关键词: 玉米秸秆, 溴化锂, 气凝胶, 全组分

Abstract:

Corn straw was used as raw material to prepare the whole component aerogels of corn straw by dissolving in lithium bromide solution and tert-butanol solution replacement. The experimental conditions were optimized by single factor test, and the properties of aerogels were characterized by scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FT-IR), N₂ adsorption-desorption test, and optical contact angle test. The results showed that the gelation time of the whole components of corn stalk dissolved in lithium bromide was less than 10 min under different conditions. The density of whole components aerogel of corn stalk was as low as 0.027 4 g/cm³, and the specific surface area was 98.434 8 m²/g under the optimal conditions, i.e., the mass fraction of lithium bromide was 66%, the reaction temperature was 130 ℃, the solid-liquid ratio was 1∶45(g∶g), and the reaction time was 50 min. Furthermore, the aerogel had super hydrophilic and super lipophilic properties, and the maximum adsorption rates of deionized water and soybean oil were 15.04 and 18.78 g/g, respectively. The SEM result showed that the prepared aerogel had two dimensional sheet and three dimensional network structure, and the FT-IR result indicated that the aerogels contained cellulose, hemicellulose and lignin, and the hydrogen bond network in cellulose was destroyed.

Key words: corn straw, lithium bromide, aerogel, all-components