Production of Polymer Hydrogel Composites and Their Applications

Abstract

Hydrogels are three-dimensional cross-linked stable network insoluble in water, which gives them a remarkable capacity to absorb both water and biological fluids. Hydrogel has been synthesized from natural or synthetic polymers and/or monomers, which have made tremendous advancements in many different applications. Composite hydrogel is a type of hydrogel prepared by grafting hydrophilic groups, such as hydroxyl (–OH), carboxylic acid (–COOH), imide (–CONH), sulfonic acid (–SO3H), amine (–NH2), and amide (–CONH2), into the polymer chain’s backbone and adding some additives such as kaolin, zeolite, or even different types of nanoparticles. Whereas the polymeric composite hydrogels exhibit stimuli for different properties such as pH, temperature, or light, which may affect swelling, mechanical properties, and self-healing, which in turn play vital roles in different areas. Hence, numerous efforts have been made to synthesize polymer-based composited hydrogels via physical or chemical crosslinking techniques to enhance their physiochemical, biological, and many other properties. Many researchers are currently paying attention to hydrogels and their applications, including wastewater treatment and purification, medical and biomedical applications, agricultural applications, and many other industrial applications. The aim of this review is to summarize the classification of composite hydrogels based on their chemical and physical crosslinking techniques, in addition to the different polymers and additives used to prepare composite hydrogels. Furthermore, the impact of hydrogel on health and the environment has been discussed. Other significant issues were also presented, including the challenges that face hydrogel production and application, which have been discussed.

Swelling Kinetics of Acrylamide Grafted Polysaccharides Blend Hydrogel

“…Grafting evidence of acrylamide onto polysaccharides blend (PsB) has been confirmed by comparing FTIR spectra of the raw PsB mixture with the grafted PsB as shown in Figure (1). For the raw PsB, there are peaks at 1157, 1080, 1016, and 927 cm -1 due to the C=O stretching , the following peaks which belong to starch: a peak at 3390 cm -1 (O-H stretching) and a band at 2926 cm -1 (C-H stretching) , the characteristic peaks of chitosan are 1600 cm -1 (N-H bend), 1327 cm -1 (C-N stretch), 1155 cm -1…”

“…Recently, there has been considerable interest in water-swellable polymers which are capable of absorbing and holding a large amount of water while maintaining the physical dimension structure. Hydrogels are 3-dimensional networks of hydrophilic polymers held together by crosslinks of covalent bonds or ionic and/or secondary forces in the form of hydrogen bonds or hydrophobic interactions [1]. This excellent swelling property of hydrogels has the potential to sustain water and nutrient levels for plants and crops grown in agricultural applications [2,3].…”

3D shape morphing of stimuli-responsive composite hydrogels

“…Moreover, based on their constitution, composite hydrogels are divided into single-network, doublenetwork, and multiple-network composite hydrogels. 21 Regarding functional additives, on the one hand, incorporating stiff additives can strengthen the specific region of the hydrogel matrix, 67 which is commonly accompanied by the decrease of swelling ratios of hydrogels when specific interactions occurred between additives and matrices. 68 It is noteworthy that composite hydrogels exhibit a dependency on additives dispersion.…”

“…Moreover, based on their constitution, composite hydrogels are divided into single-network, double-network, and multiple-network composite hydrogels. 21…”

“…In recent years, composite hydrogels, an effective way to fabricate smart hydrogels, attract significant attention due to their numerous advantages and unique properties that allow them to overcome some limitations, including low strength, limited functionalities, and isotropic volume change, inherent to traditional hydrogels. 19,21,22 Typically, composite hydrogels involve combining a hydrogel matrix with other materials, such as inorganic fillers, organic compounds, or other polymers, significantly enhancing their functionality and performance. One key advantage of composite hydrogels is their improved mechanical properties.…”