纳米材料在环境毒理中的作用与研究

纳米技术作为一种时代的主流技术,将人们对微观世界的认识水平及改造水平提升到了前所未有的高度,但是纳米材料也对环境产生了一定的危害。文章从环境毒理学的角度简述了纳米材料产生环境毒理学效应的途径与机制,以及纳米材料对土壤、大气和水体的毒理行为。同时,结合国内外文献报道,对目前有关纳米材料环境毒性研究方面的工作进展情况进行了总结与展望。     

Optimization of nanocapsules preparation by the emulsion-diffusion method for food applications

The aim of this work was to establish the conditions to obtain polymeric nanocapsules containing food ingredients by the emulsification-diffusion method. The Response Surface Methodology was used to optimize the process. The variables studied were shear rate (3070-18,920 s⁻¹), polymer-wall concentration: poly-?-caprolactone (PCL, 100-300 mg), and stabilizer concentration: polyvinyl alcohol (PVAL, 25-100 g/L). The analyzed responses were particle size (PS), polydispersion index (PDI), density (ρ_nc), and zeta potential (ζ). The results of ρ_nc and micrographs confirmed the presence of capsular structures. The most efficient conditions to obtain nanocapsules were 10,917 s⁻¹, 50 g/L of PVAL and 256 mg of PCL, predicting a response of PS = 250 nm, ρ_nc = 1.021 g/cm³, PDI = 0.045, and ζ = −20.02. It was concluded that keeping the same preparation conditions, the formation of nanocapsules is also possible from other food oily materials with similar characteristics (predicting values PS ≈ 300 nm and ζ ≈ −25). The proposed nanocapsules may have application in food preservation and storage.     

纳米气敏传感器研究进展

纳米传感器具有传统的传感器所不能比拟的优越性能。本文介绍了目前纳米传感器的发展概况,重点介绍了纳米气敏传感器的发展。     

Smart Dust: Monte Carlo Simulation of Self-Organised Transport

Smart dust is envisaged as swarms of miniature communication/sensor devices useful for remote monitoring in space exploration. With diameters and densities comparable to sand particles the behaviour of passive dust will be identical to the movement of airborne sand. Here we examine algorithms for the adaptive shape change of smart dust modes that permits a change in drag coefficient depending on whether or not the random motion is in a favourable direction. Monte Carlo simulations are reported for swarms of smart dust devices transporting in the wind-dominated environment of the Martian landscape. It is concluded that relatively simple shape changing algorithms, activated through an electro-active polymer sheath, will permit self-organised transport over large distances.     

Measurement of Nano-Assembly Parameters for Quantum Threads Made from Nanoparticles in a Nonuniform Field

Results are given for experimental studies in creating a system for measuring the parameters of nanotechnological preparation of electronic devices made from quantum threads by their assembly from nanoparticles __________ Translated from Izmeritel'naya Tekhnika, No. 10, pp. 27–29, October, 2005.     

Self‐assembled honeycomb polyurethane nanofibers

Electrospinning uses a high voltage electric field to produce fine fibers. A new phenomenon of self‐assembly in the electrospinning of polyurethane nanofibers is observed. This report is the first known self‐assembling phenomenon in polyurethane electrospun nanofibers. Electrospun polyurethane nanofibers self‐assemble into unique honeycomb patterns on the collector surface. This novel observation opens up new and interesting opportunities for electrospun fibers in the areas of drug delivery devices, protective clothing, filters, and tissue scaffolds. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3121–3124, 2006     

Quartz Resonators for Monitoring Thin-Film Mass and Thickness

A detailed analysis is presented for a quartz resonator-film system that substantially improves the accuracy in determining the mass and thickness. A proposed method of measuring the mass and other physical properties of the films is tested by experiment, which does not require preliminary calibration.__________Translated from Izmeritelnaya Tekhnika, No. 2, pp. 29–32, February, 2005.