Fourier transform infrared microspectroscopy of phase-separated mixed biopolymer gels

Durrani, C. Matin; Donald, Athene M.

doi:10.1021/ma00079a017

Cited by 22 publications

(6 citation statements)

References 7 publications

(10 reference statements)

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“…Unfortunately the mutual contrast would most likely be very low, so special techniques, for example, by raising immunofluorescent stains for one or other of the proteins, would be needed to visualize this protein in the presence of the other within the gel system. Another useful approach may be FTIR microscopy, as used by Durrani and co-workers. , …”

Section: Discussionmentioning

confidence: 99%

“…Another useful ap- proach may be FTIR microscopy, as used by Durrani and co-workers. 18,19 Although it would be reasonable to assume that binary protein mixtures formed a kind of mixed gel, it is not easy to explain the experimental data for such mixed gels. In Figure 8, t c does not change as a linear function of protein ratio.…”

Section: Mixed-protein Gel Systemsmentioning

confidence: 99%

See 1 more Smart Citation

Heat-Induced Gelation of Globular Proteins. 2. Effect of Environmental Factors on Single-Component and Mixed-Protein Gels

Tobitani

Ross‐Murphy

1997

Macromolecules

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In the first paper in this series, we investigated heat-induced gelation of single component systems of the globular protein, bovine serum albumin. A series of rheological experiments revealed that we can describe gelation time in terms of two physical parameters, concentration and temperature. In this paper we examine more complex systems, including the effect of pH and ionic strength, on heat-induced gelation of bovine serum albumin (BSA), and another globular protein, β-lactoglobulin (β-Lg). These factors significantly influenced protein gelation, a result which has not been reported in detail before. However, no detailed analysis was possible, because the behavior is very complex. We also consider the extension of both model and experiments to (quasi-) binary mixed systems, viz. the gelation of binary systems chosen from three globular proteins: BSA, β-Lg, and α-lactalbumin (α-La). We have obtained reliable results only for the BSA and β-Lg system because of experimental difficulties. From the data of the BSA/β-Lg system, it was found that gelation behavior changed significantly with the ratio of the two proteins. The change in the gelation time and temperatures was not expressed as a linear equation but required a cross-term. This strongly suggests that current models for the concentration dependence of modulus for mixed biopolymer gels will need to be modified.

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Section: Discussionmentioning

confidence: 99%

Section: Mixed-protein Gel Systemsmentioning

confidence: 99%

Heat-Induced Gelation of Globular Proteins. 2. Effect of Environmental Factors on Single-Component and Mixed-Protein Gels

Tobitani

Ross‐Murphy

1997

Macromolecules

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“…They reported that their micrographs appeared quite similar to those observed in a number of synthetic interpenetrating networks (referred to as IPNs), and showed phase separation into the two polymer networks with possible phase inversion at a certain mixture composition. Durrani et al , derived a phase diagram for the ternary amylopectin−gelatin−D 2 O mixture in the sol state by the use of Fourier-transformed infrared microspectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Thermoreversible Gelation with Two-Component Networks

Tanaka

Ishida

1999

Macromolecules

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This paper studies thermoreversible gelation in two-component polymer mixtures (A/B) in which both polymers carry associative groups capable of forming reversible pairwise bonds. The type of association is classified into the following three main categories: (i) association of polymers within the same species (AA and BB); (ii) association only between the different species (AB); (iii) all associations allowed (AA, BB and AB). On the basis of a recent theory of associating polymers, we derive possible phase diagrams for interpenetrating networks, alternating networks, and randomly mixed networks corresponding to each category, with special attention to the interference between gelation and macroscopic phase separation. For all types, homogeneously mixed networks are most easily stabilized near the stoichiometric concentration where the total number of A associative groups in the mixture agrees with that of B associative groups.

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“…They reported that their micrographs appeared quite similar to those observed in a number of synthetic interpenetrating networks (referred to as IPNs) 110,111 , and showed phase separation into the two polymer networks with possible phase inversion at a certain mixture composition. Durrani et al 112,113 derived a phase diagram for the ternary amylopectin-gelatin-D 2 O mixture in the sol state by the use of Fourier transformed infrared microspectroscopy.…”

Section: Multicomponent Gelationmentioning

confidence: 99%

Theoretical Study of Molecular Association and Thermoreversible Gelation in Polymers

Tanaka

2002

Polym J

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ABSTRACT:This paper reviews our recent theoretical studies of molecular association and thermoreversible gelation in polymer solutions and blends. We first classify fundamental types of association, and propose their static and dynamic characterization. We then develope general theory of associating polymers to study phase transitions induced by molecular association. These transitions include macro-and microphase separation, micellization, hydration, thermoreversible gelation and liquid-crystalization. As for the origin of associative forces, we focus on hydrogen bonding and hydrophobic aggregation. Detailed study on thermoreversible gelation with multiple cross-link junctions is presented. Paying special attention to the multiplicity and sequence length of the network junctions, we derive phase diagrams with coexisting gelation and phase separation, and compare them with experimental data. Local and global structures of the gel networks are studied from molecular point of view. The theory is applied to more complex thermoreversible gels such as binary networks (interpenetrating networks, alternating networks and randomely mixed networks), hydrated networks with high-temperature gelation, gelation strongly coupled to polymer conformational transitions such as coil-to-helix transition. To study dynamics of thermoreversible gels, a simple transient network model is introduced, and creation and annihilation of junctions in the networks are theoretically described. Stationary non-linear viscosity and the dynamic mechanical moduli are calculated as functions of the shear rate, frequency and the chain disengagement rate. From the peak of the loss modulus, the lifetime τ × of the junction is estimated, and from the high frequency plateau of the storage modulus, the number of elastically effective chains in the network is found. Transient phenomena such as stress relaxation and stress overshoot are also theoretically studied. Results are compared with the recent experimental reports on the rheological study of hydrophobically modified water-soluble polymers.KEY WORDS Associating Polymers / Thermoreversible Gelation / Junction Multiplicity / Multicriticality / Transient Networks / Shear Thickening / Elastically Effective Chains / This paper reviews our recent theoretical studies of molecular association and thermoreversible gelation in polymer solutions. We introduce new theoretical frameworks to study phase transitions induced by association of polymer chains and dynamics of aggregation/dissociation processes.In most polymer blends or solutions, polymer chains carry active groups interacting with each other via strongly associative forces which are capable of forming temporal bonds. Hence description of the system in terms of van der Waals type contact energy -or χ-parameter in lattice theoretical terminology -is insufficient. These associative interactions include hydrogen bonding, ionic aggregation, electrostatic interaction, micro-crystallite formation, stereocomplex formation, solvent-complex formation, etc. Since ...

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Fourier transform infrared microspectroscopy of phase-separated mixed biopolymer gels

Cited by 22 publications

References 7 publications

Heat-Induced Gelation of Globular Proteins. 2. Effect of Environmental Factors on Single-Component and Mixed-Protein Gels

Heat-Induced Gelation of Globular Proteins. 2. Effect of Environmental Factors on Single-Component and Mixed-Protein Gels

Thermoreversible Gelation with Two-Component Networks

Theoretical Study of Molecular Association and Thermoreversible Gelation in Polymers

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