Coalescence behavior of eco-friendly Pickering-MIPES and HIPEs stabilized by using bacterial cellulose nanofibrils.

O/W Pickering emulsions containing oil phase with different volume fractions (50-75 v%) were facilely prepared by using bacterial cellulose nanofibrils (BCNFs) alone. The effect of oil phase volume, storage time on the surface coverage, and coalescence rate of the Pickering-MIPEs and HIPEs (medium internal phase emulsions/high internal phase emulsions) were investigated. The Pickering-MIPEs/HIPEs exhibited excellent physical stability and low coalescence rate with droplet size varying from 32 to 91 µm. The increasing of particle contents could obviously decrease the droplet size and enhance the stability of the emulsions by strengthening the network structure and increasing the steric hindrance. The result of rheology analysis confirmed the formation of a three-dimensional network, endowing the exceptional stability of the emulsions. The emulsions revealed superb stability against a wide temperature (4-50 °C) range and salt condition (0-100 mM). This novel eco-friendly Pickering-MIPEs and HIPEs would provide great opportunities for their effective utilization in green-labelled food industry.

Natural Colorants: Historical, Processing and Sustainable Prospects.

With the public's mature demand in recent times pressurized the textile industry for use of natural colorants, without any harmful effects on environment and aquatic ecosystem, and with more developed functionalities simultaneously. Advanced developments for the natural bio-resources and their sustainable use for multifunctional clothing are gaining pace now. Present review highlights historical overview of natural colorants, classification and predominantly processing of colorants from sources, application on textiles surfaces with the functionalities provided by them. Chemistry of natural colorants on textiles also discussed with relevance to adsorption isotherms and kinetic models for dyeing of textiles.

An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics.

In the present study Terminalia chebula was used as an eco-friendly natural colorant for sustainable textile coloration of woolen yarn with primary emphasis on thermodynamic and kinetic adsorption aspects of dyeing processes. Polyphenols and ellagitannins are the main coloring components of the dye extract. Assessment of the effect of pH on dye adsorption showed an increase in adsorption capacity with decreasing pH. Effect of temperature on dye adsorption showed 80 °C as optimum temperature for wool dyeing with T. chebula dye extract. Two kinetic equations, namely pseudo first-order and pseudo second-order equations, were employed to investigate the adsorption rates. Pseudo second-order model provided the best fit (R (2) = 0.9908) to the experimental data. The equilibrium adsorption data were fitted by Freundlich and Langmuir isotherm models. The adsorption behavior accorded well (R (2) = 0.9937) with Langmuir isotherm model. Variety of eco-friendly and sustainable shades were developed in combination with small amount of metallic mordants and assessed in terms of colorimetric (CIEL(∗) a (∗) b (∗) and K/S) properties measured using spectrophotometer under D65 illuminant (10° standard observer). The fastness properties of dyed woolen yarn against light, washing, dry and wet rubbing were also evaluated.