Facile preparation of all cellulose composite with excellent mechanical and antibacterial properties via partial dissolution of corn-stalk biomass

Preparation and characterization of tea tree essential oil microcapsule-coated packaging paper with bacteriostatic effect

We prepared tea tree essential oil microcapsules, and the microcapsules and pullulan were coated on kraft paper to prepare an antibacterial paper. The antibacterial activity, structural characterization, and thermal stability of the prepared microcapsules and packaging paper were then tested. We found that the retention rate of microcapsules reached 87.1% after a 70 min of high-temperature treatment. The minimum inhibitory concentrations of microcapsules to S. aureus and E. coli were 112 mg/mL and 224 mg/mL, and the bacteriostatic zones of the packaging paper to E. coli and S. aureus were 17.49 mm and 22.75 mm, respectively. The prepared microcapsules were irregular. The paper coating was formed via hydrogen bonding, which filled the pores of paper fibers. When compared with the base paper, the roughness of the paper was reduced to 7.16 nm (Rq) and 5.61 nm (Ra), and no thermal decomposition occurred at <288 °C, which together implies a good application prospect.

Integrated Hemicellulose Extraction and Papermaking Fiber Production from Agro-Waste Biomass

The present study deals with the valorization of corn stalks in an integrated processing strategy targeting two products: extracted hemicelluloses (HC) and papermaking fibers. Preliminary trials were conducted to assess the individual or the combined effects of biomass treatment on the quality of the obtained hemicelluloses and papermaking fibers. Depending on the hot alkaline extraction (HAE) conditions, the extracted HC had a xylan content between 44-63%. The xylan removal yield ranged between 19-35%. The recovery of HC from the extraction liquor and final black liquor was significantly affected by process conditions. The experimental approach continued with the study of HAE conditions on the obtained paper's mechanical properties. The optimization approach considered conserving paper strength properties while achieving an equilibrium with the highest possible HC extraction yield. The optimal values are sodium hydroxide concentration (1%), process time (33 min), and temperature (100 °C). The xylan content in the separated HC sample was ~55%. An extended extraction of HC from the resulting pulp under hot alkaline conditions with 5% NaOH was performed to prove the HC influence on paper strength. The xylan content in HC samples was 65%. The consequence of xylan content reduction in pulp leads to 30-50% mechanical strength loss.