scholarly journals Pyrolytic Behavior of Long-Chain Alkyl Quaternary Ammonium Bromide Inside Nanopores

2021 ◽  
Vol 9 ◽  
Author(s):  
Yanhui Niu ◽  
Wenbin Yu ◽  
Shuguang Yang ◽  
Quan Wan
Keyword(s):  
Quaternary Ammonium ◽  
Combustion Temperature ◽  
Amorphous State ◽  
Carbon Chain ◽  
Ammonium Bromide ◽  
Scanning Calorimetry ◽  
Different Diameters ◽  
Nanopore Confinement ◽  
Transformation Processes ◽  
Long Chain

The pyrolytic behavior of organic matter inside nanopores was studied by simultaneous thermogravimetric/differential scanning calorimetry analyzer coupled with Fourier transform infrared spectroscopy (STA/TG-FTIR). Nanoporous silica was prepared by a hydrothermal method using long-chain alkyl quaternary ammonium bromide (CnTAB, n = 12, 14) as a template. The pyrolytic behavior of CnTAB inside nanopores with different diameters was investigated and compared with that of CnTAB inside and outside nanopores. The results showed that the pyrolytic removal process consisted of the following features: 1) CnTAB underwent carbon chain decomposition and oxidation; 2) the DSC exothermal peak of CnTAB came mainly from its oxidative combustion, and the oxidative combustion temperature decreased with increasing pore size; 3) the CnTAB inside nanopores underwent crystallization–amorphous state phase transition, and CnTAB got trapped inside the calcined nanopores. In addition, the pyrolytic behavior of CnTAB inside the calcined nanopores was found to be similar to that of the uncalcined nanopores. This study aims to understand the storage and transformation processes of organic hydrocarbons under nanopore-confinement effect.

scholarly journals Synthesis and Surfactant Studies of Dialkyl Dimethyl Quaternary Ammonium Bromide Formulations

2006 ◽  
Vol 5 (3) ◽  
Author(s):  
Rocky Barney ◽  
Tony Stark ◽  
Dru Delaet
Keyword(s):  
Quaternary Ammonium ◽  
Carbon Chain ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Ammonium Bromide ◽  
Tertiary Amines ◽  
Alkyl Bromide ◽  
Component Systems ◽  
Multiple Component ◽  
Chain Lengths

Quaternary ammonium salts (otherwise known as quats) are commonly used active ingredients in biocide formulations used in the anti-microbial industry. Although quats have been established to be effective biocides, there are few studies investigating the maximization of biocidal efficacy in multiple component formulations using various carbon chain lengths. Reported here is the synthesis based on the Sn2 reaction of tertiary amines with alkyl bromide. Surfactant studies of the single and dual component systems were conducted, and the evaluation is explored.

scholarly journals FTIR and DSC Studies of Binary Mixtures of Long-Chain Aliphatic Compounds: Lauric Acid – Cetyl-trimethylammonium Bromide

2018 ◽  
Vol 63 (5) ◽  
pp. 413
Author(s):  
T. Gavrilko ◽  
I. Gnatyuk ◽  
V. Styopkin ◽  
N. Shcherban ◽  
J. Baran ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Binary Mixture ◽  
Binary Mixtures ◽  
Lauric Acid ◽  
Condensed State ◽  
Ammonium Bromide ◽  
Scanning Calorimetry ◽  
Supramolecular Compounds ◽  
Dsc Studies ◽  
Long Chain

Structural and thermal properties of a solid-state binary mixture of long-chain cationic and anionic surfactants (so-called catanionic complexes) composed of cetyltrimethyl-ammonium bromide, [H3C–(CH2)15–N+(CH3)3]Br−(CTAB), and saturated fatty acid (FA), CH3(CH2)12COOH (lauric acid, kC12), are studied. To clarify the effect of intermolecular interactions on the crystalline structure and phase transitions in this class of supramolecular compounds, the 1 : 1 kC12-CTAB binary mixture is investigated by means of X-ray diffraction, differential scanning calorimetry (DSC), and temperature-variable Fourier transform infrared spectroscopy (FTIR). Based on the comparison of the obtained results with those of other CTAB-FA binary mixtures with different alkyl chain length mismatches, the possible molecular packing in the crystal phase of CTAB-FA complexes and the mechanism of successive phase transitions in the condensed state are proposed.

Structure and properties of polypropylene/organic rectorite nanocomposites

Clay Minerals ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Yun Huang ◽  
Xiaoyan Ma ◽  
Guozheng Liang ◽  
Hongxia Yan
Keyword(s):  
Loss Modulus ◽  
Polarized Light ◽  
Clay Content ◽  
Crystal Form ◽  
Ammonium Bromide ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Monoclinic Crystal ◽  
X Ray

AbstractMelt blending using a twin-screw extruder was used to prepare composites of polypropylene (PP)/organic rectorite (PR). The organic rectorite (OREC) was modified with dodecyl benzyl dimethyl ammonium bromide (1227). Wide-angle X-ray diffraction (WAXD) and transmission electron microscopy were used to investigate the dispersion of OREC in the composites. The d spacings of OREC in PR composites was greater than in OREC itself. The dispersion of OREC particles in the PP polymer matrix was fine and uniform when the clay content was small (2 wt.%). The rheology was characterized using a capillary rheometer. The processing behaviour of the PR system improved as the amount of OREC added increased. Non-isothermal crystallization kinetics were analysed using differential scanning calorimetry. It was shown that the addition of OREC had a heterogeneous nucleation effect on PP, and can accelerate the crystallization. However, only when fine dispersion was achieved, and at lower rates of temperature decrease, was the crystallinity greater. Wide-angle X-ray diffraction and polarized light microscopy were used to observe the crystalline form and crystallite size. The PP in the PR composites exhibited an a-monoclinic crystal form, as in pure PP, and in both cases a spherulite structure was observed. However, the smaller spherulite size in the PR systems indicated that addition of OREC can reduce the crystal size significantly, which might improve the ‘toughness’ of the PP. The mechanical properties (tensile and impact strength) improved when the amount of OREC added was appropriate. Dynamic mechanical analysis showed that the storage modulus (E′) and loss modulus (E″) of the nanocomposites were somewhat greater than those of pure PP when an appropriate amount of OREC was added. Finally, thermogravimetric analysis showed that the PR systems exhibited a greater thermal stability than was seen with pure PP.

The Use of N-alkanes for Estimating Intake and Passage Rate in Horses

1996 ◽  
Vol 1996 ◽  
pp. 98-98
Author(s):  
B M L McLean ◽  
R W Mayes ◽  
F D DeB Hovell
Keyword(s):  
Recent Work ◽  
Chain Length ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Passage Rate ◽  
Forage Crops ◽  
Carbon Chains ◽  
Naturally Occurring ◽  
Chain Lengths ◽  
Long Chain

Alkanes occur naturally in all plants, although forage crops tend to have higher alkane contents than cereals. N-alkanes have odd-numbered carbon chains. They are ideal for use as markers in feed trials, because, they are inert, indigestible and naturally occurring, and can be recovered in animal faeces. Synthetic alkanes (even-numbered carbon chains) are available commercially and can also used as external markers. Dove and Mayes (1991) cite evidence indicating that faecal recovery of alkanes in ruminants increases with increasing carbon-chain length. Thus the alkane “pairs” (e.g. C35 & C36, and C32 & C33) are used in calculating intake and digestibility because they are long chain and adjacent to each other. However, recent work by Cuddeford and Mayes (unpublished) has found that in horses the faecal recovery rates are similar regardless of chain lengths.

Evaluation of Biodegradability of Amine Collectors

2010 ◽  
Vol 113-116 ◽  
pp. 267-271 ◽  
Author(s):  
Heng Zhen Yan ◽  
Wen Qi Gong ◽  
Guang Jun Mei ◽  
Xiao Ye Liu ◽  
Shao Hua Chen
Keyword(s):  
Chemical Structure ◽  
Ester Group ◽  
Carbon Chain ◽  
Ammonium Bromide ◽  
Evaluation Standards ◽  
Testing Method

Amine collectors are widely used as oxidized ore collectors.Based on OECD 301B testing method, the biodegradability of amine collectors were analyzed and evaluated, and the values of IB of lauryl amine, octadecylamine, laurtrimonium chloride, lauryl trimethyl ammonium bromide, decane-propyl ether amine and dodecyl propyl ether amine were 173.4, 162.2, 164.6, 171.2, 160.8 and 149.4, respectively. The biodegradation of six test substances all exceeded 10% in 10 days, and all up to over 50% within 28 days. Considering comprehensively the two evaluation standards, the six amine collectors are all biodegradable. Evaluation of the biodegradability of amine collectors provides information that the chemical structure influences the biodegradability of amine collectors. It seems that the existence of ester group decreases the biodegradability of ether amine, and the shorter the carbon chain, the greater the biodegradation occurred.

Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

2012 ◽  
Vol 727-728 ◽  
pp. 1552-1556
Author(s):  
Renata Barbosa ◽  
Dayanne Diniz Souza ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Chemical Structure ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Degradation Mechanisms ◽  
Scanning Calorimetry ◽  
Higher Temperature ◽  
Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

scholarly journals Thermal solid-state Z/E isomerization of 2-alkylidene-4-oxothiazolidines: Effects of non-covalent interactions

2011 ◽  
Vol 76 (3) ◽  
pp. 317-328 ◽  
Author(s):  
Zdravko Dzambaski ◽  
Milovan Stojanovic ◽  
Marija Baranac-Stojanovic ◽  
Dragica Minic ◽  
Rade Markovic
Keyword(s):  
Solid State ◽  
1H Nmr Spectroscopy ◽  
Amorphous State ◽  
Intramolecular Hydrogen Bonding ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Configurational Isomerization ◽  
Non Covalent Interactions ◽  
Intramolecular Hydrogen ◽  
Covalent Interactions

Configurational isomerization of stereo-defined 5-substituted and unsubstituted 2-alkylidene-4-oxothiazolidines 1 in the solid state, giving the Z/E mixtures in various ratios, was investigated by 1H-NMR spectroscopy, X-ray powder crystallography and differential scanning calorimetry (DSC). The Z/E composition can be rationalized in terms of non-covalent interactions, involving intermolecular and intramolecular hydrogen bonding and directional non-bonded 1,5-type S...O interactions. X-Ray powder crystallography, using selected crystalline (Z)-4- oxothiazolidine substrates, revealed transformation to the amorphous state during the irreversible Z ? E process. A correlation between previous results on the Z/E isomerization in solution and now in the solid state was established.

Pseudopodium Induction by the Action of Quaternary Ammonium Ions on Amoeba Proteus

1969 ◽  
Vol 4 (1) ◽  
pp. 17-24
Author(s):  
J. E. BREWER ◽  
L. G. E. BELL
Keyword(s):  
Cell Membrane ◽  
Cell Surface ◽  
Quaternary Ammonium ◽  
Amoeba Proteus ◽  
Carboxyl Groups ◽  
Ammonium Ions ◽  
Quaternary Nitrogen ◽  
Quaternary Ammonium Ions ◽  
Ammonium Compounds ◽  
Long Chain

Some aliphatic long-chain quaternary ammonium compounds and choline derivatives have been examined for their ability to induce pseudopodia from Amoeba proteus. The reaction involved in pseudopodium induction is believed to be between the quaternary nitrogen cations and polysaccharides on the cell surface. Not all of the carboxyl groups of the polysaccharide are involved in this reaction. The mechanism of pseudopodium induction is discussed in terms of changes in the surface charge and the permeability of the cell membrane.

scholarly journals The Effect of Crystallinity on the Toughness of Cast Polyamide 6 Rods with Different Diameters

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 293
Author(s):  
Miklós Odrobina ◽  
Tamás Deák ◽  
László Székely ◽  
Tamás Mankovits ◽  
Róbert Zsolt Keresztes ◽  
...  
Keyword(s):  
Impact Strength ◽  
Impact Test ◽  
Charpy Impact ◽  
Polyamide 6 ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Tensile Impact ◽  
Different Diameters ◽  
The Impact ◽  
The Degree Of Crystallinity

The present paper concentrates on the toughness and the degree of crystallinity of the magnesium-catalyzed polyamide 6 rods cast in different diametres, which are commonly used for gear manufacturing. Its toughness cannot be regarded as a constant feature due to the casting technology. The mechanical properties of the semi-finished products are sensitive to the manufactured dimension, e.g., cast diameter, which are investigated by the Charpy impact test and tensile impact test. It is generally accepted that the impact strength and tensile-impact strength correlate with the degree of crystallinity beside many other material’s feature. Crystallinity is evaluated by Differential Scanning Calorimetry. The aim of this study is to determine the relationship between toughness and crystallinity of the magnesium-catalyzed cast PA6 rods with different diameters. For the research cast rods between 40 and 300 mm diameter were selected in seven-dimensional steps. Based on the results, it was found that the toughness depends strongly on the diameter size. Furthermore, it is proved that the crystallinity explains 62.3% of the variation of the Charpy’s impact strengths, while the tensile impact method was not suitable to detect the difference between the test samples.

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