Explore the vast range of titles available.

Diaryldithiocarbamate complexes, [Fe(S2CNAr2)3], have been prepared and their structure, reactivity, and thermal degradation to afford iron sulfide nanomaterials have been investigated. The addition of three equivalents of LiS2CNAr2 to FeCl2·4H2O in water-air affords dark red [Fe(S2CNAr2)3] in high yields. All show magnetic measurements consistent with a predominantly high-spin electronic arrangement at room temperature. The molecular structure of [FeS2C(N-p-MeOC6H4)23] reveals the expected distorted octahedral geometry, but Fe-S distances are more consistent with a low-spin electronic configuration, likely a result of the low temperature (120 K) of the data collection. The thermal stability of [FeS2C(N-p-MeC6H4)23] has been investigated. TGA shows that it begins to decompose at a significantly lower temperature (ca. 160 °C) than previously observed for [Fe(S2CNEt2)3], and this is further lowered (to ca. 100 °C) in oleylamine. The decomposition of [FeS2C(N-p-MeC6H4)23] in oleylamine, via either a heat-up or hot injection process, affords nanoparticles of Fe3S4 (greigite), while in contrast, dry heating at 450 °C affords FeS (troilite) as large agglomerates.

Nickel-doped cerium dioxide nanoparticles exhibit room temperature ferromagnetism due to high oxygen mobility within the doped CeO2 lattice. CeO2 is an excellent doping matrix as it can lose oxygen whilst retaining its structure. This leads to increased oxygen mobility within the fluorite CeO2 lattice, leading to the formation of Ce3+ and Ce4+ species and hence doped ceria shows a high propensity for numerous catalytic processes. Magnetic ceria are important in several applications from magnetic data storage devices to magnetically recoverable catalysts. We investigate the effect doping nickel into a CeO2 lattice has on the room temperature ferromagnetism in monodisperse cerium dioxide nanoparticles synthesised by the thermal decomposition of cerium(III) and nickel(II) oleate metal organic precursors before and after annealing. The composition of nanoparticles pre- and post-anneal were analysed using: TEM (transmission electron microscopy), XPS (X-ray photoelectron spectroscopy), EDS (energy-dispersive X-ray spectroscopy) and XRD (X-ray diffraction). Optical and magnetic properties were also studied using UV/Visible spectroscopy and SQUID (superconducting interference device) magnetometry respectively.

Thin films of PbSxSe(1−x) (0 ≤ x ≤ 1) have been deposited by spin coating of bis(dodecylxanthato)lead(II) (1) and/or bis(N,N-diethyl-N′-naphthoylselenoureato)lead(II) (2) complexes onto glass substrates followed by heating. The mole fraction of the selenium precursor in the coating mixture was varied from 0 to 1 by mixing the S and Se precursors. The as-prepared thin films were then heated at temperatures ranging from 250 to 400 °C. Powder X-ray diffraction showed all films were of the halite structure with preferred orientation along (200) plane. The PbS films showed a closely packed network of nanorods, each comprised of smaller nanoparticles. The nanorods were about 500 nm in length and 25 nm in width; the adhered particles had ca. 30 nm sides. The PbSe nanoparticles were also cubic. The alloys showed an intermediate morphology between the rods and cubes depending on the precursor ratio in the coating mixture. The band gaps estimated from Tauc plots for the films heated at 250 °C for 30 min were 1.03 and 0.79 eV for PbS and PbSe, respectively. The alloyed PbSxSe(1−x) thin films exhibited band gaps between those of PbS and PbSe. The band gaps and lattice parameters of the alloys varied in a Vegardian manner and could be closely correlated with the composition of the precursor mixture.

Thin films of PbS x Se (1− x ) (0 ≤  x  ≤ 1) have been deposited by spin coating of bis (dodecylxanthato)lead(II) ( 1 ) and/or bis ( N , N -diethyl- N′ -naphthoylselenoureato)lead(II) ( 2 ) complexes onto glass substrates followed by heating. The mole fraction of the selenium precursor in the coating mixture was varied from 0 to 1 by mixing the S and Se precursors. The as-prepared thin films were then heated at temperatures ranging from 250 to 400 °C. Powder X-ray diffraction showed all films were of the halite structure with preferred orientation along (200) plane. The PbS films showed a closely packed network of nanorods, each comprised of smaller nanoparticles. The nanorods were about 500 nm in length and 25 nm in width; the adhered particles had ca. 30 nm sides. The PbSe nanoparticles were also cubic. The alloys showed an intermediate morphology between the rods and cubes depending on the precursor ratio in the coating mixture. The band gaps estimated from Tauc plots for the films heated at 250 °C for 30 min were 1.03 and 0.79 eV for PbS and PbSe, respectively. The alloyed PbS x Se (1− x ) thin films exhibited band gaps between those of PbS and PbSe. The band gaps and lattice parameters of the alloys varied in a Vegardian manner and could be closely correlated with the composition of the precursor mixture.

An orally-administered system for targeted, on-demand drug delivery to the gastrointestinal (GI) tract is highly desirable due to the high instances of diseases of that organ system and harsh mechanical and physical conditions any such system has to endure. To that end, we present an iron oxide nanoparticle/wax composite capsule coating using magnetic hyperthermia as a release trigger. The coating is synthesised using a simple dip-coating process from pharmaceutically approved materials using a gelatin drug capsule as a template. We show that the coating is impervious to chemical conditions within the GI tract and is completely melted within two minutes when exposed to an RF magnetic field under biologically-relevant conditions. The overall simplicity of action, durability and non-toxic and inexpensive nature of our system demonstrated herein are key for successful drug delivery systems.

Diaryldithiocarbamate complexes, [Fe(S[sub.2]CNAr[sub.2])[sub.3]], have been prepared and their structure, reactivity, and thermal degradation to afford iron sulfide nanomaterials have been investigated. The addition of three equivalents of LiS[sub.2]CNAr[sub.2] to FeCl[sub.2]·4H[sub.2]O in water-air affords dark red [Fe(S[sub.2]CNAr[sub.2])[sub.3]] in high yields. All show magnetic measurements consistent with a predominantly high-spin electronic arrangement at room temperature. The molecular structure of [FeS[sub.2]C(N-p-MeOC[sub.6]H[sub.4])[sub.2][sub.3]] reveals the expected distorted octahedral geometry, but Fe-S distances are more consistent with a low-spin electronic configuration, likely a result of the low temperature (120 K) of the data collection. The thermal stability of [FeS[sub.2]C(N-p-MeC[sub.6]H[sub.4])[sub.2][sub.3]] has been investigated. TGA shows that it begins to decompose at a significantly lower temperature (ca. 160 °C) than previously observed for [Fe(S[sub.2]CNEt[sub.2])[sub.3]], and this is further lowered (to ca. 100 °C) in oleylamine. The decomposition of [FeS[sub.2]C(N-p-MeC[sub.6]H[sub.4])[sub.2][sub.3]] in oleylamine, via either a heat-up or hot injection process, affords nanoparticles of Fe[sub.3]S[sub.4] (greigite), while in contrast, dry heating at 450 °C affords FeS (troilite) as large agglomerates.

Thin films of PbS.sub.xSe.sub.(1-x) (0 [less than or equal to] x [less than or equal to] 1) have been deposited by spin coating of bis(dodecylxanthato)lead(II) (1) and/or bis(N,N-diethyl-N'-naphthoylselenoureato)lead(II) (2) complexes onto glass substrates followed by heating. The mole fraction of the selenium precursor in the coating mixture was varied from 0 to 1 by mixing the S and Se precursors. The as-prepared thin films were then heated at temperatures ranging from 250 to 400 °C. Powder X-ray diffraction showed all films were of the halite structure with preferred orientation along (200) plane. The PbS films showed a closely packed network of nanorods, each comprised of smaller nanoparticles. The nanorods were about 500 nm in length and 25 nm in width; the adhered particles had ca. 30 nm sides. The PbSe nanoparticles were also cubic. The alloys showed an intermediate morphology between the rods and cubes depending on the precursor ratio in the coating mixture. The band gaps estimated from Tauc plots for the films heated at 250 °C for 30 min were 1.03 and 0.79 eV for PbS and PbSe, respectively. The alloyed PbS.sub.xSe.sub.(1-x) thin films exhibited band gaps between those of PbS and PbSe. The band gaps and lattice parameters of the alloys varied in a Vegardian manner and could be closely correlated with the composition of the precursor mixture.

Colloidally-stable inorganic nanocrystals have a wide range of envisaged applications in biological environments. To reach their potential, the nanocrystals need to be stable in aqueous environments and have pendant functionality available for attachment of biomolecules. In this thesis, new methods for the transfer of nanocrystals from organic to aqueous media are developed and the interaction of aqueous stabilised particles with serum proteins is investigated. In Chapter 3, a new method for the synthesis of a thin silica layer upon the surface of nanocrystals is demonstrated. The method uses the hydrophobic interaction between an amphiphilic polymer and nanocrystal ligands to provide a foundation for growth of a silica layer. The coated nanocrystals are characterised using a wide range of techniques confirming that the presence and location of the silica shell. In Chapter 4, custom-synthesised amphiphilic polymers for water transfer and functionalisation of nanocrystals are synthesised, characterised and tested. Commercially-available polymers used for this purpose are examined, leading to a rationale for custom-design. Partial water transfers were achieved using activated ester copolymers with styrene but no transfers were achieved the octadecylacrylate copolymers. Poly(ethylene glycol) containing monomers were also used but yielded no transfers. This suggests that behaviour of the polymer during the coating procedure is intimately linked to the structure of the polymer. In Chapter 5, small-angle neutron scattering is used to elucidate structural information for the protein corona formed on nanocrystals and silica nanoparticles. Information on the packing of ligands on colloidal nanocrystals without a amphiphilic polymer coating was determined. The fitting of the protein corona upon silica nanoparticles was explored using core-shell form factors but was hampered by complexities within the scattering profiles which were not accounted for using simple form factors.