An increase of environmental awareness recently has increased the interest of researchers in using of biopolymer-based films. The films have been prepared extensively by utilizing starch, carboxymethyl cellulose, chitosan, protein, gelatin, carrageenan, alginate, pectin, guar gum and pullulan. They are typically modified with surface-active agents (surfactants) such as glycerol monostearate, sucrose ester, sodium stearoyl lactate, sodium dodecyl sulfate, ethyl lauroyl arginate HCl, Span 20 to 80, Tween-20 to 80 and soy lecithin for improving the functional properties of the films. In this brief review, two types of biopolymer-based films that prepared through casting method were categorized, specifically solution- and emulsion-based films. The four types of surfactants, namely non-ionic, anionic, cationic and amphoteric surfactants that are regularly used to modify biopolymer-based films are also described. The functional properties of the films modified with different types of surfactants are briefly reviewed. This study enhances the attraction of researchers in biopolymer-based films and the improvement of new concepts in this niche area.

PLASTICIZING EFFECT OF CHOLINE CHLORIDE/UREA EUTECTIC-BASED IONIC LIQUID ON PHYSICOCHEMICAL PROPERTIES OF AGAROSE FILMS

An enhancement of environmental concern lately has improved the awareness of researchers in employing eco-friendly solvents for processing biopolymers. Recently, ionic liquids have been utilized to prepare biopolymer blends as they are non-volatile and recyclable. Biopolymers such as cellulose, chitin, chitosan, keratin, lignin, silk, starch, and zein are widely used for the preparation of biopolymer blends via dissolution in ionic liquids, followed by coagulation procedure. In this concise review, three types of ionic liquids based on imidazolium cations combined with different counter anions that are frequently utilized to prepare biopolymer blends are described. Moreover, three types of biopolymer blends that are prepared in ionic liquids were classified, specifically polysaccharide/polysaccharide blends, polysaccharide/polypeptide blends, and polysaccharide/bioplastic blends. The physicochemical properties of biopolymer blends prepared in different imidazolium-based ionic liquids are also concisely reviewed. This paper may assist the researchers in the polymer blend area and generate fresh ideas for future research.

The recent growth of nanotechnology consciousness has enhanced the attention of researchers on the utilization of polymer nanocomposites. Nanocomposite have widely been made by using synthetic, natural, biosynthetic, and synthetic biodegradable polymers with nanofillers. Nanofillers are normally modified with surfactants for increasing the mechanico-thermal properties of the nanocomposites. In this short review, two types of polymer nanocomposites modified by surfactants are classified, specifically surfactant-modified inorganic nanofiller/polymer nanocomposites and surfactant-modified organic nanofiller/polymer nanocomposites. Moreover, three types of surfactants, specifically non-ionic, anionic, and cationic surfactants that are frequently used to modify the nanofillers of polymer nanocomposites are also described. The effect of surfactants on mechanico-thermal properties of the nanocomposites is shortly reviewed. This review will capture the interest of polymer composite researchers and encourage the further enhancement of new theories in this research field.

Increased environmental awareness has encouraged researchers to seek alternatives to replace the use of hazardous chemicals in the extraction of nanocellulose for environmental conservation. Lately, ionic liquids have been used as a medium for processing cellulose and other biopolymers because they are recyclable and reusable. Recently, ionic liquids have been used to extract nanocellulose for a variety of applications. In this short review, examples of ionic liquids that are usually used for the extraction of nanocellulose are demonstrated. Additionally, sources of cellulose that are employed as raw materials for nanocellulose have also been shown. Moreover, the synthesis of ionic liquids and the process of nanocellulose extraction using ionic liquids are exhibited in this paper. In addition, the properties of nanocellulose extracted by different ionic liquids were also shortly reviewed. On top of that, the knowledge gained from this review provides a clearer comprehension of the process of nanocellulose extraction and the important properties of the extracted nanocellulose. In conclusion, this short review revealed that different mechanisms of nanocellulose extraction using ionic liquids give distinct properties to the extracted nanocellulose.