Fabrication and characterisation of ultrafine leather powder: a functional reinforcement containing SiO2 particles

The water-based dispersion of ultrafine leather fibres was firstly prepared in the authors´ laboratory by high-pressure homogenisation. The hybridisation method of ultrafine leather fibres and SiO₂ particles was used to eliminate the serious agglomeration of ultrafine leather fibres, and finally the dry hybrid leather powder (HLP) was obtained successfully. The morphology of the HLP was investigated using scanning electron microscopy (SEM). The micrograph of SEM revealed that the leather fibres were coated with a layer of scattered SiO₂ particles and still maintained their intrinsic fibrous structures. Surface element analysis (energy dispersive X-ray spectrometry) confirmed that the SiO₂ particles were anchored on the surface of the leather fibres. Furthermore, the formation of bonding effect between the leather fibres and the SiO₂ particles was also demonstrated by X-ray photoelectron spectrometry measurement. The obtained leather fibres were observed to be approximately less than 30 μm in length and 70 nm in width. X-ray diffraction analysis and thermogravimetric analysis were also used to investigate the characterisation of ultrafine leather powders, and one of the results showed that the HLP had greater thermal stability than leather shavings.