Emulsion Polymerization Technique Research Articles

Mini review polyurethane hybrids: preparation, characterization and applications

Polyurethane hybrids (PUHs) are a type of versatile materials with a broad variety of possible applications. Considering the connections between their structure and characteristics, this is especially true. Because of its special mechanical stability, toughness, stickiness, sustainability of the finished product, biological properties, and chemical properties, PUHs are the subject of extensive research and development for use in a wide range of applications. Polyurethane /acrylic hybrids are important type of binders in coating industries due to their exceptional properties. This mini review aims to provide an overview of different types of polyurethane/acrylic hybrids, including waterborne, blending, and UV curable hybrids. The synthesis of these hybrids through addition and emulsion polymerization techniques is discussed, emphasizing the importance of achieving intimately homogenous latex. The hybrids (PUHs) enhanced the physical, chemical, and mechanical properties of the final products including coatings, paints, adhesives, and performance of other products. In addition, the anticorrosion coatings based on PUHs exhibits the properties of polyurethane and acrylic to reduce or prevent the corrosion.

Fabrication of cationic microgels doped MnO2/Fe3O4 nanocomposites, and study of their photocatalytic performance and reusability in organic transformations

AbstractThis article reports, the fabrication of cationic microgel doped MnO2/Fe3O4 nanocomposites (CM@MnO2/Fe3O4) via free radical emulsion polymerization technique, and an economical and environmental friendly approach to some organic transformations, such as heterogeneous photocatalytic reduction of methylene blue (MB, toxic dye), para‐nitro phenol (PNP, harmful pollutant) and dimethyl amino benzaldehyde (DMAB, skin allergic reagent) in presence of UV light (38 W). First of all, three different crosslinked grades of cationic microgels (CMs) have been synthesized by using styrene, dimethyl acrylamide, cyclohexyl methacrylate, [2‐(acryloyloxy)ethyl] trimethylammonium chloride and N‐hydroxymethyl acrylamide monomers by taking different amounts of N‐hydroxymethyl acrylamide, and keeping the other monomers in fixed quantities. Further, all the grades of CMs have been doped by bimetallic MnO2/Fe3O4 nanoparticles, through hydrothermal method. Fabrication of CMs and CM@MnO2/Fe3O4 nanocomposites has been confirmed by the characteristic peaks observed in FT‐IR spectral analysis and their thermal stability has been evidenced by thermogravimetric analysis. TEM and DLS analyses have revealed their particular size. The surface morphology of CMs and CM@MnO2/Fe3O4 nanocomposites has been visualized by scanning electrode microscope analysis. The nanocomposites have effectively and efficiently catalyzed the reduction reactions of MB, PNP, and DMAB, in presence of UV light, by 98%, 98%, and 86%, respectively. The photocatalysts have been reused up to eight cycles without any loss of their catalytic activity. The photocatalytic reductions have also been studied for their kinetics, and exhibited pseudo first order kinetics (kapp, 10−2 min−1).

Synthesis and characterization of novel poly cysteine methacrylate nanoparticles and their morphology and size studies.

Polymer nanoparticles (PNPs) have significantly advanced the field of biomedicine, showcasing the remarkable potential for precise drug delivery, administration of nutraceuticals, diagnostics/imaging applications, and the fabrication of biocompatible materials, among other uses. Despite these promising developments, the invention faces notable challenges related to biodegradability, bioactivity, target-site specificity, particle size, carrier efficiency, and controlled release. Addressing these concerns is essential for optimizing the functionality and impact of PNPs in biomedical applications. Here, new poly cysteine methacrylate nanoparticles (PCMANPs), ca. (200 nm) in size have been synthesized from the cysteine methacrylate (CysMA) monomer using different strategies, including emulsion and inverse emulsion polymerization techniques. The monomer was synthesized using the Michael addition reaction, involving the addition of 3-(acryloyloxy)-2-hydroxypropyl methacrylate to the sulfhydryl group (-SH) of the cysteine (Cys) active site, with the aid of dimethyl phenyl phosphine (DMPP) as a nucleophilic agent as previously reported. To enhance nano-polymerization, a thorough exploration of various initiators, including ammonium persulfate (APS) and 4,4'-azobis (4-cyanovaleric acid) (ACVA), alongside surfactants, such as polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), and sodium dodecyl sulfate (SDS), was conducted. Additionally, critical parameters, such as reaction time, temperature, and solvents, were systematically investigated due to their substantial influence on the shape, size, stability, and morphology of the synthesized polymer nanoparticles. This comprehensive approach aims to optimize the synthesis process, ensuring precise control over the key characteristics of the resulting nanoparticles for enhanced performance in diverse applications. Various characterization techniques, including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), zeta potential, and zeta sizer dynamic light scattering (DLS) analysis, were utilized to investigate purity, morphology, and particle size of the PNPs. As a result, a spherical, monodispersed (homogenized), and stable PCMANP with defined size and morphology was achieved. This may exhibit a remarkable achievement in the future of drug delivery systems and therapeutic index.

Synthesis of silane- and quaternary ammonium-bearing copolymers and application as a coating resin on cotton fabric.

In this study, silane and quaternary ammonium functional methacrylate monomers were synthesized and used to construct a copolymer using an emulsion polymerization technique to control the reaction rate. The copolymer was then designed using different ratios of silane and quaternary ammonium groups to investigate the relationship between the structure and properties. The presence of the ethoxy silane group in the copolymer series provided covalent bonding through the silanol group onto cotton fabric. The presence of cationic groups also helped to cover the fabric surface. After coating the cotton textile fabric, the resistance of the dye on the fabric surface to friction was assessed and tests were conducted on washing, rubbing, water, and light fastness. Finally, the textile surfaces were investigated for their antibacterial activity against Staphylococcus aureus and Escherichia coli. It was observed that the copolymer series showed >99% killing efficiency against S. aureus but had no effect on E. coli.

PH-Sensitive Acrylic Terpolymers for the Coating of Orally Administered Drugs Used for Colonic Release.

Polymeric coatings are a promising option for the development of delivery systems for orally administered drugs. However, the gastrointestinal conditions to which they are subjected, which include low pH and solubility as well as peristaltic movements, can limit their applications. In this work, different formulations of polymeric coatings were produced using pH-sensitive materials consisting of copolymers of methyl acrylate, methyl methacrylate, and methacrylic acid. The polymers were synthesized by the emulsion polymerization technique, obtaining small average particle sizes (56-190 nm), molecular weights between 200,000 and 400,000 g/mol, and a glass transition temperature above 35 °C, which are suitable for film formation at room temperature. Thus, they were assessed as coatings for hydroxypropyl methylcellulose capsules (HPMC) using the immersion method, showing adequate capacity to protect the capsule at gastric pH (pH 1.2) and dissolve at the simulated intestinal pH (pH= 7.2). In particular, the higher the content of the acidic monomer, the higher the release time of the test molecule contained in the acrylic terpolymer-coated HPMC capsules proposed, which was a curcuminoid derivative due to their bright color and potential medical benefits. In addition, a minimum number of immersions was required for coating the HPMC capsules at high acidic concentrations, which further facilitates the delayed release needed for colonic treatment. However, too high proportions of methacrylic acid may result in cytotoxicity issues. Consequently, a biocompatible formulation containing a proportion of methyl acrylate, methyl methacrylate, and methacrylic acid of 7:3:3 is proposed as the most adequate for colonic release. Thus, by chemically modulating the molar percentages of the acrylic monomers, it was possible to obtain tailored acrylic terpolymer coatings with different characteristics and desired properties in order to modulate the release kinetics of an active substance in a colonic environment.

MXene Clay (Ti2C)-Containing In Situ Polymerized Hollow Core-Shell Binder for Silicon-Based Anodes in Lithium-Ion Batteries.

Silicon, an attractive anode material, suffers fast capacity fading due to the electrical isolation from massive volumetric expansion upon cycling. However, it holds a high theoretical capacity and low operation voltage in its practical application. In this study, a new water-based binder, MXene clay/hollow core-shell acrylate composite, was synthesized through an in situ emulsion polymerization technique to alleviate the fast capacity fading of the silicon anode efficiently. The efficient introduction of conductive MXene clay and the hollow core-shell structure, favorable to electron and ion transport in silicon-based electrodes, gives a novel conceptual design of the binder material. Such a strategy could alleviate electrical isolation after cycling and promises better electrochemical performance of the high-capacity anodes. The effect of the MXene introduction and hollow core-shell on the binder performance is thoroughly investigated using various characterization tools by comparison with no MXene-containing, core-shell acrylate, and commercial styrene-butadiene latex binders. Consequently, the silicon-based electrode containing the MXene clay/hollow core-shell acrylate binder exhibits a high capacity retention of 1351 mAh g-1 at 0.5C after 100 cycles and good rate capability of over 1100 mAh g-1 at 5C.

Europium recovery process by means of polymeric nanoparticles functionalized with acrylic acid, curcumin and fumaramide

Polymeric nanoparticles of poly(methyl methacrylate) were obtained by emulsion polymerization techniques in a process of two stages. The particles were functionalized with acrylic acid, curcumin, and fumaramide and three series of polymeric particles were obtained. The incorporation of functional groups was confirmed by Fourier transform-infrared spectrosocopy (FT-IR) and ultraviolet–visible (UV–Vis) methods. The spherical morphology of particles with an average diameter of 100 nm was observed by scanning electron microscopy (SEM). The polymeric materials were used for recovery of [Eu] from synthetic solutions. The nanoparticles show excellent chelation capacity to trap rare-earth ions, because they recover more than 85% of [Eu] at pH of 2. The images of SEM after extraction process show arrays between particles with larger average particle sizes to 1.5 μm. In addition, the particles have a good stripping capacity, exceeding 50% of it, maintaining their homogeneity in morphology and good stability in dispersion for the recovery and stripping processes. A pseudo-second model order is obtained for the extraction and stripping processes while the best results of stripping process are obtained at pH of 6.

Antibacterial and angiogenic potential of iron oxide nanoparticles-stabilized acrylate-based scaffolds for bone tissue engineering applications

Pickering emulsion polymerization, stabilized by inorganic nanoparticles such as iron oxide nanoparticles (IONPs), can be used to fabricate scaffolds with the desired porosity and pore size. These nanoparticles create stable emulsions that can be processed under harsh polymerization conditions. IONPs, apart from serving as an emulsifier, impart beneficial bioactivities such as antibacterial and pro-angiogenic activity. Here, we coated IONPs with three different weights of oleic acid (5.0 g, 7.5 g, and 10.0 g) to synthesize oleic acid-IONPs (OA-IONPs) that possess the desired hydrophobicity (contact angle > 100°). Next, glycidyl methacrylate and trimethylolpropane triacrylate were polymerized using the Pickering emulsion polymerization technique stabilized by the OA-IONPs. The physicochemical properties of the resulting porous scaffolds were thoroughly characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), and a universal testing machine (UTM). The SEM images confirmed the formation of a porous scaffold. The IONPs content, measured using inductively coupled plasma mass spectrometry (ICP-MS), was in the range of 22–26 µg/mg of the scaffold. The mechanical strengths of the scaffolds were in the range of cancellous bone. The degradation profile of the scaffolds varied between 29% and 41% degradation over 30 days. In vitro cytotoxicity studies conducted using the fibroblast (L929) and osteosarcoma (MG-63) cell lines proved that these scaffolds were non-toxic. SEM images showed that the MG-63 cells adhered firmly to the scaffolds and exhibited a well-spread morphology. The antibacterial activity was confirmed by percentage inhibition studies, SEM analysis of bacterial membrane distortion, and reactive oxygen species (ROS) generation in the bacteria. Chick chorioallantoic membrane assay showed that the total vessel length and branch points were significantly increased in the presence of the scaffolds. These results confirm the pro-angiogenic potential of the fabricated scaffolds. The physicochemical, mechanical, and biological properties of the material suggest that the developed scaffolds would be suitable for bone tissue engineering applications.

Acrylic Finished Leather Upgraded with Thermoplastic Polyurethane Filament using 3D Printing – A New Generation Hybrid Leather of Synthetic and Natural Polymer

Leather manufacturing process involves a lot of waste disposal which pollutes environment, some of the processes are inevitable. In the present investigation, 3D printing technology was used to reduce the wastage and to cover defective regions in leather. The present study focuses on synthesis of acrylic binder using emulsion polymerization technique. These binders were analysed for solid content for better optimisation of the amount of binder to be utilised for finishing operation. The experimental binder was prepared with 26% solids. Particle size and thermogravimetric analyses were carried out to understand the size and shape of the particles and their thermal resistance. These binders were used for leather finishing and the performance of leather was studied. Surface morphology changes of leathers were studied using Scanning Electron Microscopy (SEM). Wet and dry rub fastness, finish film adhesion, light fastness and organoleptic properties were studied and found to be superior compared with control leathers. The acrylic finished leather with minor defects was taken for 3D printing and designed using Thermoplastic Polyurethane (TPU) as filament. The acrylic finished leather shows good adhesion for TPU and it results in numerous designs in short duration. The new additive was added to leather using 3D printing technology to produce a tailor-made valuable design without any waste disposal and chemical discharge. This invention may convert the rejected waste leather into valuable material and lead to the new generation hybrid leather for use.

Acrylates-based hydrophilic co-polymeric nanobeads as nanocarriers for imaging agents

Acrylates-based co-polymeric nanoparticles (PNPs) are widely used in nanomedicine applications due to their tunable hydrophilic surface, physical and chemical versatility. Particularly attracting is their use as nanocarriers for imaging agents. Herein, methyl methacrylate (MMA) and N,N-dimethylacrylamide (DMAA) monomers were used to synthesize hydrophilic p(MMA-co-DMAA) nanoparticles in the 200–600 nm size range via surfactant-free radical emulsion polymerization technique. Different MMA/DMAA molar ratios, temperatures, and reaction times were investigated to evaluate their role in determining the average particle size, polydispersity, and optimizing surface properties of PNPs. Nanoparticles formation, stability (in water and culture medium for cell growth), swelling behavior, structural features and molecular weights were assessed by spectroscopic, non-spectroscopic, and chromatographic techniques. Morphological profiles confirming spherical-shaped NPs were obtained at solid state via microscopies (FESEM, AFM). To use such colloids as potential imaging agents, PNPs were loaded with Y3+(aq) ions by the addition of aqueous solutions of YCl3 at different concentrations, and results compared with p(MMA-co-AA)-DTPA NPs (AA = acrylic acid) functionalized with DTPA chelating agent. Yttrium ions loading percentage was ca. 90% for both p(MMA-co-DMAA) and p(MMA-co-AA)-DTPA, with negligible release (<15%) over a month. Parallelly, optical imaging nanoprobes were obtained by physical encapsulation of fluorescein isothiocyanate isomer I (FITC) dye during the synthesis process, and the spontaneous FITC incorporation was evaluated by spectroscopic studies and fluorescence microscopy. Cytotoxicity studies on pristine and yttrium-loaded nanoparticles were done in vitro on human glioblastoma T98G cell line within 24 h of treatment. Transmission electron microscopy (TEM) studies on cancer cells treated with NPs confirmed an active uptake of PNPs through multiple endocytic pathways to reach the perinuclear region of the cell. Overall, this work elucidated the role of synthetic parameters for a rational design of hydrophilic PNPs as nanocarriers for imaging agents with potential applications in theranostics.

Development of levan-coated PIBCA nanoparticles and their antiproliferative activity against MDA-MB-231 and B16F10 cells

Polysaccharides have been described as a successful alternative in developing nanosystems to reach specific sites. Levan is an exopolysaccharide with several biological activities, including immunostimulant, blood plasma substitute, and drug action prolonging agent. The present work aimed to develop poly-isobutyl cyanoacrylate (PIBCA) nanoparticles coated levan (Np-Lev) and to verify its cytotoxicity in two cancer cell lines. Levan was obtained through the fermentation of ZAG 12 Zymomonas mobilis. The nanoparticles were prepared using the anionic emulsion polymerization technique and characterized in size, zeta potential, morphological analysis, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. The cell lines MDA-MB-231 (metastatic breast cancer cells) and B16F10 (melanoma cells) were used to evaluate the antiproliferative activity and cellular uptake of Np-Lev. The technique of obtaining the levan allowed a higher yield than the reference methodology, achieving 71.4% more. The novel nanoparticles (Np-Lev) presented spherical shapes, size of 244 ± 2 nm with homogeneous distribution and zeta potential of −12 ± 1 mV. Characterization techniques, such as infrared spectroscopy and X-ray diffraction, confirmed the presence of levan in the nanoparticles. The thermogravimetric analysis results showed greater thermal resistance when compared to free levan. In addition, Np-Lev were more cytotoxic than levan in both cell lines. This toxicity may be related to the internalization of nanoparticles inside the cells since Np-Lev were captured by the cells, which could increase the activity of levan cytotoxicity. Thus, it was verified a substantial increase in levan yield, also that the levan produced could be used to prepare PIBCA nanoparticles, and finally these Np-Lev showed antiproliferative activity against breast cancer and melanoma cell lines. The results exposed here are of interest to explore levan potential, in addition to nanotechnology, as a promising nanosystem with various biological applications. Further studies are needed to understand the biological behavior of nanoparticles and assess their stability for future therapeutic application.

Temperature and pH-responsive PNIPAM@PAA Nanospheres with a Core-Shell Structure for Controlled Release of Doxorubicin in Breast Cancer Treatment

Stimuli-responsive polymers have been of great interest in the fabrication of advanced drug delivery systems. In this study, a facile approach was developed to synthesize a dually temperature/pH-responsive drug delivery system with a core-shell structure to control the release of doxorubicin (DOX) at the target site. For this purpose, poly(acrylic acid) (PAA) nanospheres were first synthesized using the precipitation polymerization technique and were used as pH-responsive polymeric cores. Then, poly(N-isopropylacrylamide) (PNIPAM) with thermo-responsivity properties was coated on the outer surface of PAA cores via seed emulsion polymerization technique to render monodisperse PNIPAM-coated PAA (PNIPAM@PAA) nanospheres. The optimized PNIPAM@PAA nanospheres with an average particle size of 116.8 nm (PDI= 0.243), had a high negative surface charge (zeta potential= -47.6 mV). Then, DOX was loaded on PNIPAM@PAA nanospheres and the entrapment efficiency (EE) and drug loading (DL) capacity were measured to be 92.7% and 18.5%, respectively. The drug-loaded nanospheres exhibited a low leakage at neutral pH and physiological temperature, but drug release significantly enhanced at acidic pH (pH= 5.5), indicating the tumor-environment responsive drug release behavior of the prepared nanospheres. Also, kinetics studies showed that, the sustained release of DOX from PNIPAM@PAA nanospheres was consistent with the Fickian diffusion mechanism. Moreover, the anticancer efficacy of DOX-loaded nanospheres was evaluated in vitro against MCF-7 breast cancer cells. The obtained results revealed that, the incorporation of DOX into PNIPAM@PAA nanospheres increases its cytotoxicity against cancer cells compared to the free DOX. Our results suggest that, PNIPAM@PAA nanospheres can be considered as a promising vector to release anticancer drugs with dual-stimuli responsivity to pH and temperature.

Preparation and investigation of properties of deproteinized natural rubber nanocomposites incorporating functionalized nano‐alumina by in situ emulsion polymerization

AbstractThe present study reports the preparation, characterization, and investigation of properties of DNR/f‐Al2O3 nanocomposites through an in situ emulsion polymerization technique. The method consists of the dispersion of pretreated nano‐alumina (f‐Al2O3 NPs) onto deproteinized natural rubber (DNR) latex, followed by the polymerization reaction with the K2S2O8/K2S2O5 redox initiation system, after deproteinization of natural rubber using urea in the presence of a surfactant. To improve the compatibility and reactivity of the nanofillers with DNR latex, the nano‐alumina surface was treated with 3‐methacryloxypropyltrimethoxysilane (MPS) to produce f‐Al2O3 NPs. The thermo‐gravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy approved that the MPS was bound onto the surface of Al2O3 NP. The resulting nanocomposites were characterized using standard techniques for physical properties and structural morphology, including X‐ray diffraction (XRD) analysis, FTIR spectroscopy, scanning electron microscopy (SEM), and TGA. The SEM images showed a homogeneous distribution of f‐Al2O3 NPs throughout DNR matrix. Due to such monodisperse particles, the DNR/f‐Al2O3 nanocomposite films revealed significant enhancement in thermal stability with increasing nano‐alumina loading as compared with the neat DNR.

Microencapsulation of n-tetradecane with poly (methyl methacrylate-co-methacrylic acid) shell by seeded emulsion polymerisation and its thermal energy storage characteristics

This study aims to enhance the latent heat storage properties of the microcapsules by altering the amount of crosslinking agent from 3 to 20%w/w, the core-to-shell ratio from 1:1 to 2:1, and the amount of initiator from 1 to 3%. The phase change material n-tetradecane (C-14) was microencapsulated by using poly (methyl methacrylate -co- methacrylic acid) as a shell material through an oil by water-seeded emulsion polymerisation technique. The structural, morphological, and thermal properties of microcapsules were evaluated by using Fourier transform infrared spectroscopy, optical microscopy, scanning electron microscopy, differential scanning calorimetry analysis, and thermogravimetric analysis. The average particle size of the microcapsules ranges from 01 to 15 µm. The results showed that the microcapsules have a higher melting enthalpy value of 127.3 ± 0.06 J/g with a microencapsulation efficiency of 66.72% when a 20% w/w crosslinker was used. The thermal stability of the phase change material (PCM) was increased by ∼30 ± 2 °C by encapsulation.

Carbon Encapsulated Silicon for High-Capacity Durable Anodes

One of the biggest challenges of the near future is how to meet the increasing energy demand without any adverse environmental impact. Lithium-Ion batteries (LIBs) are one of the promising alternative energy storage systems to replace conventional non-rechargeable batteries. LIBs are becoming one of the most widely used energy storage devices because of their relatively high specific energy density (~300 Wh/kg), excellent stability over a wide temperature range, and lower cost than other battery systems. Intense research is in progress to increase the capacity of anode electrodes for realizing high-energy LIBs. In this context, silicon (Si) has a great potential to replace commercial graphitic anode active materials mainly due to its high theoretical specific capacity (4200 mAh/g) and low working potential (0.37 to 0.45 V vs. Li/Li+). To harness and maintain a high capacity from Si-based anodes, we must deal with two main challenges: (i) volume changes of Si (>300%) during charging and discharging, which cause pulverization of the material and loss of electrical contact, and (ii) unstable growth of solid-electrolyte interphase (SEI) layer, which can cause early degradation of performance in Si-anode batteries. To overcome these challenges, different approaches have been taken. This includes developing graphite/Si anodes with limited amounts of Si (<30 wt.%), conformal coating of Si active materials (e.g., CVD carbon coating), etc. However, these challenges still could not be fully overcome.To advance the use of Si materials in LIB anodes, we developed a viable technology to create a hybrid silicon-carbon material, called Si@C, in which a soybean-derived carbon cloud protects Si nanoparticles during the battery operation. We employed soybean oil in a scalable oil-in-water emulsion polymerization technique to produce Si-containing polymeric particles. In this method, we emulsified two immiscible solutions. One contains a homogeneous Si mixture in epoxidized soybean oil (ESO), and another contains a uniform dispersion of ball-milled lignin or soyhull powders in water. Citric acid, a crosslinking agent, was used to help polymerize the ESO and integrate carbon-rich lignin/soyhull with polymerized particles. The final Si@C product was achieved by carbonizing the polymerized solid product at 500 °C (under argon) and ball milling to get a fine powder. Several Si@C hybrid materials containing 20 wt.% to 50 wt.% Si were successfully prepared and utilized for anode preparation. Electrodes were made by coating a slurry of Si@C active material, carbon black, and binder with a mass ratio of 60:20:20 onto an ion-permeable Bucky Paper (BP, a flexible and conductive paper made of carbon nanotubes). Anodes with different binding systems were prepared to determine an appropriate binder for Si@C based batteries. The 2032-type coin cells were assembled for battery testing using 1M LiPF6 in EC:DMC in a volume ratio of 1:1 as the electrolyte, Li chips as the counter electrode, and Celgard 2325 as the separator. The coin cells were cycled at a current rate of 0.1C (420 mA/gSi) over the potential range of 0.01 – 1.0 V at room temperature.Battery results showed that Si@C hybrid materials increased the capacity of Si anodes by a factor of >2. At Si mass loading of 1.0 mg/cm2, implementing our carbon cloud approach led to an increase in the discharge capacity of anodes from 0.5 mAh (corresponding to anode with bare Si) to >1.0 mAh (corresponding to anode with Si@C hybrids). Results from battery cycling at 0.1C demonstrated excellent capacity retention of >95% after 130 cycles for anodes prepared using our Si@C active materials. The Si content of Si@C hybrid particles was also found to be an influential factor in the cycling performance of anodes. Finally, we observed that the use of water-based polyacrylic acid (PAA) and carboxymethyl cellulose (CMC) binders improve the electrochemical performance of Si@C based anodes. These water-based binders are ideal for preparing Si-based slurries, and the need for using toxic solvents (e.g., NMP) to prepare slurries can be averted. In conclusion, we innovated a viable technology that uses biomass (soybean oil and soyhulls) to enhance Si-based batteries' performance. We demonstrated that our Si@C materials with a carbon cloud protecting the Si nanoparticles are promising active materials to improve the capacity and cycling stability of LIB anodes.

Pickering emulsion polymerized Fe3O4@graphene oxide-polystyrene composite particles and their electro/magnetorheological responses

In this study, magnetic and semiconducting Fe3O4@graphene oxide (GO)-polystyrene (PS) composite particles were fabricated using the Pickering emulsion polymerization technique. The Fe3O4@GO composite particles were initially synthesized via a co-precipitation method and then used as a Pickering emulsifier. The basic properties, such as the morphology, chemical properties, and the magnetic properties of the Fe3O4@GO-PS composite particles, were characterized using transmission electron microscopy, Fourier-transform infrared spectroscopy, and VSM. The Fe3O4@GO-PS composite particles were then dispersed in silicone oil to obtain electrorheological (ER) and magnetorheological (MR) fluids. The ER and MR properties were tested using a rheometer with two different geometries under electric and magnetic fields. The ER dynamic yield stresses were obtained using the Bingham model fitting method, whereas the MR dynamic yield stresses were obtained using the Casson model fitting method. Furthermore, the yield stress was obtained by fitting the complex viscosity using the Carreau model. All three yield stresses were also fitted with respect to the electric or magnetic field strengths, and a slope of 1.5 was determined.

Developing new polymeric nanoparticles for controlled release of quercetin as an alternative material protecting from COVID-19

Research of drugs for COVID-19, the most striking studies include the ACE-2 receptors used by COVID-19 by binding to the lung cells for entry. In the researchers conducted, it was determined by the results of the docking studies performed on the agents that block the receptor by binding to the receptor, such as COVID-19, several molecules have the interest to bind to this receptor. One of these numbered molecules is herbal flavonoid called "Quercetin". In this study, quercetin imprinted polymeric materials were designed, synthesized and characterized. For synthesis, emulsion polymerization technique was used for obtaining quercetin imprinted polymeric materials. SEM and Zeta-Size analysis were used as preliminary characterization. After a week release experiment, quercetin imprinted polymeric nanoparticles were released by 14%. In the light of these results, it is predicted that quercetin printed polymeric material can be used for protection from COVID-19 and treatment of COVID-19 on the inhaler route.

Combined Effect of Layered Double Hydroxides and Nano silver on Bacterial Inhibition and Gas Barrier Properties of Chitosan Grafted Polyacrylonitrile Nanocomposites

ABSTRACT Herein, chitosan-grafted-poly(acrylonitrile) (CS-g-PAN) nanocomposites are prepared by emulsifier-free emulsion polymerization technique with dispersion of layered double hydroxides(LDHs) and nano silver(AgNPs). The interactions of AgNPs and LDH with co-polymeric matrix are investigated by FTIR and XRD. It is noticed that LDH platelets are intercalated and partially exfoliated within the copolymeric matrices. Dispersion of fillers creates tortuous path which enhances the gas barrier properties up to seven folds. Antibacterial behavior of nanocomposites is achieved due to incorporation of silver nanoparticles and LDH. Thermal stability, chemical resistance and biodegradable properties of the synthesized material are also increased due to combined effect of LDH and AgNPs.

Synthesis and Application of Reactive Acrylic Latexes: Effect of Particle Morphology.

The aim of the study is the synthesis and characterization of epoxy functional reactive polyacrylic latexes, e.g., poly (BA-co-MMA-co-AN-co-GMA) with core/shell and non-structured (random) particle morphologies. Additionally, their performance as binders and coating ability in leather finishing were studied. The epoxy functional polymers were synthesized via the seeded emulsion polymerization technique and the obtained latexes were characterized by means of particle size, zeta potential, FTIR, TEM, DSC, DMTA, and TGA. The results showed that the particle size and zeta potential values were very similar for both latexes, except core/shell latex had slightly higher particle size. DSC, TEM, and DMTA studies verified the successful synthesis of core/shell latex morphology. The copolymer films were elastic in nature and had low Tg values (−13 and −20 °C). The performance results showed some different behavior for core/shell and random copolymer coatings. The abrasion resistance of the leather finish with random copolymer as binder exhibited slightly better values, especially in wet conditions. On the other hand, the leathers finished with core/shell binder showed better performance in flexing endurance and the water spotting test.

Dye Ligand Affinity Nanoparticles for the Depletion of Biomolecules in Proteomics

Objective: Serum proteins are indicators for certain diseases. However, detection of the biomarkers is difficult because the more abundant proteins mask the less abundant ones. The depletion of abundant serum proteins will help in the discovery and detection of less abundant proteins that may prove to be informative disease markers. Dye ligands have attracted great attention because of their cost-effectiveness, easy immobilization, stability, and high binding capacity. Due to these advantageous properties, dye ligands have also been chosen as an alternative for biological ligands such as antibodies, enzymes, etc. Materials and Methods: Poly (ethylene glycol dimethacrylate) [p (EGDM)] nanoparticles were prepared using the surfactant-free emulsion polymerization technique. Then, Reactive Red 120 (RR 120) dye was immobilized to nanoparticles in a nucleophilic substitution reaction. The RR120 attached nanoparticles were characterized. Results: The size/size distribution of p (EGDM) nanoparticles was measured with a Zeta sizer. The scanning electron microscope (SEM) images were found to support a measurement of around 100 nm. The maximum adsorbed amount of albumin was observed at pH 6.0. The maximum depleted albumin concentration was found to be 453.9 mg/g nanoparticles according to the experimental results. Desorption studies were carried out by addition of 0.5 M of KSCN to the albumin solutions. The desorption results showed that the binding of albumin to the nanoparticle was reversible. Conclusion: Our results demonstrated that dye attached nanoparticles have the potential for depleting albumin from serum in proteomics.