Cellulose/tannin hydrogel and preparation method thereof

Abstract

The invention belongs to the technical field of materials and provides cellulose / tannin hydrogel. The cellulose / tannin hydrogel is a product which is obtained by adding a cross-linking agent into a mixed liquid of tannin and cellulose to perform cross-linking and immobilization reaction. A preparation method of the cellulose / tannin hydrogel comprises the following steps: (1) dissolving the cellulose into a solvent which consists of urea, alkaline and water or thiourea, alkaline and water at a low temperature to obtain a cellulose liquid; (2) adding tannin into the cellulose liquid to obtain a mixture I, putting the mixture I into an ice bath for ultrasonically dispersing uniformly to obtain a mixed liquid of tannin and cellulose; and (3) adding the cross-linking agent into the mixed liquid obtained in the step (2) and performing cross-linking and immobilization reaction at the same time to obtain the cellulose / tannin hydrogel. According to the cellulose / tannin hydrogel and the preparation method of the cellulose / tannin hydrogel disclosed by the invention, the cellulose is taken as an immobilization carrier, and tannin, especially condensed tannin with relatively good stability is fixed to the cellulose by adopting a homogeneous reaction way, so that the tannin is immobilized and processed into material so as to obtain a gel adsorbent with good performance, and thus, the cellulose / tannin hydrogel can be widely applied to water treatment.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a cellulose / tannin hydrogel and also relates to a preparation method thereof. Background technique [0002] Tannin is a natural polyphenol compound found in the bark and fruit of various trees (such as rubber trees, sumac trees, etc.). The molecular structure of tannin is rich in ortho phenolic hydroxyl groups, so that it can electrostatically bond and complex with heavy metal ions or cationic organic dyes to form a five-membered chelate ring, so it has good water treatment ability[ Sep. Purif. Technol. , 2006, 47, 113]. However, the very water soluble nature limits the use of tannins as good adsorbent materials. In order to solve this problem, scientists considered combining tannins on silica, activated carbon[ J. Mol. Catal. A : Chem. , 2010, 320, 40], resin [ J. Hazard. Mater. , 2009, 166,1488] and hydrotalcite[ Appl. Clay Sci. , 2008, 42, 214] and oth...

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Problems solved by technology

For this method of "heterogeneous immobilization" of tannins, the structure of the carrier itself (such as the pore structure) largely affects whether the immobilization reaction occurs on the surface or inside of the carrier, thus affecting the immobilization effect of tannins, and Fixed tannins are easily released from the carrier [J. Chem. Technol. Biotechnol., 2004,79, 335]

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