scholarly journals Preparation And Properties Of Bionanocomposite Films Reinforced With Nanocellulose Isolated From Moroccan Alfa Fibres

2015 ◽  
Vol 15 (3) ◽  
pp. 164-172 ◽  
Author(s):  
Benyoussif Youssef ◽  
Aboulhrouz Soumia ◽  
El Achaby Mounir ◽  
Cherkaoui Omar ◽  
Lallam Abdelaziz ◽  
...  
Keyword(s):  
Carboxymethyl Cellulose ◽  
Food Packaging ◽  
Fourier Transforms ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
Vapour Permeability ◽  
Force Microscopy ◽  
Atomic Force ◽  
Bionanocomposite Films

AbstractNanocellulose (NC) were extracted from the Moroccan Alfa plant (Stipa tenacissima L.) and characterised. These Alfa cellulosic nanoparticles were used as reinforcing phase to prepare bionanocomposite films using carboxymethyl cellulose as matrix. These films were obtained by the casting/evaporation method. The crystallinity of NC was analysed by X-ray diffraction, the dimension of NC by atomic force microscopy, molecular interactions due to incorporation of NC in carboxymethyl cellulose (CMC) matrix were supported by Fourier transforms infrared (FTIR) spectroscopy. The properties of the ensuing bionanocomposite films were investigated using tensile tests, water vapour permeability (WVP) study and thermogravimetric analysis. With the progress of purification treatment of cellulose, the crystallinity is improved compared to the untreated fibres; this can be explained by the disappearance of the amorphous areas in cellulose chain of the plant. Consequently, the tensile modulus and tensile strength of CMC film increased by 60 and 47%, respectively, in the bionanocomposite films with 10 wt% of NC, and decrease by 8.6% for WVP with the same content of NC. The NC obtained from the Moroccan Alfa fibres can be used as a reinforcing agent for the preparation of bionanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials.

scholarly journals Nanoporous Sodium Carboxymethyl Cellulose-g-poly (Sodium Acrylate)/FeCl3 Hydrogel Beads: Synthesis and Characterization

Gels ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 49
Author(s):  
Bijender Kumar ◽  
Ruchir Priyadarshi ◽  
Sauraj ◽  
Farha Deeba ◽  
Anurag Kulshreshtha ◽  
...  
Keyword(s):  
Carboxymethyl Cellulose ◽  
Sodium Carboxymethyl Cellulose ◽  
Sodium Acrylate ◽  
X Ray Diffraction ◽  
Hybrid Hydrogel ◽  
X Ray ◽  
Hydrogel Beads ◽  
Force Microscopy ◽  
Atomic Force ◽  
Potential Applications

Novel sodium carboxymethyl cellulose-g-poly (sodium acrylate)/Ferric chloride (CMC-g-PNaA/FeCl3) nanoporous hydrogel beads were prepared based on the ionic cross-linking between CMC-g-PNaA and FeCl3. The structure of CMC and CMC-g-PNaA were elucidated by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, and the elemental composition was analyzed by energy dispersive X-ray analysis (EDX). The physicochemical properties of the CMC-g-PNaA/FeCl3 hydrogel beads were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). The swelling percentage of hydrogel beads was studied at different time periods. The obtained CMC-g-PNaA/FeCl3 hydrogel beads exhibited a higher nanoporous morphology than those of CMC-g-PNaA and CMC beads. Furthermore, an AFM image of the CMC-g-PNaA/FeCl3 beads shows granule type topology. Compared to the CMC-g-PNaA (189 °C), CMC-g-PNaA/FeCl3 hydrogel beads exhibited improvement in thermal stability (199 °C). Furthermore, CMC-g-PNaA/FeCl3 hydrogel beads depicted a higher swelling percentage capacity of around 1452%, as compared to CMC-g-PNaA (1096%). Moreover, this strategy with preliminary results could be useful for the development of polysaccharide-based hybrid hydrogel beads for various potential applications.

scholarly journals New thermoplastic poly(carbonate-urethane) elastomers

2011 ◽  
Vol 13 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Anna Kultys ◽  
Magdalena Rogulska
Keyword(s):  
Soft Segment ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Melt Polymerization ◽  
Atomic Force ◽  
Amorphous Structures ◽  
A Chain ◽  
Poly Carbonate

New thermoplastic poly(carbonate-urethane) elastomersTwo series of novel thermoplastic poly(carbonate-urethane) elastomers, with different hard-segment content (30 - 60 wt %), were synthesized by melt polymerization from poly(hexane-1,6-diyl carbonate) diol of Mn= 2000 as a soft segment, 4,4'-diphenylmethane diisocyanate (MDI) or hexane-1,6-diyl diisocyanate (HDI) and 6,6'-[methylenebis(1,4-phenylenemethylenethio)]dihexan-1-ol as a chain extender. The structure and basic properties of the polymers were examined by Fourier transform infrared spectroscopy, X-ray diffraction analysis, atomic force microscopy, differential scanning calorimetry, thermogravimetric analysis, Shore hardness and tensile tests. The resulting TPUs were colorless polymers, showing almost amorphous structures. The MDI-based TPUs showed higher tensile strengths (up to 21.3 MPa vs. 15.8 MPa) and elongations at break (up to 550% vs. 425%), but poorer low-temperature properties than the HDI-based analogs.

Aromatic polyurethanes: the effect of hard segment and chain structure on their properties

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Abhinay Mishra ◽  
Pralay Maiti
Keyword(s):  
Hard Segment ◽  
Tensile Modulus ◽  
Chain Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hard Segment Content ◽  
Microscopic Studies ◽  
The Difference

Abstract Structural variation and its effect on the properties of aromatic polyurethanes (PUs) with different chain structures have been reported. Polarized optical microscopic studies of aromatic PUs demonstrate the development of micro clusters with increasing hard segment content (HSC). Higher crystallinity has also been proven from differential scanning calorimeter (DSC) and X-ray diffraction (XRD) studies. A globular pattern has been observed through atomic force microscopy (AFM) and the pattern depends on the type of diisocyanate used to prepare the PU. The difference in surface morphology is evident for two different PUs. The tensile modulus increases systematically with increasing HSC while toughness decreases, due to the presence of bigger crystallites in higher HSC polymer. Both the modulus and toughness vary on the type of diisocyanate present in PUs.

scholarly journals All-Cellulose Nanocomposite Made from Nanofibrillated Cellulose

2010 ◽  
Vol 19 (6) ◽  
pp. 096369351001900 ◽  
Author(s):  
Hossein Yousefi ◽  
Takashi Nishino ◽  
Mehdi Faezipour ◽  
Ghanbar Ebrahimi ◽  
Alireza Shakeri ◽  
...  
Keyword(s):  
Tensile Tests ◽  
Solvent System ◽  
Nanofibrillated Cellulose ◽  
Dissolution Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cellulose Nanocomposites ◽  
Core Part

Commercial microfibrillated cellulose (MFC) was ground and turned into nanofibrillated cellulose (NFC), then all-cellulose nanocomposites (ACNC) were prepared by partially dissolving method. The nanocomposites, with different ratios of undissolved core part of NFC in a matrix of partially dissolved skin part of NFC, were produced using DMAc/LiCl as solvent system. Five dissolution times of 5, 10, 20, 30 and 60 minutes were used as variables and the results were compared with the properties of neat MFC and NFC sheets. The structure and properties of MFC, NFC and nanocomposites were characterized using atomic force microscopy, field emission scanning electron microscopy, X-ray diffraction and tensile tests. The mechanical properties of NFC are significantly larger than those of MFC. As dissolution time increased, the apparent crystallinity of ACNC decreased and more amount of matrix covered the nanofibre surfaces. The ACNC showed best tensile strength (156 MPa) and Young's modulus (13.2 GPa) at 10 minutes dissolution time. The advantage of ACNC is that they are fully bio-based, easily recyclable, fully biodegradable and strong materials.

Fabrication of sulfated nanofilter membrane based on carboxymethyl cellulose

2016 ◽  
Vol 74 (11) ◽  
pp. 2611-2619 ◽  
Author(s):  
Sima Gasemloo ◽  
Mahmoud Reza Sohrabi ◽  
Morteza Khosravi ◽  
Siavoush Dastmalchi ◽  
Parvin Gharbani
Keyword(s):  
Carboxymethyl Cellulose ◽  
Separation Efficiency ◽  
Crosslinking Agent ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pyridine Complex ◽  
Acidic Conditions ◽  
Sulfating Agent

The aim of this study is to prepare sulfated carboxymethyl cellulose (SCMC) nanofilter membrane using sulfur trioxide pyridine complex (SO3/pyridine) as sulfating agent and glutaraldehyde (GA) as a crosslinking agent onto polysulfone supporting membrane. The prepared nanofilter was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, atomic force microscopy and zeta potential. To evaluate the prepared nanofilter, various amounts of SO3/Pyridine were used and efficiency of them was investigated. The results showed that increasing the sulfate groups raised the flux from 13.87 to 29.54 L/(m2·h−1), whereas percentage rejection was increased during the separation of salt aqueous solutions and then decreased. It can be concluded that, SCMC-GA-2 (with molar ratio of SO3/pyridine to CMC of 1) shows high separation efficiency in acidic conditions and improves the hydrophilicity and charge density of the filter.

A Novel Modified Starch/Carboxymethyl Cellulose/Montmorillonite Bionanocomposite Film: Structural and Physical Properties

2013 ◽  
Vol 10 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Babak Ghanbarzadeh ◽  
Hadi Almasi ◽  
Seyed Amir Oleyaei
Keyword(s):  
Mechanical Properties ◽  
Carboxymethyl Cellulose ◽  
Corn Starch ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Modified Starch ◽  
Force Microscopy ◽  
Atomic Force ◽  
Bionanocomposite Films ◽  
Starch Films

Abstract A novel glycerol-plasticized and citric acid (CA)-modified starch/carboxymethyl cellulose (CMC)/montmorillonite (MMT) bionanocomposite films were prepared from corn starch by casting, to study the effect of the 10% CA, 10% CMC and four different loadings of MMT on the properties of starch films. Atomic force microscopy surface analysis showed that starch/CMC/MMT films had the highest roughness. X-ray diffraction test showed that the clay nanolayers formed an intercalated structure in the bionanocomposites. However, completely exfoliated structure formed only in the pure starch/MMT nanocomposites (without CA and CMC). CA, CMC and MMT improved mechanical properties of starch films. MMT had the greatest effect on the mechanical properties. The MMT addition at content of 7% caused to increase in ultimate tensile strength by more than threefold in comparison to modified starch/CMC films. The water vapor permeability (WVP) decreased significantly (p < 0.05) by the addition of CA and CMC. When the MMT content of the starch films reached to 7%, the WVP decreased about 75% in comparison to the neat starch film. However, the hydrophilic character of bionanocomposites increased as the increasing of MMT content.

scholarly journals Preparation of Cellulose Films from Sustainable CO2/DBU/DMSO System

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 994 ◽  
Author(s):  
Longming Jin ◽  
Jianyun Gan ◽  
Gang Hu ◽  
Long Cai ◽  
Zaiquan Li ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Food Packaging ◽  
Solvent System ◽  
Light Transmittance ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Cellulose Films ◽  
Atomic Force ◽  
Dmso System ◽  
Amorphous Structures

Cellulose films are regarded as sustainable materials having wide applications in food packaging, separation, etc. Their preparation substantially relies on sufficient dissolution. Herein, various celluloses adequately dissolved in a new solvent system of carbon dioxide,1, 8-diazabicyclo [5.4.0] undec-7-ene and dimethyl sulfoxide (CO2/DBU/DMSO) were made in to films using different regeneration reagents. The films regenerated from ethanol and methanol presented homogeneous and smooth surfaces, while those from 5 wt % NaOH (aq.) and 5 wt % H2SO4 (aq.) showed rough surfaces, as analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The films regenerated from 5 wt % NaOH (aq.) and 5 wt % H2SO4 (aq.) rendered cellulose II structures, while those regenerated from alcohols had amorphous structures as evidenced using fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results. The films made of microcrystalline cellulose had a good light transmittance of about 90% at 800 nm with a tensile strength of 55 MPa and an elongation break of 6.5%, while those from wood pulp cellulose demonstrated satisfactory flexibility with a tensile strength of 91 MPa and an elongation break of 9.0%. This research reports a simple, environmental, and sustainable method to prepare cellulose films of good mechanical properties.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Low Molecular Weight Microfibers with Light Sensing Properties

2017 ◽  
Vol 54 (4) ◽  
pp. 655-658
Author(s):  
Andrei Bejan ◽  
Dragos Peptanariu ◽  
Bogdan Chiricuta ◽  
Elena Bicu ◽  
Dalila Belei
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Force Microscopy ◽  
Light Sensing ◽  
Sensing Applications ◽  
Atomic Force ◽  
Low Molecular Weight Compounds

Microfibers were obtained from organic low molecular weight compounds based on heteroaromatic and aromatic rings connected by aliphatic spacers. The obtaining of microfibers was proved by scanning electron microscopy. The deciphering of the mechanism of microfiber formation has been elucidated by X-ray diffraction, infrared spectroscopy, and atomic force microscopy measurements. By exciting with light of different wavelength, florescence microscopy revealed a specific optical response, recommending these materials for light sensing applications.

Structural and Optical Properties of InAsSbBi Grown by Molecular Beam Epitaxy on Offcut GaSb Substrates

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 215
Author(s):  
Rajeev R. Kosireddy ◽  
Stephen T. Schaefer ◽  
Marko S. Milosavljevic ◽  
Shane R. Johnson
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optical Quality ◽  
X Ray Diffraction ◽  
Interface Quality ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Lateral Variations

Three InAsSbBi samples are grown by molecular beam epitaxy at 400 °C on GaSb substrates with three different offcuts: (100) on-axis, (100) offcut 1° toward [011], and (100) offcut 4° toward [011]. The samples are investigated using X-ray diffraction, Nomarski optical microscopy, atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The InAsSbBi layers are 210 nm thick, coherently strained, and show no observable defects. The substrate offcut is not observed to influence the structural and interface quality of the samples. Each sample exhibits small lateral variations in the Bi mole fraction, with the largest variation observed in the on-axis growth. Bismuth rich surface droplet features are observed on all samples. The surface droplets are isotropic on the on-axis sample and elongated along the [011¯] step edges on the 1° and 4° offcut samples. No significant change in optical quality with offcut angle is observed.

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