Investigation on Photoluminescence Behaviour of 2, 3-Diphenylquinoxalin-6-Vinyl Benzaldehyde

Abstract

Open Access Research Articlesuccess of electrospinning will rely on the proper optimization of several process parameters including flow rate of spinning solution, applied voltage and distance from the needle tip to the fiber collector, as well as relevant solution properties such as viscosity, viscoelasticity, concentration, electrical conductivity and surface tension [6,14,28].Food-grade hydrocolloids of commercial importance include polysaccharides (natural carbohydrate polymers) and proteins. Food-grade hydrocolloids, alone or combined, are widely used by the food industry to improve texture, processing conditions and the overall quality of food products [3,17]. Processing hydrocolloids by electrospinning is often challenging since most of these compounds show inadequate or limited spinnability [28].Starch and guar gum are two cost-attractive hydrocolloids often used together in food formulations [8]. Starch is present in plants as semi crystalline granules which shape, size, morphology and composition (e.g. amylose/amylopectin ratio) will depend on the starch source and cultivation conditions [3,13]. The granules are composed of amylose or (1→4)-linked α-glucopyranose, a linear macromolecule responsible for starch's gelling properties [18], and amylopectin or (1→4)-linked α-glucopyranose with α-(1→6) branch linkages, a highly branched component that may form very weak gels [20]. Guar Gum (GG) is extracted from Cyampsis tetragonolobus seeds [32] and is formed by linear chains of β-(1-4)-D-mannan with side units of α-(1-6) linked galactose [24].Electrospinning of starch and GG have been studied separately in a few papers. Lubambo et al. [16] found that fibers obtained from GG solutions were not uniform and had insoluble aggregates between fibers and within their structure. These authors concluded that sequential filtration steps were needed after GG purification to reduce the aggregates and improve fiber morphology. Pure starch fibers in turn, could only be obtained from Dimethyl Sulfoxide (DMSO) solutions using electro-wetspinning technology due to the non-volatile nature of the organic solvent [12,13]. Starch derivatives have also been electrospun from formic acid solutions [15,34] while composite fibers have been produced from blends of starch with non-food grade polymers such as polyvinyl alcohol [29] and polylactic acid [30]. AbstractIn this study, electrospun nanofibers were prepared for the first time, from aqueous blends of guar gum (GG) and corn starch with amylose contents of 27.8% (CS28) and 50% (CS50). The fiber morphology and fiber diameter sizes (FDS) were correlated with solution rheology. The spinning solutions were prepared with 3 wt% total concentration and mass ratios ranging from 4:1 to 1:4 GG/CS. The GG alone (3 wt%) was highly viscous and predominantly elastic (G'>G'') over the range of tested frequencies. Both CS were effective rheological modifiers that facilitated the electrospinning process. Partial substitution of GG by CS decreased solution viscosity and moved the elastic plateau (...