Fugitive dust is a serious threat to unpaved road users from a safety and health point of view. Dust suppressing materials or dust suppressants are often employed to lower the fugitive dust. Currently, many dust suppressants are commercially available and are being developed for various applications. The performance of these dust suppressants depends on their physical and chemical properties, application frequency and rates, soil type, wind speed, atmospheric conditions, etc. This article presents a comprehensive review of various available and in-development dust suppression materials and their dust suppression mechanisms. Specifically, the dust suppressants that lower the fugitive dust either through hygroscopicity (ability to absorb atmospheric moisture) and/or agglomeration (ability to cement the dust particles) are reviewed. The literature findings, recommendations, and limitations pertaining to dust suppression on unpaved roads are discussed at the end of the review.

Cellulose nanofibril (CNF) is the fundamental unit of almost all types of natural fibers and is regarded as one of the main factors that influence their mechanical properties. Besides, owing to having a high aspect ratio, it is increasingly being used in the research of nanocomposite as a reinforcement recently. In order to utilize CNF as reinforcement more effectively, it is important to have a comprehensive idea about the mechanical properties of individual CNFs. Most of the studies are focused on the elastic modulus in the longitudinal direction, but the study of the elastic modulus in the transverse direction is still lacking. In this study, a single strand of CNF was subjected to an atomic force microscopy to characterize the surface morphology of CNF and determine the transverse elastic modulus through nanoindentation. The transverse elastic modulus of CNF was calculated to be 6.9 [Formula: see text] 0.4 GPa using extended JKR model.

Kenaf ( Hibiscus cannabinus L.) fiber is being extensively used as a reinforcement material in composites due to its excellent mechanical properties. To use this fiber more efficiently, it is necessary to understand its mechanical properties at micro/nano meter scale. Despite the evidence of some past studies to determine the elastic modulus of kenaf fiber, most of them were performed on fiber bundles. Bundle-based method to find the elastic moduli has some obvious issues of foreign materials being present, incorrect gauge length, and sample diameter due to void spaces. These issues pose as obvious hurdles to determine the elastic modulus accurately. In this study, individual kenaf micro fiber was used to find elastic modulus in the radial direction. The radial elastic modulus of the fiber was characterized by atomic force microscopy-based nanoindentation. To determine the radial elastic modulus from the force versus sample deformation data, the extended Johnson–Kendall–Roberts model was used which considered adhesion force from the fiber surface. The radial elastic modulus of the kenaf fiber was found to be 2.3 GPa.