The Surface Areas of Proteins. IV. Sorption of Polar Gases<sup>1</sup>

Benson, Sidney W.; Seehof, Jerrold M.

doi:10.1021/ja01155a010

Cited by 18 publications

(14 citation statements)

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“…The term sorption is used to describe gas or solvent uptake by adsorption on surfaces or at specific molecular sites and by swelling due to the formation of solvent clusters in a polymer matrix. Early works on the investigation of the surface area of proteins have shown that the adsorption of nonpolar gases such as nitrogen or oxygen takes place at the surface whereas the sorption of polar gases such as water or ammonia takes place by swelling and involves the solvation of specific polar groups. − Depending upon the entropies and enthalpies of mixing, different modes of sorption can be distinguished. , …”

Section: Introductionmentioning

confidence: 99%

Thermodynamics of Amorphous Starch−Water Systems. 2. Concentration Fluctuations

Benczédi¹,

Tomka²,

Escher³

1998

Macromolecules

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This paper presents a theoretical and experimental study of the sigmoidal water sorption isotherms of amorphous starch. Sorption isotherms have been measured by gas chromatography at infinite dilution of water in starch and by isothermal and isosteric sorption experiments in an extended concentration and temperature range in which the biopolymer behaves either as a brittle glass or as a rubbery melt. A maximum value of the isothermal activity coefficient of water is observed at a composition corresponding to the glass transitions measured by calorimetry. Therefore, the partial derivatives of the activity coefficient of water with respect to concentration and temperature are positive in glasses and negative in melts. A transition from sigmoidal to Flory type sorption is estimated to occur at 175 °C, which is lower than the glass transition of dry starch. The distribution of water molecules in glasses and melts is analyzed with the Kirkwood theory of solutions. In glasses, water shows large negative excluded volumes typical of an antiplasticizer, as reflected also in the density increase observed at low water concentrations. In melts, water shows positive excluded volumes typical of a plasticizer having recovered its motional freedom restricted in the glassy state. Up to 80 °C, the self-clustering functions of water in melts diverge at higher water contents. These functions only take finite values above this temperature once a full melting of the starch−starch hydrogen bond interaction has occurred. The sigmoidal water sorption isotherms are analyzed with a new explicit relationship combining the generalized Freundlich adsorption model and the Flory model of polymer solutions. A restricted translational and rotational freedom is predicted for the adsorption water, and a clustering tendency is predicted for the solution water. The Freundlich−Flory sorption model provides a consistent description of the solvation, the swelling, and the dissolution of hydrophilic polymer glasses in a solvent like water whereas the Brunauer−Emmet−Teller model is only physically meaningful for the adsorption of nonsolvents such as oxygen or nitrogen gases.

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Section: Introductionmentioning

confidence: 99%

Thermodynamics of Amorphous Starch−Water Systems. 2. Concentration Fluctuations

Benczédi¹,

Tomka²,

Escher³

1998

Macromolecules

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“…All the BET surface areas are obviously larger than that of BSA (6 m 2 g −1 ) and that of egg albumin (5-21 m 2 g −1 ). [ 20 ] The BET surface area of the fi brin-AuNPs-GOx-GA is even comparable with that of multiwalled carbon nanotubes (60 m 2 g −1 ). [ 21 ] The above data demonstrate that the organized fi brin network exhibits a higher surface area than that of protein aggregates, and the incorporation of nanoparticles promotes the porosity.…”

Section: Fabrication and Characterization Of The Fibrin-boned Compositesmentioning

confidence: 84%

Bio‐Inspired Preparation of Fibrin‐Boned Bionanocomposites of Biomacromolecules and Nanomaterials for Biosensing

Han

et al. 2014

Adv Funct Materials

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Learning from nature is one of the most promising ways to develop advanced functional materials. Here, inspired by blood coagulation, novel fi brin-boned bionanocomposites are reported as effi cient immobilization matrices of biomacromolecules and nanomaterials for biosensing. Glucose oxidase (GOx), Au nanoparticles (AuNPs), and Fe 3 O 4 magnetic nanoparticles (MNPs) are adopted as the model biomacromolecules and nanomaterials. By integrating the thrombin-triggered coagulation of fi brin with advanced surfi cial modifi cation techniques, four kinds of immobilization strategies are developed and evaluated. Digital imaging, UV-vis spectroscopy, scanning/transmission electron microscopy, electrochemical methods, and N 2 adsorption-desorption isotherms are used to investigate the formation, immobilization effi ciency, and performance of various bionanocomposites. The fi brin-boned networks show inherent biocompatibility, excellent adsorbability, porosity, and functionalization ability, endowing the bionanocomposites with high effi ciencies in capturing AuNPs, MNPs and GOx (99%, 98%, and 57% captured under the given conditions, respectively), as well as signifi cant mass-transfer and biocatalysis effi ciencies. Therefore, the fi brin-boned bionanocomposites show great potential for biosensing, for example, a fi brin-AuNPs-GOx-glutaraldehyde bionanocomposites modifi ed Au electrode is highly sensitive to glucose (145 µA cm −2 mM −1 ) allowing for a limit of detection down to 25 nM, being much superior to those of the reported analogues. The presented experimental platform/strategy may fi nd wide applications in the development of other bio/nano-materials/devices.

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“…If a definite compound is formed between the amino groups and HCI, it is also difficult to explain the absence of isobars in the desorption curves which Benson and Seehof obtained in their investigation of egg albumin [1,2]. The sorption isobars indicate a compound corresponding to 0.95 mM HC1 per gram of protein at a pressure of 0.11 cm; yet the desorption curve from a pressure of 0.40 cm shows no break except perhaps at a very small pressure (0.01 cm).…”

Section: Residual Hc1 Contentmentioning

confidence: 96%

“…It will be convenient to review these two papers separately. In discussing the paper by Seehof and Benson, it will be necessary to refer to some of their earlier work [1,2) .…”

Section: Introductionmentioning

confidence: 99%

The Sorption of HCl by Textile Fibers

Larose

1955

Textile Research Journal

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The Surface Areas of Proteins. IV. Sorption of Polar Gases¹

Cited by 18 publications

References 0 publications

Thermodynamics of Amorphous Starch−Water Systems. 2. Concentration Fluctuations

Thermodynamics of Amorphous Starch−Water Systems. 2. Concentration Fluctuations

Bio‐Inspired Preparation of Fibrin‐Boned Bionanocomposites of Biomacromolecules and Nanomaterials for Biosensing

The Sorption of HCl by Textile Fibers

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The Surface Areas of Proteins. IV. Sorption of Polar Gases1

Cited by 18 publications

References 0 publications

Thermodynamics of Amorphous Starch−Water Systems. 2. Concentration Fluctuations

Thermodynamics of Amorphous Starch−Water Systems. 2. Concentration Fluctuations

Bio‐Inspired Preparation of Fibrin‐Boned Bionanocomposites of Biomacromolecules and Nanomaterials for Biosensing

The Sorption of HCl by Textile Fibers

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The Surface Areas of Proteins. IV. Sorption of Polar Gases¹