High molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) were mixed at different ratios and cross-linked with 1,4-butanediol diglycidyl ether (BDDE) to prepare five hyaluronic acid hydrogels A–E. Enzymolysis stability, swelling rate, crosslinking degree, rheological characteristics, BDDE residual rate, surface microstructure, and cytotoxicity of different hydrogels were investigated. The results showed that hydrogel B obtained by 10% HA (w/v, HMW-HA and LMW-HA having a mass ratio of 4 : 1) crosslinking with 1% BDDE (v/v) had stronger in vitro anti-degradation ability, better mechanical properties and lower cytotoxicity than those prepared by mixing in different proportions. Hydrogel B has potential applications in regenerative medicine and tissue engineering.

Rhamnolipids have significant emulsifying activity and the potential to become a component of pesticide emulsifier. Rhamnolipids are usually composed of two main components: mono-rhamnolipids (Rha-C₁₀-C₁₀) and di-rhamnolipids (Rha₂-C₁₀-C₁₀). The proportion of di-rhamnolipids in the products ranged between 15% and 90%, affected by the production strains and fermentation process. In this paper, three kinds of rhamnolipid products containing di-rhamnolipids proportions, of 25.45, 46.46 and 89.52%, were used to test their emulsifying ability toward three conventional solvents used in pesticide (S-200, xylene, cyclohexanone) and antifungal activities against five strains of plant pathogenic fungi (Phytophthora capsici, Phytophthora parasitica var.nicotianae, Colletotrichum destructivum, Colletotrichum sublineolum, Fusarium oxysporum). The results indicated that although the CMC of the three rhamnolipids were significantly different, their emulsification properties had no remarkable differences, at a concentration of 10 g/L. However, their antifungal activities were significantly different: the more di-rhamnolipids, the stronger the antifungal activity. This work helps to promote the application of rhamnolipids as pesticides adjuvants.

As a type of important bio-based vicinal diol, 2,3-butanediol could be transformed into methyl ethyl ketone and 2-methyl propanal through a pinacol rearrangement mechanism under acid catalysis conditions. In this paper, a series of P/HZSM-5 (Si/Al = 360) samples with various phosphate contents were prepared and tested via the catalytic transformation of 2,3-butanediol, with particular focus on the effect of phosphate content on the ratio of methyl ethyl ketone to 2-methyl propanal. The catalyst structures were studied using several physico-chemical methods such as XRD, N₂ sorption, NH₃-TPD and FT-IR. At 180 °C, the ratio of methyl ethyl ketone to 2-methyl propanal increased from 5.1 to 37.5 when the content of phosphate increased from 0.5 to 8.0. When the reaction temperature increased from 180 °C to 300 °C over 4% P₂O₅/HZSM-5, the ratio of methyl ethyl ketone to 2-methyl propanal decreased from 15.6 to 2.5. The configuration of 2,3-butanediol would affect the conversion but not the selectivity. The characterization results demonstrated that the phosphate modification of HZSM-5 could not only reduce the strong and medium acid sites but also produce new weak acid sites. Strong acid sites and high reaction temperatures could promote the formation of 2-methyl propanal through methyl migration via carboniums. Based on these results, a possible surface reaction model was proposed.