Competitive interaction of polyanions and 2-(4′-hydroxyphenylazo) benzoic acid with bovine serum albumin

The binding of the anionic dye 2-(4′-hydroxyphenylazo) benzoic acid (HABA) to bovine serum albumin (BSA) at pH 6.0–7.5 was studied by spectrophotometry. The values of the dissociation constants were obtained by use of a modified Langmuirtype equation for HABA. Competitive binding of the polyanions sodium poly(styrene sulfonate) (PSSNa), potassium poly(vinyl sulfate) (PVSK), poly(acrylic acid) (PAA), and poly(methacrylic acid) (PMAA), with HABA to BSA were evaluated by variations in the difference spectra of BSA-HABA-polymer systems.     

Interpolymer complexes of novel linear and crosslinked acrylic acid–Schiff base copolymers

Novel linear and crosslinked copolymers of acrylic acid and Schiff base, containing the amine groups in the main chain and the carboxylic groups in the side chain, have been synthesized by the Michael addition reaction followed by radical copolymerization. The copolymers that exhibited poly(ampholyte–electrolyte) behaviour were used to prepare complexes by reaction with anionic (poly(acrylic acid), poly(styrene sodium sulfonate)), cationic (polyethyleneimine, poly(hexamethylene guanidine)) and non‐ionic (poly(N‐vinylpyrrolidone), poly(ethylene glycol), poly(vinyl alcohol)) polymers. The influence of external factors, such as solvent quality, temperature, pH and ionic strength, on phase (coil–globule) and volume (swelling–collapse) transitions has been studied. © 2003 Society of Chemical Industry     

Fluorescence study of interaction between an anionic conjugated polyelectrolyte and bovine serum albumin

The interaction between an anionic conjugated polyelectrolyte, poly[9,9-bis(3′-butyrate)fluoren-2,7-yl] sodium (BBS-PF), and bovine serum albumin was investigated by fluorescence spectroscopy. The emission of BBS-PF was effectively quenched by BSA with a quenching constant K _SV of 3.1 × 10⁷ L/mol when BSA was at nanomolar concentrations, but the emission increased when the concentration of BSA was at micromolar level. The excitation band of BBS-PF blue-shifted when the emission was quenched where the negatively charged BSA induced the aggregation of BBS-PF, yet the excitation band of BBS-PF red-shifted when the emission increased where the BSA acted as a surfactant and formed hydrophobic interaction with BBS-PF. BBS-PF could also quench BSA through energy transfer by resonance with a quenching constant K _SV of 1.1 × 10⁶ L/mol. The emission band changes of BSA reflected the conformation transitions of BSA from class II to class I and the binding of BBS-PF with BSA made the BSA more folded.     

Synthesis of anionic water‐borne polyurethane with the covalent bond of a reactive dye

We successfully synthesized an anionic water‐borne polyurethane (PU) capable of reacting with a reactive dye to form a covalent bond with the dye molecule. The anionic water‐borne PU was synthesized and grafted with the reactive dye to form a dyed PU. First, the PU prepolymer was synthesized from 4,4′‐methylene bis(isocyanatocyclohexane), poly(tetramethylene glycol), 2,2′‐bis(hydroxymethyl) propionic acid (as an anionic center), and triethyleneamide (as a neutralizer). Then, pure water was added to emulsify and disperse the prepolymer to form an anionic water‐borne PU prepolymer. Finally, the extender N‐(2‐hydroxyethyl) ethylene diamine was used to extend the anionic water‐borne prepolymer to form a PU polymer with hydroxyl groups that could further react with the reactive dye molecule. With respect to the heating properties, the dyed PU polymers exhibited higher glass‐transition temperatures of the hard segment than those without dye molecules. However, neither the glass‐transition temperature of the soft segment nor the melting temperature of the soft segment varied in the presence of dye molecules, but they were changed with various chain lengths of the soft segment. As for the mechanical properties, the modulus and strength of the dyed PU polymers decreased because of the bulkiness of their dye molecules, but the breaking elongation increased. Moreover, the inherent viscosity decreased in the presence of the dye molecules. As for the dyeing properties, the percentage of dye grafting was greater than 90%. The dye‐grafted PU exhibited a lower percentage of migration than PU extended with ethylene diamine (without hydroxy groups) and also showed a higher grade of colorfastness to light. © 2002 John Wiley & Sons, Inc. J Appl Polym Sci 84: 797–805, 2002; DOI 10.1002/app.10336     

In situ studies of bovine serum albumin adsorption onto functionalized polystyrene latices monitored with a quartz crystal microbalance technique

The adsorbability of bovine serum albumin (BSA) onto poly(styrene‐co‐itaconic acid) (PS–IA), poly(styrene‐co‐hydroxyethyl methacrylate) (PS–HEMA), poly(styrene‐co‐acrylic acid) (PS–AA), and poly(styrene‐co‐methacrylic acid) (PS–MAA) latices were investigated with a quartz crystal microbalance. The amount adsorbed onto the functionalized latices, except for PS–MAA, was greater than that adsorbed onto polystyrene (PS) latex. To explain this result, two kinds of interaction forces were considered, hydrogen bonding and hydrophobic interactions, whereas electrostatic interaction was assumed to be small. When comparing the two extremes of hydrophobic interaction and hydrogen bonding, the latter was stronger. The corrected adsorption mass suggested that the BSA molecules were adsorbed onto the PS–MAA latex in a side‐on mode. However, in the case of the PS, PS–IA, PS–HEMA, and PS–AA latices, the BSA molecules were probably adsorbed in multiple layers. The presence of the BSA in the latex particle surface was verified by attenuated total reflectance/Fourier transform infrared spectroscopy and atomic force microscopy. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42055.     

Preparation of polyelectrolyte giant capsules using cross-linked alginate gels as core material

Polyelectrolyte giant capsules whose diameter is in a millimeter level were prepared by a layer-by-layer deposition of poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) (PSS) on an alginate (AGA)-Ca²⁺ sphere followed by dissolution of the AGA core in an ethylenediaminetetraacetic acid or NaCl solution. A fluorescent-labeled bovine serum albumin (BSA) was successfully encapsulated in the PAH/PSS polyelectrolyte capsule. The release of the BSA from the capsule was suppressed in the presence of higher concentration of salt, while the effect of pH was small. In addition, the thickness of the PAH/PSS layer in the capsule wall gave an effect on the release rate of the BSA.     

The Binding of Anionic Dyes by Cross-Linked Cationic Starches

Adsorption of anionic dyes on the cross-linked with epichlorohydrin starches containing quaternary ammonium groups (CCS) was investigated and compared with that of modified starches containing only quaternary ammonium groups (CS). The adsorption of anionic dyes on CS and CCS closely follows the Langmuir model of adsorption. The computed Langmuir saturation capacity Q _o increases with increasing degree of substitution (DS) of CS or CCS and has the value from 0.81 mol/kg to 3.22 mol/kg for CCS and from 0.88 mol/kg to 1.87 mol/kg for CS. The effectiveness of the cationic groups in dye binding was about 1 mol/equiv for CSS with DS from 0.47 to 0.62 and all the cationic groups had attached one anionic groups of the dye. Increasing DS of CS decreases the effectiveness of dye binding due to the increase in solubility of CS, and the soluble part of CS binds the dye as a typical soluble polyelectrolyte. CCS are more suitable than CS for the anionic dye adsorption from a textile dyeing solution. DS of CCS should be about 0.5–0.6. They adsorb the anionic dyes in few minutes and acts in the wide range of pH of the solutions. The Langmuir saturation capacity Q _o and the effectiveness of the cationic groups in dye binding increase with an increase of the adsorption temperature. The positive values of the enthalpy and entropy suggest that the adsorption is endothermic and during the adsorption of the anionic dye on CCS the randomness of the system increases.     

Metal ion sorption properties of water-insoluble resins based on sodium styrene sulfonate and different comonomers

A set of water-insoluble resins based on sodium styrene sulfonate and different comonomers were synthesized. The resins poly(mono-2-(methacryloyloxy)ethyl succinate-co-sodium 4-styrene sulfonate) P(MOES-co-SSNa), poly(2-acrylamido glycolic acid-co-sodium 4-styrene sulfonate) P(AGA-co-SSNa), poly(acrylamide-co-sodium 4-styrene sulfonate) P(AAm-co-SSNa), and poly(2-(dimethylamine)ethyl acrylate-co-sodium 4-styrene sulfonate) P(DMAEA-co-SSNa) were synthesized by solution radical polymerization. The metal ion retention properties were studied by batch procedure for Cd(II), Zn(II), Pb(II), and Hg(II). Resins performance was compared with a poly(sodium 4-styrene sulfonate) (PSSNa) resin in order to evaluate the effect of comonomer on sorption properties. The effect of pH, time, temperature, and maximum retention capacity were studied. In addition, sorption experiments were carried out under competitive ion conditions to study the selectivity of resins. The resins P(AAm-co-SSNa) and P(AGA-co-SSNa), showed the most important differences compared with PSSNa resin, the former present higher sorption and the latter presented selectivity for Hg(II) at pH 2.     

Nanocomposite hydrogels for selective removal of cationic dyes from aqueous solutions

Removal of organic dyes from waste water has received a significant attention in recent years. In this work, a set of nanocomposite hydrogels (NHs) were prepared and their capacity to absorb crystal violet (CV), a cationic dye, and acid yellow‐23 (AY), an anionic dye, from aqueous solutions was determined. NHs were prepared by in situ formation of Fe₃O₄ magnetic nanoparticles (MNPs) inside poly(acrylamide‐co‐4‐styrene sulfonic acid sodium salt) (P[AAm‐co‐SSA]) hydrogel matrices. The dye absorption capacity of the magnetic NHs (MNHs) was compared with simple hydrogels (hydrogels or SHs) without the MNPs The prepared hydrogels were characterized by FTIR, XRD, thermogravimetric analysis, high resolution TEM, field emission SEM, and vibrating sample magnetometer measurement. From HRTEM, it was confirmed that the prepared MNPs in hydrogel matrices were in the size range of about 8 to 10 nm. The MNHs showed greater swelling behavior as well as greater removal efficiency of cationic dye from aqueous solutions in comparison to the SHs. With increase of SSA mole percentage, dye removal efficiency was also increased for both types of hydrogels. The present study indicates that the hydrogels containing MNPs can be potentially used as an efficient absorbent material for removal of cationic dyes from waste water. POLYM. ENG. SCI., 56:776–785, 2016. © 2016 Society of Plastics Engineers     

Rheological and electrical properties of bentonite in anionic polystyrene sulfonate and nonionic poly(vinyl alcohol)

The flow properties of bentonite were studied with a combination of anionic polystyrene sulfonate (molecular weight = 70,000 g/mol) and nonionic poly(vinyl alcohol) (molecular weight = 50,000 g/mol). This combination had a significant effect on clay suspensions depending on the sequence of the polymer addition. The addition of 50 mg/L anionic polystyrene sulfonate followed by 200 mg/L nonionic poly(vinyl alcohol) improved the rheological properties with a 7% bentonite suspension, especially at 20°C and after 24 h of aging. However, by the reversal of this addition sequence, the rheological properties of bentonite suspensions were reduced. The ζ potential of bentonite suspensions of the individual polymers at the same concentration was ?42 mV for polystyrene sulfonate and ?63 mV for poly(vinyl alcohol). The combined effect of anionic polystyrene sulfonate followed by nonionic poly(vinyl alcohol) noticeably changed the ζ potential (?95 mV). With the reversal of the addition sequence, this parameter did not change. Potential energy profiles were constructed to investigate the suspension stability. Potential energy profiles of polystyrene sulfonate added to bentonite suspensions and followed by poly(vinyl alcohol) produced high repulsion potential energy between clay surfaces, reflecting high suspension stability. By the reversal of this sequence, a significant reduction of the energy barrier was observed. On the basis of the rheological and electrical properties of this system, the addition of polystyrene sulfonate followed by poly(vinyl alcohol) provides a promising tendency for a 7% clay concentration to meet desirable drilling mud properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3886–3894, 2007     

Interactions between dyes and surfactants in inkjet ink used for textiles

Optimal preparation of inkjet ink should be possible through the elucidation of the relationship between dye/additive interactions and ink performance. In the present study, the interactions between the dyes and surfactant additives were investigated. To investigate the physical properties of the surfactants used, the critical micelle concentration (cmc) and the aggregation number (N) were determined using electron spin resonance, static light-scattering, and fluorescence spectroscopy. On the basis of the cmc and N values, the visible absorption spectra of aqueous acid dye solutions (C. I. Acid Red 88, 13, and 27) containing surfactants (i.e., Surfynol 465 (S465), octaethylene glycol monododecyl ether (OGDE), and sodium dodecyl sulfate (SDS)) were measured. From the dependence of the spectra on the surfactant concentration, the binding constants, K(bind), of the acid dyes with the surfactant micelles were calculated: the K(bind) values decreased in the order of C. I. Acid Red 88 > C. I. Acid Red 13 > C. I. Acid Red 27, which correlates with the number of sulfonate groups. For all the dyes, the K(bind) values with the nonionic surfactants, S465 and OGDE, were much larger than those with the anionic surfactant, SDS. The thermodynamic parameters of the binding, i.e., the enthalpy change, ΔH(bind), and entropy change, ΔS(bind), were determined via the temperature dependence of the binding constants. The positive ΔH(bind) value for S465 indicates an endothermic binding process, while the negative ΔH(bind) values for SDS and OGDE indicate exothermic binding processes.     

Dilute solution properties of anionic poly(potassium-2-sulfopropylmethacrylate)

The dilute solution properties of an anionic polyelectrolyte, poly(potassium-2-sulfopropylmethacrylate) [poly(SPM)], are studied by measurements of polymerization rate, intrinsic viscosity, degree of binding, ionic strength, and critical micelle concentration. The polymerization of SPM in 0.5M NaCl aqueous solution proceeded more easily than that of SPM in pure water. The polymerization rate of SPM is found to pass through an extreme value as a function of pH. The intrinsic viscosity of this polyelectrolyte is related to the type and concentration of the salt added. The intrinsic viscosity for anionic polyelectrolyte resulting from the electrostatic repulsive force of the polymer chain is in contrast with the polyampholyte. The polyelectrolyte in a high concentration of NaCl has a low degree of binding, indicating that the proton ion (H⁺) is relatively difficult to bind to the sulfonate group (SO⁻₃) at the polymer end. An increase in ionic strength causes the pKa (dissociation constant) to decrease at the half-neutralization point. The monomer solutions exhibit a plot typical of those observed for detergents, with a break in the curve occurring at the critical micelle concentration. For the polymer solutions, no break in the equivalent conductance curve was found for the concentrations studied. The polymer is adapted for use as viscosity-controlling agents in secondary oil recovery operations by water flooding. We have the proposed models to account for the poly(SPM) solution viscometrics. © 1997 John Wiley & Sons, Inc.     

Thermoreversible hydrogels. XVIII. Synthesis,swelling characteristics,and diffusion behaviors of porous,ionic, thermosensitive hydrogels

Porous, ionic, thermosensitive hydrogels were prepared from N‐isopropylacrylamide, a cationic monomer [trimethyl (acrylamido propyl) ammonium iodide (TMAAI)], an anionic monomer [acrylic acid (AA)], a zwitterionic monomer [N′,N′‐dimethyl (acrylamido propyl) ammonium propane sulfonate], or a nonionic monomer [poly(ethylene glycol) methyl ether acrylate], and a pore‐forming agent [poly(ethylene glycol) (PEG)] of different molecular weights. Some fundamental properties and dynamic swelling kinetic parameters and solute permeation for these porous gels were investigated. The results showed that the gel containing the cationic monomer TMAAI had a higher equilibrium swelling ratio. The diffusion coefficients showed that the swelling rates for the gels with the anionic monomer AA and PEG with a higher molecular weight (20,000) were faster. The results showed that the fast swelling–deswelling behavior for the porous structure gels was due to them being more available than the gels with long hydrophilic side chains. In addition, the interactive force between the solutes and gels and the solute permeation through the porous gels were investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2214–2223, 2003     

Synergistic Behavior of a Triblock Copolymer with Anionic and Cationic Surfactants in Aqueous Solution

The synergistic behavior of poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymer in aqueous solution with the synthesized anionic surfactants [decyl sulfonate (A10), myristyl sulfonate (A14) and cetyl sulfonate (A16)] and cationic surfactants [decyl pyridinium bromide (C10), myristyl peridinium bromide (C14) and cetyl pyridinium bromide (C16)] was investigated using a surface tension technique at 25 °C. The results show that the CMC values of binary mixtures for anionic and cationic surfactants with the triblock copolymer are lower than that of single surfactants. The synergistic interaction between surfactant molecules and copolymer molecules in binary mixed solution enhance the adsorption of surfactant molecules at the interface. The micellar mole fractions (X _m) and the interaction parameter (β) of these surfactants in mixed micelles were determined.

Binding of some dyes onto crosslinked poly (N-vinylpyrrolidone)

Summary Bindings of some anionic dyes containing sulfonyl group(s), namely, Acid Blue 74 (AB-74), Acid Orange 7 (AO-7), Acid Green 1 (AG-1), Direct Blue 53 (DB-53), and Calconcarboxylic acid (CCA) onto crosslinked poly(N-vinylpyrrolidone) (CPVP) have been investigated using adsorption isotherm parameter. The dyes were linked positively charged on the tertiary nitrogen atom on the pyrrolidone ring in polymer chain resulting keto-enol tautomerism from sulfonyl group on the benzene ring in the dyes molecules. In the experiments of adsorption, L (Langmuir) type adsorption in the Giles classification system was found. Monolayer coverages (n) of polymer/dye system were founds by "B point" methods. Adsorption studies indicated that monolayer coverages of CPVP by the anionic dyes containing sulfonyl group(s) were increased with following order; CCA > AG-1 >> DB-53 > AO-7 > AB-74. Received: 10 April 2000/Revised version: 26 May 2000/Accepted: 6 June 2000     

Preparation and performance of a transparent poly(3,4‐ethylene dioxythiophene)–poly(p‐styrene sulfonate‐co‐acrylic acid sodium) film with a high stability and water resistance

Poly(p‐styrene sulfonate‐co‐acrylic acid sodium) (PSA) from the copolymerization of acrylic acid sodium and p‐styrene sulfonate monomers were used to dope poly(3,4‐ethylene dioxythiophene) (PEDOT) to generate PEDOT–PSA antistatic dispersions. Compared to those of the PEDOT–poly(p‐styrene sulfonate sodium) (PSS), the physical and electrical properties of the PEDOT–PSA conductive liquids were much better. The PEDOT–PSA films possessed a better water resistance without a decrease in the conductivity. The sheet resistance of the PEDOT–PSA–poly(ethylene terephthalate) (PET) films was about 1.5 × 10⁴ Ω/sq with a 100 nm thickness, the same as the PEDOT–PSS–PET films. The transmittance of the PEDOT–PSA–PET films exceeded 88%. Furthermore, the environmental dispersity of the PEDOT–PSA antistatic dispersion was apparently improved by the dopant PSA so that the stability was extraordinarily promoted. Meanwhile, the water resistances of the PEDOT–PSA–PET and PEDOT–PSA films were also enhanced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45163.     

Poly(sodium 4‐styrene sulfonate) and poly(2‐acrylamido glycolic acid) polymer–clay ion exchange resins with enhanced mechanical properties and metal ion retention

This research presents the synthesis of novel nanocomposite ion exchange resins based on poly(sodium 4‐styrene sulfonate) and poly(2‐acrylamido glycolic acid). Nanocomposites were synthesized by in situ radical polymerization using organic modified montmorillonite as filler and different clay contents. Loaded resins showed improvements in mechanical properties compared with unloaded resins: specifically, when the nominal montmorillonite content was 2.5 wt%, poly(sodium 4‐styrene sulfonate) nanocomposite increased its shear modulus from 323 to 910 Pa and doubled its elastic recovery ratio, and the yield point was almost 20 times higher than for unloaded resins. In the case of metal ion retention, the effect of pH and clay content were studied for Cd(II), Pb(II), Cu(II), Cr(III) and Al(III) by a batch procedure. Results showed high efficiency, reaching over 80% after only 1 h of contact. Poly(2‐acrylamido glycolic acid) presented a higher pH dependence than poly(sodium 4‐styrene sulfonate). In addition, it was observed that montmorillonite contributes to retention capacity from the increase in distribution coefficients for loaded resins compared with unloaded resins. Copyright © 2011 Society of Chemical Industry     

Poly(p‐phenylene benzoxazole) fiber chemically modified by the incorporation of sulfonate groups

Two kinds of modified poly(p‐phenylene benzoxazole) (PBO), the copolymer of TPA (SPBO) and p‐SPBO, containing ionic groups in the macromolecular chains were obtained by copolymerization from 1,3‐diamino‐4,6‐dihydroxybenzene dihydrochloride (DAR) and terephthalic acid (TPA), with the addition of selected amounts (1.5–5.0% molar ratio over DAR) of 5‐sulfoisophthalic acid monosodium salt or sulfoterephthalic acid monopotassium salt in place of the TPA, respectively, in poly(phosphoric acid) (PPA). The resultant PBO/PPA, SPBO/PPA, and p‐SPBO/PPA lyotropic liquid‐crystalline solutions were spun into fibers by a dry‐jet wet‐spinning technique. Chemically modified PBO fibers with sulfonate salt pendants in the polymer chains were obtained for the first time. The surface wetting behavior and interfacial shear strength between the fiber and epoxy resin were investigated. The interference of sulfonate salt pendants on the crystalline morphology was measured. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

质子化剩余污泥吸附染料的性能及机理

以城市污水处理厂的剩余污泥为原料,经过质子化处理制备成生物吸附剂,进行了吸附水溶液中活性红4(RR4)和亚甲兰(MB)的研究。溶液的pH值是影响吸附效果的一个重要因素,阴离子型的RR4在酸性条件下吸附量大,而阳离子型的MB则在中性和碱性条件下吸附量大。吸附RR4和MB的数据对Langmuir等温吸附式拟合良好,在pH=2条件下,生物吸附剂对RR4的最大吸附量（qm）为(25.8±0.4)mg·g-1;在pH=7条件下,对MB的最大吸附量（qm）为(161.2±10.0)mg·g-1。电位滴定及FTIR分析表明,这种生物吸附剂主要含有磺酸基、磷酸基及氨基等功能团,其对染料的吸附以单分子层的化学吸附为主,功能团在不同的pH条件下呈现不同的电离性能并在吸附过程中发挥重要作用。     

Binding of the phenothiazinium dye methylene blue with single stranded polyriboadenylic acid

The binding of the phenothiazinium dye methylene blue to single stranded poly(riboadenylic acid) was investigated by spectroscopic and calorimetric techniques. The binding was cooperative and the affinity was of the order of 10⁶ M⁻¹ at 100 mM [Na⁺] as determined from absorbance, fluorescence and calorimetric studies. Ferrocyanide quenching studies showed intercalative binding of methylene blue to poly(riboadenylic acid). The binding perturbed the circular dichroism spectrum of poly(riboadenylic acid) with concomitant formation of prominent exciton split type of extrinsic CD bands in the 550-700 nm region. The interaction involved a single binding mode with a 1:2 binding stoichiometry. The binding affinity increased with [Na⁺] ion concentration in the range 10-200 mM [Na⁺]. Dye binding induced self-assembled duplex formation in poly(riboadenylic acid). The biological utility of the dye methylene blue in probing nucleic acid structure is revealed from these studies.