ABSTRACT
A porous organic polymer (marked as DT-POP), which contains abundant free phenolic hydroxyl groups, is synthesized by the well-known green azo-coupling reaction in water, characterized, and utilized as an effective adsorbent for the elimination of methylene blue (MB) from water solutions. The presence of permanent mesopores, abundant active functional groups, and π-electron enrichment ascribed to phenyl rings make DT-POP an efficient adsorbent for MB due to strong hydrogen bonding, π-π, and electrostatic interactions with the cationic dye MB. DT-POP with high stability and high adsorption capacity can be reused many times and thus shows high applicability in pollutant disposal.
ABSTRACT
Carrageenan (CRG) is a kind of linear sulfated polysaccharide that emerging as a promising substituent in food, pharmaceutics, and cosmetics. In recent years, biological properties of CRG polysaccharides such as antiviral, immunomodulatory, anticoagulant, antioxidant, and anticancer have been broadly studied, however, systematical summary of their structure-property relationships is scarce. Moreover, chemical modification is of great significance to explore biological and physiochemical properties of CRG polysaccharides which should be focused on. Chemical modification of CRG polysaccharides, e.g., carboxymethylation, thiolation, acetylation, phosphorylation, oversulfation, oxidization, and cationic or other derivatives, can improve their bioactivities and facilitate their applications in different biological systems. Hence, this review aims to elucidate structure-property relationships of CRG and its chemically modified derivatives with different structures and bioactivities, so as toxicity of CRG as food additive for the guidance of its clinical application.
