Lignin is a natural and renewable aromatic polymer, but only about 2% of lignin is utilized with high added value. Polydispersity and heterogeneity are the key reasons for the difficulty in separation, fractionation, characterization, purification and utilization of lignin. However, the molecular weight of lignin is still described from the overall perspective of number-/weight-average molecular weight (Mn and Mw), which if far from enough to understand the heterogeneous and dispersed lignin. To provide a tool for understanding the molecular weight of lignin from a molecular perspective, an integral method for quantifying the molecular characteristics of lignin molecules at arbitrary molecular intervals on the molecular weight distribution curve of lignin was established. The molecular contents of wheat straw lignin as well as its soluble and insoluble fractions at different intervals were calculated. The ease of fractionation of small molecules with weights lower than 8000 g/mol into soluble fractions, and that of large molecules with weights higher than 10,000 g/mol into insoluble fractions were quantitatively analyzed. The established integral method will significantly help in the understanding the properties of lignin at the molecular-level, as well as the fractionation and utilization of lignin.

Rice straw hydrotropic lignin was extracted from p-Toluene sulfonic acid (p-TsOH) fractionation with a different combined delignification factor (CDF). Hydrotropic lignin characterization was systematically investigated, and alkaline lignin was also studied for the contrast. Results showed that the hydrotropic rice straw lignin particle was in nanometer scopes. Compared with alkaline lignin, the hydrotropic lignin had greater molecular weight. NMR analysis showed that β-aryl ether linkage was well preserved at low severities, and the unsaturation in the side chain of hydrotropic lignin was high. H units and G units were preferentially degraded and subsequently condensed at high severity. High severity also resulted in the cleavage of part β-aryl ether linkage. ³¹P-NMR showed the decrease in aliphatic hydroxyl groups and the increasing carboxyl group content at high severity. The maximum weight loss temperature of the hydrotropic lignin was in the range of 330–350 °C, higher than the alkaline lignin, and the glass conversion temperature (T_g) of the hydrotropic lignin was in the range of 107–125 °C, lower than that of the alkaline lignin. The hydrotropic lignin has high β-aryl ether linkage content, high activity, nanoscale particle size, and low T_g, which is beneficial for its further valorization.

Nanocellulose-based composite aerogels have the advantages of high porosity, biodegradability, and biocompatibility, with wide applications in many fields, such as adsorption, separation, energy storage, and heat insulation. In this study, a nanocellulose-based composite aerogel (NCA) was prepared using the one-pot method with cellulose nanofibrils (CNFs), tannic acid (TA), and polyvinyl alcohol (PVA) as raw materials. The adsorption behaviors of Pb²⁺, Cd²⁺, and Cu²⁺ were also studied. FT-IR analysis confirmed that TA successfully solidified on the nanocellulose, while SEM analysis revealed that the prepared NCA exhibited significantly higher porosity compared with the cellulose nanofibril-only aerogel. The results of the adsorption experiment demonstrated that the adsorption behavior of heavy metal ions using the prepared NCA followed pseudo-second-order kinetics. The adsorption isotherms fit well with the Langmuir adsorption model, indicating that the process of aerogels adsorbing heavy metal ions is that of monolayer adsorption. Under conditions of pH 6 and an initial heavy metal ion concentration of 100 mg/L, the maximum adsorption capacity calculated for the prepared NCA was up to 196.850 mg/g, 181.488 mg/g, and 151.515 mg/g for Cu²⁺, Cd²⁺, and Pb²⁺, respectively. Furthermore, the prepared NCA exhibited excellent reusability, with more than 90% efficiency retained after three cycles. NCAs have the potential to become an efficient material for absorbing heavy metal ions in water.

As the noble gardening tree growing specifically in China, Osmanthus fragrans is widely used to produce high-grade essence, special drugs and aromatic tea form its flowers. However, O. fragrans leaves are still underutilized and hence wasted. Therefore, in order to better utilize O. fragrans leaves and hence to expand its utility values and industrial scopes, we attempted to analyze the bioactive components, especially biomedical constituents from O. fragrans leaf by the way of Py-GC/MS (Pyrolysis- gas chromatograph/ mass spectrometer). After acetone extraction on O. fragrans fresh leaf by ultrasonic extraction for 5 h at 90degC, and with the removal of solvent, the extractive was pyrolyzed in 590degC He atmosphere, then the pyrolysis product was analyzed by online linked GC/MS. Relative content of each component was determined by area normalization, and 64 compounds representing 97.85% of the acetone ultrasonic extractive were identified from 65 peaks (Figure 1). The main constituents were as: friedelan-3-one (38.87%), lup-20(29)-en-3-one (12.46%), Stigmasterol,22,23- dihydro- (6.23%), Urs-12-ene (5.45%), benzoic acid,4-hydroxy-3- methoxy- (2.08%), stigmasterol (1.96%), cyclotetracosane (1.92%), acetone (1.59%), beta-amyrin (1.57%), benzoic acid,4- hydroxy- (1.32%), l,6-anhydro-.beta.-D-glucopyranose (1.32%), toluene,3-(2-cyano-2-phenylethenyl-) (1.22%), taraxasterol (1.20%), 1,2-propanediamine (1.07%), hexadecanoic acid (1.00%), ergosta-4,6,22-trien-3.alpha.-ol (1.00%), 1,2-benzenediol (0.91%), vitamin E (0.90%), campesterol (0.89%), etc. The results of function analyses suggested that the pyrolysis product from the acetone ultrasonic extractive of O. fragrans leaf is abundant in materials of noble natural medicines, and also contains constituents which can be developed into top value- added materials of cosmetics, biofuel and industrial. This is the first report here that showed underutilized leaf of O. fragrans contains abundant biomedical constituents and can be developed into top value-added products.