Capillary-driven Water Transport in Microfiber Textiles: Experimental Characterization and Application in a High-efficiency Multi-stage Passive Solar Desalination

Given the escalating water and energy crises worldwide, the development of passive desalination systems has become inevitable. Among various approaches, particular attention has been directed toward capillary-driven systems, yet despite numerous studies in this field, selecting textiles with optimal capillary and evaporative properties remains a key research challenge. Unlike prior studies, this research for the first time systematically evaluates and compares the wicking performance of two distinct microfiber textile structures (woven (A) vs. brushed knit (B)) with capillary-related properties of the textiles for application in multi-stage passive solar desalination systems. Furthermore, this study introduces a new figure of merit, the Water Turnover Ratio (WTR), to assess textile suitability for wick‑based multi‑stage solar desalination, and establishes a clear structure–property–performance relationship for this application. A single-stage desalination system was constructed and the results showed that sample B exhibited a ۱۹% higher Recovery Ratio and an ۱۸.۸% higher WTR compared to sample A. Consequently, the sample B is identified as a suitable candidate for passive desalination systems due to its superior performance. Subsequently, this textile was used to construct multi-stage desalination system. Results demonstrated a freshwater collection rate of ۲.۷۷ l/m²h and a gained output ratio (GOR) of ۱۸۹% for the ۵-stage system under a ۱۰۰۰ W/m² heat flux. Finally, an empirical correlation was proposed and validated to predict the freshwater production of the multi‑stage system over a wide range of operating conditions. The findings indicate that this system, with its low manufacturing cost, holds significant potential for use in remote areas.

کلیدواژه ها:

Multi-stage solar still ، Interfacial solar evaporation ، Passive desalination ، Capillary wicking ، Microfiber textile