Methacryloxyethyltrimethyl Ammonium Chloride Research Articles

Adsorption of Low Charge Density Polyelectrolyte Containing Poly(ethylene oxide) Side Chains on Silica: Effects of Ionic Strength and pH

Adsorption characteristics of a random copolymer of poly(ethylene oxide) monomethyl ether methacrylate and methacryloxyethyl trimethylammonium chloride (PEOMEMA:METAC) on silica were studied using stagnation point adsorption reflectometry (SPAR), quartz crystal microbalance with dissipation (QCM-D), and contact angle techniques. The PEOMEMA:METAC copolymer used in this study is a low charge density polyelectrolyte, with 2% of the monomer units carrying permanent positive charges and 98% containing poly(ethylene oxide) side chains that are approximately 45 repeating units long. The surface excess was determined as a function of pH and concentration of indifferent electrolyte. It was found that the presence of a small amount of 1:1 electrolyte decreases the adsorbed amount significantly. Further, increasing the pH at a constant ionic strength, 10 mM, results in decreasing surface excess. It is suggested that the adsorption is realized via a combination of non-Coulomb interactions between the poly(ethylene oxide), PEO, grafts and protonated silanol groups at the silica-solution interface and an electrostatic interaction between the charged segments and the oppositely charged surface. Increasing pH and/or salt concentration results in progressive charging of the silica surface with the consequent decrease in affinity between silica and PEO, explaining the decrease in the adsorbed amount of the polymer.

Polyelectrolyte complexes of poly(methacryloxyethyl trimethylammonium chloride) and poly(ethylene oxide)-block-poly(sodium methacrylate) studied by asymmetrical flow field-flow fractionation and dynamic light scattering

Polyelectrolyte complex (PEC) formation between cationic poly(methacryloxyethyl trimethylammonium chloride) (PMOTAC) and anionic poly(ethylene oxide)-block-poly(sodium methacrylate) (PEO- b-PMANa) was studied by asymmetrical flow field-flow fractionation and dynamic light scattering. The influence of ionic strength and mixing ratios of the charged units of the polyelectrolytes on the complex formation was evaluated. The diffusion coefficients and the hydrodynamic diameter distributions of the free and complexed polyelectrolytes were measured. In the absence of salt, the weight averaged hydrodynamic diameters were 48 and 28 nm for PMOTAC and PEO- b-PMANa, respectively. In the presence of salt, the particles were smaller, with weight averaged hydrodynamic diameters of 44–45 and 8–10 nm, respectively. In salt-free solution, at 1:1 mixing ratio of the charged monomer units of PMOTAC and PEO- b-PMANa, polydisperse particles with diameters of 2000–4000 nm were formed. In the presence of 20, 80, and 160 mM of sodium chloride, the 1:1 complexes were relatively monodisperse particles with weight averaged hydrodynamic diameters of 93, 124, and 120 nm, respectively.

Complexation of DNA with poly(methacryl oxyethyl trimethylammonium chloride) and Its poly(oxyethylene) grafted analogue.

Intermolecular complexes of genomic polydisperse DNA with synthetic polycations have been studied. Two cationic polymers have been used, a homopolymer poly(methacryl oxyethyl trimethylammonium chloride) (PMOTAC) and its analogue grafted with poly(oxyethylene). The amount of poly(oxyethylene) grafts in the copolymer was 15 mol % and Mw of the graft was 200 g/mol. Salmon DNA (sodium salt) was used. The average molecular weight (Mw) of DNA was 10.4 x 10(6) g/mol. Conductivity, pH, and dynamic light scattering studies were used to characterize the complexes. The size and shape of the polyelectrolyte complex particles have been studied as a function of the cation-to-anion ratio in aqueous solutions of varying ionic strengths. The polyelectrolyte complexes have extremely narrow size distributions taking into account the polydispersity of the polyelectrolytes studied. The poly(oxyethylene) grafts on PMOTAC promote the formation of small colloidally stabile complex particles. Addition of salt shifts the macroscopic phase separation toward lower polycation content; that is, complexes partly phase separate with the mixing ratios far from 1:1. Further addition of salt to the turbid, partly phase separated solution results in the dissociation of complexes and the polycation and DNA dissolve as individual chains.

Complexation of linear and poly(ethylene oxide)‐grafted poly(methacryl oxyethyl trimethylammonium chloride) with poly(ethylene oxide‐block‐sodium methacrylate)

AbstractThe interactions between oppositely charged polyelectrolytes were studied in saline aqueous solutions as functions of the temperature and the salt and polymer concentrations. The polyanion was a diblock copolymer composed of a poly(ethylene oxide) block and a poly(sodium methacrylate) block. Two polycations were used, the homopolymer poly(methacryl oxyethyl trimethylammonium chloride) and its poly(ethylene oxide)‐grafted analogue. By dynamic light scattering and turbidity measurements, it was observed that the salt concentration, temperature, and counterion size had a significant effect on the formation of the polymer complexes in aqueous solutions. At a fixed salt concentration and a fixed temperature, it was possible to form completely soluble complexes of an ionic polymer in aqueous solutions between poly(ethylene oxide)‐grafted poly(methacryl oxyethyl trimethylammonium chloride)and the polyanion with a poly(ethylene oxide) block at a 1:1 anion/cation ratio. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1904–1914, 2003

Humidity sensor using gel polyelectrolyte prepared from mutually reactive copolymers

Two mutually reactive three components copolymers were prepared for the humidity sensitive membrane. The major ingredient of humid membrane is gel polyelectrolyte consisting of cross-linked copolymers of vinylbenzyl chloride (VBC)/bis(2-methoxyethyl)itaconate (B-2-MEI)/[2-(methacryloxy)ethyl]trimethyl ammonium chloride (METAC) and 2-(dimethylamino)ethyl methacrylate (DAEMA)/B-2-MEI/METAC=30/10/20, 25/10/25 and 20/10/30. The cross-linked copolymers of VBC/B-2-MEI/METAC=20/10/30 and DAEMA/B-2-MEI/METAC=20/10/30 showed average impedance of 560, 37 and 3.4 kΩ at 30, 60 and 90% RH, respectively. Temperature dependence, frequency dependence and response time were also measured. The temperature dependence between 5 and 45 °C is −0.94 to −0.86% RH/°C and the hysteresis falls on the range of ±2% RH. The humidity sensors using gel polyelectrolyte were quite resistant to water. The humidity-sensing characteristics of the sensor do not change when the sensor was soaked in water after 2 h.

Humidity-sensitive properties of a cross-linked polyelectrolyte prepared from mutually reactive copolymers

Two mutually reactive three component copolymers were synthesized to utilize as humidity-sensitive membranes. The major ingredient of a humid membrane is the cross-linked polyelectrolyte obtained from the copolymers 4-vinylpyridine (VP)–(methacryloxyethyl)trimethylammonium chloride (METAC)–n-butyl acrylate (BA) = 1 ∶ 2 ∶ 1, 2 ∶ 2 ∶ 1, 2 ∶ 3 ∶ 1 and 3 ∶ 2 ∶ 1, and 2-chloroethyl acrylate (CEA)–METAC–BA = 1 ∶ 2 ∶ 1, 2 ∶ 2 ∶ 1, 2 ∶ 3 ∶ 1 and 3 ∶ 2 ∶ 1. The humidity sensor prepared from the reaction of VP–METAC–BA = 3 ∶ 2 ∶ 1 with CEA–METAC–BA = 3 ∶ 2 ∶ 1 showed average impedance of 620, 41.9 and 3.38 kΩ at 30, 60 and 90% relative humidity humidity (RH), respectively. Temperature dependence, frequency dependence and response time were measured. The variation of humidity on temperature between 5 and 35 °C was −0.62 to −0.67% RH °C−1 and the hygrometric hysteresis between humidification and desiccation processes were less than ±2% RH. The humidity sensors using polyelectrolyte cross-linked were quite resistant to water.

Evaluation of chemical structural heterogeneity of cationic acrylamide copolymers by high-performance liquid chromatography

The chemical structural heterogeneities of two cationic acrylamide copolymers, methacryloxyethyl trimethylammonium chloride—acrylamide (AAM) and diallyldimethyl ammonium chloride—AAM, have been determined by high-performance liquid chromatography. In this method aqueous size-exclusion chromatography is combined with ion-exchange chromatography. Gradient elution with a sodium chloride solution is used. The resulting chromatogram shows the heterogeneity between polymer chains in solution. A comparison of the chromatograms of the original copolymer and its degradation product showed the heterogeneity along the copolymer chains.

Application of powdered ceramics support to the production of l-tryptophan by resting Escherichia coli K-12 cells

Escherichia coli K-12 cells having tryptophanase activity could be readily adsorbed to the surface of commercial ceramic powders such as γ-alumina, silica, titania, zirconia or glass, when they were suspended in a neutral or alkaline buffer solution in the presence of poly(methacryl-oxyethyl trimethyl ammonium chloride) (PMAAC), a cationic flocculant. Tryptophanase activity of the cells treated with PMAAC was somewhat less than that of the untreated cells, however, the activity of the cells adsorbed to titania, zirconia or glass powder after five recyclings was appreciably more stable than that of the intact cells.