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The unique characteristics of polyether ether ketone (PEEK) including low elastic modulus, high mechanical strength, and biocompatibility have made it an attractive alternative for the metallic biomaterials. However, its bioinert property is always the main concern, which could lead to poor osseointegration and subsequent clinical failure of the implant. Changing the surface structure to porous structure and mixing it with bioactive hydroxyapatite (HA) are the common methods, which could be used to enhance the properties of the PEEK-based implants. In this study, friction stir processing was utilized for the fabrication of porous HA/PEEK surface nanocomposite. Scanning electron microscopic image of the nanocomposite surface showed nano-scale roughness of the porous structure. Water contact angle test confirmed the increase in the wettability of the treated specimens. In vitro bioactivity test via simulated body fluid solution, initial cell adhesion, cell proliferation, and cell differentiation assay also confirmed the enhancement in bioactivity of the treated surface in comparison to the bare PEEK. This surface modification method requires no special equipment and would not damage the heat-sensitive PEEK substrate due to the low temperature used during the fabrication process.

In this work, ultrafiltration (UF) mixed matrix membranes (MMMs) incorporated with hydrophilic hydrous manganese oxide (HMO) nanoparticles were synthesized and used for the treatment process of a highly concentrated oily solution. The MMMs were fabricated via a phase inversion process and were characterized with respect to physiochemical properties and filtration performances. The results showed that the MMMs demonstrated higher water flux and better oil rejection rates compared to the control membrane (without HMO incorporation) when tested at three different oily solutions with oil concentration in the range of 5000–15?000?ppm. The membrane incorporated with the highest amount of HMO (labelled as MMM-2) in particular showed the best results even when subjected to 15?000?ppm oily solution filtration, recording water flux of 32.2 L/m2?·?h?·?bar and oil rejection of 82?%. The enhanced performance can be attributed to improved surface hydrophilicity coupled with better structural integrity and higher porosity that contributed to lower degree of oil molecules deposition and greater water transport rate. It was also reported that with the use of a feed spacer during the filtration process, the degree of flux deterioration of MMMs could be further reduced without compromising rejection. The findings of this work indicated the potential of MMMs for the treatment of highly concentrated oily effluent produced from industries, by producing permeate of high quality at reasonably good water permeability.

For the first time, engineered osmosis was performed using commercial nanofiltration (NF) membranes for the treatment process of aerobically treated palm oil mill effluent (AT-POME). Compared to conventional forward-osmosis (FO) membranes with dense rejection layer, the NF-like FO membranes offer a higher water flux with minimum reverse solute flux provided appropriate solutes like divalent salts or polyelectrolytes were used in the draw solution. Both NF membranes were able to treat the AT-POME by completely preventing the color component from passing through the permeate side under FO and pressure-retarded osmosis (PRO) orientation. The water fluxes of the membranes were higher under PRO orientation owing to the reduced internal concentration polarization effect. Relatively loose membranes for the engineered osmosis application could address severe surface fouling of membranes tested under pressure-driven filtration.