics of fluorescently labeled molecules, and can be applied both in vitro and in vivo for two-and three-dimensional systems. This chapter discusses the three basic FRAP methods: traditional FRAP, multi-photon FRAP (MPFRAP), and FRAP with spatial Fourier analysis (SFA-FRAP). Each discussion is accompanied by a description of the appropriate mathematical analysis appropriate for situations in which the recovery kinetics are dictated by free diffusion. In some experiments, the recovery kinetics are dictated by the boundary conditions of the system, and FRAP is then used to quantify the connectivity of various compartments. Since the appropriate mathematical analysis is independent of the bleaching method, the analysis of compartmental connectivity is discussed last, in a separate section.

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Thermally activated diffusion in reversibly associating polymers

Cited by 14 publications

References 20 publications

Physical chemistry of supramolecular polymer networks

Physical chemistry of supramolecular polymer networks

Synthesis, swelling behavior, and viscoelastic properties of functional poly(hydroxyethyl methacrylate) with ureidopyrimidinone side-groups

Single- and Two-Photon Fluorescence Recovery after Photobleaching

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