A sustainable one-step pretreatment of cotton gray fabric with 18-crown-6 as phase transfer in supercritical carbon dioxide

With increasing awareness in environmental protection from the world, traditional pretreatment methods for textiles, which entail high costs and cause severe pollutions, can no longer meet the requirements of green and sustainable development in textile industry. Therefore, to explore a new pretreatment method to overcome those drawbacks is of great importance. In this work, green and environmentally friendly method was developed in supercritical carbon dioxide fluid to pretreat cotton gray fabric for removing various impurities with one step and one bath, by utilizing an 18-crown-6 phase transfer system. Various process parameters, such as the pH value of buffer solution, the dosage of phase transfer catalyst, hydrogen peroxide, buffer solution, and the system temperature, pressure, treatment duration, were investigated and optimized by employing the weight loss percent and the capillary rise height as assessment index. The obtained results show that the developed alkali-hydrogen peroxide one-step method involving the 18-crown-6 phase transfer system in supercritical carbon dioxide exhibits a good feasibility for the removal of various sizing agents and other impurities from cotton fabric, and a satisfactory pretreatment performance and efficiency were achieved. The pretreatment parameters showed an important and various effects on the pretreatment efficiency of cotton substrate during a phase transfer oxidative one-step process in supercritical carbon dioxide. Moreover, a phase transfer oxidative one-step process was also recommended for cotton gray fabric pretreatment in supercritical carbon dioxide, by achieving a fabric weight loss at 6.21% and a satisfactory capillary rise height at 8.0 cm under an optimized condition. Additionally, an oxidative one-step pretreatment mechanism by employing 18-crown-6 to phase transfer reactive species for cotton gray fabric in SCF-CO2 was further supposed.

Automated summary

With the increasing awareness of environmental protection, a green and environmentally friendly method was developed using supercritical carbon dioxide with an 18-crown-6 phase transfer system to pretreat cotton fabric, achieving efficient removal of impurities in one step. Various parameters were optimized to achieve satisfactory pretreatment performance and efficiency.