engleski

Bio-Innovated Cotton Cellulose – Surface Free Energy

Raw cotton fibres contain around 95% of pure cellulose balanced by the non-cellulosic impurities of proteins, oils, waxes, pectins, carbohydrates and inorganic materials which should be removed in desizing, scouring, and bleaching processes. The enzymatic pre-treatments of cellulose fabrics have received much attention in the last decade due to its environmental benefits and special performance in comparison with the conventional processing of textiles. The use of protease, lipase, pectinase, cutinase and cellulase, individually or in a mixture can replace alkaline scouring. Amylase, glucose oxidase and peroxidase enzymes can be used for desizing and bleaching of cotton-like fabrics (Agrawal 2008, Grancaric 2001, 2002, 2009, Forte-Tavcer 2012). For that reason, the research was focused on the application of amylase, alkali and neutral pectinase, and cellulase for the bio-inovation of cotton cellulose. Textile wettability and adsorption are the most important phases in textile finishing processes, which depend to a large extend on the kind and magnitude of the solid surface free energy. Changing the number of functional fiber surface groups, e.g. by pretreatment, modification, finishing or dyeing of the fabric, affect the distribution of surface charge, resulting in change of its surface free energy and wettability (Grancaric 2005). Therefore, the influence of bio-innovation of the plain woven cotton fabric to its surface free energy (Grancaric 2002, 2008), as well as its hydrophilicity and whiteness, was researched in this paper. Hydrophilicity of cotton samples was determined according to drop test (AATCC 79-2010), vertical (DIN 53924) and horizontal wicking methods. Degree of whiteness (WCIE) was calculated from spectral characteristics measured on remission spectrophotometer SF 600 PLUS CT (Datacolor) according to DIN 6167. Pre-treatment processes of cotton fabrics cause the change in the textile surface properties resulting in a great change of its surface free energy. Raw as untreated cotton is apolar with SLW equals to its total surface free energy, STOT. The pre-treatment of cotton results in the high increase of the S- value, but does not have a significant effect on the increase of S+. This suggests that the pretreated cotton fabrics can be described as monopolar surfaces of strong electron donor capacity. When considering the hydrophilicity and whiteness, as well as from the ecological point of view, the use of neutral pectinase was of benefit as there was no need for neutralisation of the wastewaters.

surface free energy ; bio-innovation of cotton ; amylase ; pectinase ; cellulase

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