Oil spills on ocean waters represent a major threat to marine ecosystems. A significant part of the spilled oil is dispersed in microdroplets that are not recovered by traditional oil-removing methods. In this work, we report on the manufacture of cellulose acetate (CA) electrospun non-woven membranes, stamped with different cellulose nanocrystal (CNC) patterns. We demonstrate the use of the membranes produced as selective oil microdroplets removal from water emulsions with an efficiency up to 80%. Screenprinting was used to imprint different CNC designs on the CA surface membranes. To promote the adhesion between the CNCs and the CNCs with the CA fibers the membrane was subjected to a thermal and chemical treatments. Oil droplets were collected under water in the oleophilic CNC pattern while the water could flow through the hydrophilic CA electrospun non-woven membrane.

Cellulose micro/nanomaterials (CMNM), comprising cellulose microfibrils (CMF), nanofibrils (CNF), and nanocrystals (CNC), are being recognized as promising bio-nanomaterials due to their natural and renewable source, attractive properties, and potential for applications with industrial and economical value. Thus, it is crucial to investigate their potential toxicity before starting their production at a larger scale. The present study aimed at evaluating the cell internalization and in vitro cytotoxicity and genotoxicity of CMNM as compared to two multi-walled carbon nanotubes (MWCNT), NM-401 and NM-402, in A549 cells. The exposure to all studied NM, with the exception of CNC, resulted in evident cellular uptake, as analyzed by transmission electron microscopy. However, none of the CMNM induced cytotoxic effects, in contrast to the cytotoxicity observed for the MWCNT. Furthermore, no genotoxicity was observed for CNF, CNC, and NM-402 (cytokinesis-block micronucleus assay), while CMF and NM-401 were able to significantly raise micronucleus frequency. Only NM-402 was able to induce ROS formation, although it did not induce micronuclei. Thus, it is unlikely that the observed CMF and NM-401 genotoxicity is mediated by oxidative DNA damage. More studies targeting other genotoxicity endpoints and cellular and molecular events are underway to allow for a more comprehensive safety assessment of these nanocelluloses.