The improvement of dispersity, thermal stability and mechanical properties of collagen fibers by silane modification: an exploration for developing new leather making technology

The effect of hydrophobic modification on the performances of collagen fibers(CFs)was investigated by using silane coupling agents with different alkyl chains as hydrophobic modifiers.It was found silane could be easily grafted onto CF surface through covalent bonds under 5%water content.This modification led to the transformation of surface wettability of CF from hydrophilic to hydrophobic.Interestingly,the change of surface wettability resulted in substantial improvement of the modified CF properties,presenting well dispersity of collagen fibers,higher thermal stability and enhanced mechanical properties in comparison with natural CF.The degree of improvement mainly depended on the length of alkyl chain in silane.Longer alkyl chain produced strong hydrophobicity and subsequently more superior performances of the modified CF.When the length of alkyl chain increased to 18 carbon atoms,the modified CF possessed durable superhydrophobicity even exposed to aqueous solutions of different pH,UV,and organic solvents,and had excellent thermal and mechanical properties like leather fibers.In general,this work clearly revealed that the properties of CF are closely and positively related to the hydrophobicity,which is suggestive in developing new leather making technology.