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Thermogravimetric analysis

About: Thermogravimetric analysis is a research topic. Over the lifetime, 37248 publications have been published within this topic receiving 862144 citations. The topic is also known as: thermal gravimetric analysis & TGA.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a simple approach to the synthesis of MWNT/polypyrrole nanotubes was described by the in situ chemical polymerization of pyrrole on the carbon nanotsubes using ferric chloride as an oxidant.

207 citations

Journal ArticleDOI
TL;DR: In this paper, the characteristics of synthetic hydroxyapatite sintered at high temperature were studied by means of X-ray diffraction, infrared and differential thermal analysis, and thermogravimetric analysis.
Abstract: The characteristics of synthetic hydroxyapatite sintered at high temperature were studied by means of X-ray diffraction, infrared and differential thermal analysis, and thermogravimetric analysis. The results show that synthetic HAp with a Ca/P ratio near 1.67 is stable when sintered in dry or wet air below 1200°C. Even after long times, no tricalcium phosphate (TCP) can be observed. Beyond 1200°C, HAp loses its OH groups gradually and is transformed to oxyapatite [Ca10O(PO4)6 or Ca(PO4)6O.□]. At 1450°C oxyapatite dissociates into the products α-Ca3(PO4)2, Ca2P2O7 and Ca4P2O9.

207 citations

Journal ArticleDOI
TL;DR: In this article, the raw fibers were mercerized with NaOH solutions; they were then submitted to acid hydrolysis using three different types of acids (H2SO4, a mixture of H 2SO4/HCl and HCl) and found that increasing the NaOH solution concentration in the mercerization resulted in a decrease of hemicellulose and lignin contents and consequently an increase of cellulose content.
Abstract: Curaua nanofibers extracted under different conditions were investigated. The raw fibers were mercerized with NaOH solutions; they were then submitted to acid hydrolysis using three different types of acids (H2SO4, a mixture of H2SO4/HCl and HCl). The fibers were analyzed by cellulose, lignin and hemicellulose contents; viscometry, X-ray diffraction (XRD) and thermal stability by thermogravimetric analysis (TG). The 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, crystallinity by XRD and thermal stability by TG. Increasing the NaOH solution concentration in the mercerization, there was a decrease of hemicellulose and lignin contents and consequently an increase of cellulose content. XRD patterns presented changes in the crystal structure from cellulose I to cellulose II when the fibers were mercerized with 17.5% NaOH solution. All curaua nanofibers presented a rod-like shape, an average diameter (D) of 6–10 nm and length (L) of 80–170 nm, with an aspect ratio (L/D) of around 13–17. The mercerization of fibers with NaOH solutions influenced the crystallinity index and thermal stability of the resulting nanofibers. The fibers mercerized with NaOH solution 17.5% resulted in more crystalline nanofibers, but thermally less stable and inferior DP. The aggregation state increases with the amount of HCl introduced into the extraction, due to the decrease of surface charges (as verified by Zeta Potential analysis). However, this release presented nanofibers with better thermal stability than those whose acid hydrolysis was carried out using only H2SO4.

207 citations

Journal ArticleDOI
04 Oct 2006-Polymer
TL;DR: In this paper, a conductive polyaniline (PANI) layer was chemically grafted on the surface of the self-assembled monolayer (SAM) coated TiO2 nanoparticles, resulting in PANI/SAM-TiO2 composites.

206 citations

Journal ArticleDOI
TL;DR: In this paper, an alkyl carboxylate-modified layered double hydroxides (LDH) was prepared and used as nanofillers for poly(methyl methacrylate) (PMMA) and polystyrene (PS).
Abstract: Alkyl carboxylate-modified layered double hydroxides (LDH) were prepared and used as nanofillers for poly(methyl methacrylate) (PMMA) and polystyrene (PS). The LDH intercalated with long-chain linear alkyl carboxylates (CH3(CH2)nCOO−, n = 8, 10, 12, 14, 16, 20) were prepared via anionic exchange of MgAl–nitrate, showing a systematic increase in basal spacing with longer alkyls. MgAl–undecenoate LDH was prepared by co-precipitation. The MgAl–LDHs were melt blended with poly(methyl methacrylate) and bulk polymerized with styrene to form nanocomposites. The dispersion of the MgAl–LDH in the polymers was investigated by transmission electron microscopy and X-ray diffraction. Thermal and fire properties were studied using cone calorimetry and thermogravimetric analysis; the thermal stability of both polymers was enhanced and a very significant reduction in the peak heat release rate was observed for almost all of the poly(methyl methacrylate) composites and a few of the polystyrene composites.

206 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
20232,906
20225,921
20212,097
20202,157
20192,095