Narrow Results

We present a controlling technique of microporous structure by laser irradiation during self-organization process. Polymer solution was dropped on the substrate at high humid condition and the honeycomb structure of regularly aligned pores on the film was fabricated by attaching of water droplets on the solution surface. We demonstrated that it was possible to prevent forming of pores at the region of laser irradiation and flat surface was fabricated. The method of our study is microfabrication processing technique that combines the advantages of bottom up and top down techniques. This method is expected that it is applied to photonic crystals, biological cell culturing, surface science and electronics fields.

New methods for water treatment are required as a result from an increasing awareness in the reduction of the pollution impact in the environment. In the perspective of the photo-oxidation of organic pollutants present in water, the principal incentive for the preparation of heterogeneous photocatalysts is their easy recovery from the reaction mixture, which allows their reuse in successive runs, minimizing the loss of their original photocatalytic properties. Different types of supports can be used in the immobilization of photoactive species, such as porphyrins (Pors) and phthalocyanines (Pcs). This mini-review will consider the different methodologies for the immobilization of Pors and Pcs and their photocatalytic performance in the photodegradation of organic pollutants in water, addressing also their recycling ability in successive water treatments.

SO₂ is one of the major pollutants in the atmosphere. N-doped microporous carbon spheres (NCS) have been demonstrated to be effective for SO₂ adsorption. Here we report the synthesis of monodispersed NCS by the extended Stöber method with urea resorcinol-formaldehyde resins as carbon source, urea as nitrogen source and ammonia as catalyst in an ethanol-water mixed solvent. The obtained carbon spheres show a uniform diameter of around 550nm, specific surface area of 476m²g${}^{-1}$, micropores pore volume of 0.20cm³g${}^{-1}$ and nitrogen doping. The NCS manifest special performance for SO₂ capture with capability of 75.34mgg${}^{-1}$ and good cycling stability, due to the large surface area, abundant micropores and nitrogen functionality.

Water molecules confined in a microporous metal–organic framework (MOF) UiO-66 are characterized by a low-field ¹H nuclear magnetic resonance (NMR) spectroscopy. Measurements are performed of the longitudinal ($T_1)$ and transverse ($T_2)$ relaxation times as a function of water content from fully saturated to incomplete coverage of the first-adsorbed monolayer. The results obtained indicate that the relaxation of water molecules confined in UiO-66 is within the fast-exchange regime. When the amount of water exceeds filling ratio $f$ = 0.4, the averaged relaxation time is approximately linearly dependent on water filling ratio in pore. When the water amount cannot support a full coverage of surface monolayer, the relaxation rate increases with less filling ratio, illustrating that the mobility of water molecules is more restricted. Analysis of the measured values and the simulated ones leads to the conclusion that the surface-affected zone in UiO-66 is not confined to the surface monolayer.