Jan Bock

Macromolecular complexes in chemistry and biology

I. Hydrophobically Associating Polymers.- 1 Synthesis and Characterization of Hydrophobically Associating Water-Soluble Polymers.- 1.1 Introduction.- 1.2 Synthesis.- 1.3 Copolymerization.- 1.4 Postpolymerization Modification.- 1.5 Characterization-Hydrophobe Incorporation.- 1.6 Summary.- 1.7 References.- 2 Analysis of Hydrophobically Associating Copolymers Utilizing Spectroscopic Probes and Labels.- 2.1 Introduction.- 2.2 Emission Probes and Labels.- 2.3 Absorption Probes.- 2.4 Concluding Remarks.- 2.5 References.- 3 Solution Properties of Hydrophobically Associating Water-Soluble Polymers.- 3.1 Introduction.- 3.2 Polymer Systems.- 3.3 Solubility Characteristics.- 3.4 Solution Stability.- 3.5 Solution Rheological Properties.- 3.6 Summary.- 3.7 References.- 4 Aggregation of Hydrophobically Modified Polyelectrolytes in Dilute Solution: Tonic Strength Effects.- 4.1 Introduction.- 4.2 Experimental.- 4.3 The Polymers.- 4.4 Dilute Solution Viscosity.- 4.5 Fluorescence Spectroscopy.- 4.6 Intrinsic Viscosity.- 4.7 Concluding Remarks.- 4.8 References.- 5 Microdomain Composition in Two-Phase Hydrogels.- 5.1 Introduction.- 5.2 Background.- 5.2.1 Microphase Separation in Polymers.- 5.2.2 Importance of Graft Polymers.- 5.3 Results.- 5.3.1 Hydrogels from Surfactant Solutions.- 5.3.2 Hydrogels from Ethanol/Water Solutions.- 5.3.3 Solute Uptake by Gels.- 5.4 Conclusions.- 5.5 References.- 6 Molecular Association and Polymerization of 1-Alkyl-4-vinylpyridinium Ions.- 6.1 Complexation in 1-Alkyl-4-vinylpyridinium Ions and Related Polymers.- 6.2 Homopolymerization of 1-Alkyl-4-vinylpyridinium Ions.- 6.3 Copolymerization of 1-Alkyl-4-vinylpyridinium Ions.- 6.4 Conclusion.- 6.5 References.- 7 Fluorocarbon-Modified Water Soluble Polymers.- 7.1 Introduction.- 7.2 Experimental.- 7.3 Results and Discussion.- 7.4 Conclusions.- 7.5 References.- II. Polyelectrolyte Complexes.- 8 Static Light Scattering of Polyelectrolyte Complex Solutions.- 8.1 Introduction.- 8.2 Survey of Static Light Scattering Studies on PEC Solutions.- 8.3 Interpretation of Light Scattering Experiments.- 8.4 Experimental.- 8.4.1 Materials.- 8.4.2 Methods of Investigation.- 8.5 Results and Discussion.- 8.6 Conclusion.- 8.7 References.- 9 Interaction Between Oppositely Charged Low Ionic Density Polyelectrolytes: Complex Formation or Simple Mixture?.- 9.1 Introduction.- 9.2 Material and Techniques.- 9.2.1 Polymer Synthesis.- 9.2.2 Polymer Characterization.- 9.2.3 Other Techniques.- 9.3 Phase Diagram.- 9.3.1 Phase Diagram Representation.- 9.3.2 Influence of the Charge Density.- 9.3.3 Influence of the Ionic Strength.- 9.3.4 Influence of the Molecular Weight of the Samples.- 9.3.5 Phase Diagram and Complex Formation.- 9.4 Polymer-Polymer Affinity and Phase Diagram.- 9.5 Conclusion.- 9.6 References.- 10 Basic Properties of Soluble Interpolyelectrolyte Complexes Applied to Bioengineering and Cell Transformations.- 10.1 Introduction.- 10.2 Kinetic and Equilibrium Properties of Interpolyelectrolyte Complexes.- 10.3 Interpolyelectrolyte Complexes as Protein Carriers.- 10.4 Complexes of DNA with Synthetic Polycations for Cell Transformation.- 10.5 Conclusion.- 10.6 References.- 11 Conformation Presumption for Polysaccharide-Polylysine Complexation.- 11.1 Introduction.- 11.2 Complex Formation.- 11.3 Pectate-Polylysine Interaction.- 11.4 Polyguluronate Rich Alginate-Polylysine Interaction.- 11.5 Polymannuronate Rich Alginate-Polylysine Interaction.- 11.6 Conclusion.- 11.7 References.- 12 Interpolymer Complexes and their Ion-Conduction.- 12.1 Introduction.- 12.2 Classification of Interpolymer Complexes.- 12.3 Formation of Interpolymer Complexes from PAA with POE.- 12.4 Thermodynamics of Interpolymer Complexes from PAA (or PMMA) with POE.- 12.5 Selective and Substitution Interpolymer Complexation.- 12.6 Solid Properties of a Hydrogen-Bonding Complex.- 12.7 Ion Conduction and Solid Polymer Electrolytes.- 12.8 Ion Conduction of Hydrogen-Bonding Complexes.- 12.9 References.- 13 Fluorescence Probe Studies of Poly(acrylic acid) Interchain Complexation Induced by High Shear Flow and Influence of Cationic Surfactants on the Complexation.- 13.1 Introduction.- 13.2 Experimental.- 13.2.1 Materials.- 13.2.2 Flow Processing.- 13.2.3 Fluorescence Measurements.- 13.3 Results and Discussion.- 13.3.1 Drag Reduction (DR) and PAA Conformation.- 13.3.2 Local Chain Rigidity.- 13.3.3 Hydrophobic Association.- 13.3.4 Hydrophobe-Assisted Rigidity.- 13.4 References.- III. Biopolymer Systems.- 14 Water-Soluble Biospecific Polymers for New Affinity Purification Techniques.- 14.1 Introduction.- 14.2 Discrimination on the Basis of High Molecular Weight.- 14.2.1 Biospecific Ultrafiltration.- 14.2.2 Biospecific Gel Filtration.- 14.3 Discrimination on the Basis of High Density of Charges: Affinophoresis.- 14.4 Discrimination on the Basis of Surface Tension Properties: Affinity Partition.- 14.5 Discrimination on the Basis of Reversible Solubility: Affinity Precipitation.- 14.6 Advantages and Drawbacks of Techniques Involving Water-Soluble Biospecific Polymers.- 14.7 References.- 15 Protein-Polyelectrolyte Complexes.- 15.1 Introduction.- 15.2 Investigation Methods.- 15.3 Factors Influencing Protein-Polyelectrolyte Complexation and Structures of the Protein-Polyelectrolyte Complexes.- 15.4 Protein Separation by Polyelectrolytes.- 15.5 Enzymes in Polyelectrolyte Complexes.- 15.6 Conclusion.- 15.7 References.- 16 Precipitation of Proteins with Polyelectrolytes: Role of Polymer Molecular Weight.- 16.1 Introduction.- 16.2 Materials and Methods.- 16.3 Results and Discussion.- 16.4 Conclusions.- 16.5 References.- 17 Complex Coacervation: Micro-Capsule Formation.- 17.1 Introduction and Terminology.- 17.2 Simple Coacervation.- 17.3 Complex Coacervation.- 17.4 Theory of Complex Coacervation.- 17.5 Coacervation as a Method of Microencapsulation.- 17.6 Materials and Methods.- 17.7 Results.- 17.8 Conclusions.- 17.9 References.- 18 Complexation of Proteins with Polyelectrolytes in a Salt-Free System and Biochemical Characteristics of the Resulting Complexes.- 18.1 Introduction.- 18.2 Experimental Section.- 18.3 Results and Discussion.- 18.4 Conclusions and Topics for Future Research.- 18.5 References.- IV. Ionomers in Solution.- 19 Ionomer Solutions: Polyelectrolyte or Ionomer behavior.- 19.1 Introduction.- 19.2 Sulfonated Polystyrene Ionomer Solutions in Nonpolar Solvents.- 19.3 Sulfonated Polystyrene Ionomer Solutions in Polar Solvents.- 19.4 Perfluorinated Ionomer Solutions.- 19.5 Conclusion.- 19.6 References.- 20 Scattering Studies of Ionomer Aggregates in Nonpolar Solvents.- 20.1 Introduction.- 20.2 Experimental.- 20.3 Light Scattering Analysis.- 20.4 Results and Discussion.- 20.5 References.

Relationship between fundamental interfacial properties and foaming in linear and branched sulfate, ethoxysulfate, and ethoxylate surfactants

Abstract The effect of hydrocarbon chain branching on the foaming performance of a variety of sulfate, ethoxysulfate, and ethoxylate surfactants was determined by the Ross—Miles test. Data from static and dynamic surface tension experiments were used to obtain a structure—property—performance correlation. Initial foam heights correlated with π (CMC), the effectiveness of surface tension reduction, while foam instability correlated with R 1 2 , the rate of surface tension reduction at the air—water interface. Hydrocarbon chain branching resulted in increased π (CMC) and R 1 2 . Consequently, surfactants wherein the hydrocarbon chain is branched exhibited high initial foam heights and low foam stability.

Relationships between dynamic contact angle and dynamic surface tension properties for linear and branched ethoxylate, ethoxysulfate, and sulfate surfactants

Abstract The process of dynamic wetting of Teflon and its modification by linear and branched ethoxylates, ethoxysulfates, and sulfates has been examined via measurement of dynamic contact angles. A linear correlation between advancing dynamic contact angle and the air-liquid meso-equilibrium dynamic surface tension was observed. A value of 21 mN/m was obtained for the critical meso-equilibrium surface tension for complete dynamic wetting of Teflon. Surfactants that tend to meso-equilibrate quickly at the air-liquid interface are more effective in reducing the dynamic contact angle than those that equilibrate slowly. Branched hydrophobe surfactants exhibit better effectiveness in modifying dynamic wetting of Teflon than linear hydrophobe surfactants.

Model for microemulsions. I: Effect of sulfonate surfactant cation and chain size and concentration on phase behavior

One/one aqueous NaCl/decane systems containing C12 o-oxylene sulfonates neutralized with mono-, di-, and triethanol amines were equilibrated and phase volumes determined. The systems phase split into 1 to 3 surfactant-rich phases in equilibrium with excess brine and/or decane. Both birefringent and optically homogeneous surfactant phases showed trends in phase volumes with varying salinity, head group size, chain length, and surfactant concentration. Monoethanol ammonium (MEA) and triethanol ammonium (TEA) sulfonates showed opposite trends with increasing concentration; optimal salinity rose with increasing TEA sulfonate and dropped with MEA sulfonate concentration. The diethanol ammonium (DEA) sulfonate showed an optimal salinity essentially independent of surfactant concentration as did equal weight mixtures of MEA and TEA sulfonates. Optimal salinity increased in the order MEA < DEA = MEA/TEA (11) < TEA indicating that surfacant hydrophilicity increases with increasing head group size. These trends and those with varying chain length are consistent with a proposed model mutually relating water and oil uptakes, interfacial curvature, and head and chain size. The model focuses on the structure of the surfactant at the brine/oil interface and relates structure to surfactant capacity to hold brine and oil together in the microemulsion. It examines the influence of surfactant head and chain volumes and water oil interfacial “solubility” on the direction and extent of interfacial curvature. The effect of these variables on interfacial curvature is in turn related to water and oil uptake. Water uptake increases and oil uptake decreases with increasing head/chain volume ratio, oil alkane carbon number and temperature (sulfonates), and decreasing salinity and aromaticity. The model postulates the coexistence of domains of water and oil continuity and applies spherical geometry to oil and water droplets in these domains. The resulting equations relate water and oil uptakes to the relative thicknesses and volumes of surfactant heads and chains. These structural parameters at balance are evaluated from surfactant heads and chains molecular olumes and interfacial areas. The model provides a physical explanation for the well-known empirical hydrophile/lipophile balance (HLB) system. It extends the HLB concept to include the influence of salinity, temperature, and oil composition.

Model for microemulsions: III. Interfacial tension and droplet size correlation with phase behavior of mixed surfactants

Abstract We have developed a model for microemulsions which relates surfactant structure to microemulsion droplet size, interracial tension, and phase behavior. The concept of curvature parameter, developed to describe microemulsion phase behavior (M. L. Robbins and J. Bock, J. Colloid Interface Sci.124, 462 (1988)), is expanded to cover interfacial tension, droplet size, and phase behavior correlations. The curvature parameter is made up of contributions from the thickness and volumes of surfactant polar heads and hydrocarbon chains at the water/oil interface. A set of equations is developed interrelating water and oil uptakes, droplet interfacial tensions, and droplet sizes via the curvature parameter and applied to equilibrated microemulsions prepared with mixtures of ethoxylated dinonyl phenol and the monoethanol amine salt of dodecyl o-xylene sulfonic acid in 1 1 decane/aqueous NaCl of varying salinity. The model predicts that droplet interfacial tensions should vary inversely with water and oil uptakes and that the square root of droplet tensions should vary linearly with the curvature parameters. Curvature parameters calculated from water and oil uptakes were found to plot linearly against salinity (see previous reference), suggesting that the square root of interracial tension should also plot linearly against salinity. Measured bulk interfacial tensions when plotted as √γ vs salinity gave linear plots as opposed to the conventional semilogarithmic plots which are highly curved. Measured bulk interfacial tensions varied inversely with water and oil uptakes and correlated very well with calculated droplet interfacial tensions using a sifigle empirical constant. Based on limited data, this constant appears to be universal for the systems tested. The current paper extends testing of theoretical correlations to include microemulsion droplet size. Droplet sizes in lower- (water-continuous) and upper- (oil-continuous) phase anionic microemulsions were measured as a function of aqueous salinity using dynamic (laser) light scattering on microemulsions prepared with the surfactant combination of monoethanol ammonium dodecyl ortho-xylene sulfonate/tertiary amyl alcohol (C12∗XS-MEA/TAA) in 1 1 oil/aqueous NaC1. The model predicts that micro-emulsion droplet size should be inversely proportional to the square root of the interfacial tension (√γ), which is in turn inversely related to water and oil uptakes ( V w V s and V o V s . The value of the proportionality constant depends on the thickness and compressibility of the surfactant layer at the water/oil interface. Using the length of the C12∗XS-MEA molecule measured from molecular model projections, droplet sizes calculated from water and oil uptakes agree very well with those determined by dynamic light scattering experiments, lending further support to the model.

A polymer—microemulsion interaction: The coacervation model

A model which successfully predicts many of the qualitative features of the phase separation can be based upon the assumption that the microemulsion particle retains its integrity when diluted with external phase or when mixed with a polymer (which does not complex with the surfactants). In this case, the microemulsion particle behaves thermodynamically in a manner similar to a macromolecule so that one can predict that the polymer—microemulsion phase diagram will have qualitative similarities to that exhibited by the polymer—polymer2-solvent case. Most of the experiments were conducted by following the phase boundaries by measurements of the cloud points of the polymermicroemulsion mixtures. The cloud points of the mixtures were found to be (usually) linear functions of the weight fraction of the added polymer and decreased with increasing molecular weight. Plots of the logarithm of the slopes of these curves against the logarithm of the polymer molecular weight were linear, with a slope designated as β. The values for β for twenty-five systems studied fell within the narrow range of 0.55 ± 0.15. These values were seen to be the same as the Mark—Houwink exponents in the relationship between the intrinsic viscosity and the polymer molecular weight. The reason for this correspondence appears to be that the coacervation occurs at a polymer concentration about equal to the threshold overlap concentration. Ternary phase diagrams with microemulsion particles, brine, and polymer selected as pseudocomponents also exhibit many of the features predicted by the model. The phase boundary asymmetry is in the direction expected and asymptotes with the expected independence upon microemulsion and polymer molecular weights are also demonstrated. In agreement with the model, it is shown that the controlling variable is polymer weight average, rather than z or number average molecular weight.

Effect of hydrocarbon chain branching on interfacial properties of monodisperse ethoxylated alcohol surfactants

Abstract Surfactant properties at the air-water, decane-water, and Teflon-water interfaces are strongly influenced by branching of the hydrocarbon chain of an ethoxylate surfactant. Although chain branching reduces chain length, branched ethoxylates exhibit properties intermediate between those of linear surfactants of the same carbon number and linear surfactants of the same chain length. Steric factors that disfavor micellization in bulk result in enhancement of adsorption properties at interfaces. Compared to linear ethoxylates, branched ethoxylates with the same number of oxyethylene groups exhibit a higher critical micelle concentration and are more effective in reducing the surface tension at the air-water interface by occupying a larger area per molecule. Better dynamic air-water interfacial properties result from branching the hydrophobe as branched ethoxylates attain meso-equilibrium faster and the surface tension at meso-equilibrium is lower than the corresponding linear hydrophobe surfactant. At the decane-water interface the effect of branching on critical aggregation concentration and effectiveness in interfacial tension reduction depends on the nature of branching. The water wettability of a hydrophobic Teflon surface is enhanced by branched hydrocarbon chain ethoxylates.

Development of Corexit 9580—A Chemical Beach Cleaner

ABSTRACT Chemical beach cleaners can facilitate cleanups of oiled shorelines by improving the efficiency of washing with water. The improvement is a result of reduced adhesion of the oil coating, which makes it easier to remove from shoreline surfaces, thereby reducing washing time and lowering the temperature of the wash water needed to clean a given area. The criteria established for use of chemical beach cleaners in the Exxon Valdez spill cleanup included demonstrating enhanced cleaning with low levels of toxicity to marine biota and with minimal oil dispersion. Since no commercially available products satisfactorily met these criteria for use in Alaska, a new product, Corexit 9580, was specifically developed in response to this need. This paper describes the successful development of this chemical, including both laboratory testing and field testing in Prince William Sound.

Perturbation of a nonionic microemulsion by the introduction of a charged surfactant. I: Light scattering

Abstract A nonionic microemulsion with a small fraction of its nonionic surfactant, Brij 96, replaced by sodium oleate was used to vary the charge on the presumed microemulsion droplets in a controllable fashion. Cloud points and other evidence indicate that the mixed microemulsion was formed. The molecular weight and second virial coefficient of the droplets were measured as a function of added salt and showed that the molecular weight of the ionized microemulsion was only slightly changed from the nonionic case, while the changes in second virial coefficient could be described by a hard sphere plus double-layer potential. The particles were shown to undergo ordering at very low salt concentrations.

Model for microemulsions: II. Hydrophile—lipophile balance (HLB)—salinity—oil molar volume phase maps

Abstract The previously described model for microemulsions (10) has been expanded to generate theoretical phase maps defining the boundaries for transitions in microemulsion types. Winsors I a III a II transition boundaries (lower a middle a upper phase microemulsions) are defined for alkyl o-xylene sulfonates with simultaneously varying cation size, chain length, and aqueous phase salinity. Variation in cation size and chian length is reduced to a single variable, the hydrophile/lipophile ( H L ) volume ratio (Vr), which also includes interfacial water and oil. Interfacial water and oil is shown to depend on the packing area of surfactant molecules in the interface relative to the areas occupied by surfactant heads and chains, respectively. Theoretical 1 a m and m a u transition boundaries are evaluated and plotted in H L ratio-salinity phase space together with the locus of optimal salinities. Trajectories crossing these phase boundaries are evaluated and plotted for specific surfactants. This theoretical phase map, when used with the model equations, contains all the information necessary to calculate water ( V w V s ) and decane ( V o V s ) uptakes at constant surfactant concentration with varying salinity and H L ratio for the entire homologous series of alkyl o-xylene sulfonates containing ethanol amine cations of varying size. The concepts embodied in the H L ratio-salinity phase map are qualitatively expanded to describe transitions and water and oil uptakes in multidimensional phase space, e.g., H L ratio-salinity-oil alkane carbon number space.