Styrene-methacrylic Acid Research Articles

Facile construction of magnetic hydrophilic molecularly imprinted polymers with enhanced selectivity based on dynamic non-covalent bonds for detecting tetracycline

While a number of methods towards water-compatible molecularly imprinted polymers (MIPs) have been reported, new strategies affording simple preparation process and enhanced adsorption selectivity towards templates are needed to promote the further development of MIPs. Herein, we propose a novel method for preparing water-compatible MIPs (Cu-CMMIPs) with enhanced selectivity for tetracycline (TC) based on the dynamic physically cross-linking. The as-synthesized styrene-methacrylic acid copolymer was introduced as hydrophilic cross-linking functional monomers instead of conventional functional monomers and cross-linkers, thus eliminating the need of optimizing the cross-linkers/functional monomers ratio. The copper ions served as cross-linker, and in view of increased adsorption capacity and enhanced selectivity of the prepared MIPs, it was hypothesized that the introduction of copper ions would result in the strong interaction between the polymer network and TC. The imprinting process of TC is carried out by direct physical cross-linking of active groups of TC with functional groups of the polymeric network. The resultant Cu-CMMIPs exhibited excellent hydrophilicity, outstanding adsorption capacity and selectivity towards TC in water. Finally, the developed Cu-CMMIPs were applied as magnetic solid phase extraction adsorbents for the specific recognition of TC in environmental water combined with HPLC-DAD detection (LOD is 3.75 μg/L and the recoveries ranging from 91.2 % to 101.3 %). The proposed concept in this work for fabrication of MIPs with facile preparation process, enhanced selectivity and satisfactory hydrophilicity would inspire more ideas to implement in cost-effective adsorbents construction.

Preparation of carbon fiber substrates with structural colors based on photonic crystals

It is well-known that carbon fiber (CF) cannot be colored by traditional dyeing methods due to the strong inertness of fiber surface. With the increasing demand of consumers for fashion, colorful and diverse CF have attracted extensive attention. In this paper, inspired by the structural colors in nature, structural coloration of CF substrates by rapidly constructing photonic crystals (PCs) with structural colors was realized. The poly (styrene-methacrylic acid) (P(St-MAA)) colloidal microspheres prepared by a soap-free emulsion polymerization were used as building units to construct PCs. The influence of mass fraction of colloidal microspheres and the density of substrates on the structural colors of CF fabrics was investigated. The spraying method was also used to achieve structural color patterns on CF boards. Moreover, in order to improve the durability of structural colors, the resultant CF boards with structural colors were encapsulated with polydimethylsiloxane (PDMS). The results showed that according to Bragg diffraction law, P(St-MAA) colloidal microspheres with particle sizes of 213 nm, 235 nm, 255 nm and 307 nm can present PCs structural colors. When the mass fraction of the colloidal microspheres was 10%, brighter structural colors can be obtained on the CF fabrics with the higher density. The structural colors of patterns on the CF boards were bright and vivid. Furthermore, the colored CF boards encapsulated with PDMS could still maintain bright structural colors after rubbing and rinsing tests. The research will provide new approaches to ecological coloration of CF substrates.

Maltodextrin as stabilizer for emulsion polymerization: Adsorption and grafting behavior

AbstractEmulsion polymerization of the three‐monomer system butyl acrylate–styrene–methacrylic acid was performed in batch using a commercial maltodextrin derived from starch degradation as stabilizer. Stable latexes with narrow particle size distributions were obtained in all examined cases. A method was developed to analyze and quantify the partitioning of the maltodextrin between the continuous phase (supernatant) and the particle phase. Significant differences between the polysaccharides adsorbed onto particles with or without emulsion polymerization reaction were observed. The possible reactions of maltodextrin in presence of a radical initiator were studied in aqueous phase, thus confirming maltodextrin degradation. The formation of copolymers involving the original monomers and the stabilizer according to two different reactive pathways was also confirmed. In terms of adsorbed maltodextrin, two different contributions were observed: maltodextrin physically adsorbed and maltodextrin chemically grafted and/or physically incorporated into the polymer.

Disperse dye/poly (styrene-methacrylic acid) nanospheres with high coloration performance for textiles

Dye/polymer nanosphere is a novel kind of colorant that can significantly enhance the dye utilization efficiency on textile. In order to improve the coloration ability of colored nanospheres, disperse dye/P(St-MAA) nanospheres with rough surface were successfully prepared through alkali pretreatment at pH 12 and coloration of disperse dyes. TEM image and particle size analysis indicate that the colored nanospheres had rough surfaces with the average particle size of 158.1 nm. The dye content of colored rough nanospheres was 63.7 mg/g, higher than the un-alkali-treated ones. The reason for the change of morphology, particle size and dye content was due to the swelling of nanospheres at alkali condition. The XRD, TGA and DSC diagrams show that the disperse dye molecules formed strong interaction with the macromolecular chains and aggregated to form crystals in the rough nanospheres. The printed cotton fabric shows higher color performance using the colored rough nanospheres because of the lower visible light reflectance. The printed fabric also exhibits satisfactory color fastness for practical application.

A New Type of Dispersant [Sodium Salt of Styrene–Methacrylic Acid Copolymer (SSMA)/Montmorillonite (MMT) Nanocomposite] for Pesticide Water Dispersible Granules

AbstractA new type of dispersant [sodium salt of styrene–methacrylic acid copolymer (SSMA)/montmorillonite (MMT) nanocomposite] with different content of the MMT was synthesized through in situ solution free radical copolymerization. X‐ray diffraction measurements and electron microscopy observations prove that SSMA molecules can enter the interlayer space of MMT and form an intercalated structure. There are both fully intercalated and partly intercalated structures in the nanocomposites, which are related to the loading content of MMT. Transmission and scanning electron microscopy images indicate that the exfoliation degree of MMT in the nanocomposites decrease with increasing MMT content. Infrared spectroscopy (FTIR) analysis shows that there are hydrogen‐bonding interactions between carboxyl groups of SSMA and hydroxyl groups of MMT. Atrazine water dispersible granules were prepared by using SSMA/MMT nanocomposite as dispersant and their suspensibility in aqueous solution was determined to evaluate the dispersion properties of the nanocomposite. The results show that the addition of MMT can not only increase the steric effect of the SSMA to improve its dispersion properties, but also reduce the production cost of SSMA. The optimum loading content of MMT is 10 wt%.

Fabrication of patterned photonic crystals with brilliant structural colors on fabric substrates using ink-jet printing technology

In order to develop a fast, efficient and drop-on-demand method to produce structural colors, ink-jet printing technology was applied in fabricating photonic crystals on fabric substrates. The formulation of poly (styrene-methacrylic acid) (P(St-MAA)) colloidal inks, especially, the “coffee ring” effects on deposited droplets and the related suppression method were detailedly investigated through characterizing the morphology and color changes of the ink-jetted droplets, and different drop-on-demand ink-jet printers were used to print the photonic crystal patterns. The results showed that 10vol% P(St-MAA) colloidal microspheres and 4–6vol% Formamide (FA) were the main components of the colloidal inks, in which the addition of FA effectively suppressed the “coffee ring” effects by producing a surface tension gradient from the edge of the droplet to center and inducing an inward capillary flow from the edge to the center along the droplet surface due to its higher boiling point and lower surface tension. In addition, the resultant photonic crystal patterns exhibited vivid structural colors and distinct iridescent phenomenon.

Large-Scale Fabrication of Polymer Microcavities with Adjustable Openings and Surface Roughness Regulated by the Polarity of both Seed Surface and Monomers.

Polymer microcavities with adjustable openings and surface roughness are fabricated on a large scale via single-hole poly(glycidyl methacrylate) (PGMA) swelling seed particles. The size of openings of these microcavities can be adjusted by changing the amount of hydrophilic monomer, and the degree of surface roughness is easily regulated relying on the adjustment of the polarity of monomer. Furthermore, the morphology of PGMA/poly(styrene-methacrylic acid) (PGMA/P(S-MAA)) microparticles from microcavity to erythrocyte shape is controlled by the polarity of seed surface. From transmission electron microscopy images of PGMA/P(S-MAA) microparticles, a fresh polymer particle appears in the cavity. To confirm this phenomenon, thermal annealing process in dioxane/water solution is carried out. Considering the flexibility of polymers, the openings and closing of the prepared microparticles are regulated following the increase in volume ratio of dioxane/water. Ball-in-bowl-shaped PGMA/P(S-MAA) microparticles are further presented, which proves secondary nucleation of monomer in the polymerization stage.

Carboxylated Magnetite Composite Polymer Nanoparticles with Mosaic Structure for Biomedical Application

In this article, a microemulsion method for preparation of magnetite composite polymer nanoparticles of Fe3O4@poly(styrene-methacrylic acid) (MNP@PSMA) crosslinked with1,6-hexanediol diacrylate (HDD) insitu with carboxyl functionality on the surface has been reported. Structure and morphology of the nanoparticles was studied by Fourier Transform Infrared spctroscopy (FTIR), X ray Diffraction (XRD), Thermal Gravimetric Analyser (TGA), Vibrating Sample Magnetometer (VSM) and Transmission Electron Microscopy (TEM). VSM studies confirmed saturation magnetization of 20.0 emu/g in an external magnetic field. Nanoparticles formed were of 30 nm in diameter with narrow size distribution and mosaic structure providing a large surface area useful for application in bioseparation. Experimental results of covalent coupling of composite nanoparticles indicated maximum protein binding capacity of 350 mg bovine serum albumin (BSA) per gram.

Study on the high hydrophobicity and its possible mechanism of textile fabric with structural colors of three-dimensional poly(styrene-methacrylic acid) photonic crystals

The fabrics with P(St-MAA) photonic crystals possess high hydrophobicity and vivid structural colors. The possible mechanism of hydrophobicity and model of water droplets on the resultant fabric are investigated.

Enzymatic Production of Biodiesel from Soybean Oil by Using Immobilized Lipase on Fe3O4/Poly(styrene-methacrylic acid) Magnetic Microsphere as a Biocatalyst

A magnetic composite poly(styrene-methacrylic acid) microsphere, was prepared using oleic acid-coated magnetic nanoparticles as seeds by microemulsion copolymerization of styrene (St) and methacrylic acid (MAA). The lipase from Candida rugosa was then covalently bound to the magnetic polymer-coated microspheres by using 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDAC) as an activation reagent. The immobilization of lipase could enhance the thermal and pH stability of lipase activity when compared to free lipase. The immobilized lipase microspheres were characterized by lipase activity assays, Fourier transform infrared spectroscopy, powder X-ray diffraction, transmission electron microscopy, and vibrating-sample magnetometer techniques. The bound lipase showed high activities to soybean oil transesterification with methanol to produce biodiesel. It was found that the oil conversion of 86% was attained at a reaction temperature of 35 °C for 24 h. The immobilized lipase is stable with re...

A novel approach to prepare core/shell polymer latex particles with high sulphonate contents

Crosslinked x-P(St-MAA) seed latex was first prepared via soap-free emulsion copolymerization of styrene (St) and methyl methacrylic acid (MAA) with divinyl benzene as crosslinker and ammonium persulfate as initiator, and x-P(St-MAA)/x-P(St-NaSS) core/shell latex particles were then synthesized through a novel seeded emulsion copolymerization of St and sodium styrene sulphonate (NaSS) in the presence of water-soluble crosslinker N,N′-methylene bisacrylamide (BAA) using oil-soluble 2,2-azobis isobutyronitrile as initiator. TEM observation indicated that narrow dispersed core/shell latex particles were obtained, and element analysis showed that NaSS unit content in the whole particle and in the shell reached 22.8 wt% and 51.2 wt%, respectively.

无皂种子乳液聚合制备新型增稠剂

采用无皂种子乳液聚合方法制备了一种新型丙烯酸酯共聚物增稠剂。为了获得表面清洁和表面富含羧基的功能性聚合物乳胶粒子，首先合成了种子颗粒直径在250~300纳米的聚(苯乙烯-甲基丙烯酸)(P(St-MAA))种子乳液；然后，在无乳化剂的条件下，聚合丙烯酸乙酯(EA)，甲基丙烯酸十二酯(LMA)，苯乙烯(St)和甲基丙烯酸(MAA)；最后，得到颗粒直径在380~440纳米的稳定乳液。重点研究了甲基丙烯酸十二酯含量对乳液颗粒大小和乳液稳定性的影响。研究表明，该聚合物乳液具有很好的增稠性能，良好的悬浮能力，透明性好，易于使用。采用傅里叶变换红外光谱仪(FT-IR)、示差扫描量热仪(DSC)、透射电子显微镜(TEM)对其结构和形貌进行了表征。 A kind of acrylates copolymer thickener was prepared by soap-free and seeded emulsion polymerization. In order to obtain functional polymer latex particles with clean surface and with surface carboxyl groups, Poly (styrene-methacrylic acid) (P (St-MAA)) seed particles with the diameter of 250 - 300 nm were synthesized via soap-free emulsion polymerization. Then the seeded emulsion copolymerization of ethylacrylate (EA), lauryl methlacrylate (LMA), St and MAA onto the seed particles were performed in the absence of emulsifier. The content of LMA effected for the particles size and the stability of the emulsion was studied. The thickening performance of this polymer latex was quite good with the high thickening performance, good suspension ability, good transparence and easy to use. The factors of the copolymerization and the properties of the emulsion were discussed. Its structure and morphology were characterize by fourier transform infrared spectrometer (FT-IR) and transmission electron microscope (TEM).

Ni-doped TiO2 hollow spheres as electrocatalysts in water electrolysis for hydrogen and oxygen production

This work represented the electrocatalytic properties of Ni-doped titania hollow sphere materials in hydrogen and oxygen evolution during water electrolysis from acidic media. Titania hollow sphere particles were synthesized using poly(styrene-methacrylic acid) latex as template material, and various amount of nickel were doped over the sphere using nickel (II) sulfate as the precursor of nickel. The presence of rutile TiO2 and NiO phases were revealed during XRD analysis, indicating the critical growth of nickel on the surface of the hollow sphere catalysts. BET surface area results also shown the 166.76 m2 g−1 value for 30 wt% Ni/TiO2 hollow sphere sample. The SEM and TEM images were confirmed the hollow sphere structure of the catalysts with diameter of 0.8–0.9 μm. The cyclic voltammetric studies proved the presence of both hydrogen and oxygen evolution peaks for all the hollow sphere samples. The anodic peak current density value, which usually represents the oxygen evolution phenomenon, was revealed as 13 mA cm−2 for 25 wt% Ni-loaded sample; whereas, the hydrogen evolution peak was most intense for 30 wt% Ni/TiO2 material with cathodic peak current density of 32 mA cm−2. The average value of −1.42 were determined as the reaction order of the system irrespective of the nickel loading and heating duration in the synthesis of hollow sphere materials. During photocatalytic water splitting, 30 wt% Ni/TiO2 hollow sphere sample yielded the highest amount of hydrogen in all irradiation time span.

Preparation and characterization of nanocomposites of natural rubber with polystyrene and styrene-methacrylic acid copolymer nanoparticles

Composites of natural rubber (NR)/vinyl polymer nanoparticles as polystyrene (PS) and poly(styrene- methacrylic acid) (P(S-MAA)) were prepared by heterocoagulation technique. The polymer nanoparticles were prepared by emulsifier-free emulsion polymerizations at 70°C using potassium persulfate as initiator. Under acidic condition where pos- itive charge was present on the NR latex (NRL) surface, the nanoparticles having negative charge mainly from sulfate group of initiator were able to adsorb on the NRL surface, the electrostatic interaction being the driving force. The scanning electron micrographs showed that the polymer nanoparticles are homogenously distributed throughout NR matrix as nano- clusters with an average size of about 500 and 200 nm for PS and P(S-MAA), respectively. The mechanical properties of NR/PS and NR/P(S-MAA) composite films were compared with the NR host. The nanocomposites, particularly when the polymer nanoparticles are uniformly dispersed, possess significantly enhanced mechanical properties strongly depending on the morphology of the nanocomposites.

A Timesaving Solution Route for Hollow Polymer Microspheres by Alkali Neutralization Method

A novel and timesaving preparing process for hollow polymer microspheres(HPMs) was proposed based on the improved alkali neutralization method. In the process, uniform HPMs were prepared by synthesizing poly(styrene-methacrylic acid){P(St-MAA)} particles with carboxylic functional groups by emulsion polymerization and subsequently hydrophilic and hydrophobic phases separating by alkali neutralizing. The morphology, diameter and monodispersion of P(St-MAA) particles were controlled by varying the content of methacrylic acid(MAA). Scanning electron microscopy(SEM) and transmission electron microscopy(TEM) were used to characterize the products and to demonstrate that the polymer microspheres were hollow. The results indicated that the optimum MAA content was about 10%.

Effects of the Type of Solvents on the Morphology of Styrene-Methacrylic Acid Random Copolymers Cast onto Silicon Wafer

The effects of the type of solvents on the aggregation behavior of poly(styrene-ran-methacrylic acid) (PSMAA) cast onto silicon wafer were studied using a SEM method. It was found that polystyrene prepared from DMF formed non-spherical aggregates but that PSMAA formed mixtures of ellipsoids and spheres. As the acid content increased, the spheres having a distinct boundary started contacting each other, and the average size of spherical particles decreased. Upon neutralization, the spherical particles became contacted spheres covered with much smaller spheres (ca. 20 nm in their sizes) and formed micro-gels. These results were compared to the data in the previous study of samples obtained from either water or THF. It was observed that the solubility parameters of the copolymers and ionomers, and polarity of solvents were some of key factors that determine the aggregation behavior of the polymers. The volatility of the solvent was also found to be an important factor for the aggregation behavior of polymers.

Preparation and characterization of poly(styrenemethacrylic acid)/MCM-41 core/shell nanocomposite microspheres

AbstractIn acidic media, poly(styrene-methacrylic acid)/MCM-41 [P(St- MAA)/MCM-41] core/shell microspheres were synthesized using monodisperse P(St-MAA) particles contained in soap-free emulsion and cetyltrimethylammonium bromide as co-templates by adsorption self-assembly method. The effects of P(St- MAA) composition on shell structure of the core/shell microspheres were investigated. The morphology and composition of P(St-MAA)/MCM-41 microspheres were characterized by TEM, XRD and FTIR. The results show that the ordering degree of MCM-41 shells increased as the molar ratio of MAA to St increased. When n(MAA)/n(St) is 0.2, the average diameter and the shell thickness of nanocomposite microspheres are about 170 nm and 20 nm, respectively.

Electrocatalytic performance of Ba-doped TiO 2 hollow spheres in water electrolysis

Barium doped titania hollow sphere catalysts of various compositions were prepared and their electrocatalytic performance was evaluated in acidic media. Titania hollow sphere particles were prepared using poly (styrene–methacrylic acid) latex as template material, and BaCl 2 was used precursor material during barium doping over spheres. The morphology and structure of Ba/TiO 2 hollow spheres were characterized by BET, XRD, TGA and TEM analysis. XRD results had confirmed the presence of rutile TiO 2 and BaTiO 3 phases in the catalysts. The catalysts have shown almost similar surface area values (around 97 m 2/g) irrespective of their compositions. On the other hand, surface area values were diminished remarkably with rise in the calcination temperatures. In TEM images, hollow sphere formation with uniform layer of barium over the spheres could clearly be observed. Diameter of Ba-doped TiO 2 hollow sphere was found 0.4–0.5 μm irrespective of the variation in calcination temperatures. In cyclic voltammograms, both the hydrogen and oxygen evolution peaks were present for all the hollow sphere samples; although the peak positions had changed to some extent for few samples. Anodic polarization curves have shown 60 mA cm −2 current density for 20 wt% Ba/TiO 2 hollow sphere sample. Tafel slope is revealed as 122 mV for the same electrocatalyst. Barium doped titania hollow spheres have also shown long time electrocatalytic stability in acid solution.

Effect of stirring on preparation of hollow copolymer particles by alkali/cooling method

Hollow particles were prepared by the treatment of styrene-methacrylic acid copolymer particles with alkali/cooling method. The influences of stirring position (in aqueous phase or at the interface of O/W) and stirring speed (90, 110 and 240 r/min) on the formation of hollow particles were investigated. It is found that the soft stirring in aqueous phase at 90 r/min leads to the formation of monohollow particles, while the violent stirring at the interface of O/W and 240 r/min gives non-hollow products. In contrast, the weak stirring in aqueous phase at 110 r/min results in sterically heterogeneous dispersion of methacrylic acid-rich regions within the original particles, and hence the formation of multihollow particles. Further investigation indicates that the change of stirring efficiency provides a way to tune the diffusion behavior of monomer styrene, and therefore influences the distribution of methacrylic acid units in the original particles as well as the morphology of the treated particles.

Synthesis of magnetic poly(styrene-methacrylic acid) spheres prepared by miniemulsion polymerization

Synthesis of magnetic poly(styrene-methacrylic acid) spheres prepared by miniemulsion polymerization