Methylenebisacrylamide Concentration Research Articles

A superabsorbent and pH-responsive copolymer-hydrogel based on acemannan from Aloe vera (Aloe barbadensis M.): A smart material for drug delivery

Combining natural polysaccharides with synthetic materials improves their functional properties which are essential for designing sustained-release drug delivery systems. In this context, the Aloe vera leaf mucilage/hydrogel (ALH) was reacted with acrylic acid (AA) to synthesize a copolymerized hydrogel, i.e., ALH-grafted-Polyacrylic acid (ALH-g-PAA) through free radical copolymerization. Concentrations of the crosslinker N,N′-methylene-bis-acrylamide (MBA), and the initiator potassium persulfate (KPS) were optimized to study their effects on ALH-g-PAA swelling. The FTIR and solid-state NMR (CP/MAS 13C NMR) spectra witnessed the formation of ALH-g-PAA. Scanning electron microscopy (SEM) analysis revealed superporous nature of ALH-g-PAA. The gel fraction (%) of ALH-g-PAA was directly related to the concentrations of AA and MBA whereas the sol fraction was inversely related to the concentrations of AA and MBA. The porosity (%) of ALH-g-PAA directly depends on the concentration of AA and MBA. The ALH-g-PAA swelled admirably at pH 7.4 and insignificantly at pH 1.2. The ALH-g-PAA offered on/off switching properties at pH 7.4/1.2. The metoprolol tartrate was loaded on different formulations of ALH-g-PAA. The ALH-g-PAA showed pH, time, and swelling-dependent release of metoprolol tartrate (MT) for 24 h following the first-order kinetic and Korsmeyer-Peppas model. Haemocompatibility studies ascertained the non-thrombogenic and non-hemolytic behavior of ALH-g-PAA.

Superabsorbent Hydrogel from Cassava Waste Pulp – Acrylamide – Acrylic Acid to Increase Water Holding Capacity in Sandy Soils

In this investigation, a superabsorbent hydrogel was produced from cassava waste pulp (CWP) and acrylic acid (AA) – acrylamide (AAm) in a ratio of 2:1.5:1 (CWP:AA:AAm) by grafting and crosslinking methods. The grafting procedure is initiated with ammonium persulfate (APS) at a concentration of 1%. In this study, cross-linked structures were produced using several concentrations of methylene bisacrylamide (MBA) (0%, 0.5%, 1%, and 1.5%). The impact of MBA concentration on the properties of the superabsorbent hydrogel was observed. The parameters investigated in this study included the equilibrium degree of swelling (EDS), grafting degree, gel fraction, and swelling kinetics (comprising the swelling exponent, swelling constant, and diffusion coefficient). Following this, the hydrogels were sprinkled into sandy soil with the purpose of examining the effects of hydrogel incorporation on the soil’s water holding capacity. The sample with a concentration of 0.5% MBA yielded the highest EDS at 9178% (g/g), as determined by the results. The gel fraction value obtained for the sample was 81.04% (g/g) and the crosslink density of this sample was measured to be 2.78 × 1023 m-3, while the maximal water holding capacity was found to be 54.16%.

Formulation and Characterization of Polymeric Cross-Linked Hydrogel Patches for Topical Delivery of Antibiotic for Healing Wound Infections.

Wound healing faces significant challenges in clinical settings. It often contains a series of dynamic and complex physiological healing processes. Instead of creams, ointments and solutions, alternative treatment approaches are needed. The main objective of the study was to formulate bacitracin zinc-loaded topical patches as a new therapeutic agent for potential wound healing. A free radical polymerization technique was optimized for synthesis. Polyethylene glycol-8000 (PEG-8000) was chemically cross-linked with acrylic acid in aqueous medium, using Carbopol 934 as a permeation enhancer and tween 80 as surfactant. Ammonium persulfate and N,N'-Methylenebisacrylamide (MBA) were utilized as initiator and cross-linker. FTIR, DSC, TGA, and SEM were performed, and patches were evaluated for swelling dynamics, sol-gel analysis, in vitro drug release in various media. A Franz diffusion cell was used for the permeation study. Irritation and wound healing with the drug-loaded patches were also studied. The characterization studies confirmed the formation of a cross-linked hydrogel network. The highest swelling and drug release were observed in formulations containing highest Polyethylene glycol-8000 and lowest N,N'-Methylenebisacrylamide concentrations. The pH-sensitive behavior of patches was also confirmed as more swelling, drug release and drug permeation across skin were observed at pH 7.4. Fabricated patches showed no sign of irritation or erythema as evaluated by the Draize scale. Faster wound healing was also observed with fabricated patches compared to marketed formulations. Therefore, such a polymeric network can be a promising technology for speeding up wound healing and minor skin injuries through enhanced drug deposition.

Adsorptive removal of cationic dye by synthesized sustainable xanthan gum-g p(AMPS-co-AAm) hydrogel from aqueous media: Optimization by RSM-CCD model

This research aims to treat toxic methylene blue (MB) dye from contaminated water due to its harmful effects on human health and the environment. For this purpose, xanthan gum-based hydrogel was prepared by grafting acrylamide (AAm) and 2-acrylamido-2-methly propane sulfonic acid (AMPS) onto xanthan gum (XG) with methylene bis acrylamide (MBA) as a crosslinking agent. With the introduction of sulfonate and carboxylate groups, the XG molecules were rearranged with better regularity, and based on rheology analysis; higher mechanical stability was approved. The central composite design (CCD) experimental design was used to evaluate the main and interaction effects of the independent hydrogel composition parameters (AMPS, AAm, and MBA concentration) and to derive a model from predicting optimization of the hydrogel composition to remove methylene blue (MB) dye. Accordingly, the concentrations of AAm (6 wt%), AMPS (4.09 wt%), and MBA (0.12 wt%) was found to be the optimum amount for the prepared pH-sensitive adsorbent to remove 98.85% of MB from an aqueous solution using CCD-RSM optimization. The fabrication of hydrogel and its interaction with monomers was specified by FTIR, TGA, rheology, FESEM, and ESEM techniques. The high porosity of hydrogel when swelled was confirmed based on ESEM images. A pseudo-first-order model and Langmuir isotherms best described the adsorption kinetics and adsorption equilibrium, respectively. The maximum equilibrium adsorption capacity of MB was obtained at 384.62 mg/g. The thermodynamic parameters indicated that the adsorption is endothermic and a process that increases irregularity. The hydrogel was regenerated for up to five cycles without significant reduction.

The Release of Fertilizer on Corncob Cellulose – Based Acid-Acrylamide Hydrogel Prepared by Chemical Cross-Binding Method

Farmers' knowledge of the amount and dosage of fertilizers recommended for a practical fertilization system is low. As the result, the plant does not fully absorb the given fertilizer. Some fertilizers are leached by the flowing water and wasted into the soil layer. In long term basis, this practice can cause environmental pollution, especially on the land, water and air. Due to this fertilization problem in agriculture practice, a material with a high-water absorption capacity, which further releases it together with the fertilizer over a desirable period of time, is needed. One way to effectively provide water and nutrients to the plants and improve the physical and chemical properties of the fertilizzer is by the application of hydrogel. In this work, the release of urea fertilizer in a hydrogel-based on corncob cellulose was prepared using N, N'-Methylene Bis-acrylamide (MBA) as a crosslinker was studied. This research aims to produce a hydrogel with good physical and mechanical properties using acrylamide based on corn cobs cellulose and can be applied as a fertilizer carrier matrix whose structure can regulate fertilizer release. The treatments tested were MBA concentrations of 0%, 1%, and 2%, while the ratio of cellulose: solvent was 1: 2 and the addition of urea fertilizer with a concentration of 5%. The results showed that the swelling value increased with increasing acrylamide in the treatment ratio of the concentration of cellulose: acrylamide-acrylamide (NS: AAm). Fertilizer factors also gave a good swelling value. This shows that the addition of fertilizers gives maximum results. The hydrogel with the best treatment, namely the concentration ratio of 1% MBA, produced a swelling value of 7633.3%, a gel fraction of 76.51%, 1.73 miligram fertilizer loading, fertilizer release by 2.9%, a hardness of 7,865 N, with the morphology showing urea crystals in the form of white spots and showing the results of a slow but optimum release rate of fertilizer so that it can be applied for agriculture that requires a lot of nutrients at the beginning of growth.Keywords: corncorb; cellulose; hydrogel; N’,N’-Methylene Bis-acrylamide (MBA), slow released fertilizer

Fabrication and Characterization of Diclofenac Sodium Loaded Hydrogels of Sodium Alginate as Sustained Release Carrier.

The aim of the current study was to fabricate naturally derived polymer based hydrogels for controlled release of diclofenac sodium (DS) for a long duration of time. In this research work, sodium alginate-co-poly(2-acrylamido-2-methyl propane sulphonic acid) (SA-co-poly(AMPS)) hydrogels were prepared by the free radical polymerization technique, where sodium alginate (SA) and 2-acrylamido-2-methyl propane sulphonic acid (AMPS) were used as the polymer and monomer while ammonium peroxodisulfate (APS) and N,N′-Methylene bisacrylamide (MBA) were used as the initiator and cross-linker, respectively. A swelling study was performed to determine the swelling index of developed hydrogels in both acidic (pH 1.2) and basic (pH 7.4) media and pH-independent swelling was observed due to the presence of AMPS. An in vitro release study was conducted to evaluate the percentage of drug released, and a high release of the drug was found at the higher pH of 7.4. Sol–gel analysis was performed to analyze the crosslinked and uncrosslinked part of the hydrogels, and results showed a rise in gel fraction as the composition of SA, AMPS and MBA increased while the sol fraction decreased and vice versa. This work demonstrated a potential for sustained delivery of diclofenac sodium by employing various concentration of SA, AMPS and MBA.

Hydroxypropyl Methylcellulose-Based Hydrogel Copolymeric for Controlled Delivery of Galantamine Hydrobromide in Dementia

The study aims to prepare a smart copolymeric for controlled delivery of Galantamine hydrobromide. The synthesis of the hydrogel was executed through free radical polymerization using HPMC (Hydroxypropyl methylcellulose) and pectin as polymers and acrylic acid as monomer. Cross-linking was performed by methylene bisacrylamide (MBA). HPMC-pectin-co-acrylic acid hydrogel was loaded with Galantamine hydrobromide (antidementia drug) as a model drug for treatment of Alzheimer based dementia. Formulated hydrogels (SN1–SN9) were characterized for Fourier transform-infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and energy dispersive X-ray. Drug loading efficiency, gel fraction, measurements of porosity, and tensile strength were reported. Swelling and release studies were performed at pH 1.2 and 7.4. Drug liberation mechanism was evaluated by applying different release kinetic models. Galantamine hydrobromide was released from prepared hydrogels by Fickian release mechanism. Swelling, gel fraction, porosity, and drug release percentages were found to be dependent on hydroxypropyl methylcellulose, pectin, acrylic acid, and methylene bisacrylamide concentrations. By increasing HPMC amount, swelling was increased from 76.7% to 95.9%. Toxicity studies were conducted on albino male rabbits for a period of 14 days. Hematological and histopathological studies were carried out to evaluate safety level of hydrogel. Successfully prepared HPMC-pectin-co-acrylic acid hydrogel showed good swelling and release kinetics, which may help greatly in providing controlled release drug effect leading to enhanced patient compliance for dementia patients.

Design and in vitro evaluation of pH-sensitive crosslinked chitosan-grafted acrylic acid copolymer (CS-co-AA) for targeted drug delivery

In current research study, novel chitosan-based hydrogel was formulated via crosslinking graft copolymerization of acrylic acid (AA) and chitosan. Potassium persulfate was used as free radical generator in the presence of crosslinker (methylene bis acrylamide (MBA)). FTIR spectroscopy was employed to elucidate structure of hydrogel. Moreover, sample morphology was examined by scanning electron microscopy (SEM) and thermal analysis was conducted by using thermogravimetric analysis (DSC/TGA). The influence of reaction variables such as concentration of chitosan (CS), acrylic acid (AA) and MBA was optimized to attain hydrogel with significant swelling capacity. Chitosan-g-AA hydrogel depicted pH responsive attributes and swelling–deswelling pulsatile behavior was recorded at pHs 1.2 and 7.4. This on–off switching makes hydrogel ideal candidate for controlled drug delivery.

Encapsulation of pectinase within polyacrylamide gel: characterization of its catalytic properties for continuous industrial uses

Pectinase as a biocatalyst play a significant role in food and textile industries. In this study, the pectinase was immobilized by encapsulation within polyacrylamide gel to enhance its catalytic properties and ensure the reusability for continuous industrial processes. 9.5% acrylamide and 0.5% N, N′- methylenebisacrylamide concentration gave high percentage of pectinase immobilization yield within gel. The catalytic properties of immobilized pectinase was determined with comparison of soluble pectinase. The immobilization of pectinase within polyacrylamide gel didn't effect catalytic properties of pectinase and both the free and immobilized pectinase showed maximum pectinolytic activity at 45 °C and pH 10. The Michaelis-Menten kinetic behavior of pectinase was slightly changed after immobilization and immobilized pectinase showed somewhat higher Km and lower Vmax value as compared to soluble pectinase. Polyacrylamide gel encapsulation enhanced the thermal stability of pectinase and encapsulated pectinase showed higher thermal stability against various temperature ranging from ranging from 30 °C to 50 °C as compared free pectinase. Furthermore, the surface topography of polyacrylamide gel was analyzed using scanning electron microscopy and it was observed that the surface topography of polyacrylamide gel was changed after encapsulation. The encapsulation of pectinase within polyacrylamide gel enhanced the possibility of reutilization of pectinase in various industries and pectinase retained more than 50% of its initial activity even after seven batch of reactions.

Dextran-graft-poly(hydroxyethyl methacrylate) biosorbents for removal of dyes and metal cations

Dextran-graft-poly(hydroxyethyl methacrylate) gels were prepared and used as a biosorbent for removal of dyes and heavy metal cations. For this propose, the effects of three main parameters during the preparation of gels including concentrations of monomer (hydroxyethyl methacrylate), the crosslinking agent (N,N’-methylenebisacrylamide (MBA)) and initiator (ammonium persulfate) on their swelling and absorbability of dyes and heavy metal cations were investigated. Methylene blue (MB) and rose bengal (RB) as model dyes and Fe(III) and Cu (II) as model metal cations were selected. Increasing the poly(hydroxyethyl methacrylate) content within the gels resulted in higher Equilibrium water absorption (EWA) values and consequently better dye and cation adsorption. Higher concentration of MBA led to lower dye adsorption values. Increasing the ammonium persulfate (APS) concentration did not change significantly the dyes and metal cations adsorption. The results indicated that this biosorbents system could be potentially used in the removal of heavy metal and dye from wastewater.

Selective removal of cationic dyes using response surface methodology optimized gum acacia-sodium alginate blended superadsorbent

Gum acacia and sodium alginate were blended to synthesize highly efficient superadsorbent formed by grafting of poly(acrylic acid) (AA) used as monomer onto the hybrid of gum acacia and sodium alginate and the polymeric chains were crosslinked through N,N′-methylene bisacrylamide (MBA). The overall reaction followed free radical polymerization with ammonium persulphate (APS) used as initiator. Response surface methodology integrated with central composite design (RSM-CCD) could synthesize semi-Interpenetrating network (semi-IPN) having maximum swelling capacity of 1749.2% at MBA, APS and AA concentrations of 0.89 × 10−2 mol L−1, 3.29 × 10−2 mol L−1 and 1.46 mol L−1, respectively using 15 mL water at 70 °C for 2.5 h. The synthesized sample was found to be selective for removal of cationic dyes upto 97.49%, 95.39% and 94.56% for auramine-O (AO), malachite green (MG) and crystal violet (CV), respectively. Adsorption capacities at equilibrium were calculated experimentally as 2.01 mg g−1, 3.06 mg g−1 and 7.55 mg g−1 for AO, MG and CV, respectively. These dyes could be desorbed with 0.1 N HCl for the recyclization of semi-IPN. Adsorption mechanism involved monolayer formation with three step process of adsorption and followed first order kinetics. Exothermic nature of adsorption was revealed by thermodynamic studies.

Research and development of foamed gel for controlling the spontaneous combustion of coal in coal mine

A new kind of compound material—foamed gel composed of compound foaming agent (CFA) and high water absorbency gel (HWAG) and formed by physical and mechanical stirring—for controlling the spontaneous combustion of coal in coal mine was researched and developed. It makes use of the all-around properties of foam and gel to control the spontaneous combustion of coal in coal mine. The composition, preparation, and controlling mechanisms of foamed gel were analyzed. To optimize the characterizations of the foamed gel, the optimal CFA concerning foaming ability and mixed ratios of single foaming agents, mass concentration, and salt-resistance performance as well as the optimal HWAG concerning optimal synthesis parameters, Fourier transform infrared spectroscopy, thermogravimetric property, and foam stability were analyzed. Meanwhile, characterizations including microstructure and controlling spontaneous combustion of coal of foamed gel were studied. The results were best when the mass fraction of compound of modification alkyl polyglucoside (APG) and sodium dodecyl sulfate (SDS) is 0.9%, the mixed ratio of APG versus SDS is 4:1, the mass fraction of HWAG is 0.4%, and methylenebis acrylamide concentration, ammonium persulfate concentration, and mass fraction ratio of soluble starch:acrylic acid of HWAG synthesis are 0.05%, 0.5%, and 1:10, respectively. This is the ideal foamed gel. The success preparation of foamed gel and the microstructures differences between CFA and foamed gel are confirmd by the microstructures analysis results of CFA and foamed gel simultaneously. Moreover, foamed gel can effectively seal air leakages, prolong moisturizing time of coal, markedly enhance cooling effect on coal of moisture, and efficaciously reduce the rate of coal oxidation reaction and the heating rate to control the spontaneous combustion of coal in coal mine.

An improved method for the durability of the flame retardant PA66 fabric

This paper describes an attempt in order to improve the durability of the flame retardant polyamide 66 (PA66) fabric prepared by the reaction of surface photografting with acrylamide (AM) under UV irradiation. In this study, N,N′-methylene bisacrylamide (MBAAm) combined with acrylamide has been used as a photosensitive monomer during flame retardant finishing of the PA66 fabric sample. “Durable efficiency” has been introduced to evaluate the durability of AM/MBAAm-g-PA66 fabric after 50 times washing with the 0.5 % commercial grade detergent solution. The result indicates that durable efficiency reaches its maximal value of 94.5 % when the MBAAm concentration is 5.0 mass%. The effect of MBAAm on the flame retardancy, thermal stability and tensile properties of the treated PA66 fabric has been investigated, respectively. And an interesting phenomenon shows that although MBAAm could improve the thermal stability of the treated fabric significantly at high temperature, it could have a negative effect on the flame retardancy and tensile properties of the fabric sample when its concentration is high. Its possible mechanism has been discussed here.

The effect of cross-linker concentration on the physical properties of poly(dimethyl acrylamide-co-stearyl acrylate)-based shape memory hydrogels

Chemically cross-linked shape memory hydrogels were synthesized, and their physical properties were studied. The gels were made from a hydrophilic monomer, i.e., N,N-dimethyl acrylamide (DMAA), and a hydrophobic monomer, i.e., stearyl acrylate (SA). The properties were characterized by varying the concentration of the cross-linker methylene bisacrylamide (MBAA), whereas the concentrations of other chemical components were held constant. It was observed that the mechanical properties strongly depended on the cross-linker concentration. The cross-linked hydrogels showed improved toughness compared to the hydrogel counterparts without cross-linking. Thermal properties were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC spectra of dried samples exhibited a complex crystalline nature, while swollen samples showed homogeneous crystallinity. The experimental results of DSC and TGA suggested that there was no significant influence of MBAA concentration on the crystallinity and thermal properties of swollen SMG hydrogels.

Poly(acrylamide) microgel-reinforced poly(acrylamide)/hectorite nanocomposite hydrogels

Abstract The relatively poor mechanical strengths of ordinary hydrogels confine their extensive practical applications in many areas. In this work, we fabricated the poly(acrylamide) (PAAm)/hectorite (Laponite ® XLS) double-network (DN) hydrogels containing neutral PAAm microgels, which displayed higher strength than the hydrogels without PAAm microgels. The mechanical strength was up to 110 KPa with 2 wt% hectorite and 0.028% N , N ′-methylenebisacrylamide (MBAA). In the hydrogel system, the continuous phase was loosely physical crosslinked PAAm/hectorite matrix, while the disperse phase was rigidly chemical crosslinked PAAm microgels. Then we further explored the influence of microgel concentration, hectorite concentration, MBAA concentration on the mechanical behavior of the hydrogels. Meanwhile, the effect of the microgel concentration on the swelling ratio of the hydrogels was investigated. These results showed that the microgels increased the crosslinking degree and formed DN microgels in the novel microgel-reinforced nanocomposite (NC) hydrogel network, which might be potential materials for further applications in biological area.

Hydrophilic modification of poly(vinylidene fluoride) ultrafiltration membranes by surface UV photo-grafting with N,N′-methylene-bisacrylamide as monomer and Ce(IV) as initiator

A UV photo-grafting method was utilised to enhance the hydrophilicity and anti-fouling property of self-made poly(vinylidene fluoride) (PVDF) ultrafiltration membranes. N,N′-methylene-bisacrylamide (MBAA) was used as monomer and Ce(IV) was used as initiator to obtain balance between grafting treatment consumption and enhanced performance. MBAA could be grafted onto the surface of pure PVDF membranes through a water-phase grafting method under UV photoradiation. When the MBAA concentration was 0.07 mol/L, the Ce(IV) concentration was 0.04 mol/L, and the irradiation duration was 3 min, the membrane surface was grafted with a sufficient amount of monomer under a UV photoradiation intensity of 5.0 mW/cm2. The water contact angle on the surface of the modified membrane decreased by approximately 16°, and flux recovery increased by approximately 40% compared with the pure PVDF membrane when treating river water. For bovine serum albumin rejection and porosity measurements no significant changes were observed between pure PVDF and graft-treated membranes. The enhanced performance of the modified membrane in this work was moderate, but the UV irradiation duration (3 min) was short. The integrative effects of UV modification in this work were satisfactory when both irradiation duration and enhanced performance were considered.

Synthesis of cellulose-based superabsorbent hydrogels by high-energy irradiation in the presence of crosslinking agent

Superabsorbent hydrogels were prepared from aqueous solutions of four cellulose derivatives (carboxymethylcellulose Na-salt – CMC, methylcellulose – MC, hydroxyethylcellulose – HEC and hydroxypropylcellulose – HPC) by gamma irradiation initiated crosslinking. CMC was used for the majority of the measurements. N,N’-methylene-bis-acrylamide (MBA) crosslinking agent was used to modify the gel properties. The crosslink density increased with the MBA concentration, leading to an improved gel fraction and lower water uptake. The crosslinking efficiency was the highest up to 1 w/wpolymer% MBA concentration. Very high MBA content (10 w/wpolymer%) led to a heterogeneous gel structure. Gelation also occurred under milder conditions in the presence of MBA: good gel properties were achieved at significantly lower doses and solute concentrations as compared to crosslinker-free solutions. The time required to reach maximum water uptake increased with the degree of swelling in equilibrium. Swelling properties of CMC gels with lower water uptake showed lower sensitivity to the ionic strength of the solvent.

Preparation and Characterization of Isosorbide Mononitrate Hydrogels Obtained by Free-Radical Polymerization for Site-Specific Delivery

Purpose: To prepare and characterize acrylic acid and ethyl cellulose hydrogels of isosorbide mononitrate for site-specific delivery.Methods: Free radical polymerization method was employed using benzoyl peroxide as initiator and N, N’-Methylenebisacrylamide (MBA) crosslinked copolymer of ethyl cellulose and acrylic acid. Benzyl peroxide and N, N'-Methylenebisacrylamide in varying amounts were dissolved in acrylic acid. The two solutions were mixed together to a final weight of 100 g. Hydrogels were evaluated for sol-gel characteristics, diffusion coefficient, and porosity. Hydrogel formation was examined by FTIR while drug loading efficiency study was carried out using 1 % (w/v) drug solution.Results: Swelling and drug release decreased with increasing acrylic acid and MBA concentrations due to high degree of crosslinking. Increasing acrylic acid content of hydrogel produced a decrease in drug release from 29.89 to 25.79 %, 75.37 to 67.87 % and 84.91 to 75.85 % at pH 1.2, 6.5 and 7.5, respectively. Remarkably, high swelling was observed at higher pH. Gel fraction and porosity results showed that acrylic acid and crosslinker raised gel fraction but reduced porosity, while ethyl cellulose exhibited a reverse effect. FTIR confirmed graft copolymer formation.Conclusion: Isosorbide mononitrate hydrogels prepared with crosslinked copolymer of ethyl cellulose and acrylic acid can be suitably formulated for targeted delivery of the drug to the small intestine.Keywords: N, N'-Methylenebisacrylamide, Ethyl cellulose, Acrylic acid, Isosorbide mononitrate, Free radical polymerization, Graft copolymer, Site-specific delivery, Hydrogel, pH-sensitive

Adsorption and recognition of protein molecular imprinted calcium alginate/polyacrylamide hydrogel film with good regeneration performance and high toughness

Protein imprinted calcium alginate/polyacrylamide hydrogel film (CA/PAM MIP) with high toughness was prepared using bovine serum albumin (BSA) as template molecule, sodium alginate and acrylamide as functional monomers, N,N′-methylenebisacrylamide (MBAA) as the covalent cross-linker and CaCl2 as the ionic cross-linker via UV radiation-reduced polymerization. Factors affecting the adsorption capacity and imprinting efficiency of the BSA-imprinted CA/PAM hydrogel films were investigated, such as ratio of polyacrylamide/sodium alginate, film thickness, MBAA concentration and CaCl2 concentration. Results showed that the CA/PAM MIP exhibited an obvious improvement in terms of adsorption capacity for BSA compared with non-imprinted polymer (NIP). The adsorption capacity of MIP for BSA reached 22.49mg/g, which was 2.7times higher than NIP. The regeneration property of the BSA-imprinted CA/PAM hydrogel was distinctly improved and the imprinting efficiency of CA/PAM MIP maintained 77.95% of the initial value after five repetitions. Single and binary proteins rebinding indicated that the CA/PAM MIP exhibited good recognition performance. Cell culture experiments showed CA/PAM MIP was more suitable for cell culture than CA/PAM NIP. The residual sodium dodecyl sulfate (SDS) in the elution process leaded to the death of mouse fibroblast cells (L929) after 3days. A moderate elution solution without residue eluent should be used to prepare MIP for cell culture.

Synthesis of a Novel Hydrogel Nanocomposite Coated on Cotton Fabric for Water–Oil Separation

A new cotton-based hydrogel nanocomposite was successfully prepared by free radical graft copolymerization of acrylamide (AAm) and acrylonitrile (AN) onto fabric followed by insertion of Ag nanoparticles. Ammonium persulfate (APS) was used as an initiator in the presence of a cross-linker, methylene bisacrylamide (MBA). Fourier transform infrared, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy were employed to confirm the structure of the hydrogel nanocomposite. Initially, the affecting variables onto graft polymerization (i.e. AAm, AN, MBA, APS, and silver concentrations) were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The resulted nanocomposite exhibits superhydrophilic and superhydrophobic properties. Therefore, the grafted fabric selectively separated water from oil/water mixtures with high separation efficiency. The influences of filter type, percentage of coated hydrogel on cotton, presence of silver nanoparticles, pH of solution, extracted oil type, as well as hydrogel nanocomposite on the separation efficiency of filters were also studied in detail. Moreover, pH of zero point charge (pHzpc) of the hydrogel nanocomposite was determined by alkaline titration method, and a value of 6.5 was obtained.