Synthesis and Properties of Lignin-Based Polyurethane Hydrogels

Hydrogels were synthesized from acetic acid lignin by chemical crosslinking with NCO-terminated polyurethane ionomers (IPUI). The swelling ratio of hydrogels increased with pH. The hydrogel prepared at the mass ratio of m_AAL/m_IPUI: 0.35:1 presented maximum swelling ratio in pH 6.8 buffer solutions. The results of thermogravimetric analysis demonstrated that the thermal stability of the hydrogels is improved by the introduction of lignin. The data of release experiments for ammonium sulfate suggests that the hydrogels can be used as coating materials to prepare a slow-release fertilizer.     

快速响应聚(N-异丙基丙烯酰胺)水凝胶的制备及性能

以N-异丙基丙烯酰胺为单体、N,N′-亚甲基双丙烯酰胺为交联剂、过硫酸铵为引发剂、N,N,N,′N′-四甲基乙二胺为加速剂,在不同浓度的羧甲基纤维素的水溶液中,在低温下聚合/交联制备了一系列快速响应的温度敏感性聚(N-异丙基丙烯酰胺)水凝胶。用SEM观察了其表面形态,测定了不同温度下达到平衡时水凝胶的溶胀比,研究了水凝胶的去溶胀动力学。结果表明,与传统水凝胶相比,该水凝胶的溶胀性能有所提高,并且对温度的变化具有较快的响应速率。以质量分数为0.75%的羧甲基纤维素水溶液中制备的水凝胶为例,该水凝胶在20℃时的溶胀比为21.4,而传统水凝胶在相同温度时的溶胀比仅为12.9;该水凝胶在1 m in内失去60%的水,在4 m in内失去约80%的水,而传统水凝胶在15 m in内仅失去66%左右的水。     

A promising porous polymer-nanoclay hydrogel nanocomposite as water reservoir material: synthesis and kinetic study

A porous hydrogel nanocopmposite based on biodegradable salep and montmorillonite (MMT) was synthesized by in-situ free radical graft polymerization of salep chains with acrylic acid (AA) monomers. The chemical structure and morphological properties of the prepared hydrogels was evaluated by FTIR spectroscopy, X-ray diffraction and SEM techniques. The effect of reaction variables such as crosslinker, initiator, monomer and clay contents on equilibrium water absorption capacity and swelling kinetic of hydrogel were investigated and optimized. Swelling behavior of the hydrogels in various pH and saline solutions was also studied. Incorporation of MMT into hydrogel matrix caused the formation of porous hydrogel network. These porous structures resulted in higher water uptake capacity and swelling rate in hydrogel nanocomposite in comparison to neat hydrogel sample. Moreover, hydrogel nanocomposite sample exhibited proper salt and pH-sensitive behavior. High swelling capacity and rate, porosity, salt and pH sensitivity make hydrogel nanocomposite a profitable candidate in agricultural and horticultural applications, such as water reservoir system.     

Poly(acrylamide/laponite) nanocomposite hydrogels: Swelling and cationic dye adsorption properties

Super adsorbent polyacrylamide (PAAm)/nanoclay (laponite, Lap) hydrogels were prepared by in situ free radical polymerization of AAm in an aqueous solution with clay as a crosslinker. The swelling properties and water‐soluble cationic dye adsorption behaviors of the PAAm/laponite (PAAm/Lap) nanocomposite (NC) hydrogels were investigated. The parameters of swelling and diffusion of water in dye solutions were evaluated for the PAAm/Lap NC hydrogels. The adsorption behavior of the monovalent cationic dyes such as Basic Blue 12 (BB 12), Basic Blue 9 (BB 9), and Basic Violet 1 (BV 1), were studied on the NC hydrogels. The effects of the clay content of the hydrogel on its cationic dye uptake behavior were studied. The adsorption studies indicated that the rates of dye uptake by the NC hydrogels increased in the following order: BB 9 > BB 12 > BV 1. This order is similar to the swelling results of the PAAm/Lap NC hydrogel in the dye solutions. The equilibrium uptakes of the different dyes by the PAAm/Lap NC hydrogel were nearly the same. In the dye absorption studies, S‐type adsorption in the Giles classification system was found for the BB 12 and BV 1 dyes, whereas L ‐type was observed for the BB 9 dye. After the heat treatment of PAAm/Lap, the rate of dye uptake and equilibrium dye uptake were increased. The NC hydrogels may be considered as a good candidate for environmental applications to retain more water and to remove dyes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of clinoptilolite on structure and drug release behavior of chitosan/thyme oil γ-Cyclodextrin inclusion compound hydrogels

Chitosan-based hydrogels involving γ-cyclodextrin inclusion compounds of thyme oil were prepared by freeze–thaw cycling method. Clinoptilolite as a natural zeolite was added to investigate its effects on the structural, mechanical, and drug release behaviors of the hydrogels. Zeolite compressed the structure and improved mechanical properties, which decreased swelling values. Release of thyme oil in prepared hydrogels were investigated by UV spectroscopy and drug release mechanism was evaluated by applying various mathematical methods. Rates of water vapor transmission of the samples were calculated as 2247–2998 g m⁻² day⁻¹ which are all in the range of an ideal wound dressing. Hydrogels with clinoptilolite had slower drug release (from 56% to 24% for hydrogels containing zeolite 1%) in comparison with that of without zeolite. Based on MTT assay, samples were low-toxic. Obtained results suggest that drug loaded hydrogels can be applied in biomedical field including drug delivery systems and wound dressings.     

Synthesis and characterization of starch‐g‐Poly(acrylic acid)/Organo‐Zeolite 4A superabsorbent composites with respect to their water‐holding capacities and nutrient‐release behavior

Novel superabsorbent composites were prepared using starch, acrylic acid, and organo‐zeolite 4A micropowder via aqueous solution graft copolymerization. The effects of organo‐zeolite 4A content on water absorbency were tested to determine the optimum conditions that ensure a high swelling ability. Under these conditions, the maximum swelling ability in distilled water was determined to be 511 g/g when the amount of organo‐zeolite 4A in the feed was 10 wt%. The prepared samples were characterized with Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscope (SEM). The SEM characterization of the samples indicated that the superabsorbent composites had more pores and water than zeolite‐free superabsorbents. The swelling capacities in distilled water, various salt solutions, and aqueous urea were studied. The on–off switching behavior and the release of urea from the loaded starch‐g‐ poly(acrylic acid)/organo‐zeolite 4A were also determined. The results indicated that the novel composite was responsive to salts and exhibited on–off switching behavior, as evidenced by reversible swelling and de‐swelling. In addition, the slow nutrient release makes this material suitable for many potential applications in the fields of agriculture and horticulture. POLYM. COMPOS., 38:1838–1848, 2017. © 2015 Society of Plastics Engineers     

Magnetic removal of crystal violet from aqueous solutions using polysaccharide‐based magnetic nanocomposite hydrogels

Magnetic Fe₃O₄@SiO₂ starch‐graft‐poly(acrylic acid) (SPAA) nanocomposite hydrogels were prepared and used as absorbents for removal of crystal violet from aqueous solutions. Dynamic swelling, effect of contact time, absorption kinetics and nanocomposite hydrogel mass for removal of crystal violet dyes from aqueous solutions were studied. Fourier transform infrared spectroscopy, scanning electron microscopy and vibrating sample magnetometer measurements were used for the characterization of the nanocomposite hydrogels. The nanocomposite hydrogels had high magnetic sensitivity under an external magnetic field, which allowed their magnetic separation from water, thus avoiding secondary pollution. The results obtained are very promising since: (i) high levels of colour removal (>85%) were achieved with low magnetic SPAA nanocomposite mass and (ii) the magnetic SPAA nanocomposites can be successfully used several times as absorbents of crystal violet in aqueous solution without needing filtration. © 2012 Society of Chemical Industry     

Swelling and auramine-<Emphasis Type="Italic">O</Emphasis> adsorption of carboxymethyl cellulose grafted poly(methyl methacrylate)/Cloisite 30B nanocomposite hydrogels

Carboxymethyl cellulose (CMC) grafted poly(methyl methacrylate)/Cloisite 30B nanocomposite hydrogels were prepared for adsorptive removal of auramine-O (as a cationic dye model) from wastewater. For the synthesis of nanocomposite hydrogel by free radical polymerization method, potassium persulfate (KPS), methyl methacrylate (MMA), N,N′-methylene bisacrylamide (MBA) and Cloisite 30B were used as initiator, monomer, cross-linker and nano-filler, respectively. The nanocomposite hydrogels were characterized by FTIR, TGA, SEM and XRD techniques. The FTIR results showed that the monomer was grafted onto carboxymethyl cellulose chains successfully. Swelling behavior of nanocomposite hydrogel as a function of KPS, MBA, MMA concentration and CMC/Cloisite 30B weight ratio was studied by Taguchi method using Minitab 16 software. According to ANOVA results, the most effective factor of equilibrium swelling of nanocomposite hydrogel was CMC/Cloisite 30B weight ratio. Addition of Cloisite 30B to hydrogel up to a certain amount improved swelling, though its high amount decreased swelling. The effects of pH and ionic strength on swelling of optimum hydrogels were investigated. Maximum swelling of nanocomposite hydrogel occurred at pH 7.0. The kinetic data of adsorption fitted well to pseudo-second-order model. The best isotherm for investigation of adsorption mechanism was Langmuir model suggesting the formation of a monolayer on the adsorbent surface. FTIR results, before and after auramine-O adsorption, showed that complexation is the main mechanism of adsorption. High adsorption capacity of nanocomposite hydrogels made them more efficient in wastewater treatment application.     

Preparation and Characterization of Porous Poly (N-isopropylacrylamide) /Clay Nanocomposite Hydrogels

Summary  A novel porous PNIPA/Clay nanocomposite hydrogel (NC hydrogel) was prepared by in situ free-radical polymerization using inorganic clay as a crosslinker and calcium carbonate (CaCO₃) particle as a pore-forming agent and subsequent extraction of CaCO₃ with acid. The structure and morphology of the hydrogels were characterized by means of FTIR, TEM and SEM. The temperature responsive behaviors, the deswelling behaviors and the mechanical properties of the NC hydrogels were investigated in detail. The results showed that the swelling ratios below VPTT and the deswelling rates of the NC hydrogels were significantly improved as compared with the hydrogels without introduction of CaCO₃. Moreover, the NC hydrogels thus prepared also exhibited good mechanical properties.     

Zeolite reinforced carboxymethyl cellulose-Na+-g-cl-poly(AAm) hydrogel composites with pH responsive phosphate release behavior

Phosphate fixation in soils is a matter of concern in agriculture. Conventional application of phosphorus fertilizer suffers from low P use constraint, particularly in acidic soils. Rhizosphere centric slow release strategy bears tremendous prospects. In the present study, monocalcium phosphate (MCP) was impregnated in zeolite reinforced CMC-Na⁺-g-cl-Poly(Aam) hydrogel composites with aim to develop slow phosphate release device for soil application. X-ray diffraction, scanning electron microscopy, and Fourier transform-infrared spectroscopy confirmed the successful synthesis of slow release fertilizer formulations. Presence of zeolite in composite matrix during polymerization resulted in higher MCP loading. The “burst release” phenomena under neutral aqueous environment as compared to diffusion led slow release mechanism under acidic condition suggesting that phosphate release from developed composite matrix was pH responsive. The developed materials possess potential to serve as tool for improving phosphate use efficiency under resource stress agriculture. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47332.     

Swelling behavior and structural characteristics of polyvinyl alcohol/montmorillonite nanocomposite hydrogels

A series of nanocomposite hydrogels based on polyvinyl alcohol containing 0–10 wt % of the organically modified montmorillonite clay were prepared by freezing‐thawing cyclic method. The morphology of the nanocomposite hydrogels was observed by the scanning electron microscopy technique. The structural properties were determined by measuring the network mesh size, crosslinking density, and average molecular weight of polymer chains between crosslinks. The swelling behavior and the effect of swelling medium temperature on the swelling kinetics and characteristics of the nanocomposite hydrogels were also investigated. The results showed that two structural characteristics i.e., network mesh size and average molecular weight of polymer chains between crosslinks have inverse dependence on the clay loading level in the nanocomposite hydrogel, while crosslinking density shows completely direct dependence. Swelling measurements demonstrated a linear relation between the degree of swelling and the square root of immersion time at all swelling medium temperatures. The results indicated that the swelling characteristics of the nanocomposite hydrogels including the equilibrium degree of weight and volume swelling and the equilibrium water content were decreased by increasing the quantity of the clay incorporated into the hydrogel as well as by decreasing the temperature of swelling medium. While, the time required to reach to the equilibrium condition, as another swelling characteristic of the hydrogels, exhibited a completely opposite behavior. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Synthesis of copolymeric acrylamide/potassium acrylate hydrogels blended with poly(vinyl alcohol): Effect of crosslinking and the amount of poly(vinyl alcohol) on swelling behavior

A novel series of copolymeric acrylamide/potassium acrylate superabsorbents, blended with poly(vinyl alcohol), have been synthesized by using N, N′‐methylenebisacrylamide as a crosslinker and potassium persulphate (K₂S₂O₈) as an initiator. Swelling behavior of these hydrogels in water was investigated; and on the basis of swelling properties, the diffusional behavior of water into these hydrogel systems was analyzed. It was observed that with the increase of amount of poly(vinyl alcohol) or crosslinking, the swelling of the hydrogels decreased. The hydrogel synthesized by addition of 5% poly(vinyl alcohol) and 0.25% crosslinking showed maximum swelling of 54445%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1927–1931, 2005     

The effects of graphene oxide on the properties and drug delivery of konjac glucomannan hydrogel

Konjac glucomannan (KGM) hydrogel has good potential application in food and medical science, although to achieve this, the physical and mechanical properties need further improvement. In this study, graphene oxide (GO) was used to improve the functionality of KGM hydrogel. KGM/GO hydrogels were prepared by freezing the alkaline KGM/GO sols. Rotational rheometer was used to study the rheological properties of different alkaline KGM/GO sols. Fourier transform infrared, Raman, differential scanning calorimetry, thermogravimetric analyses, and scanning electron microscopy were used to evaluate the structure and properties of the hydrogels. In addition, different pH solutions and an in vitro assay were used to study the swelling property and the release behavior of KGM/GO hydrogels, respectively. The result revealed strong hydrogen‐bond interaction between KGM and GO. The incorporation of GO highly improved the gel properties of KGM/GO sol, higher thermal stability, and more compact structure of KGM/GO hydrogels. KGM/GO hydrogels showed better swelling properties in deionized‐distilled water and pH 7.2 PBS. The release of 5‐aminosalicylic acid (5‐ASA) from KGM/GO (KG4) hydrogel was different in various pH media, but the initial burst release effect was very severe. Therefore, incorporation of GO have a good potential in enhancing the properties of KGM hydrogel, but KGM/GO hydrogel is not an ideal carrier for 5‐ASA release. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45327.     

Comparison the properties of PVA/Na+‐MMT nanocomposite hydrogels prepared by physical and physicochemical crosslinking

A novel physicochemical crosslinked nanocomposite hydrogel based on polyvinyl alcohol (PVA) and natural Na‐montmorillonite (Na⁺‐MMT) was synthesized by chemical crosslinking of nanocomposite hydrogel followed by a freezing‐thawing process. The effects of physical crosslinking, as well as physicochemical crosslinking, on the structure, morphology, and properties (thermal, mechanical, swelling, and deswelling) of nanocomposite hydrogels were investigated and compared with each other. The structure and morphology of nanocomposites were studied by Fourier transform infrared, X‐ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy techniques. The thermal and mechanical properties of nanocomposites that were affected by physical and physicochemical crosslinking were evaluated by thermogravimetric analysis, differential scanning calorimeter, dynamic mechanical analysis, hardness test, and Water vapor transmission rate (WVTR) experiments. The results showed that the physicochemical crosslinking of a PVA nanocomposite leads to a reduction in crystallinity and melting temperature, as well as an increase in the Hardness and WVTR compared to a physically crosslinked PVA nanocomposite hydrogel. The swelling and deswelling experiments were performed using a gravimetric method, and it was shown that controlled crosslinking of PVA nanocomposite hydrogel with glutaraldehyde causes the swelling ratio to increase and the cumulative amount of water loss to decrease. The swelling (sorption) and deswelling (desorption) kinetics data for physically and physicochemical crosslinking of nanocomposite hydrogels were fitted with a fickian model. It is concluded that through control crosslinking of PVA nanocomposite can lead to a hydrogel with higher swelling capacity than that is in conventional PVA nanocomposite hydrogel. POLYM. COMPOS., 37:897–906, 2016. © 2014 Society of Plastics Engineers     

Nanocomposite hydrogels for selective removal of cationic dyes from aqueous solutions

Removal of organic dyes from waste water has received a significant attention in recent years. In this work, a set of nanocomposite hydrogels (NHs) were prepared and their capacity to absorb crystal violet (CV), a cationic dye, and acid yellow‐23 (AY), an anionic dye, from aqueous solutions was determined. NHs were prepared by in situ formation of Fe₃O₄ magnetic nanoparticles (MNPs) inside poly(acrylamide‐co‐4‐styrene sulfonic acid sodium salt) (P[AAm‐co‐SSA]) hydrogel matrices. The dye absorption capacity of the magnetic NHs (MNHs) was compared with simple hydrogels (hydrogels or SHs) without the MNPs The prepared hydrogels were characterized by FTIR, XRD, thermogravimetric analysis, high resolution TEM, field emission SEM, and vibrating sample magnetometer measurement. From HRTEM, it was confirmed that the prepared MNPs in hydrogel matrices were in the size range of about 8 to 10 nm. The MNHs showed greater swelling behavior as well as greater removal efficiency of cationic dye from aqueous solutions in comparison to the SHs. With increase of SSA mole percentage, dye removal efficiency was also increased for both types of hydrogels. The present study indicates that the hydrogels containing MNPs can be potentially used as an efficient absorbent material for removal of cationic dyes from waste water. POLYM. ENG. SCI., 56:776–785, 2016. © 2016 Society of Plastics Engineers     

Bioactive Carboxymethyl Starch-Based Hydrogels Decorated with CuO Nanoparticles: Antioxidant and Antimicrobial Properties and Accelerated Wound Healing In Vivo

In this study, nanocomposite hydrogels composed of sodium carboxymethylated starch (CMS)-containing CuO nanoparticles (CMS@CuO) were synthesized and used as experimental wound healing materials. The hydrogels were fabricated by a solution-casting technique using citric acid as a crosslinking agent. They were characterized by Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) to evaluate their physicochemical properties. In addition, swelling, antibacterial activities, antioxidant activities, cytotoxicity, and in vivo wound healing were investigated to evaluate the wound healing potential of the CMS@CuO nanocomposite hydrogels. Growth inhibition of the Gram-positive and Gram-negative pathogens, antioxidant activity, and swelling were observed in the CMS@CuO nanocomposite hydrogels containing 2 wt.% and 4 wt.% CuO nanoparticles. The hydrogel containing 2 wt.% CuO nanoparticles displayed low toxicity to human fibroblasts and exhibited good biocompatibility. Wounds created in rats and treated with the CMS@2%CuO nanocomposite hydrogel healed within 13 days, whereas wounds were still present when treated for the same time-period with CMS only. The impact of antibacterial and antioxidant activities on accelerating wound healing could be ascribed to the antibacterial and antioxidant activities of the nanocomposite hydrogel. Incorporation of CuO nanoparticles in the hydrogel improved its antibacterial properties, antioxidant activity, and degree of swelling. The present nanocomposite hydrogel has the potential to be used clinically as a novel wound healing material.     

Silver nanoparticles embedded gum ghatti-graft-poly(N,N-dimethylacrylamide) biodegradable hydrogel: evaluation as matrix for controlled release of 2,4-dichlorophenoxyacetic acid

The present work explores the use of a nanocomposite hydrogel made using Gum ghatti (Gg), N,N-dimethylacrylamide (DMA) and N,N- methylene- bis-acrylamide (MBA) as a matrix for controlled release of 2,4-dichlorophenoxy acetic acid (2,4-D). Stable and uniformally distributed silver nanoparticles (Ag NP) were formed by the reduction of AgNO₃ using TCS within the gel network. The Gg-g-PDMA and Ag NPs entrapped gel (Gg-g-PDMA-SN) were characterized by FT-IR, XRD, TGA, SEM, EDS and TEM techniques. The presence of Ag NPs is observed to enhance the swelling ability and the release efficiency of the Gg-g-PDMA gels significantly and also showed higher biodegradability. The gels exhibited prolonged release of the 2,4-D indicating good potential to be used as matrix for controlled release applications in agriculture.     

Network parameters and volume phase transition behavior of poly(N‐isopropylacrylamide) hydrogels

Thermosensitive hydrogels were prepared by free radical polymerization in aqueous solution from N‐isopropylacrylamide (NIPA) monomer and N,N‐methylenebis(acrylamide) (MBAAm) crosslinker. The swelling equilibrium of the hydrogels in deionized water was investigated as a function of temperature and MBAAm content. The results indicated that the swelling behavior and temperature sensitivity of the hydrogels were affected by the amount of MBAAm content. The average molecular mass between crosslinks and polymer–solvent interaction parameter (χ) of the hydrogels were determined from equilibrium swelling values. The swelling variations were explained according to swelling theory based on the hydrogel chemical structure. The swelling equilibrium of the hydrogels was also investigated as a function of temperature in aqueous solutions of the anionic surfactant sodium dodecyl sulfate (SDS) and the cationic surfactant dodecyltrimethylammonium bromide (DTAB). In deionized water, the hydrogels showed a discontinuous volume phase transition at 32°C. In SDS and DTAB solutions, the equilibrium swelling ratio and the volume phase transition temperature (lower critical solution temperature) of the hydrogels increased, which is ascribed to the conversion of nonionic PNIPA hydrogel into polyelectrolyte hydrogels because of binding of surfactant molecules through the hydrophobic interaction. Additionally, the amount of free SDS and DTAB ions was measured at different temperatures by a conductometric method; it was found that the electric conductivity of the PNIPA–surfactant systems depended strongly on both the type and concentration of surfactant solutions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1756–1762, 2006     

Ion-stimuli responsive dimethylaminoethyl methacrylate/hydroxyethyl methacrylate copolymeric hydrogels: mutual influence of reaction parameters on the swelling and mechanical strength

Novel ion-stimulus-responsive copolymeric hydrogels were synthesized by free radical crosslinking copolymerization from the monomers N,N-dimethylaminoethyl methacrylate (DMAEMA) and 2-Hydroxyethyl methacrylate (HEMA) in the presence of a crosslinker, diethyleneglycol dimethacrylate (DEGDMA). The influences of the reaction parameters, the comonomer composition and the ionic strength of salt solutions on the swelling behavior of P(DMAEMA-co-HEMA) hydrogels were examined. The ion-stimulus-responsive swelling behavior of the prepared copolymers was studied in water as well as in aqueous solutions of NaCl, KCl, KBr, KI, CaCl₂, BaCl₂ and MgCl₂. It was found that, starting from some characteristic concentration of a salt, a further increase of the salt concentration results in the shrinking of copolymeric P(DMAEMA-co-HEMA) hydrogels. The Flory-Rehner theory correctly predicts the swelling behavior of the hydrogels in salt solutions if the variation of the comonomer HEMA content is taken into account. The calculation of the interaction parameter χ between P(DMAEMA-co-HEMA) network and water showed that the specific interactions between cations and side groups of polymeric network affect the mixing term of the free energy. The extent and kinetics of water absorption were studied to determine their relationship with the reaction parameters. The kinetics of the hydrogel collapse is strongly dependent on the kind of salt used. The swelling results will be useful in designing and developing novel controlled delivery systems.     

Synthesis and Characterization of Poly (CMC-g-cl-PAam/Zeolite) Superabsorbent Composites for Controlled Delivery of Zinc Micronutrient: Swelling and Release Behavior

A series of novel superabsorbent hydrogel composites, poly(CMC-g-cl-PAam/Zeolite) (ZSAPC) were prepared by in situ graft polymerization using a cellulosic backbone, acrylamide and natural zeolite. The swelling and deswelling behavior of the prepared composites was evaluated and analyzed by different empirical models. The composite with optimum water absorption capacity were impregnated with ZnSO₄ in situ during polymerization reaction. Zincated composites showed less water absorption capacity as compared to non-zincated ones. Zinc release behavior of zincated test hydrogel composites was studied in water and soil. All the test compositions exhibited non-Fickian or anomalous transport (0.43 < n < 0.84) and behaved as slow release products.