In recent decades, significant advances in drug‐delivery systems have enabled more effective drug administration. To deliver drugs to specific organs, a range of organic systems (e.g., micelles, liposomes, and polymeric nanoparticles) have been designed. They suffer from limitations, including poor thermal and chemical stability, and rapid elimination by the immune system. In contrast, silica particles offer a biocompatible, stable, and “stealthy” alternative. Bioactive molecules can be easily encapsulated within silica particles by combining sol–gel polymerization with either spray‐drying or emulsion chemistry. Spray‐drying faces challenges, including low yield, surface segregation, and size limitations. In contrast, sol–gel emulsions enable the production of nanoparticles with homogeneous drug distribution, and permit ambient temperature processing, necessary for handling biologicals. Independent control of the size and release rate can be readily achieved. Preliminary in‐vivo experiments reveal enhanced blood stability of the nanoparticles, which, coupled with sustained release of anti‐tumor agents, show good potential for cancer treatment.

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The effects of various preparation parameters on vanadium reduction in Bi 4V 2 O 11−d have been investigated using EPR, 51V MAS solid state NMR and UV diffuse-reflectance spectroscopies and also SQUID magnetometry and powder neutron diffraction. The results confirm that a greater amount of vanadium reduction is observed in rapidly quenched samples and that significant oxidation occurs when samples are slow cooled. Evidence for spin-spin dipolar coupling is seen in the EPR patterns while uncoupled V4+ spins contribute to weak paramagnetic behaviour. Band gaps of around 2 eV from the UV data suggest there may be a significant electronic component to low temperature conductivities. The 51V NMR data are not inconsistent with the presence of mainly distorted octahedral and tetrahedral coordinations for vanadium.The relationship of the three major polymorphs in Bi 4 V 2 O 11

The solid state system Bi 2 O 3 :ZrO 2 has been investigated up to 28 mol% ZrO 2 using X-ray and neutron powder diffraction, ac impedance spectroscopy and differential thermal analysis. X-Ray powder diffraction has shown that a solid solution is formed with general composition Bi 22x Zr x O 3zx/2 (0.05¡x¡0.17) for samples calcined at 850 ‡C. Members of the solid solution adopt a new b-Bi 2 O 3 type structure termed b III , which is closely related to Pb 2 F 2 O. The defect structure of a sample of composition x~0.15 has been determined by combined high-resolution neutron and X-ray powder diffraction. High temperature powder X-ray diffraction has been used to confirm the structure of the high temperature polymorph, which is a cubic d-Bi 2 O 3 analogue. In the b III -phase, solid solution formation proceeds through an anion interstitial mechanism with respect to the hypothetical end member b III -Bi 2 O 3 , with interstitial oxide ions located in channels parallel to the c-axis. The defect structure involves a pair of Zr atoms coordinated to interstitial ions in the channels. A possible conduction mechanism is proposed. Differential thermal analysis and ac impedance measurements indicate a complex phase transition to a highly conducting polymorph (s 700 ~1.02 S cm 21 ) at temperatures above ca. 690 ‡C on heating. Crystal parameters: T~298 K, Bi 1.85 Zr 0.15 O 3.075 , M~449.49, tetragonal, P4 2 /nmc, a~7.7206(8), c~5.6370(6) A ˚, Z~4, U~336.0(1) A ˚3, D c ~8.889(3) g cm 23 ; T~1023 K, cubic, Fm3 ¯m, a~5.6277(4) A ˚, U~178.24(4) A ˚3, Z~2, D c ~8.379(2) g cm 23 .{Electronic supplementary information (ESI) available: crystal data, data collection and structural refinement data, atomic coordinates, isotropic thermal parameters, bond lengths, bond angles and contact distances for b III -Bi 1.85 Zr 0.15 O 3.075 at 298 K and for d-Bi 1.85 Zr 0.15 O 3.075 at 1023 K. See