Water Diffusion Mechanisms in New Bio-Nanocomposites Based on Polyhydroxyalkanoates/Nanoclays

2013 ◽  
Vol 747 ◽  
pp. 682-685
Author(s):  
Raphaël Cretois ◽  
Nadège Follain ◽  
Jérémie Soulestin ◽  
Eric Dargent ◽  
Laurent Lebrun ◽  
...  
Keyword(s):  
Barrier Properties ◽  
Melt Processing ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Diffusion Mechanisms ◽  
Nanoclay Content ◽  
Water Transport Properties ◽  
Montmorillonite Nanoclay

Nanocomposites based on bacterial semi-crystalline polyhydroxyalkanoates, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)), and organo-modified montmorillonite nanoclay are prepared by melt processing. All nanocomposites are characterized by X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) and exhibit a mainly intercalated structure. Concerning water transport properties, a decrease of barrier properties for PHBV/nanoclay films is measured due to the affinity of nanoclay to water; whereas for P(3HB-co-4HB)/nanoclay nanocomposites, a decrease of the water permeability is observed relative to the tortuosity effect. Eventually, as a function of nanoclay content, a competition is evidenced between the tortuosity effect and the water sorption induced by nanoclay.

Effect of the Organoclay Preparation on the Extent of the Intercalation/Exfoliation and the Barrier Properties in Polyamide-6/Montmorillonite Nanocomposites

2008 ◽  
Vol 570 ◽  
pp. 78-84 ◽  
Author(s):  
Eleonora Erdmann ◽  
Marcos Lopes Dias ◽  
Victor Jayme Roget Rodriguez Pita ◽  
Fernanda Monasterio ◽  
Delicia Acosta ◽  
...  
Keyword(s):  
Clay Content ◽  
Barrier Properties ◽  
Polyamide 6 ◽  
Nanocomposite Materials ◽  
Melt Processing ◽  
Trimethyl Ammonium Chloride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Clay Surface ◽  
Mixer Chamber

This paper shows the importance of the clay surface chemistry in the preparation of nanocomposite materials. An Argentinean montmorillonite was used for preparing two modified clays. The filosilicate was intercalated with a quaternary ammonium salt derived from ε- caprolactam to obtain an organofilic material. The other modification was introduced by mixing the clay with hexadecyl trimethyl ammonium chloride. Thus, the polyamide 6 ability in dispersing clays was applied to prepare composites with the intercalated clays. The polyamide 6/clay dry composites with 3 wt % of filler were prepared by melt processing in a mixer chamber. Composites of polyamide 6/organoclay were characterized by X-ray diffraction, transmission and scanning electron microscopy and thermogravimetry. The barrier properties were determined by cyclohexane pervaporation. The results show that the dispersion and degree of delamination depend on a proper chemical treatment and the clay content influences the polyamide 6 nanocomposites solvent pervaporation resistance.

New Structure of CTAB Templated Silica Films as revealed by GISAXS coupled to HRTEM

2000 ◽  
Vol 628 ◽  
Author(s):  
Sophie Besson ◽  
Catherine Jacquiod ◽  
Thierry Gacoin ◽  
André Naudon ◽  
Christian Ricolleau ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Grazing Incidence ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Hexagonal Arrangement ◽  
Spherical Micelles

ABSTRACTA microstructural study on surfactant templated silica films is performed by coupling traditional X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) to Grazing Incidence Small Angle X-Ray Scattering (GISAXS). By this method it is shown that spin-coating of silicate solutions with cationic surfactant cetyltrimethylammonium bromide (CTAB) as a templating agent provides 3D hexagonal structure (space group P63/mmc) that is no longer compatible with the often described hexagonal arrangement of tubular micelles but rather with an hexagonal arrangement of spherical micelles. The extent of the hexagonal ordering and the texture can be optimized in films by varying the composition of the solution.

scholarly journals Ultrasonic-modified montmorillonite uniting ethylene glycol diglycidyl ether to reinforce protein-based composite films

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 433-442
Author(s):  
Hua He ◽  
Rui-jing Jia ◽  
Kai-qiang Dong ◽  
Jia-wen Huang ◽  
Zhi-yong Qin
Keyword(s):  
Ethylene Glycol ◽  
Soy Protein ◽  
Soy Protein Isolate ◽  
Composite Films ◽  
Barrier Properties ◽  
Protein Isolate ◽  
Diglycidyl Ether ◽  
X Ray Diffraction ◽  
Protein Film ◽  
Modified Montmorillonite

Abstract A novel biodegradable protein-based material (UMSPIE) that consists of natural polymer soy protein isolate (SPI), ultrasonic-modified montmorillonite (UMMT), and ethylene glycol diglycidyl ether (EGDE) was produced by solution casting. Fourier infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG), and scanning electron microscopy (SEM) were used to characterize the chemical structure and micro-morphologies of as-synthesized protein-based composite films. The results showed that the interlayer structure of MMT was destroyed by ultrasonic treatment, and the hydrogen bonding between SPI chains and the ultrasound-treated MMT plates was enhanced. The synergistic effect of UMMT and EGDE on SPI molecules made the network structure of the UMSPIE film denser. In addition, the mechanical and barrier properties of the as-synthesized films were explored. Compared with pure soy protein film, the tensile strength of the UMSPIE film has an increase of 266.82% (increasing from 4.4 to 16.14 MPa). From the above, the modified strategy of layered silicates filling combining crosslinking agents is considered as an effective method to improve the functional properties of bio-based polymer composites.

Hydrothermal Treatment of Coprecipitated YSZ Powders

2010 ◽  
Vol 660-661 ◽  
pp. 983-988 ◽  
Author(s):  
Alexander Rodrigo Arakaki ◽  
Walter Kenji Yoshito ◽  
Valter Ussui ◽  
Dolores Ribeiro Ricci Lazar
Keyword(s):  
Surface Area ◽  
Hydrothermal Treatment ◽  
Gas Adsorption ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Immersion Method ◽  
Cubic Symmetry ◽  
X Ray ◽  
Granulometric Analysis ◽  
Symmetry Surface

Zirconia stabilized with 8.5 mol% yttria (YSZ) were synthesized by coprecipitation and resulting gels were hydrothermallly treated at 200°C and 220 PSI for 4, 8 and 16 hours. Products were oven dried at 70°C for 24 hours, isostatically pressed as pellets and sintered at 1500 °C for 1 hour. Powders were characterized for surface area with N2 gas adsorption, X-ray diffraction, laser diffraction granulometric analysis and scanning and transmission electronic microscopy. Density of ceramics was measured by an immersion method based on the Archimedes principle. Results showed that powders dried at 70°C are amorphous and after treatment has tetragonal/cubic symmetry. Surface area of powders presented a significant reduction after hydrothermal treatment. Ceramics prepared from hydrothermally treated powders have higher green density but sintered pellets are less dense when compared to that made with powders calcined at 800°C for 1 hour due to the agglomerate state of powders. Solvothermal treatment is a promising procedure to enhance density.

Study on Organic Montmorillonite Modified Recycled Optical-Grade Polycarbonate Nanocomposite

2012 ◽  
Vol 214 ◽  
pp. 31-34
Author(s):  
Fu Quan Guo ◽  
Ying Ying Li ◽  
Bin Guo ◽  
Hao Liang
Keyword(s):  
Electron Microscopy ◽  
Great Increase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Montmorillonite ◽  
Modified Montmorillonite ◽  
Mechanical Measurements ◽  
Transmission Electron ◽  
Izod Impact ◽  
Optical Disks

Optical–grade polycarbonate (PC) was separated from optical disks by a chemical approach and used to prepare nanocomposite to make full use of the wasted polymers. A quaternary ammonium-modified montmorillonite (organic montmorillonite, OMMT) was chosen as a modifier and an auxiliary functional resin (CBT160) was utilized to exfoliate the layers of montmorillonite. The characterization results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) for PC/ OMMT (5wt %) revealed that an exfoliation structure of the nanocomposite was obtained. The mechanical measurements show a great increase in tensile strength and Izod impact strength of PC/ OMMT nanocomposite compared with the recycled optical–grade PC.

scholarly journals Preparation and Assessment of Heat-Treated α-Chitin Nanowhiskers Reinforced Poly(viny alcohol) Film for Packaging Application

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1883 ◽  
Author(s):  
Chao Peng ◽  
Guangxue Chen
Keyword(s):  
Heat Treatment ◽  
Composite Films ◽  
Barrier Properties ◽  
Mechanical Tests ◽  
Light Transmittance ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Chitin Nanowhiskers

In this study, poly(vinyl alcohol) (PVA) composite films enhanced by α-chitin nanowhiskers (ChWs) were prepared through heat treatment. The obtained membranes were assessed by means of FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, regular light transmittance, mechanical tests, permeability and water absorption. The influence of the nano-component and heat treatment on the mechanical, thermal and water-resistant properties of the composite membrane were analyzed. From the results of the work, the produced films with excellent barrier properties and inexpensive raw processed materials have great prospects in packaging applications.

The Effect of Polyethylene-Octene Elastomer on the Morphological and Mechanical Properties of Polyamide 6/Polypropylene Nanocomposites

2005 ◽  
Vol 13 (8) ◽  
pp. 795-805 ◽  
Author(s):  
M.U. Wahit ◽  
A. Hassan ◽  
Z.A. Mohd Ishak ◽  
A. Abu Bakar
Keyword(s):  
Mechanical Properties ◽  
Polyamide 6 ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melt Compounding ◽  
Modified Montmorillonite ◽  
Polypropylene Nanocomposites ◽  
Rubber Toughened ◽  
Izod Impact ◽  
Pp Blends

Rubber-toughened nanocomposites (RTNC) consisting of ternary blends of polyamide 6 (PA6), polypropylene (PP) and polyethylene-octene elastomer (POE) containing 4 wt% of organophilic modified montmorillonite were produced by melt compounding followed by injection moulding. The blend composition was kept constant (PA6/PP=70/30 parts by weight) while the POE content was varied between 5 and 20 wt%. Maleated PP (PP-g-MA) was used as compatibilizer. The morphology of the RTNC was studied by scanning electron microscopy and X-ray diffraction (XRD). The mechanical properties of RTNC were studied through tensile, flexural, Izod impact and fracture toughness properties. While the tensile and flexural properties were found to decrease with the increasing concentration of POE, the toughness was significantly enhanced as compared to the neat PA6/PP blends. In general, the blends containing 10-15 wt% of POE had the best balance of stiffness, strength and toughness. The addition of 30 wt% of PP in the PA6 matrix improved the compatibility between PA6 and the rubber phase. XRD established that the organoclay was well dispersed (exfoliated) and preferentially embedded in the PA6 phase.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

scholarly journals Production of Surface Layer with Gradient Microstructure and Microhardess on Copper by High Pressure Surface Rolling

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Juying Li ◽  
Qingsong Mei ◽  
Yana Li ◽  
Beihai Wang
Keyword(s):  
High Pressure ◽  
Surface Layer ◽  
Pure Copper ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
X Ray ◽  
Pressure Surface ◽  
Surface Gradient ◽  
Pressure Time ◽  
Gradient Microstructure

Pure copper was subjected to high-pressure surface rolling (HPSR) to obtain a surface gradient layer. Effects of HPSR parameters on the surface microstructure and microhardness of Cu were investigated by using optical microscopy, transmission electronic microscopy, X-ray diffraction, and the microhardness test. The HPSR surface layer has a gradient microstructure consisting of increasingly refined grains with decreasing depth from the treated surface (DFS). The thicknesses of the refined surface layer can be up to ~1.8 mm, and the grain size of the topmost surface is down to ~88 nm, depending on the HPSR parameters including pressure, time, and temperature. Microhardness of HPSR samples increases with decreasing DFS, with a maximum of ~2.4 times that of the undeformed matrix. The present results indicated that HPSR could be an effective method for the production of a mm-thick surface layer on Cu with gradient microstructure and property.

scholarly journals Ellagic Acid May Improve Mechanical and Barrier Properties in Films of Starch-A Review Paper

2016 ◽  
Vol 5 (3) ◽  
pp. 61
Author(s):  
J. M. Tirado-Gallegos ◽  
D. R. Sepúlveda-Ahumada ◽  
P. B. Zamudio-Flores ◽  
M. L. Rodríguez-Marin ◽  
Francisco Hernández-Centeno ◽  
...  
Keyword(s):  
Ellagic Acid ◽  
Structural Changes ◽  
Antioxidant Properties ◽  
Barrier Properties ◽  
Packaging Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Film Forming ◽  
Starch Films

<p>Packaging increases the shelf life of food and facilitates its handling, transportation and marketing. The main packaging materials are plastics derived from petroleum, but their accumulation has given rise to environmental problems. An alternative is the use of biodegradable materials. In this regard, starch is an excellent choice because it is an abundant and renewable source with film-forming properties. However, the films obtained from starch have some limitations with respect to their mechanical and barrier properties. Several strategies have been developed in order to improve these limitations, ranging from the addition of lipids to the modification of the polymer structure. The aim of this review was propose the use of ellagic acid as a cross-linking agent that may improves the mechanical and barrier properties in films based on exists reports that phenolic compounds interact with starch-based materials decreasing their rate of retrogradation. Furthermore, ellagic acid is a powerful natural antioxidant, which would allow the production of active packaging with antioxidant properties, in addition to the improvement of the mechanical and barrier properties of starch films. In this concern more studies such as Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis are necessary to verify the structural changes and interactions between starch and ellagic acid. We expect extensive use of it in the future of packaging materials.</p>

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