Study on microscopic physical and chemical properties of biomass materials by AFM

Biomass is created by living things like plants, animals, and microbes. It has the characteristics of abundant reserves, renewable, biodegradable and environmentally friendly. Research on biomass materials has grown almost exponentially over the last few decades. Despite current characterization techniques, it is still difficult to simultaneously characterize biomass materials' morphology and mechanics at the nanoscale level. Atomic force microscopy (AFM) offers a special benefit to get beyond this restriction. AFM provides high-resolution images of biomass materials. Moreover, the nanoscale contact force between it and the item enables it to be detected without harming the sample while sensing real-time mechanical and topographic properties on the surface of a material. The ability of AFM probes to interact with biomass materials in mild environments (including normal temperature, normal pressure or biomimetic liquids) is of great significance for studying the microscopic properties of biomass materials. This paper reviews the basic principles of AFM, the application progress in the field of research on the microscopic properties of biomass materials (including the morphology and micromechanical properties of biomass materials, surface adhesion, intermolecular interactions, etc.), and the application of AFM in conjunction with FTIR and RAMAN. In conclusion, the unique characterization method of AFM not only enables us to grasp the nanoscale structure of biomass materials more comprehensively, but also provides essential insights for us to understand the interfacial interactions between biomass materials at the molecular level, which is useful for exploring biomass materials, contributing crucial practical significance to material properties, processing properties and bionic material design.