Interaction of sodium dodecyl sulfate with polyelectrolyte complexes derived from diazoresin and sulfonate-containing polymers

The sulfonate-containing polyelectrolytes (SPE) from sulfonation of polystyrene (PS) and copolymerization of 3-sulfo-propyl methacrylate, potassium salt (SPMS) with styrene (S) were prepared. Photosensitive polyelectrolyte complexes (PEC_DR) derived from SPE and diazoresin (DR), which does not dissolve in water or organic solvent due to its ionic crosslinking structure, dissolves in aqueous solution of sodium dodecyl sulfate (SDS) due to the dissociation of PEC_DR and the hydrophobic interaction between SDS and the polymer chain. The photosensitive behavior and thermostability of the PEC_DR were investigated, and it was found that the thermostability of PEC_DR increases dramatically in SDS aqueous solution. It was proposed that the higher thermostability of PEC_DR in SDS aqueous solution is due to an aggregation of SDS molecules around the diazonium group of the PEC_DR, which protects the  N group of the DR from attack by the nucleophiles. The image-forming behavior of PEC_DR by ultraviolet (UV) light was examined and considered to be different from other PECs. It was concluded that the photoimaging behavior of PEC_DR is based on a reaction in which an ionic bond converts to a covalent bond. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2601–2606, 1999     

Adsorption, association and precipitation in hexadecyltrimethylammonium bromide/sodium dodecyl sulfate mixtures

The phase equilibria of surfactant aqueous mixtures, hexadecyltrimethylammonium bromide and sodium dodecyl sulfate, have been studied by polarizing microscopy, quasielastic light scattering, conductivity, potentiometric, electrophoretic, and surface tension measurements. Adsorption at the air/solution interface, association and precipitation in bulk solution strongly depended on the molar ratio and the concentration of surfactants. Catanionic vesicles coexisted with crystalline catanionic salts in a broad concentration range. The relative proportions of crystallites and vesicles varied according to the concentration and the molar ratio of the surfactants. The solid crystalline phase was progressively converted to catanionic vesicles with increasing surfactant molar ratio. At the highest excess of one of the surfactants transition from catanionic vesicles to mixed micelles occurred. The formation and stability of different phases are discussed in terms of surfactant molecular packing constraints and electrostatic interactions in the headgroup region. Surfactant tail-length asymmetry and the change of electrostatic interactions in the headgroup region from attractive to repulsive are governing factors for the transition from planar to curved bilayers. Received: 9 June 1998 Accepted: 18 August 1998     

Swelling of poly(ethylene oxide) gel in aqueous solutions of sodium dodecyl sulfate with added sodium chloride

The swelling behavior of poly(ethylene oxide) (PEO) gels in aqueous solutions of sodium dodecyl sulfate (SDS) with and without NaCl was investigated. In the absence of NaCl, PEO gels with different degrees of cross-linking began to swell from a concentration lower than the critical micelle concentration (cmc) of SDS, then showed sigmoidal enhancements of swelling in a higher SDS concentration region until the degrees of swelling reached maximum values. The SDS concentration at which the swelling began to appear was in reasonable agreement with the critical aggregation concentration (cac) value reported for the aqueous PEO system. For the cases where NaCl was present, the swelling behavior of PEO gel was different from that when NaCl was absent in the following way. The concentrations where the swelling begins to appear, and hence those where the degree of swelling rises steeply, decreased with an increase in NaCl concentration. The ultimate degrees of swelling at higher concentration regions also decreased with an increase in the NaCl concentration. The lowering of the SDS concentrations at which the PEO gel began to swell is in line with the decreases in the cmc of SDS solutions containing NaCl and also with the decreases in the cac of PEO solution. Electronic Publication     

Poly(N-isopropylacrylamide). I. Interactions with sodium dodecyl sulfate measured by conductivity

Conductometric titration of poly(N-isopropylacrylamide) (polyNIPAM) with sodium dodecyl sulfate (SDS) gave two apparent transitions labeled C1 and C2. The C1 transition was independent of polyNIPAM concentration in the 0.05–0.3 wt % range, whereas C2 was proportional to the polymer concentration. C1 corresponded to the onset of binding of surfactant with polymer. Arguments based on a simple mass action model for micellization are presented to show that C2, the second transition, is not due to any simple explanation such as being the point above which only free micelles are formed with surfactant addition. The cloud point of polyNIPAM increased with the amount of bound surfactant. This was attributed to electrostatic contribution of bound sulfate groups to the increased solubility of polyNIPAM. © 1993 John Wiley & Sons, Inc.     

Interaction of Sodium Dodecyl Sulfate with Poly(ethyleneimine) in Bulk Solution and at the Air-Solution Interface

Interaction of sodium dodecyl sulfate (SDS) with the cationic polyelectrolyte poly(ethyleneimine) (PEI) was investigated in this study. Turbidity measurements were performed in order to analyze the interaction and complex formation in bulk solution as a function of polymer concentration and pH. Surface tension measurements were made to investigate the properties of SDS/PEI/water mixtures at air/solution interface. Results revealed that SDS/PEI complexes form in solution depending on the surfactant and polymer concentration. A decrease was observed in surface tension values in the presence of SDS/PEI mixtures compared to the values of pure SDS solutions. Both solution and interfacial properties exhibited pH dependent behavior. A shift was seen in the critical micelle concentration of SDS solutions as a function of PEI concentration and solution pH. Monovalent and divalent salt additions showed some influence on the interfacial properties of SDS solutions in the presence of PEI.     

十二烷基硫酸钠与羟乙基纤维素的相互作用

本文用表面张力(γ)和电导率(κ)方法研究了阴离子表面活性剂十二烷基硫酸钠(SDS)与天然纤维素的水溶性改性物羟乙基纤维素(HEC)的相互作用.实验结果表明,SDS-HEC溶液的γ-lgcSDS曲线和κ～CSDS曲线均呈现双拐点特征,并且γ-lgcSDS曲线上两个SDS临界浓度值(c1 )γ及(c2)γ,与κ～CSDS...     

Ultrathin-layer sodium dodecyl sulfate disc electrophoresis of proteins in the range from 10 to 220 kDa in homogeneous,low-concentrated polyacrylamide gels

This study describes an ultrathin-layer sodium dodecyl sulfate (SDS) disc electrophoresis in polyacrylamide gels of a thickness of only 150 microm. By use of 2-amino-2-methyl-1,3-propanediol/glycine instead of traditional Tris/HCl buffer in the resolving phase of the gel, proteins with a wide range of molecular sizes (10 kDa to over 220 kDa) are separated in unusually low-concentrated gels (4%T, 3.3%C). 2-Amino-2-methyl-1,3-propanediol in the resolving part of the gel contributes to stabilization of the pH value at 8.8, while glycine improves destacking as well as separation of small proteins from the bulk of stacked SDS. This method combines both the advantages of conventional slab-gel electrophoresis and capillary gel electrophoresis. It is easy to apply and well suited for all further miniaturization attempts.     

Effect of sodium dodecyl sulfate on the reactivity of copper(II) complexes with 2-dimethylaminomethylphenol

The effects of the anionic surfactant sodium dodecyl sulfate on complex formation of 2-dimethylaminomethylphenol (1) with copper(u) in aqueous solutions and on the kinetics of the reactions of copper(n) complexes of 1 with 4-nitrophenylbis(chloromethyl)phosphinate (2) were studied. The reactivities of the complexes in these reactions are higher than that of 1 at all concentrations of SDS studied (0.010–0.200 mol L^–1 with pH 7–9.Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 361–365, February, 1996.     

Interlaboratory method validation of capillary electrophoresis sodium dodecyl sulfate (CE-SDS) methodology for analysis of mAbs

Capillary electrophoresis sodium dodecyl sulfate (CE-SDS) is an analytical method to assess the purity of proteins, commonly applied to monoclonal antibodies (mAbs) in the biopharmaceutical industry. To address the need to standardize the CE-SDS method in the pharmaceutical industry and to enhance the confidence in method transfer between laboratories operating different commercial capillary electrophoresis (CE) instrument platforms, an interlaboratory CE-SDS method validation was organized involving 13 laboratories in 13 companies on four different types of commercial capillary electrophoresis instruments. In the validation, a commercial mAb therapeutic was used as the sample. The validation process followed the analytical guidelines set by the ICH guidelines (International Conference for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use). The method's precision, accuracy, linearity and range, and limit of quantitation (LOQ) were validated in the study. Variations of all the parameters validated in the study passed the pre-set criteria defined at the beginning of the study. The definition was based on previously published works and the intended application purpose of the CE-SDS method for mAbs. The study proved that the CE-SDS method fits its intended application purpose as a size impurity assay and size heterogeneity characterization assay for mAb therapeutic products. This study is the first time a CE-SDS method is validated by multiple laboratories using different commercial CE instrument platforms and on a commercial mAb therapeutic. Its results will enhance the confidence of the biopharmaceutical industry to develop CE-SDS methods and transfer CE-SDS methods between different laboratories.     

Hydrophobically end-capped poly (ethylene oxide) urethanes. Part 3: Effect of sodium dodecyl sulphate on their association in aqueous solution

The interactions between sodium dodecyl sulphate (SDS) and three autoassociative polymers (hydrophobically end-capped poly(ethylene oxide) urethanes) are studied by conductimetry, fluorescence, and viscometry. By the first two techniques the interactions are found to increase with the hydrophobicity of the polymer and to be stronger than those observed for a polyethylene oxide (PEO) of the same order of molecular weight. The results seem to be consistent with a model where SDS micelles are formed around hydrophobic chain ends in a first stage, and along the main chain in a second stage. For the more hydrophobic sample already self-aggregated in water and of relatively large reduced viscosity, the addition of SDS induces a loss in viscosity contrary to the less hydrophobic ones and PEO. Such effect may be attributed to the destruction of the chain end association by the formation of SDS micelles around one end in the first stage of the interaction.     

Synthesis, swelling behavior and surface microstructure of poly(sodium acrylate) gels cross-linked by aluminum ions

We report the synthesis and some unique properties of polymer gels cross-linked by metal ions. They are made of poly(sodium acrylate) and aluminum ions. Cylindrical and thin plate gels were synthesized in glass molds by mixing poly(sodium acrylate) with aluminum hydroxide of various concentrations. The swelling ratio of the gels was measured by changing the solvent pH and adding NaCl with different concentrations. Each gel was found to swell at the first stage and shrink thereafter by repeated solvent exchanges; the swelling ratio ultimately returned to the initial one just after gelation. These features could be explained using a qualitative model based on the ion exchange and the formation of hydrogen bonding. A characteristic surface microstructure was observed on the dehydrated gels using an atomic force microscope. The microstructures were analyzed in terms of the autocorrelation function and the root-mean-square roughness. The surface microstructure of this system was characterized by the microdomains, the shape of which was found to depend strongly on the amount of aluminum ions and the gel thickness at gelation. It could be controlled not only by the concentration of the cross-linker but also by the dehydration condition.     

Microemulsion photopolymerization of methacrylates stabilized with sodium dodecyl sulfate and poly(N-acetylethylenimine) macromonomers

Methyl methacrylate and butyl methacrylate were polymerized in oil-in-water microemulsions that were stabilized by sodium dodecyl sulphate (SDS). A poly(N-acetylethylenimine) (PNAEI) macromer was also included in the recipe, as a cosurfactant and a comonomer. Polymerizations were initiated by UV-irradiation. The average diameters of latex particles, obtained by STM, were in the range of 17-200 nm. The experimental data evidenced that the particle size was mainly dependent on the SDS/PNAEI ratio. Polymerization yields were around 75-85%. The synthesized copolymers have viscosity average molecular weights in the range of 2.1-2.4×10⁶ and glass transition temperatures of 38.0-43.5°C, lower than those obtained without using PNAEI. The investigation by means of FTIR and 1H-NMR techniques revealed that PNAEI was incorporated into the nanoparticles.     

Effect of sodium dodecyl sulfate on the reactivity of 2-dimethylaminomethylphenol with 4-nitrophenylbis(chloromethyl)phosphinate

The reactivity of 2-dimethylaminomethylphenol (1) toward 4-nitrophenylbis(chloromethyl)phosphinate (2) was studied in micellar solutions and in the lyotropic liquid-crystalline mesophase of the sodium dodecyl sulfate (SDS)-water system. The reaction between1 and2 is inhibited in the presence of SDS, which is explained by the shift of the acid-base equilibrium of1 toward the formation of a nonreactive protonated form.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1959–1962, October, 1995.     

A cationic surfactant is bound to poly(vinylpyrrolidone) in high pH media

Interaction of tetradecylpyridinium bromide with poly(vinylpyrrolidone) was studied by use of an electrode sensitive to the cationic surfactant. In a neutral medium, there was no sign of interaction: potentiometric titration response was in agreement with Nernst equation irrespective of absence and presence of the polymer. But in a medium with pH 11.3, deviation from Nernst response appeared in a PVP solution showing binding of the cationic surfactant onto the polymer which had been thought indifferent to cationic surfactants in spite of strong affinity to anionic surfactants. The result is interpreted in terms of deprotonation from PVP at higher pH media.     

Dilute solution properties of poly(dimethyldiallylammonium chloride) in aqueous sodium chloride solutions

MW fractions of poly(dimethyldiallylammonium chloride) (PDMDAAC) were prepared by preparative size-exclusion chromatography and characterized by static and dynamic light scattering, viscometry, size-exclusion chromatography, and electrophoretic light scattering, in 0.50M NaCl solution. The behavior of fractions with MW < 2 × 10⁵ was as expected for a strong polyelectrolyte in a good solvent, with a Mark-Houwink exponent of ca. 0.8, and MW-dependencies of the hydrodynamic radius and the radius of gyration of corresponding magnitude. At higher MW, curvature appears in the MW-dependencies, which can be best explained by the presence of branching. While this notably lowers the intrinsic viscosity at high MW, the electrophoretic mobility is unchanged regardless of molar mass. Thus, the branched polymers display the electrophoretic free-draining behavior characteristic of linear polyelectrolytes. ©1995 John Wiley & Sons, Inc.     

Ionic and excited species in irradiated poly(dimethylsiloxane) doped with pyrene

The influence of temperature (77–230 K) on the fate of pyrene (Py) radical ions and Py excited states in irradiated poly(dimethylsiloxane) (PDMS) doped with Py is described. At 77 K, the Py radical ions seem to be stable, whereas the Py excited states [fluorescence (λ = 395 nm) and phosphorescence (λ = 575–650 nm)] are generated via tunneling charge transfer. In the range of the glass‐transition temperature (T_g = 152–153 K), the Py radical ions start to decay, taking part in a recombination process and leading to the Py monomer and Py excimer fluorescence (λ = 475 nm). The wavelength‐selected radiothermoluminescence (WS RTL) observed at approximately 395, 475, and 600 nm has helped us to identify the T_g range (152–153 K). The absorption maximum at approximately 404 nm, found in the temperature range under consideration, is thought to represent PyH^?, cyclohexadienyl‐type radicals produced as a result of the reaction of Py^?? with protonated PDMS macromolecules. With the initial‐rise method of evaluating the activation energy (E_a) with the WS RTL peaks observed in the T_g range, E_a values of 123–151 kJ mol^?1 have been found. Such high E_a values can be explained by the contribution of energy connected to the molecular relaxation of the matrix in the T_g range. The well‐known Williams–Landel–Ferry equation, with universal constants C₁ = 17.4 and C₂ = 12.7, has been successfully applied to the interpretation of old pulse‐radiolysis/viscosity data found for crosslinked PDMS doped with Py. The mechanisms involved in these phenomena are discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6125–6133, 2004     

Adsorption of Cu(II) in aqueous solution by sodium dodecyl benzene sulfonate-modified montmorillonite

The pristine montmorillonite (P-Mt) was modified with sodium dodecyl benzene sulfonate (SDBS) to form SDBS montmorillonite (SDBS-Mt) for the purpose of enhancing the removal performance of Cu(II) from aqueous solution. The materials were characterized by means of XRD, SEM-EDS, BET, and FTIR to analyze the surface morphology and structure. SDBS-Mt displayed a higher adsorption capacity than P-Mt. The adsorption kinetic model and the adsorption isotherm model are depicted by the pseudo-second-order kinetic equation and the Langmuir equation, respectively. The adsorption of Cu(II) on SDBS-Mt is a spontaneous and endothermic process. The order of influence of coexisting cations on the adsorption of Cu(II) is Ni(II) > Co(II) > Zn(II). In addition, the adsorbent has great regeneration performance after five cycles of regeneration. The main mechanisms of Cu(II) adsorption by SDBS-Mt may include electrostatic attraction, ion exchange, and complexation of sulfonate groups. In brief, SDBS-Mt may be a promising, simple, and low-cost adsorbent for the treatment of Cu(II) in aqueoussolutions.     

Molecular dynamics of star‐shaped poly(L‐lactide)s in tetrahydrofuran as solvent monitored by fluorescence spectroscopy

Linear telechelic, α,ω‐ditelechelic, and star‐shaped tri‐, tetra‐, penta‐, and hexa‐arm poly(L ‐lactide)s (PLAs) fitted at every arm with pyrene end group have been prepared. Internal dynamics and mobility of the PLA chains in tetrahydrofuran solution at 25 °C, with regard to the number of PLA arms in one macromolecule and the individual arm average degree of polymerization, was followed by fluorescence spectroscopy. Analysis of both static and time‐resolved spectra of the star‐shaped polymers revealed dynamic segmental motion resulting in end‐to‐end cyclization, accompanied by an excimer formation. Probability and rate of the latter reaction increased with increasing number of arms and with decreasing their polymerization degree. Moreover, time‐resolved measurements revealed that for macromolecules containing few arms (2 or 3) the pyrene moieties are located in the interior of the star‐shaped PLAs, whereas in the instance of the higher number of arms (4–6) they are located at the periphery of the star‐shaped PLAs. Thus, increasing the number of arms leads to their stretching away from the center of the star‐shaped PLA macromolecule. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4586–4599, 2005     

Poly(diallyldimethylammonium chloride) as an Efficient Phase Transfer Catalyst in Solvent‐Free Reduction of Carbonyl Compounds with NaBH4

Poly(diallyldimethylammonium chloride) resin was used as an efficient polymeric phase transfer catalyst, which catalyzed the chemoselective reduction of aldehydes and ketones by NaBH₄ to give the corresponding alcohols in high yields under solvent-free conditions.     

Studies on the interaction of poly(4-vinylpyridiniumchloride) with poly(sodiumphosphate) in an aqueous solution by conductometry

A reaction between poly(4-vinylpyridiniumchloride) and poly(sodiumphosphate) in the presence and absence of NaCl and NaBr salts was studied in aqueous solution by conductometry. The interaction of polycation and polyanion gave insoluble polyelectrolyte complex which contained polycation and polyanion in unit mole ratio in a salt-free solution. A deviation from stoichiometry was observed at high polyion concentration and in the presence of NaCl and NaBr salts. The resultant complex showed swelling property in different solvent mixtures. A maximum degree of swelling was obtained in the solvent mixture of NaBr + water and NaBr + water + acetone. Furthermore, polyelectrolyte complex sorbed salts from aqueous electrolyte solutions. The sorption of salts increased with increasing salt concentration. © 1996 John Wiley & Sons, Inc.