Initiator Ammonium Persulfate Research Articles

Fabrication of Tailored Membranes with Special Surface Wettability Features for Highly Efficient Crude Oil-in-Water Emulsion Separation.

Treating oily wastewater streams such as produced water has a huge potential to resolve the issue of wastewater disposal and generate useful water for reuse. Among different techniques employed for oily wastewater (oil-in-water; O/W emulsion) treatment, membrane-based separation is advantageous owing to its lower energy consumption, recycling, ease of operation, and wider scope of tuning the active layer chemistry for enhanced performance. In line with the possibilities of enhancing the performance of the membranes for efficient O/W emulsion separation, the current work is designed to yield five different variants of polyaniline (PANI) active layers with special surface wettability features (superhyrophilic and underwater superoleophobic) on a ceramic alumina support. To achieve variants of PANI on ceramic alumina supports, emulsion polymerization was carried out, and different concentrations of initiator ammonium persulfate (APS) were applied to lead to PANI-A@Aluminum Oxide membrane, PANI-B@Aluminum Oxide membrane, PANI-C@Aluminum Oxide membrane, PANI-D@Aluminum Oxide membrane, and PANI-E@Aluminum Oxide membrane corresponding to 0.15, 0.25, 0.35, 0.5, and 1.0 M concentrations of initiator. The variation in initiator concentration resulted in different PANI growth patterns; hence, the resultant membranes showed different structural, physical, and performance features. Different characterization techniques including 1H NMR, SEM, FE-TEM, AFM, water contact angle, XRD, EDX, and ATR-FTIR confirmed a more uniform and continuous growth of PANI (PANI-B) using a 0.25 M initiator concentration. The resultant PANI-B@Aluminum Oxide membrane showed an excellent surfactant stabilized crude O/W emulsion separation reaching >99% with a permeate flux of 2154 L m-2 h-1 (LMH) at 4 bar using a 100 ppm surfactant stabilized crude oil-in-water emulsion. The fouling and cleaning cycles revealed that the membrane can be reused with a 70% recovery of the initial permeate flux.

Acrylamide macromolecules modified wine lees‐soy protein wood adhesive

AbstractTo expand the diverse applications of wine lees and enhance the adhesive properties of its protein‐based adhesive, the supernatant of wine lees, separated using the alkali solubilization method, was combined with a small quantity of soybean protein as the raw material. Cross‐linking modification was then conducted using polyacrylamide polymers to prepare the protein‐based adhesive. The results indicated that a total mass fraction of 2.5 wt% NaOH and 3.0 wt% urea effectively stretched the protein structure. Additionally, a mass ratio of 4:10 of trimethylolpropane triglycidyl ether and acrylamide, under the action of the ammonium persulfate initiator, resulted in effective cross‐linking of polyacrylamide macromolecules. The addition of 7 wt% polyacrylamide macromolecules as a cross‐linking agent effectively facilitated the cross‐linking reaction with wine lees‐soy protein. After the cross‐linking modification, the surface of the adhesive became tight and smooth. As a result, the water‐resistance strength of the plywood increased from 0.2 to 1.27 MPa, marking a 635% enhancement, which significantly surpassed the standard for Class II plywood (GB/T 9846‐2015).

A biocompatible double network hydrogel based on poly (acrylic acid) grafted onto sodium alginate for doxorubicin hydrochloride anticancer drug release

This study involved the synthesis of a new biocompatible slow-release hydrogel named poly (acrylic acid) grafted onto sodium alginate (poly (AA-g-SA)) double network hydrogel (DNH). The hydrogel was created by polymerization of acrylic acid grafted onto sodium alginate polysaccharide using crosslinkers N,N′-methylenebisacrylamide and calcium chloride via free radical polymerization. The water absorbency of the poly (AA-g-SA) double network hydrogel was improved by optimizing the quantities of ammonium persulfate initiator, pH-sensitive monomer of acrylic acid, and crosslinkers. Various analytical techniques including attenuated total reflection Fourier-transformed infrared (ATR-FTIR), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), and Brunauer-Emmett-Teller specific surface area analysis (BET) were used to characterize the synthesized hydrogels. The swelling and on-off switching behaviors of the hydrogels were investigated in deionized (DI) water at different temperatures and pH values. The optimum poly (AA-g-SA) DNH was tested for in vitro release of a hydrophilic chemotherapeutic drug, doxorubicin hydrochloride (DOX). The eco-friendly hydrogel favorably optimized the DOX slow release owing to its swelling rate, high absorption and regeneration capabilities. The findings of this study may have significant implications for medical and scientific research.

Dielectric properties of polypyrrole and polyvenyledene fluoride blends: Effect of temperature

Polymer deploys dielectric nanostructured composites in the company of elevated dielectric permittivity along with a minimal loss have been extensively pre-owned for solicitation of energy storage in power electronics including power delivery devises. Additionally, polymer dielectrics are desirable for expanding electrical energy storage possess of their edge of mechanical pliability, facile processibility, lightweight, corrosion resistance, and great reliability together with high operating voltages. Consequently, rigorous efforts have been placed into the evolution of high-energy–density polymer dielectrics. In this exertion, an intrinsically conducting polymer i.e. polypyrrole (PPy): H(C4H2NH)nH is drawn up through the solvent casting method by introducing the fusing of p-toulene sulfonic acid (TSA) alongside ammonium persulfate (APS) initiator. Consequently, the premeditated amount of PPy forms blends by using PVDF in DMF solvent. Microstructure characterization manifests that PPy exhibits globular morphology and these particles posses homogeneous dispersion on thePVDF to form PPy/PVDF blend. Dielectric property and electrical conductivity confirm that the AC Conductivity (σac) of PPy increases and the dielectric loss (ε ') drops with the increase in frequency. Further fabrication of the PPy/PVDF blend and optimization of the blend ratio on the basis of dielectric properties is shown in this context. The implementation is mostly ascribed to the existence of PPy, which results the overall composites to dielectric composites.

Cellulose eutecticgel electrolytes based on ethylene glycol/zinc chloride deep eutectic solvent for flexible solid-state capacitors

In the present work, we successfully prepared a conductive eutecticgel with good mechanical properties, adhesion properties and excellent antifreeze properties by mixing ethylene glycol (EG) as the hydrogen bonding donor and zinc chloride (ZnCl2) as the hydrogen bonding acceptor in different molar ratios to form an anhydrous deep eutectic solvent (DES). Water-soluble cellulose acetate (WSCA), monomer acrylamide (AM), initiator ammonium persulfate (APS) and cross-linking agent MBA (N, N′-methylene bis(acrylamide)) were added into the prepared DES to form a eutecticgel by a simple one-pot cooking strategy. The mechanical properties of the eutecticgel were strengthened by cross-linking of WSCA and PAM chains through hydrogen bonding, and the addition of the DES and ZnCl2 increased the freezing-resistant property of the eutecticgel. The stresses of DES-WSCA/PAM eutecticgel increased with the content of WSCA. The stress of DES-WSCA/PAM eutecticgel gradually becomes larger with the increase of WSCA content, and it can reach 184.07 kPa at 2 % WSCA content. In addition, the capacitor prepared by DES-WSCA/PAM eutecticgel shows excellent performance, with a voltage window of 2 V and a capacitance of 371.5 F/g, which can be operated stably for a long period, and the capacitance can still reach 145.4 F/g even under the condition of −40 °C. Moreover, DES-WSCA/PAM eutecticgel capacitor has a long service life, its capacitance retention rate and coulombic efficiency can reach more than 91 % and 95 %, respectively, after 10,000 times of charging and discharging tests. In summary, DES-WSCA/PAM eutecticgel electrolyte is an ideal material for capacitors, which opens up a new way of thinking for the development of multifunctional cellulose-based eutecticgels with low-temperature resistance, good mechanical properties, and non-irritating for wearable energy storage devices.

Preparation of chondroitin sulfate and polyvinyl alcohol hydrogels as drug carriers

The chondroitin sulfate/polyvinyl alcohol based pH-sensitive hydrogels (CHS/PVA hydrogels) were synthesized by a free radical polymerization technique for controlled delivery of diclofenac sodium up to 72 h. Polymers chondroitin sulfate and polyvinyl alcohol were crosslinked with monomer acrylic acid by a cross-linker ethylene glycol dimethylacrylate in the presence of initiator ammonium persulfate. The process of polymerization was continued for 24 h at 65 °C. Fourier transform infrared spectroscopy (FTIR) indicated successful polymerization and crosslinking among the hydrogel contents. Differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA) studies demonstrated that fabricated hydrogel has higher thermal stability. The pH sensitivity of designed CHS/PVA hydrogel was investigated by performing dynamic swelling and in vitro drug release tests in pH 1.2, 4.6, and 7.4 medium. Maximum swelling was observed at pH 7.4 when compared to pH 1.2 and 4.6. The sequence of drug release from the developed hydrogel was; pH 7.4 > 4.6 > 1.2. It has been shown that porosity, swelling, and release rate of diclofenac increased with the addition of chondroitin sulfate and acrylic acid, while decreased with increasing PVA composition. Cytotoxicity studies showed that the prepared hydrogel has no toxic effect on T84. Therefore, it can be demonstrated from the results that the CHS/PVA cross-linked hydrogel can be considered as a potential delivery carrier for the controlled release of diclofenac sodium.

Enhanced removal of Cr(VI) by polyethyleneimine-modified bamboo hydrochar.

Hydrochar is an environmentally friendly and cheap adsorbent, but its adsorption amounts for anions is very limited. The functionalized hydrochar can overcome this shortcoming. Herein, polyethyleneimine-modified hydrochar (PEI-HC) was synthesized from hydrothermal carbonization (HTC) of methyl acrylate and bamboo after addition of initiator ammonium persulfate, and then modified by polyethyleneimine (PEI), which was used to treat Cr(VI). PEI-HC was tested by XANES, EXAFS, SEM-EDS, XPS, FTIR, N2 sorption isotherms, zeta potential, and elemental analyses. The characterizations showed that PEI was successfully grafted onto hydrochar, and the PEI-HC was rich in N and O functional groups, which presented high Cr(VI) sorption ability (528.41 mg·g-1 at pH 2). The bath experiments found the pseudo-second-order kinetic and Freundlich equations can well describe the adsorption kinetics and isotherm of the Cr(VI) adsorption onto PEI-HC, respectively. Electrostatic interaction, reduction, complexation, and H-bonding are the main removal mechanisms as supported by XANES, EXAFS, XPS, and FTIR. This study provides a strategy of combining HTC and free radical graft polymerization to convert agricultural and forestry wastes into functionalized hydrochar, showing highly efficient removal of Cr(VI).

Instant strong adhesion of ultrafast gelling tough nanocomposite hydrogels for antifogging coatings and soft electronics

Tough hydrogels capable of achieving instant and strong adhesion to diverse surfaces are highly desirable for various applications such as soft electronics and antifogging coatings. However, existing hydrogel adhesives currently suffer from several limitations including slow adhesion formation, weak bonding, and poor mechanical properties. Herein, we present that strong adhesion of tough nanocomposite hydrogels can be realized instantly by rapid copolymerization of precursor solution within seconds under ambient conditions. Such tough hydrogels possessing ultrashort gelation time were prepared based on self-catalytic Fe3+/tannic acid redox pairs, which could activate ammonium persulfate initiator to generate abundant sulfate radicals to trigger ultrafast copolymerization of N, N-dimethylacrylamide (DMAA) and acrylic acid (AA) in the presence of Al(OH)3 nanoparticles. The resultant hydrogels exhibit excellent mechanical properties including tensile strength of ∼1.0 MPa and compressive strength of ∼15.0 MPa, high adhesion energy of ∼1200 J m− 2, and good conductivity of 0.72 S/m. Benefiting from these features, the sustainable antifogging hydrogel coatings on diverse transparent substrates can be fabricated easily based on the combined advantages of ultrafast polymerization and instant strong adhesion. Furthermore, the conductive hydrogels can be assembled into flexible strain sensors to monitor various human motions and handwriting recognition. This work provides a promising strategy to design high-performance hydrogels with instant strong adhesion, antifogging properties, and strain sensing.

Synthesis and Performance Evaluation of Alginate-Coated Temperature-Sensitive Polymer Gel Microspheres.

With the long-term water-flooding development of the reservoir, the non-homogeneity of the formation is increasing and the reservoir environment is deteriorating; the microspheres used for deep plugging have shown disadvantages, such as poor temperature and salt resistance and faster expansion. In this study, a polymeric microsphere was synthesized that is resistant to high temperature and high salt and can achieve slow expansion and slow release for deep migration. P(AA-AM-SA)@TiO2 polymer gel/inorganic nanoparticle microspheres were prepared by reversed-phase microemulsion polymerization using acrylamide (AM) and acrylic acid (AA) as monomers, 3-methacryloxypropyltrimethoxysilane (KH-570)-modified TiO2 as the inorganic core, and sodium alginate (SA) as a temperature-sensitive coating material. Through single-factor analysis of the polymerization process, the optimal synthesis conditions were determined as follows: the oil(Cyclohexane)-water volume ratio was 8:5, the emulsifier mass ratio (Span-80:Tween-80) was 3:1 (10 wt% of the total system amount), the stirring speed was 400 r/min, the reaction temperature was 60 °C, and the initiator (ammonium persulfate and sodium bisulfite) dosage was 0.6 wt%. The size of the dried polymer gel/inorganic nanoparticle microspheres prepared by the optimized synthesis conditions was 10~40 μm with uniform particle size. The observation of P(AA-AM-SA)@TiO2 microspheres reveals that the Ca elements are uniformly distributed on the microspheres, and FT-IR indicates that the synthesized product is the target product. TGA shows that the polymer gel/inorganic nanoparticle microspheres have better thermal stability after the addition of TiO2, with a larger mass loss at 390 °C, which can adapt to the medium-high permeability reservoir environment. The thermal and aqueous salinity resistance of the P(AA-AM-SA)@TiO2 microspheres was tested, and the cracking temperature of P(AA-AM-SA)@TiO2 microsphere temperature-sensitive material was 90 °C. It still has favorable water absorption and swelling performance under the sodium salt concentration of 2.5 × 104 mg/L and can tolerate calcium salt up to 2.0 × 104 mg/L. Plugging Performance Test results show that the microspheres have good injectability between the permeability of 1.23 and 2.35 μm2 and good plugging effect near the permeability of 2.20 μm2. At high temperature and high salinity, P(AA-AM-SA)@TiO2 microspheres have a remarkable effect on profile control and water shutoff, the plugging rate reaches 95.3%, and the oil recovery rate is increased by 12.89% compared with water flooding, achieving the effect of slow swelling and slow release.

Polypyrrole-Modified Molybdenum Disulfide Nanocomposite Epoxy Coating Inhibits Corrosion of Mild Steel

The search for lightweight and low-cost anticorrosion coatings is particularly important in coastal environments with high salt and humidity. Graphene-based anticorrosion coatings are currently unable to provide long-lasting corrosion protection for metals because of their “corrosion-promoting activity”, and graphene-like materials, such as molybdenum disulfide (MoS2), are beginning to be anticipated its ability to protect against metals. This paper reported a simple method for preparing polypyrrole (PPy)-modified MoS2 nanomaterials from natural bulk MoS2. Their corrosion resistance behavior as fillers for epoxy (EP) resins was investigated in 3.5 wt.% NaCl solution. After the preparation of the MoS2 nanosheet dispersion by liquid-phase sonication using ethanol aqueous solution, the polypyrrole-coated molybdenum disulfide nanomaterials (MoS2@PPy) were directly obtained by adding pyrrole monomer to it in the presence of the initiator ammonium persulfate. Tafel polarization curves showed that the corrosion current of the MoS2@PPy/EP coating was 0.006 µA/cm2 after 15 days of immersion in 3.5 wt.% NaCl solution, much lower than that of pure EP coating (19.134 µA/cm2), effectively improving the anticorrosive properties of the coating. Overall, this study offered a practical method for the application of natural bulk MoS2 for corrosion protection.

Synthesis of cross‐linked diazaborine‐based polymeric microparticles with antiquorum sensing, anti‐swarming, antimicrobial, and antibiofilm properties

AbstractTransmission of infectious diseases and resistance by microorganisms is a global health threat. Antimicrobial polymers are increasingly being developed as biocides with greater applications than traditional antibiotics. In this study, 3‐(potassiumsulfonyl)propyl methacrylate (SPMA) monomer, ethylene glycol dimethacrylate cross‐linker and ammonium persulfate initiator were reacted to yield poly[3‐(potassiumsulfonyl)propyl methacrylate] microgels (PSPMA). Surface modification of PSPMA with thionyl chloride yielded poly[3‐(chlorosulfonyl)propyl methacrylate microparticle] (PSPMA‐Cl) which was reacted with hydrazinehydrate to obtain poly[3‐(hydrazinylsulfonyl)propyl methacrylate] microparticles (PSPMA‐NH2). Finally, 2‐formyl benzeneboronic acid was added to give the final product poly[3‐((1‐hydroxybenzo(d)(1,2,3)diazaborinin‐2(1H)‐yl)sulfonyl)propyl methacrylate] (PSPMA‐DAZ) microparticles. The modified microparticles were characterized using attenuated total reflectance‐Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and energy‐dispersive x‐ray analyses. The polymeric microparticles showed good antibiofilm activity against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Candida albicans ATCC 10239 and Candida tropicalis ATCC 13803 while low to moderate biofilm inhibitions were observed against Listeria monocytogenes ATCC 7644, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853 and Salmonella typhi ATCC 14028. Surface group modification from PSPMA, PSPMA‐Cl, PSPMA‐NH2 to PSPMA‐DAZ increased violacein inhibition, quorum‐sensing inhibition and antimicrobial activity but reduced swarming. These polymer microparticles can be used to reduce spread of microbial infections and resistance.

A Novel Cationic Polymer Surfactant for Regulation of the Rheological and Biocidal Properties of the Water-Based Drilling Muds.

The copolymer of N,N-diallyl-N,N-dimethylammonium chloride and N-[3-(Dimethylamino)propyl]methacrylamide (DADMAC-DMAPMA) was synthesized by radical polymerization reaction in an aqueous solution in the presence of the initiator ammonium persulfate (NH4)2S2O8. The molar compositions of the synthesized copolymers were determined using FTIR and 1H NMR-spectroscopy, elemental analysis, and conductometric titration. It was found that in the radical copolymerization reaction, the DMAPMA monomer was more active than the DADMAC monomer; for this reason, the resulting copolymers were always enriched in the DMAPMA monomers. The study of the influence of the DADMAC-DMAPMA copolymer on structure-formation in the bentonite suspension showed that this copolymer significantly increased the static shear stress (SSS) of the system. In this case, the structure-forming properties of the copolymer depended on the pH of the medium. The lower the pH level, the better the structure-formation was in the suspension in the presence of the copolymer. The study of antibacterial activity showed that the DADMAC-DMAPMA copolymer had a biocidal effect against sulfate-reducing bacteria (CRB) at a concentration of not less than 0.05 wt.% and can be used to inhibit the growth of this bacteria.

Synthesis and performance evaluation of carboxyl‐rich low phosphorus copolymer scale inhibitor

AbstractA novel low phosphorus terpolymer scale inhibitor P(IA‐MA‐SHP) was prepared by aqueous free radical polymerization using itaconic acid (IA), maleic acid (MA), and sodium hypophosphite (SHP) as raw materials. It was mainly used as an efficient scale inhibitor to inhibit CaCO3. The structures of the copolymers were characterized by Fourier transform infrared,1H‐NMR, and13C‐NMR, and the thermal properties, and scale sample crystal structure morphology of the copolymers were analyzed by thermogravimetric analysis, x‐ray diffraction (XRD), and scanning electron microscope (SEM). The effects of dosage, monomer ratio, temperature, and reaction time on the scale inhibition effect were investigated, and the optimal synthesis conditions were determined. The results show that: when the monomer ratio isn(IA):n(MA) = 1.0:1.0, the mass fraction of SHP is 10%, the amount of ammonium persulfate initiator is 12%, the reaction temperature is 90°C, and the reaction time is 4 h, when the dosage of the agent is 20 mg L−1, the scale inhibition rate of CaCO3is 94.30%, while it also has a favorable inhibitory effect on CaSO4. The results of SEM and XRD show that the copolymer scale inhibitor can distort the lattice and has a favorable adsorption and dispersion effect. In addition, it has a positive effect on controlling the scale.

Fabrication of pH responsive hydrogel blends of chondroitin sulfate/pluronic F-127 for the controlled release of ketorolac: its characterization and acute oral toxicity study

Objective Ketorolac tromethamine (KT), selected as a model drug, is used in management of moderate to severe acute pain. It has a short half-life (∼5.5 h) and requires frequent dose administration when needed for longer period of time. In our current project, we designed pH responsive hydrogel blends of chondroitin sulfate/pluronic F-127 (CS/Pl) for the controlled release of ketorolac. Methods Hydrogel blends were fabricated using free radical polymerization reaction technique utilizing different ratios of chondroitin sulfate (CS) (polymer) and pluronic F-127 (polymer), acrylic acid (monomer), N,N′-methyl-bisacrylamide (MBA) (cross-linker), initiator ammonium persulfate (APS) and tween-80 (surfactant). The fabricated hydrogel blends were studied and evaluated for pH responsiveness, swelling, water absorbency, in vitro drug release, and morphological characteristics such as SEM, XRD, FTIR, and TGA/DSC. Acute toxicity study was performed on rabbits. Results Maximum swelling and water absorbency were shown by CS/Pl blends being significantly greater at 7.4 (basic pH) than in 1.2 (acidic pH). In vitro dissolution demonstrated pH responsive controlled KT release following zero order at higher pH (7.4) medium up to 36 h. FTIR studies confirmed the structures of our blends; SEM results showed porous framework; thermal studies revealed higher stability of hydrogels than the individual polymers; and XRD confirmed the nature of our blends. Toxicity study revealed the nontoxic nature of the hydrogel blends. Conclusion The prepared CS/Pl hydrogels demonstrated stimuli-controlled release with delivery of drug for prolonged period of time and thus can minimize dosing frequency, safe drug delivery, increased patient compliance and easiness.

Rapid removal of anionic organic dye from contaminated water using a poly(3-aminobenzoic acid/graphene oxide/cobalt ferrite) nanocomposite low-cost adsorbent via adsorption techniques

This research study aims to remove hazardous anionic azo dyes (Congo red (CR)) from aqueous solutions via a simple adsorption method using a poly(3-aminobenzoic acid/graphene oxide/cobalt ferrite) nanocomposite (P3ABA/GO/CoFe2O4) as a novel and low-cost nanoadsorbent, as synthesized by a simple and straightforward polymerization method. Typically, 3-aminobenzoic acid (3ABA), as monomer, was chemically polymerized with graphene oxide (GO) and cobalt ferrite (CoFe2O4) in an aqueous acidic medium containing an ammonium persulfate initiator. The adsorbent P3ABA/GO/CoFe2O4 nanocomposite was characterized using various techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, energy-dispersive analysis by X-ray and Brunauer–Emmett–Teller, vibrating sample magnetometer, and zeta potential techniques. These techniques confirmed the interaction between the poly(3-aminobenzoic acid) with GO and CoFe2O4 due to the presence of π-π interactions, hydrogen bonding, and electrostatic forces. Herein, the removal efficiency of dye from aqueous solution by the adsorbent was studied according to several parameters such as the pH of the solution, dye concentration, dosage of adsorbent, contact time, and temperature. The adsorption of the dye was fitted using a Langmuir model (R2 between 0.9980 and 0.9995) at different temperatures, and a kinetic model that was pseudo-second order (R2 = between 0.9993 and 0.9929) at various initial concentrations of CR dye. In addition, the data revealed that the P3ABA/GO/CoFe2O4 nanocomposite exhibited a high adsorption capacity (153.92 mg/g) and removal for CR dye (98 %) at pH 5. Thermodynamic results showed the adsorption process was an endothermic and spontaneous reaction. It was found that, in terms of reusability, the P3ABA/GO/CoFe2O4 adsorbent can be used for up to six cycles. In this study, P3ABA/GO/CoFe2O4 nanocomposites were found to be low cost, and have an excellent removal capability and fast adsorption rate for CR from wastewater via a simple adsorption method. Moreover, this adsorbent nanocomposite could be simply separated from the resultant solution and recycled.

In-vitro and in-vivo evaluation of biocompatible polymeric microgels for pH- driven delivery of Ketorolac tromethamine

The aim of the current study was to prepare glutamic acid crosslinked poly(itaconic acid/methacrylic acid) microgels for pH-responsive delivery of ketorolac tromethamine, using aqueous free radical polymerization technique. The polymerization of polymer with monomers was carried out by a crosslinking agent N′, N′-methylene bisacrylamide in the presence of initiator ammonium persulfate. The prepared microgels were characterized for structure, surface morphology, thermal stability, and crystallinity. Similarly, studies such as sol-gel analysis, drug loading, and polymer volume fraction were performed for the fabricated microgels. The pH-sensitivity of the developed microgels was investigated at three different pH values i.e., pH 1.2, 4.6, and 7.4 by swelling and in-vitro drug release studies. Maximum swelling and drug release were found at pH 7.4 as compared to pH 1.2 and 4.6, which indicated the pH-sensitive nature of the prepared microgels. The toxicity of the prepared microgels was evaluated by cell line and HET-CAM test, which demonstrated no toxic effect of the prepared microgels. In-vivo study was carried out on rabbits and high plasma concentration was reported for the drug loaded microgels as compared to drug solution and commercial product Keten. Hence, the prepared microgel system could be employed as an excellent carrier for the controlled drug delivery system.

Delaminasi Perekat Polivinil Asetat Berbasis Air Satu Komponen untuk Aplikasi Kayu Keras Ulin dan Merbau

Water-based adhesive was one of the most important media for bonding substrates to one another because of their environmental friendly character. Previously, in the application of hardwood adhesives such as Ulin and Merbau, the type of adhesive used was a two-component system. For this reason, a one-component water-based adhesive was introduced in this study. The advantage of these was environmental friendly and high durability. In this application, delamination was one of the important parameters to determine whether the adhesive used was well penetrated or not. For this reason, delamination will be the main parameter in this study. This research includes the preparation of tools and materials, manufacture of PVA (polyvinyl alcohol) solution, polymerization of polyvinyl acetate by mixing the main raw material of vinyl acetate monomer and PVOH solution using APS (ammonium persulfate) initiator. The polymerization process was carried out at 1 atm pressure and 75oC – 80oC temperature accompanied by stirring with ±500 rpm rotation rate. Final product is a homopolymer PVAc (polyvinyl acetate) with PVOH Z-210 with AAEM (acetoacetoxy ethyl methacrylate) content having an acetoxy functional group. A delamination test was carried out on the final product with a modified test based on Japanese Agricultural Standard 1152 where the product was immersed in water for 360 minutes, then placed in an oven at 40oC for 18 hours. Samples using PVOH with AAEM content have an average delamination rate of 0.67-1.67% while existing products on the market have an average delamination rate of 45.83-52.08%.

In situ reactive coating of porous filtration membranes with functional polymer layers to integrate boron adsorber property

The state-of-the-art reverse osmosis membranes for seawater desalination have limited competence to efficiently remove boron. One promising approach for boron removal is to integrate membrane-based separation with selective adsorption of boron in pre- or posttreatment of seawater desalination; the porous support layer of established filtration membranes, constituting the largest part of total membrane volume shall be utilized for this function. Therefore, this study focuses on performing in situ modification of commercial polyethersulfone (PES) microfiltration membranes toward reactive coating the pore surface with a boron affinity polymer-based hydrogel. Modification is carried out in two steps: 1) adsorption of an amphiphilic copolymer which contains tertiary amine groups as co-initiator for surface-selective free radical generation; 2) grafting of a hydrogel layer by using a monomer solution comprising polyol-containing monomer as boron ligand, a cross-linker monomer, and the redox initiator ammonium persulfate (APS). The entire modification process is performed under flow-through conditions. Membranes with different pore sizes were modified; modification parameters, such as molar mass of macromolecular co-initiator as well as composition of reactive monomer solution, were systematically varied. It was found that using an “integrated” initiation system with low molecular weight co-initiator N,N,N′,N′-tetraethyl ethylenediamine (TEMED) added to the reactive solution, yielded significantly higher degree of grafting and therefore superior adsorber properties. Boron binding capacity of modified membranes was evaluated in terms of boron adsorption isotherms, adsorption kinetics, break-through behavior under filtration conditions and regeneration of the adsorber. The trade-off between permeance and boron binding capacity of modified membrane was studied in order to identify promising materials with competitive overall separation performance, i.e. high permeance at a specific filter cut-off in combination with high boron binding capacity.

Effect of Different Composition of Polyethylene Oxide‐Polypyrrole (PEO‐PPy) Nanofiber Mats on Antibacterial and Biocompatibility Properties

AbstractElectrospun nanofibers are unique one‐dimensional materials with high surface area to volume ratio which can be used in various applications including in antibacterial application. In this study, we demonstrated a simple fabrication of polyethylene oxide‐polypyrrole (PEO‐PPy) composite nanofibers with antibacterial properties. The polymerization of pyrrole was conducted using ammonium persulfate (APS) initiator at ambient temperature for 24 h. The resulting PEO‐PPy nanofibers were then characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), fourier transform infrared (FTIR), and tensile tests. The morphology of nanofibers observed by SEM revealed that the minimum concentration of PEO was 8 wt% to obtain the bead‐free nanofibers. Meanwhile, variation of pyrrole concentration does not alter the morphology of nanofibers significantly. The crystallinity of the nanofibers increased with increasing the PEO amount indicated by two typical peaks located at 2θ=19° and 23°, respectively. On the other hand, polypyrrole contributed the antibacterial properties significantly to the nanofibers and as a result, the antibacterial activity determined by UV‐Vis spectrophotometer increased dramatically with increasing pyrrole concentration from 0.1 to 0.2, 0.3, 0.4, and 0.5 mM. The electrospun nanofiber mats exhibited good antibacterial properties onE. coliand biocompatibility properties on L929 fibroblasts cell.

Design, Cytotoxicity, and Tumor Targeted Drug Delivery of 5Fluorouracil Encapsulated in pH-Sensitive Co-polymers GG-g-P (HEMA) Conjugate Riboflavin Thin-Film

The study finds the design, cytotoxicity, and tumor-targeted drug delivery of 5Fluorouracil encapsulated in pH-sensitive guar gum grafted polymer. Cancer targeting 5FU loaded GG grafted p(HEMA) conjugated riboflavin thin-film (GG-g-P(HEMA)-RF) was successfully fabricated from guar gum, 2-hydroxy ethyl methacrylate, and riboflavin targeting agents using N, N-methylene bis acrylamide as a crosslinking agent in the presence of tetramethylethylenediamminne (TEMED) initiator Ammonium persulfate act as a catalyst. FT-IR and XRD spectroscopy techniques were used to analyze the structural features of the GG-g-P(HEMA)-RF. The results of SEM revealed that the carrier is of uniform rod shape, with a low porosity index and outstanding performance in phrases of 5FU encapsulation and extended-release ability. Targeted drug delivery strategies have received special attention from the scientific world due to advantages such as more effective therapy and reduction of side effects. Cytotoxicity effects of 5FU loaded GG-g-P(HEMA)-RF against Ehrlich Ascites Carcinoma (EAC) cells in vitro were investigated at different concentrations (0, 25, 50, 100, and 150 μg/mL) using trypan blue exclusion assay. The MTT cytotoxic assay investigated cell viability against EAC experimental models and implied the excellent biocompatibility of the carrier. The results revealed the anti-proliferative effect along with molecular signaling of apoptosis and generated reactive oxygen species (ROS) in Ehrlich Ascites Carcinoma cell lines. The morphological changes of apoptosis were evident in EAC cells and were observed using optical microscopy after staining. DPPH free radical scavenging assay was carried out to determine the radical scavenging activity of the 5FU loaded and unloaded GG-g-P(HEMA)-RF. The 5FU loaded GG-g-P(HEMA)-RF with DNA interaction was examined by electronic and spectroscopic fluorescence methods.