A novel dual-chamber microcapsule inspired by lotus seedpod for temperature-controlled fragrance release and thermal-regulation of fabrics

Abstract

Household textiles such as anti-bug curtains and car seat cushions with fragrance-controlled release properties and temperature regulation have become increasingly popular with the improvement of living standards and health awareness. Microencapsulation is a common finishing method for functional textiles. However, traditional microcapsules are typically designed as single-chamber systems with limited functionality, making it difficult to meet the demands of complex applications. To overcome this limitation, a novel dual-chamber microcapsule was developed, with its design taking inspiration from the lotus seedpod. Robust SiO₂ nanospheres containing phase change materials were initially synthesized as Pickering emulsifiers to prepare emulsions loaded with essential oils. The melamine-formaldehyde monomers crosslinked to form the microcapsule walls under acidic conditions. Simultaneously, the SiO₂ nanospheres encapsulating phase change materials were integrated into the wall structure. The encapsulation of phase change materials and essential oils within a single capsule was optimized. The dual-chamber microcapsule system manifested fragrance-controlled release and energy-storage properties concurrently. The release studies of essential oils revealed the capacity and mechanism to govern the uniform and stable release of mint oil. Even though the temperature increased by 50 °C, the cumulative release of oil changed by a mere 9.85 %. Moreover, the dual-chamber microcapsule system not only could adjust the material temperature, but also exhibit remarkable thermal impact resistance, and it possesses high thermal stability after 100 cycles. Subsequently, the microcapsules were applied for the functional finishing of the textile, which exhibited excellent fragrance-controlled release and thermal regulation from 30 °C to 70 °C, thereby achieving a comprehensive improvement from smell to touch. Overall, these microcapsules, characterized by their innovative design, were endowed with unique functionality, thereby presenting substantial potential for applications in smart textiles.