Study on Properties of Ultrasonication Treated Pulp Fiber

Abstract

SEM and Automated Surface Area & Pore Size Analyzer were used to characterize surface morphology and specific surface area and the pore size distribution of fibers. The results showed that specific surface area and pore size distribution increase after ultrasonication. The ash content of the composites of ultrasonic treated fiber is larger than the untreated fiber, and the magnetic properties show a good superparamagnetic behavior.

Highly Ductile Cellulose-Rich Papers Obtained by Ultrasonication-Assisted Incorporation of Low Molecular Weight Plasticizers

“…11,14 Ultrasonication can be regarded as a high energy treatment similar to PFI-refining but also leading to cavitation, resulting in more pronounced peeling and exposure of hydroxyl groups. 18,20,26 The combination of PFI-refining and subsequent ultrasonication might be a new approach to treat fibers for subsequent use in ductile applications, as the main toughening component in these new composites is the cellulose fibril, and not the fibers per se. A more severe degradation of the macroscopic structure may facilitate both the physical interaction with plasticizing additives and the covalent modification of the fibrous material.…”

“…The bleached chemical fibers were mixed with equal amounts of plasticizer and then suspended in water before being sonicated and subsequently dewatered to form papers, which to the best of our knowledge has not been reported in literature. Previous studies have shown that ultrasonication will fibrillate fibers and increase the specific surface area, which in turn might aid the sorption of plasticizers by increasing the availability of hydroxyl groups. ,, …”

“…The micrograph of PFI-refined fibers in Figure b shows that the fibers are flatter due to collapse of the lumen, which is a consequence of the increased flexibility in the fiber wall due to internal fibrillation during refining. This will lead to a higher contact area at the fiber-to-fiber interface in the final paper. , External fibrillation, where fibrils are still attached to the main fiber, can also be observed. ,− , Moreover, the fibers were subjected to ultrasonication at 90% amplitude for 10 min, Figure d (fibers sonicated at 70% amplitude for 20 min are shown in c). The ultrasonication results in an increase of the degree of external fibrillation on the surface.…”

“…Previous studies have shown that ultrasonication will fibrillate fibers and increase the specific surface area, which in turn might aid the sorption of plasticizers by increasing the availability of hydroxyl groups. 18,20,26 Influence of Ultrasonication on Fiber Properties. In Figure 1a the micrographs of the untreated fibers are shown, which display a smooth and intact surface.…”

“…Both the internal and external fibrillation will lead to increased specific surface area of the fibrous material. The released fines from the fibers will act as bridging components between the fibers in the paper, creating a stronger fibrous network in the dried paper. ,− A more unconventional method for mechanical treatment of fibers is ultrasonication, which has gained significant interest lately, especially in nonpapermaking applications where the preservation of the fibrous structure is undesired. − During ultrasonic treatment, the effects arise from steam cavitation in which bubbles formed in the liquid exposed to the ultrasonic field undergo growth and thereafter implode under high energy conditions. This results in immense pressure fluctuations and high-temperature zones, giving rise to both physical and chemical treatment of the fibers in an undefined manner. , The physical effects include: high hydromechanical shear-forces from shockwaves, microjets and the collapse of formed bubbles, improved heat and mass transfer through agitation, improved solubilization of different organic matters, and reduction in crystallinity .…”