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A model is introduced to account for nonuniform channel geometries in monolithic adsorbents. Based on nonisothermal operation, fully developed parabolic flow and the full three-dimensional convection-diffusion equation, the model is applied to the adsorption of dichloromethane from an air stream flowing through a binder-less activated carbon monolith. The equilibrium parameters and the effective diffusion coefficient for adsorption are obtained independently from gravimetric adsorption experiments. The nonuniform channel model is capable of predicting breakthrough curves as a function of feed gas flow rates up to dimensionless breakthrough concentrations of about 0.4-0.6, depending on the feed flow rate. Even though the variation of effective diffusion coefficient with both concentration and temperature has been tested, successful prediction over the whole range of concentration may require the incorporation of further aspects relating to the anisotropic nature of the carbon.

Intraperitoneal cisplatin delivery has recently been shown to benefit ovarian cancer patients. Cisplatin-containing poly(lactide-co-glycolide) (PLGA) microspheres have been proposed for cisplatin delivery. The drug loading of cisplatin containing microspheres produced elsewhere is 3-10%w. Similar microspheres are reported here with a mean diameter of 38.8 µm, and a drug loading of 11.7%w, but using ethyl acetate as a safer solvent. In addition, novel formulations of cisplatin-containing solid and hollow PLGA 65:35 (lactide:glycolide) fibres were prepared and are reported here for the first time. PLGA hollow fibres were produced by phase inversion with a high drug loading of 27%w. Mechanistic mathematical models were applied to the cisplatin release profiles to allow quantitative comparison of microsphere, solid fibre and hollow fibre formulations. The diffusion coefficient of cisplatin eluting from a typical batch of PLGA microspheres was 4.8 × 10(-13) cm(2) s(-1); this low diffusivity of cisplatin in microspheres was caused by the low porosity of the polymer matrix. The diffusion coefficients of cisplatin eluting from a batch of PLGA solid fibres and hollow fibres were 6.1 × 10(-10) and 3.3 × 10(-10) cm(2) s(-1), respectively. These fibres allowed the controlled release of high doses of cisplatin over four days and may represent an improvement in slow release technology for treatment of ovarian cancer.

A highly loaded porous polyimide (PI) foam type air filter has been fabricated by incorporating antimicrobial active metals to prevent microbial growth and kill microbes, and so to provide health benefits for people in enclosed spaces. PI foams containing antibacterial agents, such as PCu80 (PI (20 wt %)/copper (80 wt %)), PNi80 (PI (20 wt %)/nickel (80 wt %)), and copper−nickel composites, were synthesized and tested against model bacterium, Erwinia carotovora (Gram negative) to determine the antibacterial efficacy of the air filter. Scanning electron microscope−energy dispersive X-ray spectroscopy (SEM−EDX) confirmed the distribution of copper and nickel throughout PCu80 and PNi80, where concentrations between 70% and 75% were detected. The copper: nickel ratio was consistent throughout the foam for PCu64Ni16 (PI (20 wt %)/copper (64 wt %)/nickel (16 wt %)). PCu80 displayed a high log reduction value (LRV) of 99.996% and, thus, exhibited a bactericidal effect. PNi80 displayed a lower LRV of 99.4%. However, a higher LRV value was observed compared to the control, 95.5% (PI foam without antibacterial agent), and thus, demonstrated a bacteriostatic effect. PCu64Ni16 exhibited and sustained exceptional microbe removal efficiencies of 99.9997% for 24 h at high humidity levels and demonstrated the highest zone of inhibition (ZOI) value of 33.90 ± 0.16 mm compared to PCu80 (27.5 ± 1.1 mm). Nickel strongly inhibited the proliferation of bacteria, while copper destroyed the bacteria on the foam filters. Therefore, such functionalized filters can potentially overcome the inherent limitation in conventional filters and imply their superiority for controlling indoor air quality.