Figure 3

Machining induced release from nanocomposites. The most extensively examined release scenario, nearly half of all the nanorelease studies utilized some form of machining. All but one of these studies reports the detection of some form of release debris; most frequently (91%) are particles of matrix, and less frequently but still common (87%) are particles of matrix with embedded nanomaterials. Less then a third of the studies (30%) report identifying dissociated nanomaterials among the release debris. Across study summaries are present in charts: (A) the added nanomaterial, (B) the matrix, (C) the released debris identified and (D) the number of experiments versus observational studies. (*) Authors report release only after a combination of weathering and machining; (-) authors report insignificant but detectable levels of dissociated nanomaterial; (?) data supporting this result are indirect or not presented, but described by the authors; (exp) rigorous experiments with replicate testing and negative controls (samples of matrix without added nanomaterial) examined; (obs) observational studies with no control samples and/or not replicate testing; (C) refers to any one of multiple forms of Carbonaceous nanomaterials, including: single and multi-walled carbon nanotubes, graphene oxide, carbon black and uncharacterized carbon nanotubes; (CSH) are calcium silicate hydrates; (%) a complex copper II with chlorinated phthalocyanine; (@) alumina based Cobalt Blue.