scholarly journals Extraction and Characterization of Cellulose and Cellulose Nanowhiskers from Almond Shell Biomass, Metal Removal and Toxicity Analysis

2021 ◽  
Vol 12 (2) ◽  
pp. 1705-1720
Keyword(s):  
Metal Removal ◽  
Separation Efficiency ◽  
Average Length ◽  
Alkali Treatment ◽  
Ir Absorption ◽  
Cellulose Nanowhiskers ◽  
Almond Shell ◽  
Industry Waste ◽  
Potential Applicability ◽  
20 Nm

Almond shell is a major agro-industry waste. Cellulose is the major crystalline component of naturally porous almond shell biomass. In this study, cellulose (ASC) was isolated from almond shell (AS) by the dewaxing-alkali treatment-bleaching method, and nanocrystalline cellulose (ASN) was obtained by sulphuric acid hydrolysis of the obtained ASC. Separation efficiency was confirmed by X-ray diffraction and IR absorption studies. ASC exhibited predominantly microporous monolithic structures under a scanning electron microscope. Its porosity resulted in significant absorption of Cu(II) and Pb(II) ions when applied as an absorbent in their solutions. Transmission electron microscopy and atomic force microscopy revealed the formation of ASN nanowhiskers with an average length and diameter of 170 nm and 20 nm, respectively. Zeta potential of -32.4 mV suggested good colloidal dispersibility of the nanowhiskers. No hemolytic toxicity to erythrocyte cells was recorded, which suggested the potential applicability of the obtained nanomaterial in foods and pharmaceuticals. Remarkably high crystallinity and thermal resistance observed from calorimetry and thermogravimetry studies indicated enhanced density of the crystalline moiety during synthesis. ASC and ASN can be developed as effective metal absorption substrates and reinforcement agents in heat-resistant composite materials.

Evaluation of morphological architecture of cellulose chains in grass during conversion from macro to nano dimensions

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Jitendra K. Pandey ◽  
Chung-Soo Kim ◽  
Won-Shik Chu ◽  
Caroline S. Lee ◽  
Dong-Young Jang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Acid Hydrolysis ◽  
Alkali Treatment ◽  
Soxhlet Extraction ◽  
Amorphous Region ◽  
Cellulose Nanowhiskers ◽  
Thick Fiber ◽  
Transmission Electron ◽  
Nano Fiber ◽  
The Matrix

AbstractThe cellulose nanowhiskers (CNW) are of imminent importance in the development of ecofriendly green material for environment. Morphological study of their structure was carried out after extraction from grass. The controlled alkali and acid hydrolysis after soxhlet extraction of bleached fiber in ethanol and water provided a mixture of micro/nano fiber which can be further converted into CNW by mechanical treatment. Width of obtained CNW were found to be ~10-65 nm with length of several nanometers as evidenced by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The changes in dimensions during alkali treatment, bleaching and acid hydrolysis of grass exhibited an interesting architecture and clarify the phenomenon of separation of nano level fibrils from the matrix of hemicellulose and lignin which starts after swelling of fibers and opening from middle followed by splitting from each other. The nanofibers were embedded in the matrix surrounded by amorphous layers. The size of fibers was directly associated with the extent of treatments. The crystalline part of fiber was intact during hydrolysis which must be attributed to easy removal of amorphous region by penetration of hydronum ions from acid. The results of SEM and TEM were correlated with the Scanning Ion Microscopy (SIM) which showed a direct evidence of breaking of thick fiber strands resulting in the formation of sharp edged crystalline entities composed of cellulose crystals.

scholarly journals Scalable Preparation of Cellulose Nanofibers from Office Waste Paper by an Environment-Friendly Method

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3119
Author(s):  
Deyuan Huang ◽  
Haoqun Hong ◽  
Weilong Huang ◽  
Haiyan Zhang ◽  
Xiaobin Hong
Keyword(s):  
Electron Microscopy ◽  
Light Transmission ◽  
Alkali Treatment ◽  
Cellulose Nanofibers ◽  
Waste Paper ◽  
Narrow Particle Size Distribution ◽  
Cellulose Content ◽  
Tempo Oxidation ◽  
20 Nm ◽  
Bleaching Treatment

Waste paper is often underutilized as a low-value recyclable resource and can be a potential source of cellulose nanofibers (CNFs) due to its rich cellulose content. Three different processes, low acid treatment, alkali treatment and bleaching treatment, were used to pretreat the waste paper in order to investigate the effect of different pretreatments on the prepared CNFs, and CNFs obtained from bleached pulp boards were used as control. All sample fibers were successfully prepared into CNFs by 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) oxidation. It was quite obvious that the bleached CNFs samples showed dense fibrous structures on a scanning electron microscopy (SEM), while needle-like fibers with width less than 20 nm were observed on a transmission electron microscopy (TEM). Meanwhile, the bleaching treatment resulted in a 13.5% increase in crystallinity and a higher TEMPO yield (e.g., BCNF, 60.88%), but a decrease in thermal stability. All pretreated CNFs samples showed narrow particle size distribution, good dispersion stability (zeta potential less than −29.58 mV), good light transmission (higher than 86.5%) and low haze parameters (lower than 3.92%). This provides a good process option and pathway for scalable production of CNFs from waste papers.

scholarly journals Cytotoxicity Property of Nano-TiO2Sol and Nano-TiO2Powder

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Pingting He ◽  
Jie Tao ◽  
Jianjun Xue ◽  
Yulan Chen
Keyword(s):  
Electron Microscope ◽  
Average Length ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Experimental Protocols ◽  
20 Nm

A homogeneous and transparent titania (TiO2) sol with nanosized anatase TiO2particles was prepared by hydrothermal synthesis method. The transmission electron microscope and X-ray diffraction were used to characterize the structure and morphology of particulates in the TiO2sol and purchased TiO2powder. The results show that the homogeneous anatase crystalline phase was formed and the size of the spindle-like particle in sol was about 20 nm in width and 150 nm in average length, and the particulates of the purchased powder were globular-like about 50 nm in diameter. In addition, a consistent set of in vitro experimental protocols was used to study the effects of nano-TiO2sol as prepared and nano-TiO2powder on mouse peritoneal macrophage. The cytotoxicity tests in vitro indicate that, with the increasing of TiO2sol concentration contaminated with the cells, the relative proliferation rate of macrophage cells was improved slightly after the cells contaminated for 24 h, but it reduced rapidly after contaminated for 48 h. The purchased nano-TiO2powder inhibited the growth of the cells obviously as cultivating with macrophage both for 24 h and 48 h.

Effect of Alkali Treatment on the Quality of Hemp Fiber

2014 ◽  
Vol 9 (2) ◽  
pp. 155892501400900 ◽  
Author(s):  
Jie Zhang ◽  
Hua Zhang ◽  
Jianchun Zhang
Keyword(s):  
Chemical Composition ◽  
Experimental Design ◽  
Average Length ◽  
Alkali Treatment ◽  
Orthogonal Experimental Design ◽  
Average Weight ◽  
Range Analysis ◽  
Experimental Conditions ◽  
Hemp Fiber

An orthogonal experimental design was employed to study the effects of the bath ratio, time, and alkali dosage of alkali treatment on the chemical composition, fineness, average length, and staple rate of hemp fiber. Through normalization and average weight distribution of multiple indices, the quality of hemp fiber was quantified. Results of range analysis showed that the optimum quality of hemp fiber can be achieved under the following conditions: alkali treatment bath ratio, 1:10; time, 5 h; alkali dosage, 10 g/L; and length of hemp fiber, 16 mm to 29 mm. The reliability and repeatability of the best experimental conditions were further confirmed.

scholarly journals CaRBoKem: A Biofilter to Treat Heavy Metals by using the Household Waste Products

2020 ◽  
Author(s):  
Milan Maria Sajeev ◽  
Uma Krishnakumar ◽  
Merrin John ◽  
Amal Raj ◽  
Hanna Thomas
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
Asian Country ◽  
Chemical Precipitation ◽  
Toxic Waste ◽  
Household Waste ◽  
Chemical Agent ◽  
Surface Absorption ◽  
Waste Products ◽  
Industry Waste

Abstract Environmental toxic waste from heavy metals along with minerals within the waste matter is one of the most significant issue in an Asian country. The activities like industrial operations particularly mining, agricultural processes and disposal of industry waste materials; their concentration has redoubled to hazardous levels. Major metals in industrial sewage represent Cu, Cr3+and Pb etc. So far, varieties of inexpensive strategies are reviewed for the removal of these metals. The various processes include chemical precipitation, reverse diffusion, electro qualitative analysis, nanofiltration and floatation. But these strategies have many disadvantages like high chemical agent demand, unpredictable metal particle elimination, and production of unhealthful sludge. Surface absorption method being terribly straightforward, economical, effective and versatile has become the most popular strategies for removal of unhealthful contaminants from waste matter. This paper gives a new idea for the utilization of natural materials as adsorbents for significant metal removal from industrial waste water. The components used are mustard plant roots, human hair and some common house hold waste products such as, egg shell and coconut shell. Utilizing their adsorbent properties in an efficient way, it can be used to filter industrial heavy metals which cause pollution.

scholarly journals Heterogeneity of protein–polysaccharides of porcine articular cartilage. The chondroitin–sulphate proteins associated with collagen

1971 ◽  
Vol 123 (5) ◽  
pp. 747-755 ◽  
Author(s):  
K. D. Brandt ◽  
Helen Muir
Keyword(s):  
Articular Cartilage ◽  
Sodium Acetate ◽  
Chondroitin Sulphate ◽  
Average Length ◽  
Alkali Treatment ◽  
Molar Ratio ◽  
Sodium Acetate Solution ◽  
Acetate Solution ◽  
Keratan Sulphate ◽  
Collagenase Digestion

Pig articular cartilage, from which protein–polysaccharides soluble in iso-osmotic sodium acetate had been removed, was extracted in three further stages with 8m-urea in 2m-sodium acetate and with tris–HCl buffer after bacterial collagenase digestion, followed by the same urea–sodium acetate solution, thus leaving only 2% of the original uronic acid in the tissue. The histological appearance of the cartilage was unaltered until after collagenase digestion. The collagenase used did not affect the viscosity or molecular size of a protein–polysaccharide preparation obtained previously. The protein–polysaccharides in each extract differed in size, amino acid composition and protein content, but protein and keratan sulphate contents were not related to hydrodynamic size, in contrast with protein–polysaccharides extracted previously before collagenase digestion. Hydroxyproline could not be removed from those obtained by the first urea–sodium acetate extraction until degraded by heat. The galactosamine/pentose molar ratio agreed closely with the galactosamine/serine molar ratio that was destroyed on treatment with 0.5m-sodium hydroxide, showing that chondroitin sulphate was attached only to serine residues. From these molar ratios the chondroitin sulphate chains were calculated to be of the same average length in protein–polysaccharides in all three extracts although somewhat shorter than in protein–polysaccharides extracted previously. Some threonine residues were also destroyed on alkali treatment suggesting that keratan sulphate may be attached to threonine. These findings together with previous results show that differences in size, composition and physical state extend to all the protein–polysaccharides in cartilage.

scholarly journals Investigation of the structure of alpha-lactalbumin protein nanotubes using optical spectroscopy

2013 ◽  
Vol 81 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Özgür Tarhan ◽  
Enver Tarhan ◽  
Şebnem Harsa
Keyword(s):  
Protein Structure ◽  
Optical Spectroscopy ◽  
Conformational Changes ◽  
Self Assembly ◽  
Average Length ◽  
La Protein ◽  
The Fourier Transform ◽  
20 Nm ◽  
Nanotube Growth ◽  
Alpha Lactalbumin

Alpha-lactalbumin (α-la) is one of the major proteins in whey. When partially hydrolysed with Bacillus licheniformis protease, it produces nanotubular structures in the presence of calcium ions by a self-assembly process. This study presents investigation of α-la protein structure during hydrolysis and nanotube formation using optical spectroscopy. Before spectroscopic measurements, nanotubes were examined with microscopy. The observed α-la nanotubes (α-LaNTs) were in the form of regular hollow strands with a diameter of about 20 nm and the average length of 1 μm. Amide and backbone vibration bands of the Raman spectra displayed remarkable conformational changes in α and β domains in the protein structure during nanotube growth. This was confirmed by the Fourier-transform infrared (FTIR) spectroscopy data. Also, FTIR analysis revealed certain bands at calcium (Ca++) binding sites of COO− groups in hydrolysed protein. These sites might be critical in nanotube elongation.

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