Preparation method for oil-water separation type alginate aerogel having nano-micron gradient hierarchical pore structure

Abstract

The invention relates to a preparation method for an oil-water separation type alginate aerogel having a nano-micron gradient hierarchical pore structure. The method comprises the following steps: firstly, preparing a foaming liquid with a certain foaming ratio by using sodium alginate, a foaming agent, a nano pore-forming agent and a chemical cross-linking agent, and performing freeze drying by using a freeze-drying technique to obtain an ultra-light sponge-like alginate aerogel with a fluffy porous structure; and immersing the sponge-like alginate aerogel in a certain concentration of a calcium ion solution to make the alginate aerogel further absorb water for cross-linking, and performing soaking in a hydrophobic modified mixed solution to prepare the superhydrophobic calcium alginate material with rich nano-micron pores. The method realizes controllable construction of the pore structure of the sodium alginate, and a large pore-meso pore-micro pore gradient hierarchical special pore structure is formed, so that the adsorption and mechanical properties of the calcium alginate are significantly improved; the method is simple and easy to implement, has low preparation costs, and does not use harmful organic solvent; the combination of the physical foaming technology, the nano pore-forming technology and the freeze drying technology is used, and the hydrophobic aerogel is subjected to further hydrophobic modification by an inorganic modifier, so that the purpose of oil-water separation is realized; and the cheap calcium alginate material prepared by the method has good oil-water separation ability, high application potential, and higher economic production value.

Description

technical field [0001] The invention relates to a method for preparing an oil-water separation type alginate airgel with a special pore structure, in particular to a preparation method for an oil-water separation type alginate airgel with a nano-micron gradient graded pore structure, which belongs to biomass The technical field of preparation of base functional materials. [0002] technical background [0003] Over the past century, marine pollution caused by frequent oil spill accidents has brought enormous damage to the marine ecological environment. Therefore, how to achieve efficient oil-water separation has become a hot research direction. Developing a superhydrophobic and superoleophilic functional material is a simple and easy way to solve this problem. At present, sodium alginate airgel is widely studied because of its low price, environmental friendliness, and easy formation of hydrophobic gel with calcium ions. Its structure contains a large number of functional g...