Redox flow batteries (RFBs) are enjoying a renaissance due to their ability to store large amounts of electrical energy relatively cheaply and efficiently. In this review, we examine the components of RFBs with a focus on understanding the underlying physical processes. The various transport and kinetic phenomena are discussed along with the most common redox couples.

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Redox flow batteries: a review

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/pdf/user-s-manual-for-wateq4f-with-revised-thermodynamic-data-1btcfvp3ho.pdf

User's manual for WATEQ4F, with revised thermodynamic data base and text cases for calculating speciation of major, trace, and redox elements in natural waters

The enzymatic hydrolysis of cellulose encounters various limitations that are both substrate- and enzyme-related. Although the crystallinity of pure cellulosic Avicel plays a major role in determining the rate of hydrolysis by cellulases from Trichoderma reesei, we show that it stays constant during enzymatic conversion. The mode of action of cellulases was investigated by studying their kinetics on cellulose samples. A convenient method for reaching intermediate degrees of crystallinity with Avicel was therefore developed and the initial rate of the cellulase-catalyzed hydrolysis of cellulose was demonstrated to be linearly proportional to the crystallinity index of Avicel. Despite correlation with the adsorption capacity of cellulases onto cellulose, at a given enzyme loading, the initial enzymatic rate continued to increase with a decreasing crystallinity index, even though the bound enzyme concentration stayed constant. This finding supports the determinant role of crystallinity rather than adsorption on the enzymatic rate. Thus, the cellulase activity and initial rate data obtained from various samples may provide valuable information about the details of the mechanistic action of cellulase and the hydrolysable/reactive fractions of cellulose chains. X-ray diffraction provides insight into the mode of action of Cel7A from T. reesei. In the conversion of cellulose, the (021) face of the cellulose crystal was shown to be preferentially attacked by Cel7A from T. reesei.

https://febs.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1742-4658.2010.07585.x

Cellulose crystallinity--a key predictor of the enzymatic hydrolysis rate

This review provides a critical assessment of the use of cellulosic materials for reinforcement in polymer composites. The review focuses on structure–property interrelationships and the compatibilization of cellulosic materials for optimal performance of the resulting composite materials. Optimal material and physical properties are characterized on the basis of the reinforcement’s physical dimension and the nature of the interface between reinforcement and matrix. We explore how very different cellulosic materials—bacterial, microcrystalline, microfibrillated or nanocrystalline—can cause distinctly different reinforcment.

Cellulose reinforced polymer composites and nanocomposites: a critical review

Bimetallic nanorods are propelled in aqueous solutions by the catalytic decomposition of hydrogen peroxide to oxygen and water. Several mechanisms (interfacial tension gradients, bubble recoil, viscous Brownian ratchet, self-electrophoresis) have been proposed for the transduction of chemical to mechanical energy in this system. From Tafel plots of anodic and cathodic hydrogen peroxide reactions at various metal (Au, Pt, Rh, Ni, Ru, and Pd) ultramicroelectrodes, we determine the potential at which the anodic and cathodic reaction rates are equal for each metal. These measurements allow one to predict the direction of motion of all possible bimetallic combinations according to the bipolar electrochemical (or self-electrophoretic) mechanism. These predictions are consistent with the observed direction of motion in all cases studied, providing strong support for the mechanism. We also find that segmented nanorods with one Au end and one poly(pyrrole) end containing catalase, an enzyme that decomposes hydroge...

Bipolar Electrochemical Mechanism for the Propulsion of Catalytic Nanomotors in Hydrogen Peroxide Solutions

The definition of a “primary method of measurement ” has permitted a full consideration of the definition of primary standards for pH, determined by a primary method (cell without transference, Harned cell), of the definition of secondary standards by secondary methods, and of the question whether pH, as a conventional quantity, can be incorporated within the internationally accepted system of measurement, the International System of Units (SI, Systeme International d’ Unites). This approach has enabled resolution of the previous compromise IUPAC 1985 Recommendations [Pure Appl. Chem. 57, 531 (1985)]. Furthermore, incorporation of the uncertainties for the primary method, and for all subsequent measurements, permits the uncertainties for all procedures to be linked to the primary standards by an unbroken chain of comparisons. Thus, a rational choice can be made by the analyst of the appropriate procedure to achieve the target uncertainty of sample pH. Accordingly, this document explains IUPAC recommended definitions, procedures, and terminology relating to pH measurements in dilute aqueous solutions in the temperature range 5-50 °C. Details are given of the primary and secondary methods for measuring pH and the rationale for the assignment of pH values with appropriate uncertainties to selected primary and secondary substances.

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Measurement of pH. definition, standards, and procedures: (IUPAC Recommendations 2002)

Criteria for standardization of pH measurements in organic solvents and water + organic solvent mixtures of moderate to high permittivities

Chairman: J. Jordan (USA); Secretary: K. Izutsu (Japan); Titular Members: A. K. Covington (UK); J. Juillard (France); R. C. Kapoor (India); E. Pungor (Hungary); Associate Members: W. Davison (UK); R. A. Durst (USA); M. Gross (France); K. M. Kadish (USA); R. Kalvoda (Czechoslovakia); H. Kao (China); Y. Marcus (Israel); T. Mussini (Italy); H. W. NUrnberg (FRG); M. Senda (Japan); N. Tanaka (Japan); K. TOth (Hungary); NationaiRepresentatives: D. D. Perrin (Australia); B. Gilbert (Belgium); W. C. Purdy (Canada); A. A. V1ek (Czechoslovakia); H. Monien (FRG); M. L'Her (France); Gy. Farsang (Hungary); H. C. Gaur (India); W. F. Smyth (Ireland); E. Grushka (Israel); S. R. Cavallari (Italy); W. Frankvoort (Netherlands); Z. Galus (Poland); G. Johansson (Sweden); J. Buffle (Switzerland); H. Thompson (UK); J. G. Osteryoung (USA); I. Piljac (Yugoslavia).

/pdf/reference-value-standards-and-primary-standards-for-ph-48jhuo25fp.pdf

Reference value standards and primary standards for pH measurements in organic solvents and water + organic solvent mixtures of moderate to high permittivities

Measurement of pH. Definition, standards, and procedures

Chairman: K. Izutsu (Japan); Vice-Chairman: E. Pungor (Hungary); Secretary: M. Senda (Japan); Titular Members: J. Buffle (Switzerland); J. Juillard (France); K. M. Kadish (USA); R. Kalvoda (Czechoslovakia); Associate Members: A. K. Covington (UK); W. Davison (UK); R. A. Durst (USA); M. Gross (France); H. Kao (China); R. C. Kapoor (India); H. P. van Leeuven (Netherlands); Y. Marcus (Israel); T. Mussini (Italy); J. G. Osteryoung (USA); N. Tanaka (Japan); K. Tóth (Hungary); National Representatives: G. E. Batley (Australia); B. Gilbert (Belgium); W. C. Purdy (Canada); A. A.Vlek (Czechoslovakia); H. B. Nielsen (Denmark); H. Monien (FRG); M. L'Her (France); Gy. Farsang (Hungary); G. Prabhakara Rao (India); W. F. Smyth (Ireland); E. Grushka (Israel); S. R. Cavallari (Italy); W. Frankvoort (Netherlands); Z. Galus (Poland); G. Johansson (Sweden); M. L. Berkem (Turkey); H. Thompson (UK); J. Jordan (USA); I. Piljac (Yugoslavia).

/pdf/autoprotolysis-constants-in-nonaqueous-solvents-and-aqueous-3ddsad5dfh.pdf

Torquato Mussini

Papers

Measurement of pH. definition, standards, and procedures: (IUPAC Recommendations 2002)

Criteria for standardization of pH measurements in organic solvents and water + organic solvent mixtures of moderate to high permittivities

Reference value standards and primary standards for pH measurements in organic solvents and water + organic solvent mixtures of moderate to high permittivities

Measurement of pH. Definition, standards, and procedures

Autoprotolysis constants in nonaqueous solvents and aqueous organic solvent mixtures