Glückliche Reise.

Following Forest Hills High School in New York City, I attended Cornell University for a five-year program leading to a Bachelor of Chemical Engineering degree. After spending one year at the University of Rochester to obtain a Master of Science in Chemical Engineering, I came to Princeton University in 1951. Four years later, with a fresh PhD, I joined the faculty at the University of California, Berkeley, where I remained, interrupted only by sabbatical leaves in Switzerland, Germany, England, New Zealand, and Australia.

Asphaltene Adsorption from Toluene onto Silica through Thin Water Layers.

Asphaltenes in crude oil play a pivotal role in reservoir oil production because they control rock-surface wettability. Upon crude oil invasion into a brine-filled reservoir trap, rock adherence of sticky asphaltene agglomerates formed at the crude oil/brine interface can change the initially water-wet porous medium into mixed-oil wetting. If thick, stable water films coat the rock surfaces, however, asphaltenic-oil adhesion is thought to be prevented.

Wetting behavior of four polar organic solvents containing one of three lithium salts on a lithium-ion-battery separator.

Hypothesis: The wetting behavior of an electrolyte solution on the separator, determined by contact-angle measurements, has a significant effect on the internal resistance of the battery and on its cycle life. The solvent, the lithium-salt type and its concentration may affect the wettability. However, few systematic studies address the effect of salt concentration on surface tension and contact angle.

Henry's Constants of Persistent Organic Pollutants by a Group-Contribution Method Based on Scaled-Particle Theory.

A group-contribution method based on scaled-particle theory was developed to predict Henry's constants for six families of persistent organic pollutants: polychlorinated benzenes, polychlorinated biphenyls, polychlorinated dibenzodioxins, polychlorinated dibenzofurans, polychlorinated naphthalenes, and polybrominated diphenyl ethers. The group-contribution model uses limited experimental data to obtain group-interaction parameters for an easy-to-use method to predict Henry's constants for systems where reliable experimental data are scarce. By using group-interaction parameters obtained from data reduction, scaled-particle theory gives the partial molar Gibbs energy of dissolution, Δg̅, allowing calculation of Henry's constant, H, for more than 700 organic pollutants.

Delignification of miscanthus using ethylenediamine (EDA) with or without ammonia and subsequent enzymatic hydrolysis to sugars.

Pretreatment of miscanthus is essential for efficient enzymatic production of cellulosic ethanol. This study reports a possible pretreatment method for miscanthus using aqueous ethylenediamine (EDA) for 30 min at 180 °C with or without ammonia. The mass ratio of miscanthus to EDA was varied from 1:3, 1:1, and 1:0.

A simplified electrostatic model for hydrolase catalysis.

Toward the development of an electrostatic model for enzyme catalysis, the active site of the enzyme is represented by a cavity whose surface (and beyond) is populated by electric charges as determined by pH and the enzyme's structure. The electric field in the cavity is obtained from electrostatics and a suitable computer program. The key chemical bond in the substrate, at its ends, has partial charges with opposite signs determined from published force-field parameters.

Water-soluble drug partitioning and adsorption in HEMA/MAA hydrogels.

Two-photon confocal microscopy and back extraction with UV/Vis-absorption spectrophotometry quantify equilibrium partition coefficients, k, for six prototypical drugs in five soft-contact-lens-material hydrogels over a range of water contents from 40 to 92%. Partition coefficients were obtained for acetazolamide, caffeine, hydrocortisone, Oregon Green 488, sodium fluorescein, and theophylline in 2-hydroxyethyl methacrylate/methacrylic acid (HEMA/MAA, pKa≈5.2) copolymer hydrogels as functions of composition, aqueous pH (2 and 7.

High solubilities of small hydrocarbons in trihexyl tetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate.

Experimental solubilities are reported for methane, ethane, ethylene, propane, and propylene in trihexyl tetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate [P(14)666][TMPP] from 313 to 353 K up to 6.7 MPa. A literature review on solubilities of small hydrocarbons in ionic liquids shows that solubilities in [P(14)666][TMPP] are appreciably larger than those in other ionic liquids.

Aqueous-ammonia delignification of miscanthus followed by enzymatic hydrolysis to sugars.

This work concerns the effect of aqueous ammonia pretreatment at four temperatures and at 10, 20 or 30 wt.% ammonia. After 1h, more than 65% delignification is achieved at 150 or 180 °C for high and for low concentrations of ammonia.

Extraction of lignins from aqueous-ionic liquid mixtures by organic solvents.

The commercial development of ionic liquids (ILs) to pretreat lignocellulose by dissolution of whole biomass and cellulose precipitation by addition of water is hindered by the absence of an effective technique to recover the lignin content of the biomass from the IL. Three organic solvents [ethyl acetate, 1,4-dioxane, and tetrahydrofuran (THF)] were studied for their ability to form a two-liquid-phase system with water and 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]), and for partitioning model lignins and lignin monomers between the two liquid phases. Ternary diagrams were obtained for three [C(2)mim][OAc]/organic solvent/water systems at 22°C.

Addition of ammonia and/or oxygen to an ionic liquid for delignification of miscanthus.

Ammonia and/or oxygen were used to enhance the delignification of miscanthus dissolved in 1-ethyl-3-methylimidazolium acetate at 140°C. After dissolution of the gas at 9 bar, water was added as antisolvent to regenerate the dissolved biomass. In a next step, an acetone/water mixture was used to remove carbohydrate-free lignin from the regenerated biomass.

Ionic liquid pretreatment of cellulosic biomass: enzymatic hydrolysis and ionic liquid recycle.

Ionic liquids (ILs) are promising solvents for the pretreatment of biomass as certain ILs are able to completely solubilize lignocellulose. The cellulose can readily be precipitated with an anti-solvent for further hydrolysis to glucose, but the anti-solvent must be removed for the IL to be recovered and recycled. We describe the use of aqueous kosmotropic salt solutions to form a three-phase system that precipitates the biomass, forming IL-rich and salt-rich phases.

Modeling corneal metabolism and oxygen transport during contact lens wear.

Purpose: A metabolic model is developed for cornea-contact-lens system to elucidate the role of glucose metabolism in oxygenation of the cornea and to gauge the role that contact lens oxygen transmissibility plays in avoiding hypoxia-induced corneal abnormalities for extended wear applications.

Methods: Oxygen transport through the cornea and contact lens system is typically described by oxygen diffusion with reactive loss. Oxygen in the cornea, however, interacts with other metabolic species, specifically glucose, lactate ion, bicarbonate ion, hydrogen ion, and carbon dioxide via aerobic glycolysis (Krebs or tricarboxylic acid cycle) and anaerobic glycolysis.

Diffusion and Monod kinetics to determine in vivo human corneal oxygen-consumption rate during soft contact-lens wear.

The rate of oxygen consumption is an important parameter to assess the physiology of the human cornea. Metabolism of oxygen in the cornea is influenced by contact-lens-induced hypoxia, diseases such as diabetes, surgery, and drug treatment. Therefore, estimation of in vivo corneal oxygen-consumption rate is essential for gauging adequate oxygen supply to the cornea.

Role of surfactant on the proteolysis of aqueous bovine serum albumin.

Nonionic and ionic surfactants diminish the initial rate of proteolysis of aqueous bovine serum albumin (BSA) by subtilisin Carlsberg. Surfactants studied include: nonionic tetraethylene glycol monododecyl ether (C12E4); anionic sodium dodecyl sulfate (SDS), anionic sodium dodecylbenzenesulfonate (SDBS), and cationic dodecyltrimethylamonium bromide (DTAB). Kinetic data are obtained using fluorescence emission.

In vitro cytotoxicities of ionic liquids: effect of cation rings, functional groups, and anions.

In vitro cytotoxicities were measured for ionic liquids (ILs) containing various cations and anions using the MCF7 human breast cancer cell line. We measured the cytotoxicities of ionic liquids containing the cations pyridinium, pyrrolidinium, piperidinium, or imidazolium with various alkyl chain lengths, and the anions bromide, bis(trifluoromethanesulfone)imide (Tf(2)N), trifluoromethylsulfonate (TfO), or nonafluoromethylsulfonate (NfO). Three new hydrophobic, task-specific ionic liquids (TSILs), namely, [MBCNPip](+)[Tf(2)N](-), [MPS(2)Pip](+)[Tf(2)N](-), and [MPS(2)Pyrro](+)[Tf(2)N](-) designed for metal-ion extraction were also evaluated.

Pairwise-additive hydrophobic effect for alkanes in water.

Pairwise additivity of the hydrophobic effect is indicated by reliable experimental Henry's constants for a large number of linear and branched low-molecular-weight alkanes in water. Pairwise additivity suggests that the hydrophobic effect is primarily a local phenomenon and that the hydrophobic interaction may be represented by a semiempirical force field. By representing the hydrophobic potential between two methane molecules as a linear function of the overlap volume of the hydration layers, we find that the contact value of the hydrophobic potential (-0.

Solvent polarities and kamlet-taft parameters for ionic liquids containing a pyridinium cation.

Five recently synthesized pyridinium ionic liquids [(1-butyl-4-methylpyridinium, 1-octylpyridinium, 1-octyl-2-methylpyridinium, 1-octyl-3-methylpyridinium, and 1-octyl-4-methylpyridinium, all with anion bis(trifluoromethylsulfonyl)imide], were investigated to establish the influence of substituting a methyl group and the influence of alkyl chain length on the cation on polarity ET(N) and on three Kamlet-Taft parameters: dipolarity/polarizabilty (pi*), hydrogen-bond acidity (alpha), and hydrogen-bond basicity (beta). Experimental measurements cover the range 25 to 65 degrees C.

Water-Nafion equilibria. absence of Schroeder's paradox.

Water-Nafion phase equilibria and proton conductivities were measured in two ways. First, Nafion was in contact with saturated water vapor. Second, Nafion was in contact with liquid water at the same temperature.

A single-lens polarographic measurement of oxygen permeability (Dk) for hypertransmissible soft contact lenses.

A novel polarographic apparatus is described that requires only a single soft contact lens (SCL) to ascertain oxygen permeabilities of hypertransmissible lenses. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, the apparatus described here requires only a single-lens thickness. This is accomplished by minimizing (or completely eliminating) edge effects, boundary-layer resistances, and lens desiccation in the polarographic apparatus.

Protein aggregation in silico.

Protein aggregation is a challenge to the successful manufacture of protein therapeutics; it can impose severe limitations on purification yields and compromise formulation stability. Advances in computer power, and the wealth of computational studies pertaining to protein folding, have facilitated the development of molecular simulation as a tool to investigate protein misfolding and aggregation. Here, we highlight the successes of protein aggregation studies carried out in silico, with a particular emphasis on studies related to biotechnology.

Molecular simulation of protein aggregation.

Computer simulation offers unique possibilities for investigating molecular-level phenomena difficult to probe experimentally. Drawing from a wealth of studies concerning protein folding, computational studies of protein aggregation are emerging. These studies have been successful in capturing aspects of aggregation known from experiment and are being used to refine experimental methods aimed at abating aggregation.

Effect of salt identity on the phase diagram for a globular protein in aqueous electrolyte solution.

Monte Carlo simulations are used to establish the potential of mean force between two globular proteins in an aqueous electrolyte solution. This potential includes nonelectrostatic contributions arising from dispersion forces first, between the globular proteins, and second, between ions in solution and between each ion and the globular protein. These latter contributions are missing from standard models.