Swelling and dye sorption studies of AAm/SA hydrogels crosslinked by glutaraldehyde and divinylbenzene

Highly swollen acrylamide (AAm)/sodium acrylate (SA) hydrogels were prepared by free radical solution polymerization in aqueous solution of AAm with SA as comonomer and two multifunctional crosslinkers such as glutaraldehyde (GL) and divinylbenzene (DVB). Water absorption and percentage swelling were determined gravimetrically. The influence of SA content in hydrogels was examined. Percentage swelling ratio of AAm/SA hydrogels was increased up to 2946–12,533%, while AAm hydrogels swelled up to 1326–1618%. The values of equilibrium water content of the hydrogels are between 0.9297–0.9921. Diffusion behavior was investigated. Water diffusion into hydrogels was found to be non‐Fickian in character. Adsorption properties of AAm/SA hydrogels in aqueous thionin solution have been investigated. Finally, the amount of sorbed thionin per gram of dry hydrogel (q_e) was calculated to be 4.81 × 10^?6?11.69 × 10^?6 mol thionin per gram for hydrogels. Removal efficiency (RE%) of the AAm/SA hydrogels was changed range 37.03–68.82%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Radiation synthesis and characterization of poly(N‐vinyl‐2‐pyrrolidone/acrylic acid) and poly(N‐vinyl‐2‐pyrrolidone/acrylamide) hydrogels for some metal‐ion separation

Two different hydrogels, prepared from N‐vinyl‐2‐pyrrolidone/acrylic acid (NVP/AAc) and N‐vinyl‐2‐pyrrolidone/acrylamide (NVP/AAm), were studied for the separation and extraction of some heavy‐metal ions from wastewater. The hydrogels were prepared by the γ‐radiation‐induced copolymerization of the aforementioned binary monomer mixtures. Further modification was carried out for the NVP/AAc copolymer through an alkaline treatment to improve the swelling behavior by the conversion of the carboxylic acid groups into its sodium salts. The thermal stability and swelling properties were also investigated as functions of the N‐vinyl‐2‐pyrrolidone content. The characterization and some selected properties of the prepared hydrogels were studied, and the possibility of their practical use in wastewater treatment for heavy metals such as Cu, Ni, Co, and Cr was investigated. The maximum uptake for a given metal was higher for a treated NVP/AAc hydrogel than for an untreated NVP/AAc hydrogel and was higher for an untreated NVP/AAc hydrogel than for an NVP/AAm hydrogel. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2642–2652, 2004     

Equilibrium swelling studies of highly swollen acrylamide/mesaconic acid hydrogels

Acrylamide/mesaconic acid (AAm/MA) hydrogels were prepared by free radical solution polymerization in aqueous solution of acrylamide (AAm) with mesaconic acid (MA) as comonomer and two multifunctional crosslinkers such as ethylene glycol dimethacrylate (EGDMA) and 1,4‐butanediol dimethacrylate (BDMA). Swelling experiments were performed in water at 25°C, gravimetrically. The influence of mesaconic acid content in hydrogels was examined. Swelling of AAm/MA hydrogels was increased up to 2301% (for containing 20 mg MA and crosslinked by EGDMA) to 3296% (for containing 80 mg MA and crosslinked by BDMA), while AAm hydrogels swelled up to 1330% (crosslinked by BDMA) to 1400% (crosslinked by EGDMA). The values of equilibrium water content of the hydrogels are 0.9301–0.9706. Diffusion behavior was investigated. Water diffusion into hydrogels was found to be non‐Fickian in character. Diffusion coefficients of AAm/MA hydrogels were calculated by the short time approximation and found to be from 38.01 × 10^?6 cm² s^?1 to 182.73 × 10^?6 cm² s^?1. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2253–2259, 2005     

Swelling behavior and determination of diffusion characteristics of acrylamide–acrylic acid hydrogels

In this study, a random copolymer of acylamide and acrylic acid [poly(AAm‐co‐AA)] was prepared by a redox copolymerization method of their aqueous solutions. The effects of initial AAm/AA mole ratio, PEG 4000 content, and N,N′‐methylenebisacrylamide concentration on swelling behavior were investigated in water. Average molecular weights between crosslinks, percentage swelling, swelling equilibrium values, and diffusion/swelling characteristics (i.e., the structure of network constant, the type of diffusion, the initial swelling rate, swelling rate constant) were evaluated for every hydrogel systems. The hydrogels showed mass swelling capabilities in the range 789–1040% (for AAm/AA hydrogels), 769–930% (for AAm/AA hydrogels in the presence of PEG 4000), and 716–1040% (for AAm/AA hydrogels containing different concentrations of the crosslinker). The swelling capabilities of the hydrogels decreased with the increasing AA, PEG 4000, and crosslinker concentrations. The diffusion of water into AAm/AA hydrogels was found to be a non‐Fickian type. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1289–1293, 2004     

Photopolymerized pH‐sensitive semi‐IPN: Synthesis,water uptake analysis,and preliminary drug release study

A series of pH‐sensitive semi‐IPN hydrogels, composed of varying amounts of monomer acrylic acid(AAc), crosslinker N,N′ methylene bisacrylamide, polymer cellulose acetate (CA) were synthesized via photoinitiated polymerization in dimethyl formamide (DMF) medium. The CA/P (AAc) hydrogels were characterized by FTIR, and TG analysis. The equilibrium water uptake data was used to determine various network parameters. For all the samples synthesized, the swelling exponent “n,” initial diffusion coefficient D and average diffusion coefficient D_ave were found to be in the range of 0.51–0.72, 3.16 to 7.14 × 10^?6 cm² min^?1 and 94.16–120.56 cm² min^?1, respectively. The hydrogel demonstrated fair pH‐dependent swelling behavior, with nearly 20% swelling in the medium of pH 1.0 and 615% in the medium of pH 7.4 at 37°C, respectively. The gel showed excellent swelling–deswelling cycles which were interpreted quantitatively by first order kinetic swelling and deswelling models. Finally, the preliminary insulin release study, carried out in the media of varying pH, observed almost 16% release of entrapped drug in the simulating gastric fluid (SGF) of pH 1.0 in first 2 h and nearly 51% in next 6 h in simulating intestinal fluid(SIF) of pH 7.4 at 37°C. POLYM. ENG. SCI., 53:2129–2140, 2013. © 2013 Society of Plastics Engineers     

Temperature‐responsive properties of poly(acrylic acid‐co‐acrylamide)‐graft‐oligo(ethylene glycol) hydrogels

A series of temperature‐ and pH‐responsive hydrogels were prepared from acrylic acid (AAc), acrylamide (AAm), oligo(ethylene glycol)monoacrylate (OEGMA), and oligo(ethylene glycol)diacrylate by varying the AAc:AAm molar ratio and the OEGMA content. Phase‐transition temperatures and swelling ratios of the obtained poly(AAc‐co‐AAm)‐graft‐OEG gels were measured as a function of temperature and pH. At pH < 5, the obvious transition temperatures ranging from 5 to 35°C were obtained as the AAc : AAm molar ratio was varied. The highest transition temperature was obtained at the AAc : AAm ratios of 5 : 5 and 6 : 4, and the sharp transition curves were observed at the AAc : AAm ratios from 5 : 5 to 8 : 2. The transition temperature further increased with increasing OEGMA content. It was suggested that OEG graft chains with a large mobility played an important role for the formation of hydrogen bonding in the hydrogels. The gels prepared here showed obvious reproducibility of the phase transition in response to temperature changes, which suggests the feasibility of their practical applications. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 798–805, 2001     

Behaviors of polyelectrolyte AAm/AMPS/bentonite composite hydrogels in uptake of uranyl ions from aqueous solutions

Uranyl ion (UO₂²⁺) sorption properties of polyelectrolyte composite hydrogels made by the polymerization of acrylamide (AAm) with 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPS) and clay such as bentonite (Bent) were investigated as a function of composition to find materials with swelling and uranyl ion sorption properties. Highly swollen AAm/AMPS hydrogels and AAm/AMPS/Bent composite hydrogels were prepared by free radical solution polymerization in aqueous solutions of AAm with AMPS as co‐monomer and two multifunctional crosslinkers such as ethylene glycol dimethacrylate (EGDMA) and 1,4 butanediol dimethacrylate (BDMA). Swelling experiments were performed in water at 25°C, gravimetrically. The influence of AMPS content in hydrogels was examined. Uranyl ion adsorption from aqueous solutions was studied by batch sorption technique at 25°C. The effect of uranyl ion concentration and mass of AMPS on the uranyl ion adsorption were examined. Finally, adsorption capacity (the amount of sorbed uranyl ion per gram of dry hydrogel) (q) was calculated to be 0.67 × 10⁻³–2.11 × 10⁻³ mol uranyl ion per gram for the hydrogels. Removal effiency of uranyl ions (RE%) was changed range 9.05–29.92%. The values of partition ratio (K_d) of uranyl ions was calculated to be 0.10–0.43 for AAm/AMPS hydrogels and AAm/AMPS/Bent composite hydrogels, respectively. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Water and dye sorption studies of novel semi IPNs: Acrylamide/4‐styrenesulfonic acid sodium salt/peg hydrogels

In this study, it has been investigated that the incorporation of poly(ethylene glycol), (PEG) and 4‐styrenesulfonic acid sodium salt, (NaSS) into acrylamide, (AAm) hydrogel during free radical solution polymerization synthesis. Poly (ethylene glycol)dimethacrylate, (PEGDMA) was used as a multifunctional crosslinker in polymerization. The main purpose of this study was to combine both monomers and a polymer in a new polymeric system. Dye sorption properties of hydrogels and semi IPNs were investigated by using cationic dye such as Union Green B (Janus Green B, UGB). Swelling and sorption studies were carried out at 25°C. For structural characterization, FTIR analysis was made. The equilibrium percentage swelling (S_eq%) ranges are 660–1330% for AAm/NaSS hydrogels and 580–1310% for AAm/NaSS/PEG semi IPNs. To determine the sorption behaviors of cationic dye UGB, some sorption parameters such as sorption capacity (q), adsorption percentage (Ads%) and partition coefficient (K_d) of the hydrogels were investigated. Binding characterization has been studied by Langmuir linearization method. The sorption capacity values of the hydrogel systems were changed between 1.24 × 10^?4 and 4.05 × 10^?4 mol g^?1. The values of Ads% of the hydrogels were changed among 18?67%, and the values of K_d of the hydrogels were between 0.22 and 2.02. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Adsorption of phenazine dyes using poly(hydroxamic acid) hydrogels from aqueous solutions

Swelling and adsorption properties of poly(hydroxamic acid), (PHA) hydrogels in aqueous solutions of some phenazine dyes such as Neutral Red, Safranin T, and Janus Green have been investigated. PHA hydrogels containing N,N′ methylenebisacrylamide or ethyleneglycoldimethacrylate were used in experiments on swelling, diffusion and adsorption of the dyes. The equilibrium swelling (S_eq) values of PHA hydrogels in aqueous solutions of the phenazine dyes were calculated as 2.16–33.25 g g^?1. Swelling kinetic parameters such as initial swelling rate, swelling rate constant, and maximum swelling were found. Dye diffusion into hydrogels was found to be non‐Fickian in character. Diffusion coefficients are ranged 1.32 × 10^?6 cm² s^?1 ? 44.70 × 10^?6 cm² s^?1. Adsorption of the phenazine dyes onto PHA hydrogels was studied by batch technique. PHA hydrogels in the phenazine dye solutions showed the dark coloration. The data was found that Freundlich isotherm model fits. According the Freundlich constants, the adsorption isotherms are of S‐type in Giles classification. All swelling and binding parameters for PHA‐EGDMA were found to be higher than those for PHA‐NNMBA. The type of crosslinker influenced the swelling, binding, and sorption more than the type of dye. Finally, it can be said that PHA hydrogels may be used a sorbent for removal of dyes. POLYM. ENG. SCI., 58:310–318, 2018. © 2017 Society of Plastics Engineers     

Swelling behavior and diffusion studies of high‐water‐retaining acrylamide/potassium methacrylate hydrogels

Poly(acrylamide‐co‐potassium methacrylate) hydrogels were prepared by free‐radical simultaneous polymerization with aqueous solutions of acrylamide (AAm) and potassium methacrylate (KMA) with a redox initiator. The copolymerization was performed with eight different compositions of KMA at a fixed concentration of oil‐soluble crosslinkers, including 1,4‐butanediol diacrylate and ethylene glycol dimethacrylate (EGDMA). For every composition of AAm/KMA copolymer, the percentage swelling, swelling equilibrium, and diffusion characteristics were investigated. The copolymers were further studied for deswelling properties. The power law relationships of the hydrogels were evaluated for variation in terms of saline concentration. The AAm/KMA copolymers were confirmed by IR spectroscopy. Thermal studies of hydrogels were performed with differential scanning calorimetry and thermogravimetric analysis. EGDMA was found to be a better crosslinker for obtaining higher swelling and deswelling properties for the AAm/KMA hydrogels. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1153–1164, 2005     

A new composite sorbent for water and dye uptake: Highly swollen acrylamide/2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid/clay hydrogels crosslinked by 1,4‐butanediol dimethacrylate

A novel type of highly swollen hydrogels based on acrylamide (AAm) with 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPS) and clay such as bentonite (Bent) crosslinked by 1,4‐butanediol dimethacrylate (BDMA) was prepared by free radical solution polymerization in aqueous media. Water uptake and dye sorption properties of polyelectrolyte AAm/AMPS hydrogels and AAm/AMPS/Bent composite hydrogels were investigated as a function of composition to find materials with swelling and sorption properties. FTIR analyses were made. Swelling experiments were performed in water and dye solution at 25°C, gravimetrically. Highly swollen AAm/AMPS and AAm/AMPS/Bent hydrogels were used in experiments on sorption of water‐soluble monovalent cationic dye such as Lauths violet “LV, (Thionin).” Swelling of AAm/AMPS hydrogels was increased up to 1,920–9,222% in water and 867–4,644% in LV solutions, while AAm hydrogels swelled 905% in water and swelling of AAm/AMPS/Bent hydrogels was increased up to 2,756–10,422% in water and 1,200–3,332% in LV solutions, while AAm/Bent hydrogels swelled 849% in water. Some swelling kinetic and diffusional parameters were found. Water and LV diffusion into hydrogels was found to be non‐Fickian in character. For sorption of cationic dye, LV into AAm/AMPS and AAm/AMPS/Bent hydrogel was studied by batch sorption technique at 25°C. The amount of the dye sorbed per unit mass removal effiency and partition coefficient of the hydrogels was investigated. The influence of AMPS content in the hydrogels to sorption was examined. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Swelling behavior of polyelectrolyte complex hydrogels composed of chitosan and hyaluronic acid

Polyelectrolyte complex (PEC) hydrogels composed of various weight ratios of chitosan and hyaluronic acid were prepared. The PEC hydrogels were formed by the reaction of the oppositely charged chitosan polymers. The PEC films swelled in water rapidly, reaching equilibrium within 30 min, and exhibited relatively high swelling ratios, 243–322%, at 25°C. The swelling ratio increased with increasing temperature. The transport phenomena of all PEC samples were non‐Fickian and diffusion and relaxation controlled. The diffusion coefficients of the PEC films ranged from 2.22 × 10^?6 to 10.05 × 10^?6 cm²/s. The activation energy of the polyelectrolyte complexes ranged from 37.14 to 54.58 kJ/mol and proved to be hydrophilic. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1097–1101, 2004     

Simulation and experimental analysis of an intelligent tissue for controlled drug delivery

In this research, an antibiotic was loaded in the composites of polyethylene glycol (PEG), acrylamide (AAm) and acrylic acid (AAc) hydrogels matrices and their drug deliveries were tested. Effect of some parameters on the drug delivery was checked by UV‐spectrophotometer. Temperature enhancement considerably increased hydrogel swelling and the drug release in the AAc and AAm. A dynamic model based on the Maxwell–Stefan equation was developed to model the drug delivery of hydrogels. COMSOL software was also applied to simulate buffer diffusion inside the hydrogels.     

Preparation and swelling behavior of macroporous poly(acrylamide‐co‐sodium methacrylate) superabsorbent hydrogels

Macroporous superabsorbent hydrogels (SAHs) composed of acrylamide (AAm) and sodium methacrylate (NMA) were prepared by aqueous solution polymerization in the presence of a glucose solution. Their swelling capacity was investigated as a function of the concentrations of the glucose solution, sodium methacrylate, crosslinker, initiator, and activator. The porosity of the poly(acrylamide‐co‐sodium methacrylate) superabsorbent hydrogels was confirmed using scanning electron microscopy. The SAHs were characterized by IR spectroscopy. To estimate the effect on the swelling behavior, three types of crosslinkers were employed: N,N′‐methylenebisacrylamide, 1,4‐butanediol diacrylate, and diallyl phthalate. Network structural parameters such as initial swelling rate, swelling rate constant, and maximum equilibrium swelling were evaluated by water absorption measurement. The equilibrium water content (EWC%) of the AAm–NMA macroporous SAHs was found to be in the range of 93.31–99.68, indicating that these SAHs may have applications as biomaterials in the medicinal, pharmaceutical, and veterinary fields. Most of the SAHs prepared in this investigation followed non‐Fickian‐type diffusion, and few followed a case II– or super–case II‐type diffusion. The diffusion coefficients of these macroporous SAHs were investigated. Further, the swelling behavior of these SAHs also was investigated at different pHs and in different salt solutions and simulated biological fluids. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3202–3214, 2006     

Characterization and determination of swelling and diffusion characteristics of poly(n‐vinyl‐2‐pyrrolidone) hydrogels in water

Hydrogels in the form of rods with varying crosslink densities and three‐dimensional network structures were prepared from Poly(N‐vinyl‐2‐pyrrolidone) (PVP)/water and PVP/water/persulfate systems by irradiation with γ rays at ambient temperature. Average molecular weights between crosslinks, percent swelling, swelling equilibrium values, diffusion/swelling characteristics (i.e., the structure of network constant, the type of diffusion, the initial swelling rate, swelling rate constant), and equilibrium water content were evaluated for both hydrogel systems. Water diffusion to the hydrogel is a non‐Fickian type diffusion and diffusion coefficients vary from 6.56 × 10⁻⁷ to 2.51 × 10⁻⁷cm²min⁻¹ for PVP and 6.09 × 10⁻⁷ to 2.14 × 10⁻⁷ cm²min⁻¹ for PVP/persulfate hydrogel systems. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 994–1000, 2000     

Surface modification of polymethyl methacrylate intraocular lenses with the mixture of acrylic acid and acrylamide via plasma‐induced graft copolymerization

An approach is presented for the graft copolymerization of acrylic acid (AAc) and acrylamide (AAm) mixture onto the surfaces of polymethyl methacrylate intraocular lenses (PMMA IOLs) treated with an Argon gas plasma, followed by the exposure to the oxygen atmosphere. In this case, peroxides formed by the plasma treatment are likely to be responsible for initiating the graft copolymerization. The amount of peroxides on the surface of PMMA IOLs was determined using 1,1‐diphenyl‐2‐picrylhydrazyl, and the maximum amount was found with the plasma treatment at 30 W for 20 s under 5 mTorr pressure. The surfaces of the grafted PMMA IOLs were characterized using Fourier transform infrared spectroscopy‐attenuated total reflectance (FTIR‐ATR), electron spectroscopy for chemical analysis, and contact angle meter. The FTIR‐ATR spectrum of PMMA‐g‐AAc‐AAm showed the characteristic band of PAAc at 1580 cm^?1 together with those of PAAm at 1670 and 1630 cm^?1, confirming that the copolymer of AAc and AAm was successfully grafted onto the surfaces of PMMA IOLs. The experimental data of O1s/C1s and N1s/C1s reasonably concurred with the calculated data, a strong indication that the pH value of the reaction medium at 3.77 could produce a graft with an equal molar ratio. Surface tension of the samples increased to 52 dyn/cm due to the graft of the hydrophilic monomers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2361–2366, 2002     

Thermally crosslinked anionic hydrogels composed of poly(vinyl alcohol) and poly(γ‐glutamic acid): Preparation,characterization, and drug permeation behavior

pH‐sensitive anionic hydrogels composed of poly(vinyl alcohol) (PVA) and poly(γ‐glutamic acid) (γ‐PGA) were prepared by the freeze drying method and thermally crosslinked to suppress hydrogel deformation in water. The physical properties, swelling, and drug‐diffusion behaviors were characterized for the hydrogels. In the equilibrium swelling study, PVA/γ‐PGA hydrogels shrunk in pH regions below the pK_a (2.27) of γ‐PGA, whereas they swelled above the pK_a. In the drug‐diffusion study, the drug permeation rates of the PVA/γ‐PGA hydrogels were directly proportional to their swelling behaviors. The cytocompatibility test showed no cytotoxicity of the PVA/γ‐PGA hydrogels for the 3T3 fibroblast cell lines. The results of these studies suggest that hydrogels prepared from PVA and γ‐PGA could be used as orally administrable drug‐delivery systems. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Removal of paraquat pesticide from aqueous solutions using a novel adsorbent material based on polyacrylamide and methylcellulose hydrogels

This research studied the characteristics of poly(acrylamide) and methylcellulose (PAAm‐MC) hydrogels as a novel adsorbent material for removal of pesticide paraquat, from aqueous solution, with potential applications in curbing environmental risk from such herbicides. PAAm‐MC hydrogels with different acrylamide (AAm) and MC concentrations were prepared by a free‐radical polymerization method. The capability of the hydrogels in removing paraquat dichloride from aqueous solution was determined using UV–Vis analysis. The scanning electron microscopy method was used to study the morphological properties of the hydrogels, and swelling degree (Q) of the hydrogels was also measured. The entrapped MC in PAAm chains provoked significant changes in morphological, hydrophilic, and adsorption properties of the PAAm‐MC hydrogels. The adsorption capacity of hydrogels was strongly influenced by AAm, MC, and paraquat concentrations with the highest adsorption capacity (q_eq = 14.3 mg g^?1) was observed for hydrogels synthesized with 6.0% AAm with 0.75% MC swollen in 45.7 mg L^?1 of paraquat solution. Freundlich model performed better than Langmuir model in describing the adsorption isotherm of PAAm‐MC/paraquat system, implying a heterogeneous surface. These results suggest that PAAm‐MC hydrogels are potentially viable absorbents for removal of paraquat pesticide from aqueous solution and cleaning water contaminated with dyes, heavy metals, and others pesticides. © 2009 Wiley Periodicals, Inc. Journal of Appl Polym Sci, 2009     

Pervaporation separation of water/dimethylformamide mixtures using poly(vinyl alcohol)‐g‐polyacrylamide copolymeric membranes

Grafted copolymeric membranes of poly(vinyl alcohol) with acrylamide (PVA‐g‐AAm) were developed and used in the pervaporation separation of water–dimethylformamide mixtures by varying the amount of water in the feed from 0 to 100%. From these data, the permeation flux, pervaporation separation index, diffusion coefficient, swelling index, and separation selectivity were calculated at 25, 35, and 45°C. The Arrhenius activation parameters for permeation flux ranged between 22 and 63 kJ/mol, while the activation energy for diffusion ranged between 23 and 67 kJ/mol. Separation selectivity was between 15 and 22. The highest permeation flux of 0.459 kg m^?2 h^?1 was obtained for the 93% grafted membrane at 90% of water in the feed mixture. The results are discussed using the principles of the solution–diffusion model. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 273–282, 2002     

Structural aspects and nature of swelling medium as equilibrium swelling determinants of acrylamide and cellulosic‐based smart hydrogels

Hydroxypropylcellulose (HPC)‐based interpenetrating networks (IPN) with acrylamide (AAm) were synthesized in aqueous medium by simultaneous γ‐ray initiation in the presence of N,N‐methylenebisacrylamide (N,N‐MBAAm). The effect of the synthetic reaction conditions was evaluated for optimum network yield and networks of cellulose and some of its derivatives were obtained with AAm by using these conditions. FTIR, elemental analysis, and scanning electron micrography (SEM) for various structural aspects have characterized networks. Apart from kinetics of IPN formation, this article discusses swelling response of these novel hydrogels in different swelling media. Swelling behavior was studied as a function of synthetic reaction conditions, structure of cellulosics used, and nature of swelling medium (water, 0.5N NaOH, 0.5N HCl, and 5% NaCl). Equilibrium swelling was observed to depend on both structural and environmental factors. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1161–1169, 2002