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Fabrication of bioactive glass (BG) filled polyester composites by traditional thermoplastic processing techniques is limited because a thermal degradation reaction occurs between the Si-O À groups present on the surface of the BG and the C]O groups present in the backbone of the polymer at high temperatures. To overcome this problem, this study looked at the effect of mussel-inspired polydopamine (PDA) coated on the surface of BG particles. Thermogravimetric analysis demonstrated the improved thermal stability of poly(L-lactide) (PLLA) composites filled with PDA-coated BG particles compared to PLLA composites filled with uncoated BG particles. Moreover, these composites were successfully manufactured by hot-pressing, showing enhanced mechanical properties in comparison to non-coated BG filled PLLA composites. Dynamic mechanical analysis indicated a good interfacial interaction between PDA-coated BG particles and the PLLA matrix, suggesting that an immobilized layer of polymer chains was formed around the BG particles. Finally, the bioactivity of PLLA samples filled with 15 vol% of PDA-coated BG particles was confirmed via the deposition of an apatite layer on the surface of the material. In view of the results obtained it can be concluded that coating BG particles with PDA is a promising strategy as it can create composite materials with improved thermal stability and bioactivity.

Nanostructured ZnO has gained a considerable amount of attention due to its unique physical and chemical properties and due to its remarkable performance in the fields of optics, photonics and electronics. The scope of this work is to study the Structural, Optical and Electronic properties of Pure Zinc Oxide (ZnO) and Chromium doped Zinc Oxide nanoparticles. These nanoparticles were synthesized by low-temperature precipitation method at various concentrations in the range (Zn1-xCrxO; (x = 0, 0.1& 0.3)). The precursors used were analytical grade Zinc Nitrate Hexahydrate and Chromium Nitrate Nona hydrate. The synthesized nanoparticles were annealed at 400°C. The Structural property of the synthesized nanoparticles was analysed by XRD (X-Ray diffraction) and was confirmed to exhibit a crystalline hexagonal wurtzite structure with an average crystallite size of 55nm. The functional groups were analysed using FTIR (Fourier Transformed Infra-red spectroscopy). The Morphology was analysed by FESEM (Field Emission Scanning Electron Microscope) and a change in morphology from spherical to spindle like structure was observed. The Optical properties were analysed using UV-Vis spectroscopy, the absorption spectrum for electromagnetic spectrum was observed and the changes in the optical band gap of ZnO nanoparticles with Chromium dopant addition were calculated to be in the range of 3.6 eV. The Electrical property of the synthesised nanoparticles was analysed using Electrochemical Impedance Spectroscopy (EIS) and the conductivity was calculated to be in the range of 1.1e-07S/m.

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