Herein, walnut shell (WS) was utilized as the raw material for the production of purified cellulose. The production technique involves multiple treatments, including alkaline treatment and bleaching. Furthermore, two nanocellulose materials were derived from WS by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation and sulfuric acid hydrolysis, demonstrating the broad applicability and value of walnuts. The micromorphologies, crystalline structures, chemical functional groups, and thermal stabilities of the nanocellulose obtained via TEMPO oxidation and sulfuric acid hydrolysis (TNC and SNC, respectively) were comprehensively characterized. The TNC exhibited an irregular block structure, whereas the SNC was rectangular in shape, with a length of 55–82 nm and a width of 49–81 nm. These observations are expected to provide insight into the potential of utilizing WSs as the raw material for preparing nanocellulose, which could address the problems of the low-valued utilization of walnuts and pollution because of unused WSs.

Feedstock recovery plays a crucial role in the further application of polylactic acid (PLA), yet it still lacks efficient ways, resulting from an unclear understanding of PLA pyrolysis. Hence, the co-pyrolysis of PLA and the major components of biomass additives cellulose, hemicellulose and lignin was carried out to enhance the feedstock lactide yield and explore the pyrolysis mechanism. Compared to cellulose/PLA and hemicellulose/PLA, the co-pyrolysis of lignin/PLA had the strongest synergistic effects. Based on in situ FTIR and Py-GC/MS, the promoting mechanism was as follows: 4-ethyl-2-methoxy-phenol produced by the pyrolysis of lignin provided additional free radicals for the free radical reaction of PLA so that the production of lactide increased by 162.8%. The activation energy of co-pyrolysis was 30.6% and 13.8% lower than those of lignin and PLA, respectively, which was also due to the fact that lignin promoted the free radical reaction of PLA. It was indicated that co-pyrolysis required less energy than that of single pyrolysis. In addition, the generated lactide was not well-compatible with other bio-oils and solidified at room temperature, so it could be recycled by simple physical separation. This work provided a new method for the reuse of large amounts of waste PLA and lignin waste such as papermaking black liquor.

A novel fluorescent wood sponge was constructed combining hierarchical porous wood sponge and carbon dots via chemical bonding, which could simultaneously detect and remove hexavalent Cr( vi ) in an aqueous medium.

Cellulose nanocrystals (CNCs) were fabricated using rubber wood (RW) as the raw material via acid hydrolysis followed by ultrasonication. The CNCs samples were then grafted with succinic anhydride to obtain modified CNCs, hereafter called CS. The CS samples were subsequently coated with a cationic surfactant, cetyltrimethyl ammonium bromide, and the obtained samples were named as CC. The morphology, chemical structure, and thermal stability of the RW, CNCs, CS, and CC samples were characterized using transmission electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis, respectively. Finally, the drug release performance was investigated using CC as the drug carrier and hesperidin, a hydrophobic drug, as the model drug. The drug release mechanism was also considered. The results of this study identified a new route for the high-value utilization of RW and also demonstrated that RW could be used as a novel substrate for the construction of cellulose-based hydrophobic drug delivery systems.