posted on 2024-02-22, 14:05authored byZhenghao Shi, Yifeng Sheng, Jianhui Wu, Jiwei Cui, Wei Lin, To Ngai
Waterborne polyurethane (WPU) latex nanoparticles with
proven interfacial
activity were utilized to stabilize air–water interfaces of
Pickering foams through interfacial interaction with hydrophobic fumed
silica particles (SPs). The rheological properties of the Pickering
foam were tailored through adjustment of their SP content, which influenced
their formability and stability. A Pickering foam stabilized with
WPU and SPs was used as a template to prepare a WPU–SP composite
porous film. The as-prepared film had intact open-cell porous structures,
which increased its water absorption and water-vapor permeability.
The porous film was used as a middle layer in the preparation of synthetic
leather via a four-step “drying method”. Compared with
commercial synthetic leather, the lab-made synthetic leather with
a middle layer made of the WPU–SP composite porous film exhibited
a richer porous structure, acceptable wetting on a fabric substrate,
a thicker porous layer, and higher water-vapor permeability. This
work provides a novel and facile approach for preparing WPU–SP
Pickering foams. Furthermore, the foams have the potential to function
as a sustainable material for creating a porous-structured synthetic
leather made from WPU, which may be utilized as an alternative to
solvent-based synthetic leather.