Microemulsion Polymerization Research Articles

Investigation on the preparation of nanoparticles by inverse micro-emulsion polymerization for enhanced oil recovery

Polyacrylamide nanoparticles attracted increasing interest as profile control agents in oilfield development owing to the characteristics of deformation and continuous expansion in core pore. In this article, the structure and morphology of polyacrylamide nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). And the fluorescence microscopy and core displacement equipment were used to evaluate the properties of the expansion and plugging properties. Results showed that the nanoparticles prepared by inverse emulsion polymerization can be able to pass through the pores in the rocks due to the uniform particle size which is less than 500 nm. When the nanoparticles were in contact with water for 72 hours, the average particle size increased to 12.2 μm. The water-swelled nanoparticles can effectively block the high-permeability layer and improve the oil recovery in the low-permeability layer. The results obtained in this paper reveal the mechanism of elastic deformation and expansion characteristics of polyacrylamide nanoparticles, and further prove the great potential of nanoparticles to enhance oil recovery in the development of low permeability oilfields.

Selective binding of antibiotics using magnetic molecular imprint polymer (MMIP) networks prepared from vinyl-functionalized magnetic nanoparticles

Adverse effects of pharmaceutical emerging contaminants (PECs), including antibiotics, in water supplies has been a global concern in recent years as they threaten fresh water security and lead to serious health problems to human, wildlife and the environment. However, detection of these contaminants in water sources, as well as food products, is difficult due to their low concentration. Here, we prepared a new family of magnetic molecular imprinted polymer (MMIP) networks for binding antibiotics via a microemulsion polymerization technique using vinyl silane modified Fe3O4 magnetic nanoparticles. The cross-linked polymer backbone successfully integrated with 20−30 nm magnetic nanoparticles and generated a novel porous polymeric network structure. These networks showed a high binding capacity for both templates, erythromycin and ciprofloxacin at 70 and 32 mg/g. Both MMIPs were also recyclable, retaining 75 % and 68 % of the binding capacity after 4 cycles. These MMIPs have showed a clear preference for binding the template molecules, with a binding capacity 4- to 7-fold higher than the other antibiotics in the same matrix. These results demonstrate our MMIP networks, which offered high binding capacity and selectivity as well as recyclability, can be used for both removal and monitoring hazardous antibiotic pollutants in different sources/samples and food products.

Kinetic events of (micro)emulsion polymerization of styrene

Integro-differential (ID) model approach has been tested on the o/w microemulsion polymerization (MEP) of styrene (S). The effect of macroinimer (MIM), time and temperature on the MEP kinetics has been modeled. The S-shaped conversion–time curves appear in the studied runs. A presented approach with four states (conversion, active and inactive particles and micelles) is followed with conversion, temperature and additive concentration, to recognize the main events occurring in styrene MEP. The existence of diffusive (vitreous) effects has been questioned. Furthermore, the problem of understanding some underlying phenomena in MEP is addressed, with an ID approach combining simple notions and concepts from microemulsion kinetics. The procedure is applied mostly to previously reported experimental data on the polymerization of styrene (S) initiated by peroxodisulfate and peroxodisulfate/sodium thiosulfate (STS) redox system, stabilized with ionic emulsifier sodium dodecyl sulfate (SDS). It was found that the nucleation rate does not follow a linear, but a bell-shaped curve. This is the reason why the rate of polymerization versus conversion curve shows the two nonstationary-rate intervals. The addition of MIM decreases both the particle nucleation and the growth events.

Experimental and theoretical calculation investigation on effective adsorption of lead(II) onto poly(aniline-co-pyrrole) nanospheres

In the present study, poly (aniline-co-pyrrole) nano-sphere (PACPNS) was synthesized by micro-emulsion polymerization technique. The PACPNS was examined as a strong absorbent for lead(II) removal from aqueous media. The FTIR spectroscopy, TGA and XRD characterization were used for confirmation of construction, phase identification and thermal stability of PACPNS, respectively. FESEM images of the PACPNS showed a nanosphere structure with diameter ∼90 nm. The experimental data revealed that the sorption isotherm of lead(II) onto the PACPNS was in well agreement with Langmuir equation. The Lagergren pseudo-second order equation was in well agreement with adsorption data of kinetic for lead(II). According to results, the maximum adsorption capacity (Qmax) of lead(II) was determined 119.02 mg/g, under optimized conditions. The thermodynamic data implied that the adsorption procedure of lead(II) was feasible, endothermic and spontaneous in nature. Also, the adsorption of lead(II) onto the PACPNS was investigated using molecular dynamics simulation (MDS) by DL-poly software. According to experimental and theoretical data a probable mechanism for sorption of lead(II) was proposed where electrostatic interfaces controlled the lead(II) adsorption.

Nanoengineering Carbon Spheres as Nanoreactors for Sustainable Energy Applications.

Colloidal carbon sphere nanoreactors have been explored extensively as a class of versatile materials for various applications in energy storage, electrochemical conversion, and catalysis, due to their unique properties such as excellent electrical conductivity, high specific surface area, controlled porosity and permeability, and surface functionality. Here, the latest updated research on colloidal carbon sphere nanoreactor, in terms of both their synthesis and applications, is summarized. Various synthetic strategies are first discussed, including the hard template method, the soft template method, hydrothermal carbonization, the microemulsion polymerization method, and extension of the Stöber method. Then, the functionalization of colloidal carbon sphere nanoreactors, including the nanoengineering of compositions and the surface features, is discussed. Afterward, recent progress in the major applications of colloidal carbon sphere nanoreactors, in the areas of energy storage, electrochemical conversion, and catalysis, is presented. Finally, the perspectives and challenges for future developments are discussed in terms of controlled synthesis and functionalization of the colloidal carbon sphere nanoreactors with tunable structure, and the composition and properties that are desirable for practical applications.

Preparation of PMMA nanolatex via microemulsion polymerization initiated by UV direct radiation at low temperature

By combining the microemulsion polymerization with UV direct initiation, an efficient polymerization method was developed due to its advantages in terms of high polymerization rate and conversion, lower polymerization temperature, high purity polymer. To be more specific, in the absence of initiator and under UV direct radiation, the polymerizations of MMA/Water/emulsifier microemulsion system were successfully accomplished at low temperature (26 ∼ 35°C) and PMMA nanolatex with the average diameter of 9.5 nm and narrow diameter distribution was obtained. The effects of UV intensity, monomer concentration, emulsifier concentration and temperature on polymerization rate and intrinsic viscosity of polymer were researched. The apparent activation energy of the reaction and polymerization kinetics of Rp are obtained as the following: Rp∝[IUV] 1.25[M]1.04[E]−2.57, Ea=14.45KJ/mol.

Enhanced stability of Pd/SPS catalyst over the one-pot liquid-phase synthesis of methyl isobutyl ketone by adding GO

The low thermal-conductivity and poor thermal stability of resin limit the service life of commercial Pd/sulfonated polystyrene (SPS) catalyst for the industrial synthesis of methyl isobutyl ketone from acetone and H2. In this paper, a novel catalyst Pd/S(PS-GO) was fabricated via in situ microemulsion polymerization, followed by sulfonating and Pd loading. Both the long-term catalytic performance of Pd/S(PS-GO) and Pd/SPS catalysts were tested in a trickle-bed reactor. Results showed that Pd/S(PS-GO) catalyst exhibited obvious enhanced stability than Pd/SPS catalyst at 150 ℃ for 1000 h run. The characterizations of FT-IR, TGA, XPS, TEM and UV–vis revealed that the addition of GO significantly improved the thermal-conductivity and thermal stability of PS through noncovalent π–π stacking and covalent link between PS and GO sheets. As a consequence, the loss of –SO3H groups from resin matrix was efficiently depressed and led to the obvious enhanced stability of Pd/S(PS-GO) catalyst.

Fabrication of PVDF Hybrid Blending Membrane via Microemulsion Polymerization Coupling with Blending Method

Fabrication of PVDF Hybrid Blending Membrane via Microemulsion Polymerization Coupling with Blending Method

Preparation, characterization, and antibacterial activity of cationic nanopolystyrenes

ABSTRACTCationic nanopolystyrenes (CNPSs) were prepared by the polymerization of styrene with a cationic polymerizable emulsifier, N‐(2‐(methacryloyloxy)ethyl)‐N,N‐dimethyltetradecane‐1‐ammonium bromide (MDTB), in the presence of 2,2′‐azobis(2‐methylpropionamidine) dihydrochloride (APPH). The polymerization kinetics was investigated through monomer conversion versus polymerization time. 1H NMR spectra and FTIR spectra were used to confirm the structures of MDTB and nanopolymers. The particle size, ζ‐potential, molecular weight, and thermal stability were also investigated by Zetasizer, gel permeation chromatography, and thermogravimetric analysis, respectively. The antibacterial activities of the obtained products were evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Staphylococcus aureus ATCC 29913 (S. aureus, a Gram‐positive bacterium) and Escherichia coli ATCC 25922 (E. coli, a Gram‐negative bacterium). The results indicated that the polymerization has the characteristics of microemulsion polymerization, all nanopolystyrenes are cationic and can be stored in the form of a microemulsion in aqueous phase, CNPSs present stable chemical structure at 190 °C, and their MIC and MBC reach 0.0625 and 0.125 mg mL−1 for E. coli, 0.0325 and 0.0625 mg mL−1 for S. aureus, respectively. Therefore, CNPSs are a promising new type of polymer antimicrobial agent, which can be used in the development of antimicrobial polymer materials and their products. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48405.

Polyelectrolyte-colloid complex formation via polymerization: reaction kinetics in direct micelles, inverted micelles, and homogeneous solution studied by NMR and conductometry

Formation of polyelectrolyte-surfactant complexes (PESCs) in polymerization process of corresponding amphiphilic monomer is a promising way of pure stoichiometric PESC obtained in salt-free systems. Polymerization of micelle-forming monomer dodecylammonium 2-acrylamido-2-methylpropanesulfonate (DDA-AMPS) in different media was studied by means of 1H-NMR and conductance measurements. Kinetics of polymerization in direct micelles, inverted micelles, and homogeneous solution was considered in terms of classical solution polymerization and microemulsion polymerization. Reaction orders on monomer and initiator were measured in water and dioxane. The rate of polymerization is strongly dependent on monomer micelle existence, being considerably higher in micellar solution than in homogeneous one.

Surfactant-assisted graphene oxide/methylaniline nanocomposites for lead ionic sensor development for the environmental remediation in real sample matrices

Graphene oxide/methylaniline (GO/MA) nanocomposites (NCs) were synthesized by an in situ inverse microemulsion polymerization method. The characterization of nanocomposites is done by scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) methods. In addition, an efficient chemical sensor probe was fabricated with flat glassy carbon electrode (GCE) by coating with thin layer of synthesized GO/MA NCs. Then the sensor was applied for the selective detection of lead (Pb+2) ion in an aqueous phase. The sensor performance such as sensitivity (20.56 µA mM−1 cm−2) was calculated from the slope of the calibration curve. The linear dynamic range (LDR: 0.1 nM–0.01 M) was calculated on the maximum linearity line from the calibration plot. The detection limit (DL: 50.0 ± 2.5 pM) was also calculated from the slope of the calibration plot by considering of 3 N/S (signal-to-noise ratio of 3). This novel electrochemical approach introduced a reliable and efficient route to detect the heavy metal ions as selective sensor for the safety of medical, biochemical and environmental fields in broad scales.

Effective removal of methylene blue and orange II by subsequent immobilized laccase decolorization on crosslinked polymethacrylate/carbon nanotubes

In this research, methylene blue (MB) and orange II (OII) were effectively removed through subsequent immobilized laccase degradation on crosslinked polymethacrylate (PMMA)/carbon nanotubes (CNTs). PMMA was coated on CNTs by microemulsion polymerization, and then laccase was immobilized on the PMMA-CNTs. Laccase immobilized on PMMA-CNTs shows a high catalytic ability and stable reusability. The immobilized laccase exhibits a high specific laccase activity and a high decolorization rate on the azo dyes, which the maximum decolorization rate for MB can reach 96% and maximum decolorization rate for OII is 74%. Additionally, the decolorization rate was decreased only about 10% after 10 successive cycles. The immobilized laccase can be a promising multifunction material in wastewater treatment, which would be applied in the decolorization of azo dyes.

Template synthesized polypyrroles as a carrier for diastase alpha amylase immobilization

Abstract The ability of Polypyrroles in assimilating enzymes promises new candidates for enzyme immobilization. The surfactants SDS, CTAB and TWEEN -80 have been employed as templates in order to prepare spherical polypyrrole particles via micro-emulsion polymerization method. The diastase alpha amylase extracted from malt is the model enzyme for our studies. Both free and immobilized enzymes were characterized using IR, UV, BET and SEM analysis. The biochemical characterization includes optimization of pH, temperature, reusability and storage stability. The kinetic parameters Km and Vmaxwere also evaluated using Lineweaver- Burk plots. The Km values were found to be increasing and Vmax values decreases for all immobilized enzymes. After 15 cycles of reuse, immobilized enzymes retained almost 50% of its initial activity. The thermal stability and storage stability exhibited by immobilized enzymes ensure the contribution of supports for future biochemical applications.

Electric-field-directed Bicontinuous Microemulsion Polymerization of Nanoporous Polymeric Membranes

Electric-field-directed Bicontinuous Microemulsion Polymerization of Nanoporous Polymeric Membranes

Emulsion Techniques for the Production of Pharmacological Nanoparticles.

Nanoparticles have the advantages over micron-sized particles to typically provide higher intracellular uptake and drug bioavailability. Emulsion techniques are commonly used methods for producing nanoparticles aiming at high encapsulation efficiency, high stability, and low toxicity. Here, the recent developments of nanoparticles prepared from emulsions, the synthesis of nanoparticles, their physicochemical properties, and their biomedical applications are discussed. Selection of techniques, such as emulsion polymerization, miniemulsion polymerization, microemulsion polymerization, and emulsion-solvent evaporation processes, strongly influences morphologies, size distributions, and particle properties. Details in the synthetic strategies governing the performance of nanoparticles in bioimaging, biosensing, and drug delivery are presented. Benefits and limitations of molecular imaging techniques are also discussed.

Preparation of magnetic polymer nanosphere and its profile control

Fe3O4 nanoparticles with a particle size of approximately 16.5 nm were prepared by the chemical coprecipitation method with the raw materials of ferric chloride, ferrous chloride, and sodium hydroxide. The optimum reaction conditions were determined by the single factor control method; then, magnetic polymer nanoparticles were produced by microemulsion polymerization, and the synthesis conditions were optimized by orthogonal experiments with four factors and three levels. As expected, spherical particles of approximately 60 nm were obtained. The morphology, structure, and properties of the product were characterized and analyzed. The results showed that the particles possessed a uniform spherical shape, good thermal stability, and superparamagnetism, which will ensure these particles have a wide application of directional flooding profile control. Average EOR of magnetic polymer nanospheres with magnetic field was 14.41 wt%. The magnetized magnetic polymer nanospheres had better profile control ability, and were less damage to the low permeability layer. Separation experiment showed that magnetized magnetic polymer nanospheres can be effectively separated due to the low viscosity and the good magnetism. Furthermore, the separated polymer nanospheres can be reused again.

A fluorescent nanoprobe for 4-ethylguaiacol based on the use of a molecularly imprinted polymer doped with a covalent organic framework grafted onto carbon nanodots.

An efficient and rapid fluorescent nanoprobe is described for the determination of the aroma compound 4-ethylguaiacol (4-EG). A molecularly imprinted polymer was doped with a covalent organic framework (COF) grafted onto carbon nanodots that was prepared by one-pot reverse microemulsion polymerization. Amino groups at the surface of carbon nanodots coordinate to the COFs to produce a strong bond and this warrants thermal and chemical stability of the probe. Remaining free amino groups interact with the phenolic hydroxyl groups of 4-EG through acid-base pairing interactions. The probe, with excitation/emission maxima at 350/440nm, responds to 4-EG due to the charge transfer to the carbon nanodots. Under optimized conditions, fluorescence drops linearly as the concentrations of 4-EG increase from 0.025 to 1 μg mL-1, with a detection limit of 17 ng mL-1. The probe was applied to the determination of 4-ethylguaiacol in Chinese Baijiu and wine samples after pretreatment by a single dilution step. The recoveries of spiked samples ranged from 78.4to 110.1%. Graphical abstract Schematic presentation of the synthesis of a fluorescent nanoprobe based on molecularly imprinted polymers doped with covalent organic framework grafted onto carbon nanodots. It was used as an efficient and rapid nanoprobe for 4-ethylguaiacol detection with high selectivity and sensitivity.

A personal journey on using polymerization in aqueous dispersed media to synthesize polymers with branched structures

This short review is dedicated to celebrate Prof. Shoukuan Fu’s 80th birthday by discussing several of my accomplished projects over the past twenty years, which all applied radical polymerization in aqueous dispersed media for producing polymers with branched structures. These projects include the use of microemulsion polymerization for syntheses of fluorescent nanoparticles, hairy nanoparticles and hyperbranched polymers; the use of miniemulsion polymerization for synthesis of star polymers and light-emitting nanoparticles; the use of seeded emulsion polymerization for synthesis of hairy nanoparticles and hyperstar polymers; and the use of precipitation polymerization for synthesis of hollow polymer nanocapsules. Discussion of these projects demonstrates intriguing features of polymerization in biphasic dispersed media via either conventional radical polymerization or controlled radical polymerization to effectively regulate the branched structure of functional polymers.

Functionalizable composite nanoparticles as a dual magnetic resonance imaging/computed tomography contrast agent for medical imaging

ABSTRACTA dual contrast agent for computed tomography (CT) and magnetic resonance imaging (MRI) was synthesized via microemulsion polymerization. This contrast agent consists of Fe3O4 particles (d = 7 nm) with an iodine‐carrying nanopolymeric shell, with overall particle sizes ranging from 50 to 250 nm. 2‐Methacryloyloxyethyl(2,3,5‐triiodobenzoate) was used as the monomer. Sodium oleate was used as the surfactant and its amount was varied to control the overall particle size. The composite nanoparticles were mainly characterized via dynamic light scattering, with further analyses using transmission electron microscopy and atomic force microscopy. The particles provided a highly visible contrast in CT and MR images. A template for biomedical applications was created by adding a comonomer and the particles were further functionalized with the somatostatin analogue Tyr3‐octreotate. The particles were tested for specific uptake into somatostatin receptor‐positive AR42J cells. The additional uptake of the functionalized particles was investigated. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47571.

An investigation into the relationship between the electrical conductivity and particle size of polyaniline in nano scale

Polyaniline nanoparticle (nPANI) was successfully synthesized through ultrasonic-assisted reverse microemulsion polymerization method. The effect of four parameters including concentration of aniline (ANI) as monomer, molar ratio of dodecybenzene sulfonic acid (DBSA) as surfactant to ANI, molar ratio of ammonium peroxydisulfate (APS) as oxidant to ANI and polymerization temperaturewere systematically studied in terms of the structural characterizations of nPANI by applying the Taguchi method of experimental design. Data analysis indicated that there is a dependency between conductivity and particle size in the nanoscale; the maximum conductivity of nPANI was obtained when the diameter of the particles was 30 nm.