Probing crystallinity of never-dried wood cellulose with Raman spectroscopy

Agarwal, Umesh P.; Ralph, Sally A.; Reiner, Richard; Báez, Carlos

doi:10.1007/s10570-015-0788-7

Cited by 132 publications

(111 citation statements)

References 58 publications

Supporting

Mentioning

103

Contrasting

Order By: Relevance

“…[93][94][95][96] Furthermore, the validity and limitations of these methods and data fitting routines is a hotly debated topic and is beyond the scope of this work. Largely XRD is reported and the Rietveld refinement is commonly considered to be the most accurate method.…”

Section: Blue Goose Biorefineriesmentioning

confidence: 99%

Benchmarking Cellulose Nanocrystals: From the Laboratory to Industrial Production

2016

View full text Add to dashboard Cite

Abstract:The renewability, biocompatibility and mechanical properties of cellulose nanocrystals (CNCs) have made them an attractive material for numerous composite, biomedical and rheological applications. However, for CNCs to shift from laboratory curiosity to commercial applications, researchers must transition from CNCs extracted at the bench scale to material produced at an industrial scale. There are a number of companies currently producing kilogram to ton per day quantities of sulfuric acid-hydrolyzed CNCs, as well as other nanocelluloses, as described herein.With the recent intensification of industrially produced CNCs, the variety of cellulose sources, hydrolysis methods and purification procedures, characterization of these materials becomes critical. This has further been justified by the past two decades of research which demonstrate that CNC stability and behaviour is highly dependent on surface chemistry, surface charge density and particle size. This work outlines key test methods that should be employed to characterize these properties to ensure a "known" starting material and consistent performance.Of the sulfuric acid-extracted CNCs examined, industrially produced material compared well with laboratory-made CNCs, exhibiting similar charge density, colloidal and thermal stability, crystallinity, morphology and self-assembly behaviour. In addition, it was observed that further purification of CNCs, using Soxhlet extraction in ethanol, had minimal impact on nanoparticle properties and is unlikely to be necessary for many applications. Overall the current standing of industrially produced CNCs is positive suggesting that the evolution to commercial scale applications will not be hindered by CNC production.

show abstract

Section: Blue Goose Biorefineriesmentioning

confidence: 99%

Benchmarking Cellulose Nanocrystals: From the Laboratory to Industrial Production

2016

View full text Add to dashboard Cite

show abstract

“…Most likely, the chemical cross-linking among different cellulose molecules Raman spectroscopy has been recently used to estimate the water accessibility to the -CH 2 OH in cellulose by comparing the intensity changes of bands at 1380 cm −1 and 1096 cm −1 [75]. Agarwal et al concluded that when soaking a polymorphous cellulose sample with D 2 O and after full OH-to-OD exchange in the cellulosic material, the increase in the intensity of the band at 1380 cm −1 relative to that of 1096 cm −1 is an indication of the non-crystalline nature of cellulose in that sample [76]. Therefore, the fraction of amorphous cellulose in the cross-linked hydrogel can be estimated from the following relation:…”

Section: Ftir and Raman Analysis Of Accessibility Of Cellulose Hydrogelmentioning

confidence: 99%

“…where I 1380 and I 1096 are the Raman spectral intensities at 1380 cm −1 and 1096 cm −1 , respectively. It is important to stress that despite this simple method being rather qualitative, valuable information can be still inferred from the water-hydroxyl group interactions in cellulose materials [76]. In Figure 5 the estimated numbers of amorphous regions (Equation (2)) in the synthesized cellulose Polymers 2020, 12, 373 8 of 15 hydrogels are reported for the different curing conditions.…”

Section: Ftir and Raman Analysis Of Accessibility Of Cellulose Hydrogelmentioning

confidence: 99%

Simple One Pot Preparation of Chemical Hydrogels from Cellulose Dissolved in Cold LiOH/Urea

et al. 2020

View full text Add to dashboard Cite

In this work, non-derivatized cellulose pulp was dissolved in a cold alkali solution (LiOH/urea) and chemically cross-linked with methylenebisacrylamide (MBA) to form a robust hydrogel with superior water absorption properties. Different cellulose concentrations (i.e., 2, 3 and 4 wt%) and MBA/glucose molar ratios (i.e., 0.26, 0.53 and 1.05) were tested. The cellulose hydrogel cured at 60 • C for 30 min, with a MBA/glucose molar ratio of 1.05, exhibited the highest water swelling capacity absorbing ca. 220 g H 2 O/g dry hydrogel. Moreover, the data suggest that the cross-linking occurs via a basic Michael addition mechanism. This innovative procedure based on the direct dissolution of unmodified cellulose in LiOH/urea followed by MBA cross-linking provides a simple and fast approach to prepare chemically cross-linked non-derivatized high-molecular-weight cellulose hydrogels with superior water uptake capacity.Polymers 2020, 12, 373 2 of 15 enhance their potentials for applications, affect their release profiles and even allow specific processing, such as their injection [19]. In this respect, the mechanical and flow properties cannot be neglected when judging the feasibility of a hydrogel for a specific biological application. For instance, suitable flow properties allow hydrogels to be exciting candidates as injectable therapeutic delivery carriers if they are capable of shear-thinning during application at a proper shear stress; rapid self-healing; and adopting a solid-like behavior once the stress is removed [20].The general processing of cellulose, including the hydrogel formation, is challenging, since the biopolymer does not dissolve in water or in common organic solvents. Cellulose dissolution requires the disruption of the relatively extended inter-and intramolecular hydrogen bond network within its structure, as well as the van der Waals and hydrophobic interactions among the less polar faces of the anhydroglucose units [21][22][23][24].It is thus not surprising that for cellulose-based hydrogels the majority of studies have mainly focused on systems involving cellulose derivatives that can be easily dissolved in aqueous media [3,5,25,26]. Some studies have focused on physical hydrogels from several cellulose derivatives [27,28], while chemical cross-linking is more commonly used [3]. In this respect, chemically crosslinked cellulose-based hydrogels have been prepared using different methodologies, such as esterification [29], and radical and graft polymerization [30,31]. Methods involving free-radical initiation using an initiator compound or a high energy irradiation source, such as microwaves, γ-rays or glow discharge by electrolysis plasma, have also been suggested [29,[32][33][34][35][36][37][38][39]. Most of these processes involve time-consuming procedures requiring large quantities of chemicals, which make the post-treatment challenging. Consequently, these are generally expensive and poorly efficient strategies [32].Chemical cross-linking overcomes the problem of poor robustness of physical hydro...

show abstract

“…The fingerprint spectral region of 1000-1550 cm −1 shown in figure 8(b) is of particular interest, given some subtle, but highly informative differences between the two samples. The peak intensities were normalized with the 1093 cm −1 cellulose backbone band of each sample, and hence the ratios between various bands could be [47][48][49]. The ratio between the 1336 and 1375 cm −1 bands, both corresponding to O-H in-plane bending modes of the C-O-H moieties on secondary and primary carbons of the glucose molecules, respectively, increases by more than 20%.…”

Section: The Morphological and Structural Characterization Of Cncs Dementioning

confidence: 99%

Decoration of cellulose nanocrystals with iron oxide nanoparticles

Chen

Sharma

Darienzo

et al. 2020

Mater. Res. Express

View full text Add to dashboard Cite

Cellulose nanocrystals (CNCs) are excellent candidates for the design and development of multifunctional biomaterials systems to be used in a variety of technologically relevant applications. They may be used as the structural reinforcement phase of polymer matrices, act as catalyst support constituents, as well as drug delivery vectors. Modifying and functionalizing CNCs by introducing specific functional components can impart electronic, magnetic, catalytic, fluorescence and optical properties to the system. In this work we report the successful in situ tethering of iron oxide nanoparticles (IONPs) onto CNCs by the thermal decomposition of Fe(CO) 5 in a H 2 O/DMF suspension. Following this procedure, IONPs consisting of mixtures of Fe 3 O 4 and Fe 2 O 3 with an average diameter of 20 nm were attached to the CNCs. The type of iron oxide species that was generated was determined by selected area electron diffraction (SAED) and energy dispersive spectroscopy (EDS), and the particle size was evaluated by transmission electron microscopy (TEM). Raman spectroscopy was used to characterize the presence and the nature of the molecular interaction between the IONPs and the CNCs.

show abstract

Probing crystallinity of never-dried wood cellulose with Raman spectroscopy

Cited by 132 publications

References 58 publications

Benchmarking Cellulose Nanocrystals: From the Laboratory to Industrial Production

Benchmarking Cellulose Nanocrystals: From the Laboratory to Industrial Production

Simple One Pot Preparation of Chemical Hydrogels from Cellulose Dissolved in Cold LiOH/Urea

Decoration of cellulose nanocrystals with iron oxide nanoparticles

Contact Info

Product

Resources

About