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Porous polyethylene glycol terephthalate (PET) film is a kind of mesopore structure template with pore size ranging from nanometer to micrometer by chemical etching after irradiation of heavy ions. The etching rate is an important factor affecting the pore morphology and quality of the membrane. In this paper, four stacked PET film were irradiated with 140 MeV [sup.32]S ions at room temperature and vacuum. During chemical etching of irradiated samples, the path etching rate [V.sub.t] was determined by conduction method, and the bulk etching rate [V.sub.b] was determined by weighing method. The relationship between etching temperature, concentration, sensitization time, and etching rate was studied. The results show that the etching rate is exponentially correlated with the etching temperature, and increases linearly with the increase of the etching solution concentration. When the concentration of NaOH is 3 mol [L.sup.-1] and the etching temperature is 75[degrees]C, the formation of cylindrical micropores is the most favorable. The pore size of porous PET film can be adjusted, and the relationship between pore size and etching time is d(nm) = 15nm + 0.24t. This is of great significance for the preparation of nanowires with uniform size and stable properties. Highlights * We have obtained the optimal conditions for obtaining cylindrical holes. * The relationship between the diameter of holes and etching time were determined. KEYWORDS bulk etching rate, heavy ions, mesopore, path etching rate, porous PET film, 1 | INTRODUCTION Template method is one of the most effective methods for the preparation of one-dimensional nanomaterials, which has been recognized and adopted by more and more researchers due [...]

The astaxanthin nanocapsules (ASX-LNC) was prepared by high-pressure homogenization technology, the microstructure, stability, antioxidant activity, and in vitro release characteristics of ASX-LNC were characterized and evaluated. The ASX-LNC comprised a core material and wall materials. The core material was composed of astaxanthin oil, and the wall materials were composed of β-cyclodextrin, decapolyglycerol monooleate, soybean lecithin (PC60), glycerol, and deionized water. The mean particle size of the ASX-LNC was 206.9 ± 2.8 nm, and the polydispersity index (PdI) value was 0.218 ± 0.026. The zeta potential of ASX-LNC was −26.16 ± 0.87 mV. The loading amount of ASX-LNC was 0.546%±0.032%, and the encapsulation efficiency was 99.65%±0.13%, indicating that the preparation process was feasible. The stability of ASX-LNC was determined under different conditions, indicating good stability of the ASX-LNC. In antioxidant research, the inhibition rate of free radicals of ASX-LNC was 91.03 ± 0.87% under 250 μg/mL for 30 min, and the inhibition rate of free radicals of astaxanthin ethanol solution was 90.83 ± 1.37%. The antioxidant capacity of astaxanthin was not affected by the encapsulation, which demonstrated the effect of prolonging the release of active ingredients due to the protection of the biological activity of astaxanthin by encapsulation. Compared with the astaxanthin ethanol solution, the ASX-LNC had a slow-release effect and could prolong the action time of active substances. Overall, ASX-LNC is a potential carrier for application in food and health products, which can control the release of active substances. [ABSTRACT FROM AUTHOR]