Improvement of Thermal Stability of Cassava Starch Films from the Incorparation of Bentonite Clay

2019 ◽  
Vol 958 ◽  
pp. 69-73 ◽  
Author(s):  
Mayra Keroly Sales Monteiro ◽  
Victor Rafael Leal Oliveira ◽  
Francisco Klebson Gomes Santos ◽  
Eduardo Lins Barros Neto ◽  
Ricardo Henrique de Lima Leite ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Bentonite Clay ◽  
Cassava Starch ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Modified Clay ◽  
Decomposition Point ◽  
Starch Films ◽  
Cetyl Trimethyl Ammonium ◽  
Thermal Stability Of

This study considered the effect of modified and unmodified bentonite clay on the thermal properties of films based on cassava starch. The bentonite clay was modified in the presence of cetyl trimethyl ammonium bromide (CTAB). The attainment of exfoliated or intercalated nanocomposite was characterized by X-ray diffraction (XRD) and Fourier transform by infrared radiation (FTIR). In XRD, it was verified that the cassava starch dispersed the modified clay in an exfoliated way and unmodified clay in an intercalated way. In the FTIR it was characterized that the cassava starch interacted more with the modified bentonite clay compared to unmodified. Finally, thermogravimetric curves showed the thermal property of the starch films concluding that the modified clay was the reinforcing material that contributed the most to the thermal stability of the cassava starch film, retarding its decomposition point, around 35oC , in relation to the pure starch film.

Preparation, Characterization and Thermal Properties of Polyacrylonitrile/Alpha-Zirconium Phosphate Nanocomposites by Gelation/Crystallization

2010 ◽  
Vol 150-151 ◽  
pp. 951-955
Author(s):  
Dan Dan Yang ◽  
Hai Ping Xu ◽  
Lu Ping Zhu ◽  
Yi Hua Wu
Keyword(s):  
Thermal Stability ◽  
Zirconium Phosphate ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Laser Raman Spectroscopy ◽  
Ammonium Bromide ◽  
Laser Raman ◽  
Transmission Electron ◽  
Cetyl Trimethyl Ammonium ◽  
Thermal Stability Property ◽  
Thermal Stability Of

Nanocomposites of polyacrylonitrile (PAN) and Organophilic alpha-zirconium phosphate (OZrP) were prepared by gelation/crystallization. OZrP was prepared using cetyl trimethyl ammonium bromide (CTAB). The structure of PAN/OZrP nanocomposites was characterized by X-ray diffractometry (XRD) and high resolution transmission electron microscopy (HRTEM). The results showed that an intercalated or exfoliated structure was formed. Thermogravimetric analysis (TGA) was applied to characterize thermal stability property, which indicated that the thermal stability of PAN/OZrP nanocomposites was improved compared with that of pure PAN. HRTEM and Laser Raman spectroscopy were used to analyze the microstructure of the chars of PAN/OZrP nanocomposites.

Preparation and Properties of Organo-Montmorillonite Modified R-122 Nanocomposite

2012 ◽  
Vol 602-604 ◽  
pp. 254-258
Author(s):  
Chun Qing Huo ◽  
Hong Juan Gu ◽  
Zai Qian Yu ◽  
Long Zhang
Keyword(s):  
High Performance ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Organic Montmorillonite ◽  
Ft Ir ◽  
Cetyl Trimethyl Ammonium ◽  
The Impact ◽  
Thermal Stability Of

An OMMT (organic montmorillonite) was prepared by ion exchanging between Na-montmorillonite and cetyl trimethyl ammonium bromide (CTAB) and was applied to modify Dicyclopentadiene Dioxide Epoxy(R-122). FT-IR spectra showed that the organic molecules had intercalated into the layers of MMT successfully, X-ray diffraction illustrated that the spacing of layers of MMT increased from 1.43 nm to 3.85 nm. R-122 composite was prepared with this nano-organic montmorillonite. When the content of OMMT was 4.0% (wt%), the impact strenth of the composite reached to the highest(21.2 J/m), which is 92.7% higher than the pure R-122 . Morphology of the fracture checked by SEM, reveals a depth depended distribution which generated more new surface, thus can absorb more impact energy. Differential scanning calorimetry(DSC) showed that the thermal stability of the composite had improved compared with the pure resin. And what’s more, the improvement of toughness doesn’t hurt the resin’s heat resistance, it may provid a new way to prepare high performance R-122 composites.

scholarly journals Organo-montimorillonites containing a reactive thiophene group for polythiophenes nanocomposites

Cerâmica ◽  
2016 ◽  
Vol 62 (362) ◽  
pp. 133-139
Author(s):  
J. C. Macêdo-Fonsêca ◽  
A. A. A. Tino ◽  
M. P. A. Silva-Alves ◽  
R. M. Souto-Maior
Keyword(s):  
Thermal Stability ◽  
Fourier Transform ◽  
Montmorillonite Clay ◽  
Polymerization Reaction ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
Thermal Stability Of

Abstract A sodium montmorillonite clay (Na+MMT) was modified with different contents of a reactive salt derived from thiophene (trimethyl-(2-thiophen-3-yl-ethyl)-ammonium bromide) (TMETA). The thiophene salt in the organoclay (xtioMMT) was oxidatively polymerized in situ, giving rise to montmorillonite clay intercalated with a polythiophene salt (xpoltioMMT). Analysis by Fourier transform infrared spectroscopy shows a difference in organization of the salt inside the clay lamellae, before and after its polymerization. X-ray diffraction indicates that the salts, whether polymeric or not, are arranged as a monolayer for all compositions. Differently to the expected, the thermal stability of the organoclays decreases upon polymerization suggesting degradation of TMETA in the polymerization reaction.

scholarly journals Incorporation of bentonite clay in cassava starch films for the reduction of water vapor permeability

2018 ◽  
Vol 105 ◽  
pp. 637-644 ◽  
Author(s):  
M.K.S. Monteiro ◽  
V.R.L. Oliveira ◽  
F.K.G. Santos ◽  
E.L. Barros Neto ◽  
R.H.L. Leite ◽  
...  
Keyword(s):  
Water Vapor ◽  
Water Vapor Permeability ◽  
Bentonite Clay ◽  
Cassava Starch ◽  
Vapor Permeability ◽  
Starch Films

Formation and Thermal Stability of Nd0.32Y0.68Si1.7 Layers Formed by Channeled Ion Beam Synthesis

1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Beam ◽  
Hexagonal Structure ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Ion Beam Synthesis ◽  
Thermal Stability Of

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.

Study of Thermal Behaviour of EPDM/SBR Blends and Carbon Nanocoatings Deposited by Sputtering

2021 ◽  
Vol 875 ◽  
pp. 116-120
Author(s):  
Muhammad Alamgir ◽  
Faizan Ali Ghauri ◽  
Waheed Qamar Khan ◽  
Sajawal Rasheed ◽  
Muhammad Sarfraz Nawaz ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Thermogravimetric Analysis ◽  
Thermal Behavior ◽  
Thermal Behaviour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

In this study, the effect of SBR concentration (10 Phr, 20 Phr & 30 Phr ) on the thermal behavior of EPDM/SBR blends was studied. Thermogravimetric analysis (TGA) was used to check weight loss of samples as function of temperature by heating upto 600°C. X-ray diffraction (XRD) was performed to determine quality and % crystallinity of the elastomer blends. It was seen that % crystallinity improved with an increase in the content of SBR in EPDM/SBR blends. TGA revealed that the thermal stability of EPDM/SBR blends has improved by 17% than neat EPDM. Carbon nano-coatings produced by sputtering have no beneficial influence on thermal behaviour of elastomers.

Syntheses, Crystal Structures and Thermal Stability of Co(II) and Zn(II) Complexes with Ethyl Carbazate

2005 ◽  
Vol 60 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Tong-Lai Zhang ◽  
Jiang-Chuang Song ◽  
Jian-Guo Zhang ◽  
Gui-Xia Ma ◽  
Kai-Bei Yu
Keyword(s):  
Thermal Stability ◽  
Aqueous Solutions ◽  
Diffraction Analysis ◽  
Single Crystals ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Thermal Stabilities ◽  
X Ray ◽  
Thermal Stability Of

Cobalt(II) and zinc(II) complexes of ethyl carbazate (ECZ), [Co(ECZ)3](NO3)2 and [Zn(ECZ)3] (NO3)2, were synthesized. Single crystals of these two compounds were grown from aqueous solutions using a slow evaporation method. Their structures have been determined by X-ray diffraction analysis. Both of them are monoclinic with space group P21/n. The complexes are further characterized by element analysis and IR measurements. Their thermal stabilities are studied by using TG-DTG, DSC techniques. When heated to 350 °C, only metal oxide was left for both complexes.

Mobility of DR1 Molecules Embedded in Nanostructured PMMA Films

2009 ◽  
Vol 5 ◽  
pp. 135-142
Author(s):  
Jorge A. García-Macedo ◽  
A. Franco ◽  
Guadalupe Valverde-Aguilar ◽  
M.A. Ríos-Enríquez
Keyword(s):  
Second Harmonic ◽  
Sodium Dodecyl ◽  
Orientation Distribution ◽  
Decay Rates ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Poling Field ◽  
Different Temperatures ◽  
Cetyl Trimethyl Ammonium ◽  
Kinetics Of

The kinetics of the orientation of Disperse Red 1 (DR1) molecules embedded in nanostructured Polymethylmetacrylate (PMMA) films was studied under the effect of an intense constant electric poling field. The changes in the orientation distribution of the DR1 molecules were followed by Second Harmonic Generation (SHG) measurements. The SHG signal was recorded as function of time at three different temperatures. We focused on both, the signal increases under the presence of the poling field and the signal decays without the poling field. The studied PMMA films were nanostructured by the incorporation of ionic surfactants as the Sodium Dodecyl Sulfate (SDS) and the Cetyl Trimethyl Ammonium Bromide (CTAB) during their preparation. The kinds of nanostructures obtained in the films were determined by means of X-ray diffraction (XRD) measurements. Substantial differences in signal intensity and in growth and decay rates between amorphous and nanostructured films were found.

scholarly journals Polystyrene/Montmorillonite Nanocomposites: Study of the Morphology and Effects of Sonication Time on Thermal Stability

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Mashael Alshabanat ◽  
Amal Al-Arrash ◽  
Waffa Mekhamer
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Solution Method ◽  
Sonication Time ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Polystyrene Matrix ◽  
Before And After ◽  
Silicate Layers ◽  
Thermal Stability Of

Polymer nanocomposites of polystyrene matrix containing 10% wt of organo-montmorillonite (organo-MMT) were prepared using the solution method with sonication times of 0.5, 1, 1.5, and 2 hours. Cetyltrimethylammonium bromide (CTAB) is used to modify the montmorillonite clay after saturating its surface with Na+ions. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the montmorillonite before and after modification by CTAB. The prepared nanocomposites were characterized using the same analysis methods. These results confirm the intercalation of PS in the interlamellar spaces of organo-MMT with a very small quantity of exfoliation of the silicate layers within the PS matrix of all samples at all studied times of sonication. The thermal stability of the nanocomposites was measured using thermogravimetric analysis (TGA). The results show clear improvement, and the effects of sonication time are noted.

Immobilization of hemoglobin on stable mesoporous multilamellar silica vesicles and their activity and stability

2005 ◽  
Vol 20 (10) ◽  
pp. 2682-2690 ◽  
Author(s):  
Yufang Zhu ◽  
Weihua Shen ◽  
Xiaoping Dong ◽  
Jianlin Shi
Keyword(s):  
Thermal Stability ◽  
Pore Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Silica Material ◽  
Transmission Electron ◽  
Mesoporous Support ◽  
Adsorption Desorption ◽  
Thermal Stability Of

A stable mesoporous multilamellar silica vesicle (MSV) was developed with a gallery pore size of about 14.0 nm. A simulative enzyme, hemoglobin (Hb), was immobilized on this newly developed MSV and a conventional mesoporous silica material SBA-15. The structures and the immobilization of Hb on the mesoporous supports were characterized with x-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier transform infrared, ultraviolet-visible spectroscopy, and so forth. MSV is a promising support for immobilizing Hb due to its large pore size and high Hb immobilization capacity (up to 522 mg/g) compared to SBA-15 (236 mg/g). Less than 5% Hb was leached from Hb/MSV at pH 6.0. The activity study indicated that the immobilized Hb retained most peroxidase activity compared to free Hb. Thermal stability of the immobilized Hb was improved by the proctetive environment of MSV and SBA-15. Such an Hb-mesoporous support with high Hb immobilization capacity, high activity, and enhanced thermal stability will be attractive for practical applications.

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