A Critical Review of the Tensile Strength and Industrial Properties of Cellulose Nanofiber Films for Structural Components: Land Repair Applications for Sustainable Human Society

The Earth’s environment is deteriorating, and biodiversity is declining. The use of plant-based cellulose nanofibers (CNFs) as structural materials can reduce environmental impact, and further technological developments are anticipated. This review article introduces types of cellulose derived from wood, weeds, bamboo, and fruits, and examines the potential technological applications of CNFs. It is hypothesized that maintaining an appropriate content of Mn, Ca, and O—including the interactions of Ca within carbon-based structures—could contribute to plant health, while the exclusion of elements such as V, Cd, and Sn (regardless of the effectiveness of partial sequestration) could promote cell activity. Calcium deposition can influence wood growth depending on the elemental composition in the bark, and a hypothesis regarding pH adjustment for shoot formation is proposed (see textbook on inorganic chemistry). Furthermore, manufacturing processes for CNFs and their mechanical properties—including evaluation methods—are summarized. This overview focuses on nanostructures that exhibit heterogeneous functional and mechanical properties and offer potential benefits in reducing environmental impact through processes such as 3D printing and coating. CNFs derived from fruit peels can yield lightweight and durable materials. Furthermore, the roles of proteins and fruit-derived components in neutralizing acidic environments and reducing oxides are discussed. A concept is proposed that links the processing of fruit-peel-based materials with environmental applications such as forest restoration and combating desertification. The hypothesis is put forward that cytoplasmic activity and cell wall strengthening could be enhanced through chlorophyll-related processes and water transport mechanisms. Optimizing pH conditions could promote shoot formation in plants such as conifers. Sustainable greening can be achieved through the use of cellulose-based materials in combination with water-retaining components such as bamboo-derived resources. The interaction between CNFs, plant bark, and water-bound proteins can contribute to forest regeneration and the curbing of slash-and-burn practices. Overall, this approach can contribute to environmental remediation, the reduction of environmental impact, and urban greening in degraded regions.