Free radical grafting kinetics of acrylamide onto a blend of starch/chitosan/alginate

Sorour, Mohamed H.; Sayed, Marwa M. El; Moneem, Nabil Abd El; Talaat, H.A.; Shaalan, Hayam F.; Marsafy, Sahar El

doi:10.1016/j.carbpol.2013.05.067

Cited by 28 publications

(10 citation statements)

References 13 publications

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“…XRD analysis for the grafted alginate hydrogel indicates crystallinity peaks at 2θ from 23˚to 26˚and from 32˚to 36˚due to presence of polyacrylamide grafted at alginate backbone, while no such peaks are visible in the XRD pattern of raw alginate [12,13] which exhibits very small crystallinity. In addition, XRD spectra of grafted chitosan hydrogel samples show many crystalline areas between 2θ from 19˚to 22˚and from 34˚to 36˚, which may be attributed to grafting of polyacrylamide onto chitosan backbone; again, no such peaks are visible in the XRD spectra of raw chitosan, and the crystalline peaks are reduced relative to the peaks present in raw chitosan [12,13].…”

Section: Xrd Characterization Of the Prepared Hydrogelsmentioning

confidence: 93%

“…These polymers separate metal ions by binding via adsorption, chelation, and ion-exchange processes [10,11]. Various copolymers have been synthesized by graft copolymerization of vinyl monomers onto natural polysaccharides using conventional heating, microwave (MW)-assisted or ultraviolet (UV) irradiation techniques in order to produce new hybrid polymer materials with desired properties [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

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Softening of seawater and desalination brines using grafted polysaccharide hydrogels

Sorour

Hani

Shaalan

et al. 2014

Desalination and Water Treatment

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2014): Softening of seawater and desalination brines using grafted polysaccharide hydrogels, Desalination and Water Treatment, This paper investigates the potential of using polysaccharide hydrogels as softeners for saline solutions of seawater and reverse osmosis desalination brine. Grafting of acrylamide onto alginate and chitosan was conducted using microwave (MW) and ultraviolet (UV) irradiation techniques. The produced hydrogels: alginate (Alg-UV and Alg-MW) and chitosan (Ch-UV and Ch-MW) were characterized using X-ray diffraction and scanning electron microscopy. Hydrogel products were tested for their swelling behavior in distilled water and saline solutions, and their calcium and magnesium adsorption capacities in the preswollen and dry forms were measured in saline solutions. Swelling in distilled water was found to exceed that in saline solutions by 16.7-21-fold. Maximum attained swelling ratios in distilled water were 168 and 173 g/g for Alg-UV and Ch-MW grafted acrylamide hydrogels, respectively. Dry hydrogels had relative selectivity toward calcium adsorption in seawater and magnesium adsorption in brine. Furthermore, pre-swollen hydrogel manifested favorable adsorption for calcium and magnesium when compared to dry hydrogel at the same adsorbate volume. For both dry and pre-swollen hydrogels, maximum calcium adsorption capacities were 54 and 34 mg/g from seawater using Alg-MW and UV-prepared alginate and chitosan hydrogels, respectively. Maximum magnesium adsorption capacities from brine were 280 and 316 mg/g using dry alginate and chitosan hydrogels, respectively, prepared by MW technique. Magnesium adsorption capacities of the prepared hydrogels in brine were higher than those of tested commercial resins. It is concluded that alginate-and chitosan-grafted acrylamide hydrogels are promising softeners for saline solutions.

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Section: Xrd Characterization Of the Prepared Hydrogelsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Softening of seawater and desalination brines using grafted polysaccharide hydrogels

Sorour

Hani

Shaalan

et al. 2014

Desalination and Water Treatment

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“…The hydrogel showed high selectivity for removal of Co, Cu ions among testing heavy metals, including Cd, Ni, Cu, and Co. The authors succeeded in preparation and performance evaluation of several types of hydrogels and hydrogel composites . Most of the studies with polymers were performed without consideration of the techno‐economics at the production level.…”

Section: Introductionmentioning

confidence: 99%

Development and assessment of adsorptive hydrogel: Process engineering and economic considerations

Sorour

Tewfik

Abulnour

et al. 2020

Engineering Reports

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This article addresses the production of an adsorbing hydrogel to be used for removal of heavy metals. A review of literature on hydrogel adsorption of heavy metals is highlighted. The adopted process is briefly described and typical adsorption results as compared to reported work are presented. The technical specifications of an industrial scale plant of appropriate capacity of 3000 ton/year are detailed. The total capital investment and the production cost have been estimated to be about $M 10.6 and 6.5, respectively. Financial analysis determined the effect of variation of selling price within the reported international range on financial indicators. Furthermore, analysis of the effect of variation by 10% increase/decrease of capital investment and annual operating cost has been also estimated. Indicators include net present value (NPV $M), internal rate of return (IRR%), and average simple return of return (Average. SRR%), which have been estimated as 24%, 18%, and 19%, respectively. The project proves to be techno-economically viable under the estimated conditions for wider application. K E Y W O R D Scomposite adsorbents, economics, heavy metals, industrial plant INTRODUCTIONHeavy metals pollution of different water resources is of worldwide environmental concern. 1 These toxic metal ions, even at low concentration, have deteriorated water resources used for drinking water causing serious environmental and health problems. 2 Different methods have been adopted for the removal of heavy metal present in wastewaters. The most commonly used methods include but not limited to ion-exchange, chemical precipitation, electrocoagulation/floatation, and membrane separation. [3][4][5][6][7][8][9] Various adsorbents have been used for removal of heavy metals from wastewater due to their high removal capacity and economic benefits. 10,11 Adsorbent materials such as activated carbon, 12 zeolites, 9,13 clays, 14,15 ion exchange resins, 16 and hydrogel 17 have been developed and are used commercially for the removal of heavy metal ions. Organic-inorganic hybrid polymers have been recently applied. The functional variation of organic materials is combined with advantages of a thermally stable and strong inorganic substrate which results in relatively high metal ionThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

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“…A variety of initiation methods, including chemical, gamma‐ray radiation, microwave radiation, ultraviolet radiation, ultrasound, and plasma and electron beams, are used to initiate the polymerization reaction. Therein, chemical initiation, especially the redox initiation systems, was the most widely used method …”

Section: Introductionmentioning

confidence: 99%

One‐step synthesis of corn starch urea based acrylate superabsorbents

Liu

Wang

Guo

et al. 2017

J of Applied Polymer Sci

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A one‐step synthesis procedure for starch‐based acrylate superabsorbent polymers was proposed. The reaction conditions that may affect the water absorption capacity were discussed. A transparent gel‐like polymer containing urea (USAP) was successfully obtained by dissolving starch in a NaOH solution without further gelatinizing processing and using AA directly without prior neutralization. Urea was used as the nitrogen source and pore‐forming agent to improve the performance of the USAP. The optimum reaction conditions of the swelling ratio were also studied. A corn starch USAP was synthesized under the optimum conditions, and the water absorbency was 2704 ± 22, 561 ± 39, 100 ± 5, and 96 ± 4 g/g, respectively, in distilled water, running water, physiological saline, and artificial urine. Five kinds of starch‐based USAPs were also successfully prepared under the same conditions with excellent water absorption capacities, revealing that the one‐step method was a more convenient method for a potential industrial application pathway. The polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis. The results indicated that the PAA chains were successfully grafted onto the St backbone. However, the St molecular structure was not completely destroyed during the graft polymerization. The thermal analysis and nitrogen content results proved that urea was also involved in the graft copolymerization. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45175.

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Free radical grafting kinetics of acrylamide onto a blend of starch/chitosan/alginate

Cited by 28 publications

References 13 publications

Softening of seawater and desalination brines using grafted polysaccharide hydrogels

Softening of seawater and desalination brines using grafted polysaccharide hydrogels

Development and assessment of adsorptive hydrogel: Process engineering and economic considerations

One‐step synthesis of corn starch urea based acrylate superabsorbents

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