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A composite aerosol filter media was prepared by depositing nanofibers on the non-woven fabrics substrate using needleless electrospinning technique. The polyvinyl alcohol nanofibers with mean diameters of ca. 100 nm were used as top layers. The filtration performance was evaluated by measuring the filtration of sodium chloride nanoparticles (75±20 nm) through the filters. It was found that the filtration efficiency of the composite filter media for nanoparticles was increased along with the thickness of nanofibers mats which was controlled by the collection time during the electrospinning. The multi-layer arrangement for fabrication of the composite filter can achieve high filtration efficiency (up to 99.95%) which was comparable to commercial high efficiency particulate air filters but with higher quality factor and less mass

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The doping of biocompatible nanomaterials into ultrahigh molecular weight polyethylene (UHMWPE) to improve the biocompatibility and reduce the wear debris is of great significance to prolonging implantation time of UHMWPE as the bearing material for artificial joints. This study shows that UHMWPE can form a composite with nanocrystalline cellulose (NCC, a hydrophilic nanosized material with a high aspect ratio) by ball-milling and hot-pressing. Compared to pure UHMWPE, the NCC/UHMWPE composite exhibits improved tribological characteristics with reduced generation of wear debris. The underlying mechanism is related to the weak binding between hydrophilic NCC and hydrophobic UHMWPE. The hydrophilic, rigid NCC particles tend to detach from the UHMWPE surface during friction, which could move with the rubbing surface, serve as a thin lubricant layer, and protect the UHMWPE substrate from abrasion. The biological safety of the NCC/UHMWPE composite, as tested by MC3T3-E1 preosteoblast cells and macrophage RAW264.7 cells, is high, with significantly lower inflammatory responses/cytotoxicity than pure UHMWPE. The NCC/UHMWPE composite therefore could be a promising alternative to the current UHMWPE for bearing applications.