Bio-Based Ca2+-Selective Supramolecular Metallohydrogels with Ultra-mechanical Responsiveness, Selective Dye Adsorption, and Recycling.

Water pollution is one of the major problems that need to be solved in modern society, and there is a need to develop an effective adsorbent to purify the polluted water. In this article, three supramolecular metallohydrogels containing a three-dimensional network structure have been prepared from rosin derivatives. The supramolecular metallohydrogels have good thermal stability and maintain mechanical strength at high temperatures. Interestingly, the sodium N-(dehydroabiety1)maleamate/Ca2+ supramolecular metallohydrogels exhibit rare multi-stimulus responsiveness (mechanical vibration, temperature, pH, EDTA, etc.), especially to mechanical vibration with over 10 cycles, indicating ultra-mechanical response properties. More importantly, the unique three-dimensional network structure of the metallohydrogels can effectively adsorb cationic dyes in the wastewater. The adsorption amount and adsorption rate of this supramolecular metallohydrogels for rhodamine 6G after 48 h were at least 160.6 mg/g and 97%, respectively. The adsorption kinetic process of this metallohydrogel follows a quasi-secondary kinetic model, where the adsorption process is mainly electrostatic and weak π-π interactions. And the metallohydrogels can also be recovered by 0.5 mol/L hydrochloric acid solution desorption after adsorption of the dye. This is the first supramolecular metallohydrogel system prepared from the natural product rosin and applied to dye adsorption. This broadens the application of rosin in the field of supramolecular gel and dye adsorption and recycling.

Facile Construction of Bio-Based Supramolecular Hydrogels from Dehydroabietic Acid with a Tricyclic Hydrophenanthrene Skeleton and Stabilized Gel Emulsions.

Supramolecular hydrogels have attracted great attention due to their special properties. In this research, bio-based supramolecular hydrogels were conveniently constructed by heating and ultrasounding two components of dehydroabietic acid with a rigid tricyclic hydrophenanthrene skeleton and morpholine. The microstructures and properties of hydrogels were investigated by DSC, rheology, SAXS, CD spectroscopy, and cryo-TEM, respectively. The critical gel concentration (CGC) of the hydrogel was 0.3 mol·L-1 and the gel temperature was 115 °C. In addition, the hydrogel showed good stability and mechanical properties according to rheology results. Cryo-TEM images reveal that the microstructure of hydrogel is fibrous meshes; its corresponding mechanism has been studied using FT-IR spectra. Additionally, oil-in-water gel emulsions were prepared by the hydrogel at a concentration above its CGC, and the oil mass fraction of the oil-in-water gel emulsions could be freely adjusted between 5% and 70%. This work provides a convenient way to prepare bio-based supramolecular hydrogels and provides a new method for the application of rosin.

Associations of per- and polyfluoroalkyl substances and alternatives with reproductive hormones in women of childbearing age.

BACKGROUND: Experimental studies suggested that per- and polyfluoroalkyl substances (PFAS) may have endocrine-disrupting effects. However, the epidemiological evidence on the associations of PFAS with female reproductive hormones is sparse and limited to perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). OBJECTIVE: To evaluate effects of legacy and emerging PFAS alternatives on female reproductive hormones. METHODS: A total of 433 reproductive-aged females were recruited from 2014 to 2016. Information on age, age at menarche, gravity, menstrual cycle, BMI, education, and income was obtained from medical records and questionnaires. Serum samples were collected for reproductive hormones, and plasma samples for PFAS measurement by ultraperformance liquid chromatography - tandem mass spectrometer (UPLC-MS/MS). Multiple linear regression and quantile g-computation (q-gcomp) were used to examine the associations of individual PFAS and their mixture with reproductive hormones. RESULTS: Multiple linear regression analysis showed significant effects of certain PFAS on total testosterone (TT): adjusted estimate (ß) for perfluoroheptanoic acid (PFHpA) was 0.57 (95% CI: 0.18, 0.97). Moreover, a positive association was detected between PFAS mixture and TT in the q-gcomp model. Higher concentrations of 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA) were associated with significantly lower prolactin level (ß = -0.07, 95% CI: -0.14, -0.001). CONCLUSION: Our study found that exposure to PFAS alternatives was associated with altered levels of reproductive hormones in women of childbearing age.