Use of a modified Taber abrasion apparatus for investigating the complete stress state during abrasion and in-process wear particle aerosol generation
Résumé
A present challenge in chemical nano-product formulation is the prediction of structure–function relationships of designed nano-particle based chemical engineering products such as coatings or solids. A particular attention is in this framework today paid to the question whether such products will release particles to the air during their life cycle. This aerosolization of (nano-) particles impacts possibly occupational and consumer health. A possible particle release mechanism here is simply wear, i.e. for example when holding, moving or walking on nano-functionalized products. This means that further to the study of aerosolization, today's chemical engineers need to be able to study wear, enabling them to make future products ‘nanosafe by design’. The present article presents an affordable option for knowing the complete stress state, including both normal and tangential stresses, acting during alternated sliding abrasion when measuring the response of a surface to its wear. For this, a standard Taber™ linear abrasion 5750 apparatus is modified by adding a strain gauge and further coupled with a particle counter and particle sizers for quantifying the release of wear particles in air during abrasion. After the calibration, the modification is validated by comparing the force measurements with that of a commercial tribometer. Different case studies which were carried out using this modified apparatus show (i) clearly visible static and dynamic friction ranges and (ii) clear dependency of the wear behavior and the particle aerosolization on the chosen couple material–abraser.