Pretreatment assisted synthesis and characterization of cellulose nanocrystals and cellulose nanofibers from absorbent cotton

Abstract

In this work, cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were synthesized from absorbent cotton. Two pretreatments viz. dewaxing and bleaching with mild alkali were applied to the precursor (cotton). Acid hydrolysis was conducted with HSO and dissolution of cotton was achieved with a mixture of NaOH-thiourea-urea-HO at -3°C. Synthesized cellulose samples were characterized using FTIR, XRD, SEM, BET, and zeta potential. It seems that synthesis conditions contributed to negative surface charge on cellulose samples and CNCs had the higher negative surface charge compared to CNFs. Furthermore, BET surface area, pore volume and pore diameter of CNCs were found to be higher as compared to CNFs. The dewaxed cellulose nanofibers (CNF D) had a slightly higher BET surface area (0.47m/g) and bigger pore diameter (59.87Å) from attenuated contraction compared to waxed cellulose nanofibers (CNFW) (0.38m/g and 44.89Å). The XRD of CNCs revealed a semi-crystalline structure and the dissolution agents influenced the crystallinity of CNFs. SEM images showed the porous nature of CNFs, the flaky nature and the nano-sized width of CNCs. Synthesized CNF D showed a better potential as an adsorbent with an average lead removal efficiency of 91.49% from aqueous solution.

Water vapor sorption properties of cellulose nanocrystals and nanofibers using dynamic vapor sorption apparatus

“…These values were higher than those of the other cellulose fibers, such as cotton linter and α-cellulose 31 . This was attributed to the larger pore volume and pore diameter of the CNC and CNF films that were made of nanoparticles 32 . The EMC of CNF was higher than that of the CNC owing to the lower degree of crystallinity and more amorphous nature of CNF.…”

Synthesis of S-ligand tethered cellulose nanofibers for efficient removal of Pb(II) and Cd(II) ions from synthetic and industrial wastewater

“…The dissolution and reduction of degree of polymerization by alkali oxidation procedure and subsequent sulphur (S) radical tethering was done by following modified procedures reported elsewhere (Abu-Danso et al, 2017;Haskins and Hogsed, 1950). Briefly, a solution containing 2.3 M NaOH, 1.8 M CO(NH₂)₂ and 1.75 M SC(NH₂)₂ as sulphur source was cooled to ca.…”

Utilization of waste cotton linter for preparation of activated carbon to be used as catalyst support in aqueous‐phase reforming process

“…The bands around 1695 and 1430 cm −1 were attributed to the CO and CO vibration, respectively . Overall, FT‐IR spectra showed that thermal precarbonization was more effective on changing the structural integrity of cellulose before major carbonization process .…”