Flavonoid complexes have more biological activities than parent flavonoids, including antioxidant, anticancer, antibacterial, and many others. Selenium is an essential trace element for human body. Therefore, a quercetin-Se complex was synthesized and analyzed in this paper, getting the results as following: (1) A light-yellow product was obtained with the max yield of 30.30 %. (2) The complex molecule contains two quercetin units and a selenoxyl group, called selenious acid acyl diquercetin. (3) It has a strong antioxidant activity with a maximum DPPH scavenging rate of 97.71 %. In addition, we prepared a skin cream containing 1 % quercetin selenium complex, and it has excellent antioxidant activity with a DPPH scavenging rate of 82.4 %. Therefore, the generated selenious acid acyl diquercetin is a potential antioxidant material for skin care products.

No abstract

The current wastewater treatment method shows low efficiency in treating wastewater with high concentrations of chemical mechanical pulp (CMP). Therefore, a chlorine dioxide Pretreatment Anaerobic Treatment (DPAT) was developed and applied to treat the CMP wastewater to obtain higher efficiency, obtaining the following results: The biodegradability of CMP wastewater improved after chlorine dioxide pretreatment. The COD of wastewater treated with chlorine dioxide was reduced from 5634 mg/L to 660 mg/L. The removal rate for chemical oxygen demand (COD) was 88.29%, 29.13% higher than the common anaerobic treatment. The reasons for the high efficiency of the DPAT treatment were that chlorine dioxide pretreatment removed the toxic substances in the original wastewater and thereby promoted the proliferation and growth of the anaerobe. The results show that pretreatment with chlorine dioxide can effectively enhance the biodegradability of high-concentration CMP wastewater. Therefore, DPAT treatment of high-concentration CMP wastewater is beneficial to environmental protection.

No abstract

Poly(hydroquinone) (PHQ) is a class of polymers with a leading chain composed entirely of quinone-phenol structures, which possess both the heat resistance of polymers and the redox activity of the monomer quinone-phenol and have promising applications in sensors, anti-corrosion and antioxidants. However, the current synthesis efficiency is low, and the product solubility is poor, which hinders its wide application. In this paper, the copper-ammonia complex was used to catalyze the polymerization of hydroquinone. The product's structure was verified by FTIR, UV-Vis, XPS, SSNMR and EDS. The degree of PHQ obtained by GPC was 2-9, and the reaction mechanism of the polymerization process was demonstrated in detail. The experiments showed that the copper-ammonia complex not only acted as a catalyst but also participated in the reaction, firstly generating the PHQ copper-ammonia complex, which is almost insoluble in water and common organic solvents. Then by further acid washing to dislodge the copper-amino groups, the resulting PHQ was able to dissolve in solvents such as DMSO and methanol. In addition, the method is three times faster than the catalytic rate using an equivalent amount of ammonia.