Effect of Solvent on Morphological and Structural Change of Cellulose under Ball-Milling

Abstract

ABSTRACT:Cellulose derived from cotton was ball-milled with some hydrophilic and hydrophobic solvents such as water, toluene, 1-butanol and also without solvent (dry state), and effect of the solvents on morphological and structural changes of the cellulose were investigated. The original fibrous cellulose was changed to the aggregated globular particles by water and dry state ball-milling, plate-like particles by toluene processing, and a mixture of rugged globular particles and plate-like particles by 1-butanol processing. The globular particles prepared without solvent showed fairly low crystallinity and their inter-and intra-molecular hydrogen bonds were deformed, leading to an increase in free hydroxyl groups. The globular particles prepared with water exhibited a mixture of crystalline structure as cellulose I, cellulose II and non-crystalline state. In the case of the products with toluene, the plate-like particles significantly retained their original crystalline structure and hydrogen bonds. The 1-butanol processing seems to give the particles consisting of cellulose I and small amounts of either non-crystalline or cellulose II. The cellulose/dye stuff mixtures under the presence of the above solvents were prepared using 4-aminoazobenzene to investigate the differences in the surface property of the particles prepared by the ball-milling processing. Characteristic color development of each cellulose particles was clearly distinguished depending on the effect of the solvent (cinnabar; without solvent, yellow; toluene and yellowish-green; water or 1-butanol It has been shown that a typical hydrophilic solvent, water causes change in the long-periodicity of regenerated cellulose fiber at 30-40% water content 1 and the amorphous cellulose prepared by a ball-milling treatment reorganizes effectively to cellulose II crystalline by ball-milling with a specific amount of water; 30 wt %.2 Such apparent concentration-specific structural change in cellulose is also observed in measurements of 1 H spin-lattice relaxation of cellulose for a cellulose-water system as a function of concentration of water.3 Molecular mobility of cellulose increases and reaches a maximum around 30 wt % of water content, at which the water works as a thermo-plasticity agent on the cellulose in the system. 2,3On the one hand, it has been also shown that hydrophobic solvents affect the morphology and structure of cellulose: G. N. Marchenko et al. 4 reported on wood pulp and cotton that dichloromethane (DCM) facilitated an intra-fibril swelling and gave some changes in a absorption of CH 2 -vibration (IR; 1380 cm À1 ) with no practical change in X-ray crystallinity. A concentration-specific interaction of toluene with a regenerated cellulose membrane with high planar orientation has been proved to show that the orientation of (1 1 10) plane in cellulose crystal preferentially lowers around 20-40 wt % of toluene content, elucidated by X-ray diffraction patterns. 5 These observations show that cellulose molecules can transform spontaneously i...

Preparation of cellulose with controlled molecular weight via ultrasonic treatment improves cholesterol‐binding capacity

“…The untreated samples and ULC‐30 appeared approximately at the wavenumber of 3,337 and 3,344 cm −1 , respectively. The O–H stretching bands of the ULC‐30 clearly shifted toward higher wavenumbers, indicating an increase in free hydroxyl groups or the ones with weak hydrogen bonds (Ago, Endo, & Okajima, ). The bands at 1,160 and 897 cm −1 were representative of anti‐symmetric bridge stretching of C–O–C groups and the cellulose ß‐glycosidic linkage, respectively.…”

Crystallinity and surface state of cellulose in wet ball‐milling process

“…For comparison, the intensity of the peaks was normalized by the 002 peak intensity of the as‐received MC. It was obviously that the peaks of planes 002 and 040 of all the wet‐milled MCs were slightly shifted to a higher angle compared to the dry‐milled one, indicating that the volume of samples was expanded due to swelling affected by water penetration …”

“…For instance, to study the effect of the solvent polarity, cellulose derived from cotton was ball‐milled with water, toluene, and 1‐butanol. Variation in these solvents mainly affected the cellulose morphology and not the crystallinity . Ago et al .…”

Morphological and Structural Changes in Microcrystalline Cellulose from OPEFB by Mechanical Grinding

“…XRD pattern of the initial OPEFB-MCC was shown in Figure 1 (a) -(b). The crystalline structure was cellulose II showing its reflections around 2θ= 12, 20 and 22 [10,11]. After 4 h mechanical grinding course, the original fibrous MCC was converted into the aggregated globular particles resulting in decrease of the crystalline index (CrI).…”

“…The use of solventassisted and variation of revolution speed methods during the grinding course induced the transformation of crystalline cellulose of MCC. As a result, the MCC including crystalline, amorphous parts and their hydrophobic and hydrophilic planes [11] led the unique interaction between the MCC and solvent during the grinding course. Hydrophilic parts of MCC help the mobilization of solvent molecules to be adsorbed together with energy as a result of collision impact induced the crosssectional cracks on MCC fibrous.…”