Abstract—Superabsorbent polymers received much attention and are used in many fields because of their superior characters to traditional absorbents, e.g., sponge and cotton. So, it is very important but challenging to prepare highly and fast-swelling superabsorbents. A reliable, efficient and low-cost technique for removing heavy metal ions from wastewater is the adsorption using bio-adsorbents obtained from biological materials, such as polysaccharides-based hydrogels superabsorbents. In this study, novel multi-functional superabsorbent composites type semi-interpenetrating polymer networks (Semi-IPNs) were prepared via graft polymerization of acrylamide onto chitosan backbone in presence of gelatin, CTS-g-PAAm/Ge, using potassium persulfate and N,N’-methylene bisacrylamide as initiator and crosslinker, respectively. These hydrogels were also partially hydrolyzed to achieve superabsorbents with ampholytic properties and uppermost swelling capacity. The formation of the grafted network was evidenced by Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Thermogravimetric Analysis (TGA). The porous structures were observed by Scanning Electron Microscope (SEM). From TGA analysis, it was concluded that the incorporation of the Ge in the CTS-g-PAAm network has marginally affected its thermal stability. The effect of gelatin content on the swelling capacities of these superabsorbent composites was examined in various media (distilled water, saline and pH-solutions). The water absorbency was enhanced by adding Ge in the network, where the optimum value was reached at 2 wt. % of Ge. Their hydrolysis has not only greatly optimized their absorption capacity but also improved the swelling kinetic.These materials have also showed reswelling ability. We believe that these super-absorbing materials would be very effective for the adsorption of harmful metal ions from wastewater. Keywords—Chitosan, gelatin, superabsorbent, water absorbency. I. INTRODUCTION UPERABSORBENT POLYMERS (SAPs) or hydrogels have three-dimensional network structure. They are not only able to absorb large amounts of aqueous fluids in a relatively short time, but also the absorbed water is hardly removed even under some pressure. They can undergo a change in volume (swelling/shrinkage) owing to their environmental stimulants responsive, such as temperature, pH, and ionic strength. These gels are occasionally referred to as H. Ferfera-Harrar is an Professor in Chemistry Faculty, Department of Macromolecular Chemistry, at the University of Sciences and Technology Houari Boumediene USTHB, B.P. 32 El-Alia, 16111 Algiers, Algeria (Corresponding Author: e-mail: harrarhafida@yahoo.fr). N. Aiouaz and N. Dairi are graduate students in Chemistry Faculty, Department of Macromolecular Chemistry, at the University of Sciences and Technology Houari Boumediene USTHB, B.P. 32 El-Alia, 16111 Algiers, Algeria. smart materials [1], [2]. The SAPs applications is increasingly growing in special fields such as in hygienic products, agriculture, horticulture, wastewater treatment, drug delivery, water blocking tapes, food packaging, wave absorbing and sensors materials [3]-[5]. Many efforts have been supplied to enhance SAPsmaterials properties such as swelling rate and ratio and gel strength to meet applications requirement. Several SAPs have been designed by introducing inorganic particles, natural polymer nanofibers or by forming a semi- and full interpenetrating polymer networks (IPN) [6]-[9]. Even though the most of superabsorbents are based on synthetic polymers, such as acrylic acid and acrylamide, their broader use is limited by their toxic character and poor biodegradability. For environmental protection issues, the development of natural polymer-based superabsorbents has drawn much attention owing to their exceptional properties, i.e. biocompatibility, biodegradability, renewability, and non- toxicity as well as their low-cost production. As well, there is a growing notice for the application of SAPs materials having a biological origin in the removal of dyes or heavy metal ions from wastewater, which would contribute to resolve the environmental pollution. Since the cost of these materials is much lower than the commercial adsorbents, like activated carbon or ion exchange resins, the bio-adsorbents might gain a particular interest [10], [11]. Recently, the synthesis of eco-friendly SAPs through graft copolymerization of vinyl monomers onto natural polymer backbones has drawn much interest [12]-[14]. Among them, chitosan (CTS), a deactivated derivative of chitin and a copolymer of N-acetyl-glucosamine and N-glucosamine units, is a well affirmed polysaccharide owing to its inherent properties and antimicrobial activities [15], [16]. The grafting and copolymerization method allows to modify an easily available natural polymer such as CTS with a conventional and widely used synthetic hydrogel like cross-linked poly (acrylamide) [17]. Also, the presence of a large number of OH and NH 2 groups in CTS it confers a potential adsorption of heavy metal and dyes due to its chelating ability. Thus, it is likely to develop efficient low-cost bio-sorbents for the heavy metals by combining the metal ions attraction capacity of both natural polysaccharides and synthetic polymer [18], [19]. Gelatin (Ge) is a denatured derivative of protein collagen that is largely used in biomedical applications. Gelatin has a polyelectrolyte behavior, in where -NH 3 + and -COO - groups are equal at isoelectric point (IEP) but these charges alter with Synthesis and Properties of Chitosan-Graft Polyacrylamide/Gelatin Superabsorbent Composites for Wastewater Purification H. Ferfera-Harrar, N. Aiouaz, N. Dairi S World Academy of Science, Engineering and Technology International Journal of Chemical and Molecular Engineering Vol:9, No:7, 2015 849 International Scholarly and Scientific Research & Innovation 9(7) 2015 scholar.waset.org/1307-6892/10002042 International Science Index, Chemical and Molecular Engineering Vol:9, No:7, 2015 waset.org/Publication/10002042