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.

Isolation of Nanocellulose from Pomelo Fruit Fibers by Chemical Treatments

2013 ◽  
Vol 747 ◽  
pp. 363-366 ◽  
Author(s):  
Niti Yongvanich ◽  
Pattama Visuttpitukul
Keyword(s):  
Electron Microscopy ◽  
Acid Hydrolysis ◽  
Alkali Treatment ◽  
Aqueous Suspension ◽  
Cellulose Nanofibers ◽  
Compact Structure ◽  
X Ray ◽  
Chemical Treatments ◽  
Transmission Electron ◽  
20 Nm

This study aims to isolate cellulose nanofibers from locally abundant pomelo fruit. Only the inner, soft peels were selected for investigation. The peels were subjected to alkali treatment (NaOH) with different concentrations and soaking times. Acid hydrolysis was also carried out to obtain an aqueous suspension of nanocellulose. The treated cellulose fibers were characterized by various methods. The effect of alkali treatment was initially confirmed by Fourier Transformed Infrared (FTIR) Spectra which displayed disappearance of several peaks belonging to non-cellulosic materials. The sharpening of the absorption at around 914 cm-1 is attributed the β-glycosidic linkages between the sugar units in cellulose. Alkali treatment also helped eliminate the non-cellulosic constituents via reduction in the 1240 and 1750 cm-1 peak. Thermogravimetric (TG) analysis revealed an improved onset of degradation likely caused by an increase in crystallinity evidenced by X-ray diffractometry (XRD) through the presence of two well-defined reflections characteristic of cellulose. The morphological and structural characterization by Scanning electron microscopy (SEM) still revealed a compact structure even after alkali treatment. However, acid hydrolysis was successful in individualizing cellulose nanofibers as observed by transmission electron microscopy (TEM). The diameter of these nanofibers was in the 10 - 20 nm range with various lengths.

scholarly journals Effect of Steam and Bleaching Treatment on the Characteristics of Pineapple Leaves Fibre Derived Cellulose

2020 ◽  
Vol 28 (S2) ◽  
Author(s):  
Surenthiran Gnanasekaran ◽  
Siti Nur Najihah Muslih ◽  
Jun Haslinda Shariffuddin ◽  
Noor Ida Amalina Ahamad Nordin
Keyword(s):  
Room Temperature ◽  
Alkali Treatment ◽  
Chain Structure ◽  
Steam Treatment ◽  
Sodium Chlorite ◽  
Cellulose Content ◽  
Degradation Temperature ◽  
Different Temperatures ◽  
Pineapple Leaves ◽  
Bleaching Treatment

Pineapple leaf fibres (PALF) is one of the abundant residues generated from pineapple plantation. The residues are left on the plantation for nutrient cycling or burning, and this circumstance leads to environmental issues. PALF has high cellulose content among other natural fibres. Cellulose is a reinforcing element that exists as whisker-like microfibrils and has a long-chain structure. In this study, cellulose produced from PALF was treated by steam and chemical treatment. The fibre was treated with steam at 121°C, a pressure of 21 psi for 30 or 60 min. Next, the steam-treated fibre was treated with 5 wt% sodium chlorite (NaClO2) solution with pH adjusted between 4 and 5 for 90 min. The condition was varied with three different temperatures, which were room temperature, 50, and 70°C. Then, the bleached fibre was treated with 5 wt% sodium hydroxide (NaOH) at room temperature for 3 h. After the treatments, the fibre was analysed for its thermal stability, morphology, and chemical composition. Cellulose obtained from the treatment condition of steam for 60 min, bleaching at 70°C, and alkali treatment at room temperature expressed the highest degradation temperature of 276°C at 20% weight loss, percentage of cellulose of 86% and lowest moisture content (8%) compared to others sample. It also had an excellent surface morphology with finest fibril disintegration. It showed longer steam treatment (60 min) degrading more hemicellulose; and bleaching treatment at high temperature (70°C), increasing the rate of oxidative delignification. In conclusion, the suggested treatment provides a simple but efficient method to isolate cellulose that can be used for various types of applications.

scholarly journals Recycling Waste Cotton Cloths for the Isolation of Cellulose Nanocrystals: A Sustainable Approach

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 626
Author(s):  
Siti Hajar Mohamed ◽  
Md. Sohrab Hossain ◽  
Mohamad Haafiz Mohamad Kassim ◽  
Mardiana Idayu Ahmad ◽  
Fatehah Mohd Omar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cellulose Nanocrystals ◽  
Value Added ◽  
Crystallinity Index ◽  
Attenuated Total Reflection ◽  
Cellulose Content ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Alkaline Pulping ◽  
Hydrolysis Of Cellulose

There is an interest in the sustainable utilization of waste cotton cloths because of their enormous volume of generation and high cellulose content. Waste cotton cloths generated are disposed of in a landfill, which causes environmental pollution and leads to the waste of useful resources. In the present study, cellulose nanocrystals (CNCs) were isolated from waste cotton cloths collected from a landfill. The waste cotton cloths collected from the landfill were sterilized and cleaned using supercritical CO2 (scCO2) technology. The cellulose was extracted from scCO2-treated waste cotton cloths using alkaline pulping and bleaching processes. Subsequently, the CNCs were isolated using the H2SO4 hydrolysis of cellulose. The isolated CNCs were analyzed to determine the morphological, chemical, thermal, and physical properties with various analytical methods, including attenuated total reflection-Fourier transform-infrared spectroscopy (ATR-FTIR), field-emission scanning electron microscopy (FE-SEM), energy-filtered transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results showed that the isolated CNCs had a needle-like structure with a length and diameter of 10–30 and 2–6 nm, respectively, and an aspect ratio of 5–15, respectively. Additionally, the isolated CNCs had a high crystallinity index with a good thermal stability. The findings of the present study revealed the potential of recycling waste cotton cloths to produce a value-added product.

scholarly journals Study on Synthesis and Photocatalytic Activity of Porous Titania Nanotubes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Huang Liu ◽  
Yanhua Zhang ◽  
Hongtao Yang ◽  
Wei Xiao ◽  
Lanlan Sun
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Filter Paper ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Cellulose Nanofibers ◽  
Titania Nanotubes ◽  
Tetrabutyl Titanate ◽  
X Ray ◽  
Porous Titania

Using the common natural cellulose substance (filter paper) and triblock copolymer (Pluronic P123) micelles as dual templates, porous titania nanotubes with enhanced photocatalytic activity have been successfully synthesized through sol-gel methods. Firstly, P123 micelles were adsorbed onto the surfaces of cellulose nanofibers of filter paper, followed by hydrolysis and condensation of tetrabutyl titanate around these micelles to form titania layer. After calcination to remove the organic templates, hierarchical titania nanotubes with pores in the walls were obtained. The sample was characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption, Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). As compared with commercial P25 catalyst, the porous titania nanotubes prepared by this method displayed significantly enhanced photocatalytic activity for degrading methyl orange under UV irradiation. Within 10 minutes, the porous titania nanotubes are able to degrade over 70% of the original MO, while the value for the commercial Degussa P25 is only about 33%.

Effect of detergents and chemicals on purified vaccinia virus: analysis by SDS polyacrylamide gel electrophoresis and electron microscopy

1977 ◽  
Vol 23 (3) ◽  
pp. 240-252 ◽  
Author(s):  
J. Boisvert ◽  
T. Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Vaccinia Virus ◽  
Gel Electrophoresis ◽  
Alkali Treatment ◽  
Guanidine Hydrochloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Ammonium Bromide ◽  
Molecular Weights ◽  
Viral Particles

Vaccinia virus particles were dissociated into their constituent polypeptides and analysed by sodium dodecyl sulfate (SDS) gel electrophoresis. Thirty-three distinct polypeptide bands were identified and their molecular weights ranged between 11 000 and 150 000 daltons.Specific staining of gels containing polypeptides of dissociated virions revealed the presence of eight glycopeptides. No lipopeptides were detected.Analysis of chemical extracts (urea, guanidine hydrochloride, and alkali treatment) of the virus by SDS gel electrophoresis indicated that a total of 10 to 14 different polypeptides ranging in molecular weights from 11 000 to 70 000 daltons were solubilized.Analysis of detergent extracts and of the remains of extracted viral particles has shown that the detergent Nonidet P-40 (NP-40) solubilized a total of 11 polypeptides of which 6 were glycopeptides. The other detergents sodium deoxycholate (SDC) and cetyl trimethyl ammonium bromide (CTAB) were not as selective, both solubilizing more than 25 of the polypeptides composing the virus. Gel electrophoresis results also indicated that most of the small molecular weight (11 000–70 000 daltons) polypeptides were readily solubilized by NP-40, SDC, and CTAB, while those with molecular weights of 70 000 daltons and higher were not well solubilized.The effects of detergents were also analysed by electron microscopy. Evidence was obtained for subpopulations of viral particles having different susceptibility to detergent extraction.

A Facile Fynthesis of ZnS Nanostructures via Liquid-Solid Reactions

2014 ◽  
Vol 979 ◽  
pp. 184-187
Author(s):  
Weerachon Phoohinkong ◽  
Thitinat Sukonket ◽  
Udomsak Kitthawee
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Inorganic Salts ◽  
Chloride Salt ◽  
X Ray ◽  
Commercial Grade ◽  
Transmission Electron ◽  
Salt Addition ◽  
20 Nm ◽  
Scanning Electron

Zinc sulfide (ZnS) nanostructures are important materials for many technologies such as sensors, infrared windows, transistors, LED displays, and solar cells. However, many methods of synthesizing ZnS nanostructures are complex and require expensive equipment. In this study, a liquid-solid chemical reaction without surfactant was used to synthesize ZnS at room temperature. In addition, commercial grade zinc oxide (ZnO) particles were used as a precursor. The effect of the addition of acids and inorganic salts were investigated. The products were characterized by field emission scanning electron microscopy (FESEM) coupled with energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The results show that the nanoparticles of ZnS were obtained in hydrochloric acid and acetic acid addition. The diameters were in the range of 10 to 20 nm and 50 to 100 nm, respectively. In the case of a sodium chloride salt addition, a ZnS structure was obtained with a particle size of approximately 5 nm and a flake-like morphology.

scholarly journals Agroindustry Residues as a Source for Cellulose Nanofibers Production

2021 ◽  
Author(s):  
Mayra Mariño ◽  
Daniela Cypriano ◽  
Ljubica Tasic
Keyword(s):  
Crop Residues ◽  
Alkali Treatment ◽  
Cellulose Nanofibers ◽  
Value Added ◽  
Raw Material ◽  
Sodium Chlorite ◽  
Waste Biomass ◽  
Sugarcane Straw ◽  
Coffee Residues ◽  
Crop Waste

Our study was motivated by the large amount of crop residues produced in Brazil, which represent underutilized waste biomass and a serious threat to the environment because of the landfilling. For example, even though the corn crop is not popular in Brazil, it is produced in the area of around 18-20 million hectares with an average production of 5-6 t ha-1. That is the reason to seek for the crop residues value-added applications as proposed in the present study. Four Brazilian crop waste biomass: orange bagasse, corn husks, sugarcane straw and coffee residues were used for cellulose nanofibers (CNF) production. CNFs were prepared using alkali treatment, followed by bleaching with sodium chlorite and extraction with oxalic acid. All steps were applied under moderate conditions of temperature and pressure, such as temperature of 120 °C and below, water solutions with chemicals’ concentrations lower that 10% and short sonication pulses. CNFs with diameters in the range 50-70 nm were obtained and products from orange bagasse and corn husks presented high crystallinity indexes (CI), 0.72 and 0.75, respectively. The highest CNF yield was obtained from corn husks (38.5%) followed by sugarcane straw (24.0% with CI of 0.69). CNFs obtained from coffee residues showed a CI value of 0.65 after two bleaching steps. Different CNF morphologies were obtained according to the raw material. The four-crop waste biomass can be considered as excellent starting materials for CNF production in the four-steps process that adds new value to agro-industrial waste and might bring great economical valorization to Brazilian crops production.

The Structure and the Mechanical Properties of a Newly Fabricated Cellulose-Nanofiber/Polyvinyl-Alcohol Composite

2014 ◽  
Vol 1621 ◽  
pp. 149-154
Author(s):  
Yukako Oishi ◽  
Atsushi Hotta
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Cellulose Nanofibers ◽  
Small Diameter ◽  
Short Fiber ◽  
Cellulose Nanofiber ◽  
Process Conditions ◽  
Aspect Ratios

ABSTRACTCellulose nanofibers (Cel-F) were extracted by a simple and harmless Star Burst (SB) method, which produced aqueous cellulose-nanofiber solution just by running original cellulose beads under a high pressure of water in the synthetic SB chamber. By optimizing the SB process conditions, the cellulose nanofibers with high aspect ratios and the small diameter of ∼23 nm were obtained, which was confirmed by transmission electron microscopy (TEM). From the structural analysis of the Cel-F/PVA composite by the scanning electron microscopy (SEM), it was found that the Cel-F were homogeneously dispersed in the PVA matrix. Considering the high molecular compatibility of the cellulose and PVA due to the hydrogen bonding, a good adhesive interface could be expected for the Cel-F and the PVA matrix. The influences of the morphological change in Cel-F on the mechanical properties of the composites were analysed. The Young’s modulus rapidly increased from 2.2 GPa to 2.9 GPa up to 40 SB treatments (represented by the unit Pass), whereas the Young’s modulus remained virtually constant above 40 Pass. Due to the uniform dispersibility of the Cel-F, the Young’s modulus of the 100 Pass composite at the concentration of 5 wt% increased up to 3.2 GPa. The experimental results corresponded well with the general theory of the composites with dispersed short-fiber fillers, which clearly indicated that the potential of the cellulose nanofibers as reinforcement materials for hydrophilic polymers was sufficiently confirmed.

Isolation of Cellulose Nanofibers (CNFs) based on Ball-milling Technique Combined with Supercritical Carbon dioxide/ethanol Pretreatment

2021 ◽  
Author(s):  
Zhijun Hu ◽  
Xinyu Cao ◽  
Guanhong Huang ◽  
Daliang Guo
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Ball Milling ◽  
High Efficiency ◽  
Cellulose Nanofibers ◽  
Sem Images ◽  
Tempo Oxidation ◽  
Good Thermal Stability ◽  
Ethanol Pretreatment ◽  
Ball Milling Technique

Abstract Here, a new pretreatment method has been developed to produce CNFs from micro-fibrillated cellulose (MFC) by supercritical CO 2 pretreatment followed with ball-milling (SCB). MFC was obtained from cotton stalk by chemical purification.Experimental factors were controlled to enhance the properties of SCB-CNF, meanwhile a comparative study was conducted with the method of TEMPO oxidation and microfluid homogenization (TMH). Compared to TMH-CNF, the SCB-CNF has such advantages as Energy saving, high efficiency and environmental protection, indicating a wide application in heat-resistant materials, load materials and other fields. The solid yields of P-MFC after supercritical CO 2 pretreatment gradually decreased together with the temperature and the reaction time. Scanning electron microscope (SEM) images of the SCB-CNF and TMH-CNF show that the morphology of the SCB-CNF was basically acicular but that of the TMH-CNF was mainly soft fibrous. The SCB-CNF is smaller in width and shorter in length, and its size is between CNC and CNF. Thermal gravimetric results suggest that the thermal stability of the SCB-CNF was substantially higher than those of the TMH-CNF. XRD results indicate that the crystallinity showed an initial increasing trend and then declined with increasing temperature and reaction time, and the crystallinity value of SCB-CNF was larger than that of CNFs. The smaller SCB-CNF became rougher and had a larger surface area. High crystallinity make good thermal stability, short and coarse fiber, easier to disperse than CNF, less energy consumption for dispersion, better than 3D mesh. It can be widely used in polymer composites, reinforcing agents, membrane materials and other fields.

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