Supramolecular Structure ‐ A Key Parameter for Cellulose Biodegradation

Ciolacu, Diana; Ciolacu, Florin; Popa, Valentin I.

doi:10.1002/masy.200851220

Cited by 83 publications

(91 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These peaks are normally identified for cellulose in commercial α-cellulose (Figure 2) [13,14]. The peak located at 1427.32 cm -1 which was observed in all specimens except untreated kenaf corresponds to the crystallinity band [15]. These results confirmed that the crystalline cellulose was successfully extracted from kenaf bast fibers in both treatments ( Table 1).…”

Section: Resultssupporting

confidence: 69%

Effect of the chemical treatments on the characteristics of natural cellulose

Muhaimin¹,

Abdilah²,

Astuti³

et al. 2014

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. In order to characterize the morphology and size distribution of the cellulose fibers, natural cellulose from kenaf bast fibers was extracted using two chemical treatments; (1) alkali-bleaching-ultrasonic treatment and (2) alkalibleaching-hydrolysis. Solutions of NaOH, H 2 O 2 and H 2 SO 4 were used for alkalization, bleaching and hydrolysis, respectively. The hydrolyzed fibers were centrifuged at a rotation speed of 10000 rpm for 10 min to separate the nanofibers from the microfibers. The separation was repeated in 7 steps by controlling pH of the solution in each step until neutrality was reached. Fourier transform infrared (FTIR) spectroscopy was performed on the fibers at the final step of each treatment: i.e. either ultrasonic treated-or hydrolyzed microfibers. Their FTIR spectra were compared with FTIR spectrum of a reference commercial α-cellulose. Changes in morphology and size distribution of the treated fibers were examined by scanning electron microscopy (SEM). FTIR spectra of ultrasonic treated-and hydrolyzed microfibers nearly coincided with the FTIR spectrum of commercial α-cellulose, suggesting successful extraction of cellulose. Ultrasonic treatment for 6 h resulted in a specific morphology in which cellulose nanofibers (≥100 nm) were distributed across the entire surface of cellulose microfibers ( 5 m). Constant magnetic stirring combined with acid hydrolysis resulted in an inhomogeneous size distribution of both cellulose rods (500 nm-3 m length, 100-200 nm diameter) and particles 100-200 nm in size. Changes in morphology of the cellulose fibers depended upon the stirring time; longer stirring time resulted in shorter fiber lengths.

show abstract

Section: Resultssupporting

confidence: 69%

Effect of the chemical treatments on the characteristics of natural cellulose

Muhaimin¹,

Abdilah²,

Astuti³

et al. 2014

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…In contrast, the fine particles of the pulp-rich fraction are more brittle and consequently crumbly under the influence of applied frictions, owing to its low cellulose content. Indeed, according to Ciolacu et al [32], the crystallinity of the cellulose is at the origin of its resistance. The resulting fractions were compared to both the starting biomass (F0) and the reference fractions obtained by wet fractionation, in terms of color and biochemical composition in order to assess the efficiency of the applied dry fractionation routes.…”

Section: Dry Fractionationmentioning

confidence: 99%

Dry fractionation of olive pomace as a sustainable process to produce fillers for biocomposites

et al. 2018

View full text Add to dashboard Cite

“…Figure 1 shows that MCC scattering intensity of peaks decreases sharply after one hour milling. Onehour milling led to 30% reduction of the crystalline index measured according to equation (2). Hence, mechanical milling resulted in the increase of the amorphous regions number in MCC, but one hour of milling was not enough to transform MCC into amorphous cellulose, as there are some weak peaks on the XRD pattern.…”

Section: Resultsmentioning

confidence: 99%

“…Cellulose chains are located randomly in amorphous regions so interaction during reaction takes place more easily than in crystalline regions. Most of reactions takes place on plane of crystallites and in amorphous domains without affecting the intracrystalline regions [2]. The long-range order of crystalline in a mircofibril results from intermolecular interaction such as van der Waals's force and hydrogen bonds.…”

mentioning

confidence: 99%

3D model of short-range order of one-hour milled cellulose

Smirnov

Loginova

2018

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. The main purpose of this work was to investigate the structure of short-range order of microcrystalline cellulose (MCC) milled for one hour. Usually mechanical milling produces amorphous segments of crystalline cellulose. Investigation of short-range order was conducted by Debay's method to get X-ray diffraction (XRD) pattern when the coordinates of atoms in a cluster are known. The samples were studied by XRD. Crystallinity degree was measured using Segal's method. Cellulose Iα and Iβ were used as the initial structures to form clusters. The profile factor (Rp) was used, as the evaluation factor. The results showed that the cluster based on cellulose Iβ insufficiently characterized the short-range order of crystallineamorphous cellulose (Rp>18%). Consequently, we examined a unit cell consisting of one cellobiose fragment. The final modeling cluster had the size of 35Å×22Å×29Å. The cluster consisted of 3 layers orientated randomly in relation to one another. The result of comparison of theoretical and experimental XRD patterns revealed that Rp was 11.4%. Therefore, the structure of short-range order of one-hour ground cellulose can be characterized by disordered cellulose chains with the length of 21 Å. IntroductionCellulose is a linear polymer with crystalline and amorphous regions alternating along the axis of microfibril [1]. Cellulose chains are located randomly in amorphous regions so interaction during reaction takes place more easily than in crystalline regions. Most of reactions takes place on plane of crystallites and in amorphous domains without affecting the intracrystalline regions [2]. The long-range order of crystalline in a mircofibril results from intermolecular interaction such as van der Waals's force and hydrogen bonds. A physical or chemical influence may destroy intermolecular forces in crystallites of cellulose. For example, the higher the time of mechanical milling, the higher increase of amorphous degree in cellulose fibers. XRD pattern of crystalline amorphous cellulose has amorphous galo and peaks belonging to crystalline regions. Amorphous galo defines the presence of the short-range order in the structure of cellulose. The method of randomly disordered layers (Debay's method) gives information about the structure of short-range order [3]. Therefore, the aim of this paper is to use Debay's method to investigate the influence of mechanical milling on the structure of the short-range order for one-hour milled MCC.

show abstract

Supramolecular Structure ‐ A Key Parameter for Cellulose Biodegradation

Cited by 83 publications

References 21 publications

Effect of the chemical treatments on the characteristics of natural cellulose

Effect of the chemical treatments on the characteristics of natural cellulose

Dry fractionation of olive pomace as a sustainable process to produce fillers for biocomposites

3D model of short-range order of one-hour milled cellulose

Contact Info

Product

Resources

About