Effects of ultrasonic wave pretreatment on the fibrillation of cellulose fiber

Abstract

Pinus massoniana Lamb. was used as the raw cellulose fiber material to investigate effects of ultrasonic wave pretreatment and PFI pretreatment on fiber bonding and absorbability. Influences of ultrasonic wave pretreatment on fiber crystalline structure and hydrogen bonds were also analyzed by wide-angle X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. The absorption and internal bond strength of fiber pretreated by ultrasonic waves increased by 23.49% and 4.07%, respectively, in comparison with those of virgin fiber, which would result in the improvement of weak bonding and absorbability. Instead, when fiber was pretreated by PFI, absorption decreased in comparison with virgin fiber and internal bond strength increased as much as 1.33 times than that of virgin fiber. The analysis of wide-angle X-ray diffraction curves and FTIR spectroscopy curves revealed that the crystallinity of fiber decreased by 20.59% in comparison with that of virgin fiber when treated by ultrasonic waves. Moreover, the effect of ultrasonic wave pretreatment on intramolecular hydrogen bonds was rather stronger than that of intermolecular hydrogen bonds. Therefore, the optimal swelling ability of fiber would be obtained.

Sonic disruption of wood pulp fibres aided by hydrophobic cavitation nuclei

“…1) In numerous independent studies, inertial cavitation generated during ultrasonic pretreatment of wood pulp fibres has been shown to not only increase the permeability of the cell walls but also to disintegrate the structure of the fibres. [3][4][5][6] Cavitation-induced permeation was recently confirmed in solid wood, as well. 7) Whilst permeation is desirable in industrial processes, structural disintegration is not.…”

“…1) As for the experimental settings in these prior studies, the inertial cavitation-generating ultrasonic apparatus used were operating in the near-audible frequency range, whilst sonication was varied from minutes to hours. [3][4][5][6] Such acoustic conditions have been associated with the unwanted production of free radicals and deposition of heat. [8][9][10][11] Pretreatment with steam has also been shown to lead to disruptive effects, such as the visible destruction of so-called boarded pits.…”

In-situ Preparation of Nano-calcium Carbonate/Cellulose Fiber Composite and Its Application in Fluff Pulp

“…Moreover, fluff pulps with a sufficient network structure and strength of fibers are capable of carrying a large amount of the super absorbing polymers (SAPs), thus allowing a higher moisture adsorption capacity [4][5]. In order to meet or even enhance the properties above, paper boards should be subjected to dry defibration prior to the production of fluff pulp, since those key properties are highly related to the inter-fiber bonds [6][7][8]. In the defibration process, paper boards were fed into a hammermill to produce fluff pulp consisting of intact, single fibers.…”