Influence of Solvent Washing and Soxhlet Extraction on the Thermal Stability of Organically Modified Layered Silicates

2014 ◽  
Vol 29 (1) ◽  
pp. 35-40
Author(s):  
T. Mariappan ◽  
C. A. Wilkie
2004 ◽  
Vol 52 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Rick D. Davis ◽  
Jeffrey W. Gilman ◽  
Thomas E. Sutto ◽  
John H. Callahan ◽  
Paul C. Trulove ◽  
...  

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1547 ◽  
Author(s):  
Siti Zarina Zakuwan ◽  
Ishak Ahmad

Herein, hybrid k-carrageenan bio-nanocomposite films were fabricated by using two types of nanofillers, organically modified montmorillonite (OMMT), and cellulose nanocrystals (CNCs). Hybrid bio-nanocomposite films were made by casting techniques employing 4 wt% of CNCs, OMMT, and hybridized CNCs/OMMT in a 1:1 ratio. The rheological and morphological properties and thermal stability of all composites were investigated using rotational rheometry, thermogravimetry analysis, differential scanning calorimetry, field emission scanning electron microscopy, and transmission electron microscopy (TEM). The results showed that the hybrid CNC/OMMT bio-nanocomposite exhibited significantly improved properties as compared to those for the bio-nanocomposites with single fillers due to the nanosize and homogenous nanofiller dispersion in the matrix. Rheological analysis of the hybrid bio-nanocomposite showed higher dynamic shear storage modulus and complex viscosity values when compared to those for the bio-nanocomposite with individual fillers. The TEM analysis of the hybridized CNC/OMMT bio-nanocomposite revealed that more particles were packed together in the CNC network, which restricted the matrix mobility. The heat resistance and thermal stability bio-nanocomposite k-carrageenan film enhanced rapidly with the addition of hybridized CNCs/OMMT to 275 °C. The hybridized CNCs/OMMT exhibited synergistic effects due to the good affinity through interfacial interactions, resulting in the improvement of the material properties.


2018 ◽  
Vol 22 (2) ◽  
pp. 1059-1069 ◽  
Author(s):  
Changwei Zhang ◽  
Chengzhang Wang ◽  
Ran Tao ◽  
Jianzhong Ye

Non-isothermal thermogravimetric (TG) analysis was used to investigate the thermal stability and kinetics of three types of Ginkgo biloba leaves. These three types of Ginkgo biloba leaves included: Ginkgo biloba leaves before enzymolysis and ultrasound extraction (G1), Ginkgo biloba leaves after enzymolysis and ultrasound extraction (G2), and Ginkgo biloba leaves after soxhlet extraction (G3). Thermogravimetric/dynamic thermogravimetric, (dynamic TG) experiments indicated that the thermal stability of G2 and G3 were weaker than G1. Kissinger, Flynn-Wall-Ozawa, Friedman, and Coats-Redfern methods were firstly utilized to calculate the kinetic parameters and predicted decomposition mechanism of G1, G2, and G3. The thermal decomposition of G1, G2, and G3 were all corresponded to random nucleation and growth, following the Avrami-Erofeev equation, and activation energy of which were 191.4, 149.9, and 201.6 kJ/moL, respectively. In addition, the thermal decomposition G1, G2, and G3 were endothermic, irreversible and non-spontaneous.


2016 ◽  
Vol 674 ◽  
pp. 173-178
Author(s):  
Remo Merijs Meri ◽  
Janis Zicans ◽  
Tatjana Ivanova ◽  
Rita Berzina ◽  
Ruta Saldabola ◽  
...  

Acrylonitrile butadiene styrene (ABS) terpolymer is one of the major plastics in IT equipment waste stream. In the current research secondary ABS (s-ABS) is blended with polycarbonate (PC) by forming one of the most popular thermoplastics engineering system. The effect of organically modified montmorillonite clay (OMMT) on the tensile properties and thermal stability of PC+10wt.%s-ABS blend is investigated. Increase in stiffness, strength and thermal stability is observed along with rising OMMT content. Highest increments of the aforementioned properties are observed within the OMMT range of 1-1,5 wt.%.


Author(s):  
Mervat S. Hassan ◽  
Hassan El-Shall ◽  
Chearly Beaty

Naturally occurring silicates, like montmorillonite (MMT) have received much attention as reinforcement materials for polymers because of their potentially high aspect ratio and unique intercalation (exfoliation) characteristic. Montmorillonite is of particular interest because it has a layered structure typically about 1nm in thickness and a high aspect ratio ranging from 100 to 1500 that, with proper exfoliation, can lead to platelets with high stiffness and strength dispersed in the polymer matrix. In this paper, we studied the delamination of Egyptian bentonite and Cloisite Na+ (USA) using different onium ions. The organo-clays were characterized by X-ray diffraction (XRD), Differential Scanning Calorimeter (DSC), Derivativethermogravimetry (TGA), Thermogravimetry (TG), and Infrared spectroscopy (IR). Understanding the relationship between molecular structure of the modifying surfactant and the thermal stability of the organically modified layered silicates is critical to its processing and subsequent applications. Therefore, special emphasis is given to the study of the thermal degradation of the modified clays. The results of the thermal degradation of montmorillonite (MMT) and alkyl quaternary ammonium montmorillonite (OMMT) are discussed in this paper.


Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization


Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.


1991 ◽  
Vol 1 (12) ◽  
pp. 1823-1836 ◽  
Author(s):  
M. Bessière ◽  
A. Quivy ◽  
S. Lefebvre ◽  
J. Devaud-Rzepski ◽  
Y. Calvayrac

1994 ◽  
Vol 4 (4) ◽  
pp. 653-657
Author(s):  
B. Bonzi ◽  
M. El Khomssi ◽  
H. Lanchon-Ducauquis

Sign in / Sign up

Export Citation Format

Share Document