Nanocelluloses occur under various crystalline forms that are currently being selectively used for a wide variety of high performance materials. In the present study, two cellulose nanofibers (CF-I) ...were mercerized by alkaline treatment (CF-II) without degradation, the same molar mass of 560,000 g/mol was measured. Both samples were acid hydrolyzed, leading to cellulose nanocrystals in native (CNC-I) and mercerized (CNC-II) forms. This study focuses on the detailed characterization of these two nanoparticle morphologies (light and neutron scattering, TEM, AFM), surface chemistry (zetametry and surface charge), crystallinity (XRD,
13
C NMR), and average molar mass coupled to chromatographic techniques (SEC–MALLS-RI, A4F-MALLS-RI), revealing variations in the packing of the crystalline domains. The crystal size of CNC-II is reduced by half compared to CNC-I, with molar masses of individual chains of 41,000 g/mol and 22,000 g/mol for CNC-I and CNC-II, respectively, whereas the same surface charge density is measured. This study gives an example of complementary characterization techniques as well as results to help decipher the mechanism involved in mercerization.
Due to their remarkable characteristics, cellulose nanocrystals are strategic materials that has various industrial applications, and are capable of being produced from vegetable fibers derived from ...the discards of agricultural practices. Peanut(Arachis hypogaea L.) peel is a residue considered of low commercial value and high polluting potential that needs new applications in order to mitigate these problems. Thus, in this study the feasibility of extracting cellulose nanocrystals was investigated. Two chemical routes were followed for this extraction. In the first, the fibers were bleached before acid hydrolysis whereas mercerization was used in the second. The second route was more efficient, as it enabled the elimination of proteins and phenolic compounds, which could be confirmed through solid-state 13C nuclear magnetic resonance (NMR) that revealed no signs of lignin residues. The cellulose nanocrystals composed of mainly type I cellulose presented a high degree of crystallinity index, 75 %, a thermal stability up to 200 °C, considerable stability in suspension (zeta potential of –48.1 ± 2.1 mV), and an aspect ratio of 125. They represent options that could add value to this residue, which would ease environmental problems.
This work describes the preparation of new chelating materials derived from cellulose and sugarcane bagasse for adsorption of Cu
2+, Cd
2+, and Pb
2+ ions from aqueous solutions. The first part ...involved the mercerization treatment of cellulose and sugarcane bagasse with NaOH 5
mol/L. Non- and mercerized cellulose and sugarcane bagasse were then reacted with ethylenediaminetetraacetic dianhydride (EDTAD) in order to prepare different chelating materials. These materials were characterized by mass percent gain, X-ray diffraction, FTIR, and elemental analysis. The second part consisted of evaluating the adsorption capacity of these modified materials for Cu
2+, Cd
2+, and Pb
2+ ions from aqueous single metal solutions, whose concentration was determined by atomic absorption spectroscopy. These materials showed maximum adsorption capacities for Cu
2+, Cd
2+, and Pb
2+ ions ranging from 38.8 to 92.6
mg/g, 87.7 to 149.0
mg/g, and 192.0 to 333.0
mg/g, respectively. The modified mercerized materials showed larger maximum adsorption capacities than modified non-mercerized materials.
In 2020 the Cellulose and Renewable Materials Division (CELL) of the American Chemical (ACS) society celebrates its 100th anniversary. The following paper is based on a chapter from the book ...commissioned by the Division (Patterson, 2021). CELL is one of the most successful and dynamic Divisions in the ACS. It has evolved throughout its history to remain relevant and productive. One of its strengths is its diversity, while staying true to its founding vision. This perspective was present at its founding, and the following paper surveys the world of cellulose and renewable materials from the dawn of history to 1920. CELL has both industrial and scientific roots and has always welcomed the full range of participants from these communities. Rather than operating as separate tribes, the two groups have fostered innovations in each other. Many aspects of cellulose science and technology are discussed from antiquity to the early 20th century.
Generation and availability of agro-industrial waste in the world present an opportunity to obtain raw materials for the development of new sustainable materials. In order to contribute to the ...dissemination of using agro-industrial residues in lignocellulosic particleboard (eco-particleboard) manufacturing, this work aimed to investigate the influence of a chemical mercerization treatment on the physical and mechanical properties of eco-particleboards. The treatment consisted of 0.5% sodium hydroxide (NaOH). Results of analysis of variance (ANOVA) revealed that treating the fibers was responsible for significantly reducing water absorption by 35% (2 h) and 17% (24 h), as well as thickness swelling by 36% (2 h) and 40% (24 h). The apparent density of treated (WT) and untreated (UT) eco-particleboards showed homogeneity and uniformity of the test specimens analyzed, mainly due to the manufacturing process in eco-particleboard pressing. The efficiency of the chemical mercerization treatment of the fibers of acai fruit eco-particleboard (WT) was established because the eco-particleboard produced with these fibers showed higher values in their mechanical properties: screw pullout (top) 54%, modulus of rupture in static bending (31%), and internal bonding (89%) compared to eco-particleboards composed of untreated fibers (UT). The physical-mechanical results presented by the eco-particleboards composed of treated acai fibers (WT) suggest that acai fibers could be a potentially useful raw material for the production of medium density homogeneous particleboards and consequent commercial use in the construction and furniture industries.
Sisal fibers were mercerized, under tension and no tension, to improve their tensile properties and interfacial adhesion with soy protein resin. Mercerization of fibers under tension is known to ...minimize fiber shrinkage and to lower the microfibrillar angle by aligning them along the fiber axis. Mercerization improved the fracture stress and Young’s modulus of the sisal fibers while their fracture strain and toughness decreased. Mercerized sisal fiber-reinforced composites with soy protein resin showed improvement in both fracture stress and stiffness by 12.2% and 36.2%, respectively, compared to the unmercerized fiber-reinforced composites. Scanning electron microscope (SEM) photomicrographs of the composite fracture surfaces showed shorter fibrils protruding in the mercerized fiber-reinforced composites resulting in better sisal fiber/soy adhesion. Changed fiber surface properties were also responsible for better adhesion.
This study aims to assess the relationship between the surface roughness of cotton plain-woven fabric before and after each pretreatment processing stage. According to the findings of this study, the ...surface roughness values of desized fabric increased in the warp and weft directions. On the other hand, the roughness of plain-woven fabric reduced in both the warp and weft directions during the scouring, bleaching, and mercerization processes. The weft roughness values of greige, scoured, bleached, and mercerized fabrics are higher than the warp roughness values. Mercerized fabrics provide the smoothest fabric surface compared to other treatment stages. The pretreatment stages have statistically significant impacts on the surface roughness in both the warp and weft directions at a 95% confidence interval. The pairwise analysis reveals that pretreatment of the fabrics in the warp and weft directions is statistically significant for grey with desizing, grey with scouring, grey with bleaching, grey with mercerizing, desizing with scouring, desizing with bleaching, desizing with mercerization, scouring with mercerization, and bleaching with mercerization, but not for scouring with bleaching. Mercerized fabric is highly recommended for producing textile products with unique requirements in terms of tactilely sensitive surface properties.
Delignified fibres from
E. benthamii
,
E. nitens
and
E. smithii
were treated with different NaOH concentrations (up to 30%, w/v) at two different temperatures (25 °C and 80 °C) to investigate the ...polymorphic and morphological variations in cellulose. The results showed that de-crystallization and the polymorphic transformation of cellulose started at 10% (w/v) NaOH. At 10% (w/v) NaOH, the cellulose II content was similar among the samples from the different species, but changes were observed in the cellulose I content and amorphous fraction. Alkalization at 25 °C had a higher de-crystallization effect than that at 80 °C.
E. benthamii
showed the highest cristallinity index values and
E. nitens
the lowest. The crystallite size of cellulose I (
L
(200)
) increased as the NaOH concentration increased, while the temperature seemed to not have a significant influence on the
L
(200)
variation.
E. benthamii
showed the highest
L
(200)
(3.5–5.0 nm) while
E. nitens
showed the lowest (3.3–4.5 nm). The crystallite size of cellulose II (
L
(020)
) was higher (4.8–5.2 nm) than that of cellulose I
L
(200)
(3.3–5.0 nm). Alkalization at a higher temperature resulted in a higher cellulose II
L
(020)
. Morphologically, at a 0.5% NaOH concentration, the fibres were embedded in a gel-like substance, and, with the NaOH concentration above 10%, the fibres were converted into a swollen and roughened state. Thus, different
Eucalyptus
species at given NaOH concentrations displayed different structural features, which could lead to procedures and products with different requirements towards the manufacturing of cellulose derivatives.
Graphical Abstract
In this paper the possibility of applying natural dyes on cellulose fibres were researched with respect to the impact of cotton material pre-treatment (scouring, chemical bleaching, mercerization and ...mordanting), using renewable sources of natural dyes (waste as a source). As mordants, metal salts of copper, aluminium and ferrum were used, and the influence on colour change as well as on fastness properties were analysed. The natural dyes were extracted from onion peel (Allium cepa L.) and pomegranate peel (Punica granatum L.). In spectrophotometric analysis performed of the plant extracts, the onion extract has peaks at 400 and 500 nm, resulting in red-orange colourations and the pomegranate extract shows a maximum at 400 nm, i.e., in the yellow region, which is characteristic of punicalin. Results show significant influence of cotton pre-treatments on colour appearance and fastness properties, caused by pre-treatments affecting the properties and structure of the cotton itself. The positive effect of mercerization on dye absorption and bonding is confirmed. For wash and light fastness properties, more satisfactory results have been obtained for yarns dyed with pomegranate peel natural dye, and the key importance of mordants for fastness properties has been confirmed.
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