Mesoporous silica nanoparticles are used to fabricate antireflectance coatings on glass substrates. The combination of mesoporous silica nanoparticles in conjunction with a suitable binder material allows mechanically robust single layer coatings with a reflectance <0.1% to be produced by simple wet processing techniques. Further advantages of these films is that their structure results in broadband antireflective properties with a reflection minimum that can tuned between 400 nm and 1900 nm. The ratio of binder material to mesoporous nanoparticles allows control of the refractive index. In this report, we discuss how control of the structural properties of the coatings allows optimization of the optical properties.

We investigate the growth and the physical and optical properties of type-II heterostructured ZnTe/ZnSe colloidal nanocrystals, focusing on the role of the 7% lattice mismatch between the two materials in determining growth homogeneity and band structure. We find that the lattice mismatch between the two materials places limitations on the range of structures that can be grown, and for those in which coherent growth is achieved we present clear evidence that the low bulk modulus ZnTe cores are compressed by the higher modulus ZnSe shells, accentuating the red-shift of the excitonic state with increasing shell thickness. By employing a variety of characterization tools we build a clear picture of the core–shell architecture. We show how strain is manifested in structures with sharp core–shell interfaces and how intentional alloying of the interface can influence the growth and exciton energies. We show that a (2,6)-band effective mass model is able to distinguish between the as-grown “sharp” and “alloyed” interfaces, indicating that the alloyed structures incorporate reduced strain.

Lead oxide nanocrystals are synthesised by injecting oxygen gas into an air and moisture free complex of Pb oleylamine and oleic acid in octadecene. Using various characterization methods including fabrication and testing of photovoltaic devices we explore the material properties and photovoltaic application of lead oxide nanocrystal films.

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Methods for chemical surface functionalization for carbon black (CB) nanoparticles were studied to produce (CB)/polypropylene (PP) nanocomposites with superior electrical and thermal properties. Nanoparticle dispersion is known to directly control the extent to which nanocomposites maximize the unique attributes of their nanoscale fillers. As a result, tailored nanoparticle surface chemistry is a widely utilized method to enhance the interfacial interactions between nanoparticles and polymer matrices, assisting improved filler dispersion. In this work, a rapid chemical functionalization approach using a number of diarylcarbene derivatives, followed by the azo-coupling of substituted diazonium salts, for the covalent introduction of selected functional groups to the CB surface, is reported. Characterization of the modified CB by XPS, TGA, CHN, and ATR-IR collectively confirmed surface functionalization, estimating surface grafting densities of the order of 10(13) and 10(14) molecules/cm(2). Nanocomposites, synthesized by solvent mixing PP with pristine and modified CB, demonstrated macroscopic property changes as a result of the nanoparticle surface functionalization. Pronounced improvements were observed for PP nanocomposites prepared with a dodecyl-terminated diaryl functionalized CB, in which TEM analysis established improved nanofiller dispersion owing to the enhanced CB-PP interfacial interactions in the nanocomposite. Observed dielectric relaxation responses at 20 wt % loading and a reduced percolation threshold realized conductivities of 1.19 × 10(-4) S cm(-1) at 10 wt %, compared to 2.62 × 10(-15) S cm(-1) for pristine CB/PP nanocomposites at the same filler loading. In addition, thermal properties signify an increase in the number of nucleation sites by the raised degree of crystallinity as well as increased melting and crystallization temperatures.

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The electrochemical properties of a newly synthesised set of PPV derivatives were measured by cyclic voltammetry. A new octyloxy substituted PPV derivative was first synthesised (POPV). The structure of the POPV is varied systematically by the replacement of the phenyl units by naphthyl and anthryl units and the effect of these variations on the electrochemical properties is explored. The HOMO-LOMO levels of the polymers were determined from the onset potentials for the p-doping and n-doping scans. From this the electrochemical bandgap for each of the polymers was calculated. The systematic change in the structure of the POPV results in a systematic increase in the LOMO level of the polymer series whereas a concomitant increase in HOMO level results in an overall increase in the bandgap of the polymers series. The variation in the electrochemical, optical properties and vibrational properties observed within the polymer series were all found to correlate with the structural changes made, pointing towards structure property relationships and a guide to future synthetic strategies.

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