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.

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.

In this study, a pulp beating machine was used to premix the pulp fibers with high density polyethylene (HDPE) particles in water. The wet or pre-dried pulp fiber/HDPE mixture was then melt-compounded by a twin screw extruder. For further improving the dispersion of pulp fiber, some mixture was forced to pass through the twin-screw extruder twice. The resulting mixture was compression molded to the composite. The fiber distribution was observed by the aid of an optic and scanning electron microscope. The mechanical and rheological properties and creep resistance of the composites were characterized. Test results demonstrate that when the wet pulp fiber/HDPE mixture was subjected to pre-pressing and oven drying prior to extrusion compounding, the resulting composites exhibited homogeneous fiber distribution, superior flexural property, creep-resistance, and high storage modulus. Particularly, its flexural strength and modulus were 57% and 222% higher, respectively, than that of the neat HDPE, while the composites prepared without pre-dried were 19% and 100% higher, respectively. Drying the wet mixture in advance is more effective than re-passing through the extruder for improving the fiber dispersion and composite performance.

Tea stalk was used for producing carboxymethyl cellulose (CMC), and a response surface methodology was used to model effective factors relative to the degree of substitution (DS). The optimum values of the independent variables were an alkalization time of 107 min, monochloroacetic acid at 3.11 g, and an etherification time of 171 min, at which the CMC had a DS of 0.668. The yield of CMC in optimization condition was 75.9 %. The optimized CMC was in a good agreement with the commercial CMC, as based on Fourier transform infrared spectroscopy and X-ray diffractometry analyses. The optimized CMC was used to enhance paper strength, and with economic factors and paper strength enhancement taken into account, the appropriate amount of optimized CMC was determined to be approximately 0.3 %. When the amount of optimized CMC was at 0.3 %, the tensile index, burst index, tearing index, and folding endurance were 26.7 N m/g, 1.0 kPa m 2 / g 1.0\hspace{0.1667em}\text{kPa}\hspace{0.1667em}{\text{m}^{2}}/\text{g} , 12.1 mN m 2 / g 12.1\hspace{0.1667em}\text{mN}\hspace{0.1667em}{\text{m}^{2}}/\text{g} , and 2.0, respectively. Together, these results indicated that the optimized CMC exhibited comparable paper strengthening properties relative to that of commercially available CMC.