Enzymatic Preparation of Nanocrystalline Cellulose from Bamboo Fibers

2012 ◽  
Vol 441 ◽  
pp. 754-758 ◽  
Author(s):  
Yong Zhang ◽  
Guo Xin Xue ◽  
Xiu Mei Zhang ◽  
Yu Zhao
Keyword(s):  
Enzymatic Hydrolysis ◽  
Average Diameter ◽  
Degree Of Polymerization ◽  
Nanocrystalline Cellulose ◽  
Preparation Process ◽  
Enzymatic Preparation ◽  
Bamboo Pulp ◽  
Transmission Electron ◽  
Hydrolysis Process ◽  
Bamboo Fibers

This paper reports an attempt to prepare nanocrystalline cellulose from bamboo fibers through an enzymatic hydrolysis process. A type of commercial cellulase, viz. enzyme Cclast (mainly containing endoglucanase) was used in the preparation process. The morphology of the prepared bamboo cellulose nanocrystals was characterized by transmission electron microscopy (TEM) and the sugar analyses of hydrolysis residues were analyzed by ion chromatography (IC). The degree of polymerization (DP) was tested by automatic viscosimeter. All nanocrystalline cellulose from bamboo fibers presented a rod-like shape, an average diameter (D) of 5.3 nm and length (L) of 221 nm, with an aspect ratio (L/D) of around 42. It was shown that the use of enzymatic hydrolysis treatment to bleach bamboo pulp helps the preparation of well individualized rod-like nanocrystalline cellulose.

Extraction of Bamboo Nanofibers Using Acid Hydrolysis for Functional Chemicals of Ecological Dyeing and Finishing

2012 ◽  
Vol 441 ◽  
pp. 759-763 ◽  
Author(s):  
Yong Zhang ◽  
Guo Xin Xue ◽  
Xiu Mei Zhang ◽  
Yan Jun Tang
Keyword(s):  
Acid Hydrolysis ◽  
Cellulose Nanofibers ◽  
Average Diameter ◽  
Degree Of Polymerization ◽  
X Ray Diffraction ◽  
Surface Charges ◽  
Aggregation State ◽  
Transmission Electron ◽  
Different Types ◽  
Bamboo Fibers

In this work a study on the feasibility of extracting cellulose nanofibers from bamboo fibers, by means of three different procedures was carried out. These processes included the using of three different types of acids (H2SO4, HCl, and a mixture of H2SO4/HCl). The raw bamboo fibers were mercerized with NaOH solutions. They were then submitted to the three different acid hydrolysis processes. The final bamboo nanofibers were morphologically characterized by transmission electron microscopy (TEM) and their surface charges in suspensions were estimated by Zeta-potential. Their degree of polymerization (DP) was characterized by viscometry and the crystallinity was tested by X-ray diffraction (XRD). All bamboo nanofibers presented a rod-like shape, an average diameter (D) of 6-10 nm and length (L) of 100-180 nm, with an aspect ratio (L/D) of around 16-18. The aggregation state increases with the amount of HCl introduced into the extraction, due to the decrease of surface charges. However, this release presented nanofibers with litter better degree of polymerization than those whose acid hydrolysis was carried out using only H2SO4.

scholarly journals OLIGO-GLUCOMANNAN PRODUCTION FROM PORANG (Amorphophallus oncophyllus) GLUCOMANNAN BY ENZYMATIC HYDROLYSIS USING β-MANNANASE

2021 ◽  
Vol 17 (1) ◽  
pp. 23
Author(s):  
Anggela Anggela ◽  
Widiastuti Setyaningsih ◽  
Santad Wichienchot ◽  
Eni Harmayani
Keyword(s):  
Reaction Time ◽  
Enzymatic Hydrolysis ◽  
Optimum Condition ◽  
Hplc Analysis ◽  
Degree Of Polymerization ◽  
Reducing Sugar ◽  
Optimal Conditions ◽  
Hydrolysis Process ◽  
Alternative Approach ◽  
Potential Substrate

Porang (Amorphophallus oncophyllus) is an indigenous tuber of Indonesia that rich in glucomannan. An alternative approach to produce porang oligo-glucomannan (POG) as prebiotic from porang glucomannan (PGM) was made by enzymatic hydrolysis using β-mannanase. This study aimed to  produce POG under optimal conditions by controlled enzymatic hydrolysis process. The PGM flour contained 96.12% of indigestible carbohydrates. The optimum condition of enzymatic hydrolysis producing the highest reducing sugar was as follows: temperature 37°C, pH 5.5, a ratio of enzyme to the substrate (E/S) 1:1000, and reaction time 4 h. HPLC analysis confirmed that 99.45% of the resulting POG consisted of oligosaccharides with a degree of polymerization (DP) 3. Hence, the PGM utilized in this study has been proven as a potential substrate for POG production. Additionally, the resulting POG was considered as a functional ingredient due to has prebiotic potential.

scholarly journals DISPERSIBILITY OF NANOCRYSTALLINE CELLULOSE IN ORGANIC SOLVENTS

2019 ◽  
pp. 39-50
Author(s):  
Марина (Marina) Игоревна (Igorevna) Воронова (Voronova) ◽  
Олег (Oleg) Валентинович (Valentinovich) Суров (Surov) ◽  
Наталья (Natal'ya) Викторовна (Viktorovna) Рублева (Rubleva) ◽  
Наталья (Natal'ya) Евгеньевна (Evgenievna) Кочкина (Kochkina) ◽  
Анатолий (Anatoliy) Георгиевич (Georgievich) Захаров (Zakharov)
Keyword(s):  
Organic Solvents ◽  
Ph Value ◽  
Standard Procedure ◽  
Aqueous Suspension ◽  
Degree Of Polymerization ◽  
Nanocrystalline Cellulose ◽  
Degree Of Crystallinity ◽  
Atomic Force ◽  
Transmission Electron ◽  
Ethanol In Water

Aqueous suspensions of nanocrystalline cellulose (NCC) were obtained by sulfuric acid hydrolysis using the standard procedure. Suspensions, films and airgel of NCC were characterized by various methods: the degree of polymerization was determined, elemental analysis was carried out, the degree of crystallinity and crystallite size were calculated on the basis of X-ray data, the morphology of NCC aerogels was studied using scanning electron microscopy. The particle size of the NCC was determined using a transmission electron microscope, a scanning atomic-force microscope and the method of dynamic light scattering. NFC hydrosols with different pH were used to prepare lyophilized NCC samples. From NCC hydrosols with pH 2.2, by gradual replacement of water with an organic solvent, NCC organogels with acetone, acetonitrile and ethanol were obtained. The process of dispersion of lyophilized NCC and NCC organogels (acetone, acetonitrile and ethanol) in water and in 11 organic solvents was investigated. The effect of the pH of the initial aqueous suspension of the NCC and the solvent forming the NCC organogel on the repeated dispersibility of the NCC is shown. The optimum pH value of the initial aqueous suspension of NCC was determined, which determines the maximum dispersibility of the lyophilized samples in each specific solvent. It was shown that dispersion of acetone, acetonitrile and ethanol organogels in most of the solvents studied occurs with the formation of particles less than 100 nm.

scholarly journals Isolation of cellulose nanocrystals from rice husk using the formic/ peroxyformic acid process

2020 ◽  
Vol 4 (2) ◽  
pp. First
Author(s):  
An Nang Vu ◽  
Nhi Van Nguyen ◽  
Van Thi Thanh Tran ◽  
Nhan Chi Ha Thuc ◽  
Hieu Van Le
Keyword(s):  
Rice Husk ◽  
Cellulose Nanocrystals ◽  
Average Diameter ◽  
Morphological Characterization ◽  
Raw Material ◽  
Transmission Electron ◽  
Hydrolysis Process ◽  
Biomass Resources ◽  
Acid Process ◽  
Peroxyformic Acid

Cellulose nanocrystals (CNCs) is one of the interesting materials attracting many researchers from the decades, especially when they are extracted from natural biomass resources. The  aim  of  this  study  was  to  explore  the  utilization  of  rice husk  residues  as  source  for  the  production  of CNCs. Cellulose was extracted from rice husk based on chemical method, using the formic/ peroxyformic acid process in order to effectively remove lignin and hemicelluloses from raw material. The cellulose was then treated by acid hydrolysis process performing at 45oC for 30 min, using 15 mL of H2SO4 (64% wt) for each gram of cellulose. The  material  obtained  after  each  stage  of the  treatments  was  carefully  characterized  by Fourier  transform  infrared spectroscopy (FTIR), X-ray  diffraction  (XRD) and Transmission electron microscopy (TEM). Morphological characterization from TEM revealed the appearance of needle-like shaped CNCs, average diameter and length  of 15 nm and  480  nm,  respectively. FT-IR results indicated that lignin was completely removed from the samples during chemical treatment. The  thermal  stability  of  the  materials in successive  treatments was  also investigated  using  thermogravimetric  analysis  (TGA). These  promising  results  proved  revalue  of  this  by-product  for  the production  of  CNCs  and  its  potential  use  as  reinforcement  in  the  preparation  of  nanocomposites.

Enzymatic textile recycling – best practices and outlook

2021 ◽  
pp. 0734242X2110291
Author(s):  
Benjamin Piribauer ◽  
Andreas Bartl ◽  
Wolfgang Ipsmiller
Keyword(s):  
Enzymatic Hydrolysis ◽  
Complete Removal ◽  
The European Union ◽  
Textile Processing ◽  
Current State ◽  
Industrial Implementation ◽  
Hydrolysis Process ◽  
Textile Recycling ◽  
Textile Sector ◽  
Suitable Process

Recently, textiles and their end-of-life management have become the focus of public and political attention. In the European Union the revised waste framework directive defines textiles as municipal waste and stipulates their separate collection by 2025. In the context of these developments, this paper summarises briefly the current state-of-the-art in textile recycling. It is evident that recycling methods are not yet fully developed. This is especially the case with multi-material textiles, which are composed of two or more polymers that are incompatible for recycling. In the practical part of the communication, results are presented which show that enzymatic hydrolysis is a suitable process for recycling textiles made of cotton and polyester. After a complete removal of cotton, the remaining pure polyester fibres undergo a re-granulation and post-condensation step. The so obtained recycled polyester is fed back into the textile processing chain and finally towels are obtained. The main steering parameters of the enzymatic hydrolysis process are described. The study proves that solutions in accordance with the Circular Economy in the textile sector are available but an industrial implementation has not yet been realised.

scholarly journals A New Nanocomposite Packaging Based on LASiS-Generated AgNPs for the Preservation of Apple Juice

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 760
Author(s):  
Maria Chiara Sportelli ◽  
Antonio Ancona ◽  
Annalisa Volpe ◽  
Caterina Gaudiuso ◽  
Valentina Lavicita ◽  
...  
Keyword(s):  
Metal Ion ◽  
Chemical Characterization ◽  
Average Diameter ◽  
Biological Action ◽  
Metal Species ◽  
Ion Release ◽  
Bioactive Materials ◽  
Transmission Electron ◽  
Metal Ion Release ◽  
Bulk Chemical

Designing bioactive materials, with controlled metal ion release, exerting a significant biological action and associated to low toxicity for humans, is nowadays one of the most important challenges for our community. The most looked-for nanoantimicrobials are capable of releasing metal species with defined kinetic profiles, either by slowing down or inhibiting bacterial growth and pathogenic microorganism diffusion. In this study, laser ablation synthesis in solution (LASiS) has been used to produce bioactive Ag-based nanocolloids, in isopropyl alcohol, which can be used as water-insoluble nano-reservoirs in composite materials like poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Infrared spectroscopy was used to evaluate the chemical state of pristine polymer and final composite material, thus providing useful information about synthesis processes, as well as storage and processing conditions. Transmission electron microscopy was exploited to study the morphology of nano-colloids, along with UV-Vis for bulk chemical characterization, highlighting the presence of spheroidal particles with average diameter around 12 nm. Electro-thermal atomic absorption spectroscopy was used to investigate metal ion release from Ag-modified products, showing a maximum release around 60 ppb, which ensures an efficient antimicrobial activity, being much lower than what recommended by health institutions. Analytical spectroscopy results were matched with bioactivity tests carried out on target microorganisms of food spoilage.

Antifungal Effectiveness of Nanosilver Colloid against Rose Powdery Mildew in Greenhouses

2008 ◽  
Vol 135 ◽  
pp. 15-18 ◽  
Author(s):  
Hae Sic Kim ◽  
Hyun Suk Kang ◽  
Gyo Jin Chu ◽  
Hong Sik Byun
Keyword(s):  
Electron Microscopy ◽  
Powdery Mildew ◽  
Colloidal Solution ◽  
Physical Method ◽  
Average Diameter ◽  
Optical Microscope ◽  
Size Analysis ◽  
Large Area ◽  
Transmission Electron ◽  
Antifungal Effects

The antifungal effectiveness against rose powdery mildew using antimicrobial nanosilver colloidal solution was investigated. Double-capsulized nanosilver was prepared by chemical reaction of silver ion with aid of physical method, reducing agent and stabilizers. The average diameter of nanosilver was about 1.5 nm. They were highly stable and very well dispersive in aqueous solution. The Transmission electron microscopy and UV-vis spectrometer were used for measurements of size analysis and their stability, respectively. The nanosilver colloidal solution of concentration of 5000 ppm was diluted in 10 ppm of 500 kg and sprayed at large area of 3306 m2polluted by rose powdery mildew. The white rose powdery mildew fade out above 95 % after 2 days and was not recurred for a week. The antifungal effects were observed by an optical microscope and photographs.

Characterization of Al65.0Cu32.9Co2.1 Alloy Containing Nanofibres

2012 ◽  
Vol 186 ◽  
pp. 212-215
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Grzegorz Dercz ◽  
Wojciech Gurdziel
Keyword(s):  
Electron Microscopy ◽  
Average Diameter ◽  
Chemical Compositions ◽  
X Ray ◽  
Transmission Electron ◽  
Orthogonal Set ◽  
T Phase ◽  
Terminal Area ◽  
Scanning Electron

Microstructure of terminal area of Al65Cu32.9Co2.1ingots (numbers indicate at.%), obtained via directional solidification was studied. Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray powder diffraction were applied. Point microanalysis by Scanning Electron Microscope was used for examination of chemical compositions of alloy phases. It was found that tetragonal θ phase of Al2Cu stoichiometric formula was the dominate phase (matrix). Additionally the alloy contained orthogonal set of nanofibres of Al7Cu2Co T phase with the average diameter of 50-500 nm and oval areas of hexagonal Al3(Cu,Co)2H-phase, surrounded by monoclinic AlCu η1phase rim. Inside some areas of H-phase cores of decagonal quasicrystalline D phase were observed.

Tribological Behavior of Carbon Nanotubes as an Additive on Lithium Grease

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Alaa Mohamed ◽  
T. A. Osman ◽  
A. Khattab ◽  
M. Zaki
Keyword(s):  
Carbon Nanotubes ◽  
Arc Discharge ◽  
Average Diameter ◽  
Friction Reduction ◽  
Lithium Grease ◽  
X Ray ◽  
Transmission Electron ◽  
Boundary Film ◽  
Load Carrying ◽  
Worn Surface

Carbon nanotubes (CNTs) with 10 nm average diameter and 5 μm in length were synthesized by electric arc discharge. The morphology and structure of CNTs were characterized by high resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction. The tribological properties of CNTs as an additive on lithium grease were evaluated with a four ball tester. The results show that the grease with CNTs exhibit good performance in antiwear (AW) and decrease the wear scare diameter (WSD) about 63%, decrease friction reduction about 81.5%, and increase the extreme pressure (EP) properties and load carrying capacity about 52% with only 1% wt. of CNTs added to lithium grease. The action mechanism was estimated through analysis of the worn surface with a scanning electron microscope (SEM) and energy dispersive X-ray (EDX). The results indicate that a boundary film mainly composed of CNTs, Cr, iron oxide, and other organic compounds was formed on the worn surface during the friction process.

Monodisperse Fe3O4/Fe Core/Shell Nanoparticles with Enhanced Magnetic Property

2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang
Keyword(s):  
Average Diameter ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Shell Particles ◽  
Core Shell Nanoparticles

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.

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