Determination of the conformation of polymers in the amorphous solid state and in concentrated solution by neutron diffraction

Kirste, R. G.; Kruse, Walter; Ibel, K.

doi:10.1016/0032-3861(75)90140-8

Cited by 262 publications

(96 citation statements)

References 6 publications

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“…The validity of the latter assumption in the case of hydrogeneous and deuterated polystyrene (PSH and PSD) has been demonstrated through the observation of a zero second virial cnefficient hy SANS studies.9 I t should be pointed out that a small difference in thermodynamic properties between PSH and PSD has been demonstrated10 in studies on solutions of both polymers in hydrogeneous and deuterated cyclohexane. These studies have indicated a solubility-parameter difference hetween the two polymers of A132 = b 2~ -62" = -0.04 (1) If one then uses the relationship proposed by Krause" for the dependence of XAR between two polymers on the solubility-parameter difference…”

mentioning

confidence: 99%

The effect of deuteration on the phase equilibrium of the polystyrene/poly(vinyl methyl ether) blend system

Yang

Hadziioannou

Stein

1983

J. Polym. Sci. Polym. Phys. Ed.

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confidence: 99%

The effect of deuteration on the phase equilibrium of the polystyrene/poly(vinyl methyl ether) blend system

Yang

Hadziioannou

Stein

1983

J. Polym. Sci. Polym. Phys. Ed.

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“…2) Recent progress in neutron scattering techniques [10,11,12] has allowed a precise observation of the coil pair correlation function, in dilute as well as in semi-dilute solutions, over the entire intermediate The first is currently being studied and will be published elsewhere [13]. We will be concerned here with two 1) In a good solvent, in the limit of zero concentration, it is well-known [4] that the excluded volume interaction v swells the coil only if This condition expresses in fact the Ginzbourg criterion of the critical phenomena [14].…”

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confidence: 99%

“…1). The special features of the scattering technique are amply described in recent papers [10,11,12]. All measurements are performed on a small-angle scattering spectrometer of the Laboratoire Léon-Brillouin set on a cold neutron guide of the EL3 reactor at Saclay [10].…”

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confidence: 99%

Cross-over in polymer solutions

et al. 1978

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Résumé. 2014 La fonction de corrélation de paire P(r) pour les polymères en solution a été mesurée par diffusion de neutrons aux petits angles dans l'intervalle 3 RG ~ r ~ I où RG est le rayon de giration et l la longueur du monomère. A la température thêta cette fonction est décrite par la loi de Debye 1/r. En bon solvant (limite haute température) et à la limite de la concentration nulle, S. F. Edwards prédit que cette fonction est uniformément proportionnelle à r-4/3.Cependant le résultat expérimental montre que pour des concentrations assez élevées ou pour des températures intermédiaires la fonction P(r) présente les deux comportements. On trouve qu'ils sont séparés par des longueurs de cross-over r* qui dépendent de la température et de la concentration. Le scaling de r* est relié au scaling de la longueur de corrélation 03BE et du rayon RG dans le diagramme température-concen tration.Abstract. 2014 Using a small-angle neutron scattering experiment, we measured the pair correlation function P(r) in polymer solutions in the interval 3 RG ~ r ~ l, where RG is the radius of gyration and I the step length. At the theta temperature, this function is known to follow the characteristic Debye law P(r) ~ r-1. In good solvents (high temperature limit) and in the limit of zero polymer concentration this function is uniformly proportional to r-4/3, as predicted by S. F. Edwards.We observe however, that at higher concentrations or intermediate temperatures, P(r) exhibits both characteristic behaviours, depending on the range of r. The cross-over distances r* which separate the patterns are found to depend upon concentration and temperature. The scaling of r* is related to the scaling of the screening length 03BE and the radius RG in the temperature-concentration diagram.

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“…This behaviour is presumably due to the structure of agarose [ 2 , 3 ] . The gross conformation of most synthetic polymers may be described by the model of random coil [4]. In comparison with agarose gels, synthetic crosslinked gels contain, on an average, smaller pores and a more flexible matrix.…”

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confidence: 99%

“…The substrates attached via spacers to the matrix were completely hydrolyzed. 4. The initial course of the product vs time curves, as well as the dependence of the initial hydrolysis rates on enzyme concentration or substrate concentration, have been interpreted by the Nernst reaction theory.…”

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Enzymatic Attack on Immobilized Substrates

Fischer

Lange

Jakubke

1978

European Journal of Biochemistry

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1. The chyrnotrypsin-catalyzed hydrolysis of polyacrylamide-bound L-phenylalanine 4-nitroanilide was studied. As a spacer, one or two 6-aminohexanoyl residues were inserted between the matrix and ligand.2. In the course of the enzymatic hydrolysis of polyacrylamide-bound substrates, enzyme adsorption by the gel substrates was observed. A quasi equilibrium of enzyme partitioning was reached after approximately 20-min incubation time. The enzyme adsorption could be described by the Langmuir adsorption isotherm.3. The substrates attached via spacers to the matrix were completely hydrolyzed. 4. The initial course of the product vs time curves, as well as the dependence of the initial hydrolysis rates on enzyme concentration or substrate concentration, have been interpreted by the Nernst reaction theory. From the results obtained it has been concluded that the initial rate of the hydrolysis of polyacrylamide-bound L-phenylalanine 4-nitroanilide depends on the velocity of enzyme diffusion into the matrix.Results obtained with agarose-bound L-phenylalanine 4-nitroanilide show that the diffusion of the enzyme into the substrate gel does not influence the chymotrypsin-catalyzed hydrolysis to a significant degree. On the other hand, only a definite part of the bound ligand, dependent on the spacer length, is accessible to enzymatic attack [l]. This behaviour is presumably due to the structure of agarose [ 2 , 3 ] . The gross conformation of most synthetic polymers may be described by the model of random coil [4]. In comparison with agarose gels, synthetic crosslinked gels contain, on an average, smaller pores and a more flexible matrix. These parameters of synthetic gels depend on the degree of cross-linking.In the present paper we have tried to study the influence of a matrix different from agarose on the enzymatic hydrolysis of immobilized low-molecularweight substrates. For this purpose polyacrylamide (Biogel P100) was chosen. In polyacrylamide the interactions of the polymeric chains should be restricted to hydrogen bonds between the carboxyl amide groups Abbreviations. EAhx-Phe-Nan, 6-aminohexanoyl-~-phenylalanine 4-nitroanilide ; (EAhx)2-Phe-Nan, 6-aminohexanoyl-6-aminohexanoyl-L-phenylalanine 4-nitroanilide; P-, polyacrylamidebound; A-, agarose-bound; PhMeS03-, phenylmethanesulfonyl-.Enzyme. Chymotrypsin (EC 3.4.21.1).if cross-linking is neglected. As in our studies with agarose-bound substrates 111, L-phenylalanine 4-nitroanilide interposed by either one to two 6-aminohexanoyl residues was bound to polyacrylamide and used for the investigation of both the behaviour of protein adsorption and enzymatic hydrolysis. MATERIALS AND METHODS MaterialsBiogel PI00 was purchased from Bio-Rad Laboratories and crystalline chymotrypsin was purchased from Spofa (Prague). All other reagents were the purest commercially available. Synthesis of Polyacrylamide-Bound SubstratesBiogel P100, containing azide groups, was prepared according to Inman and Dintzis [5]. The ligands were coupled to the matrix in 0.2 M carbonate buffer/dimethy...

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Determination of the conformation of polymers in the amorphous solid state and in concentrated solution by neutron diffraction

Cited by 262 publications

References 6 publications

The effect of deuteration on the phase equilibrium of the polystyrene/poly(vinyl methyl ether) blend system

The effect of deuteration on the phase equilibrium of the polystyrene/poly(vinyl methyl ether) blend system

Cross-over in polymer solutions

Enzymatic Attack on Immobilized Substrates

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