Polymorphic transformations of C26H54 and C28H58 n-paraffins as typical rotator substances

Gnatyuk, I. I.; Platonova, N. V.; Puchkovskaya, G. A.; Kotelnikova, E. N.; Филатов, С. К.; Baran, J.; Drozd, M.

doi:10.1007/s10947-007-0099-4

Cited by 11 publications

(11 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They are assigned to different gauche-trans sequences of bonds in alkyl chains. It should be noted that the absorption at these wavenumbers also appear in melted n-paraffins [10]. Here these spectral peculiarities appear even at 100°C.…”

Section: Ir-spectramentioning

confidence: 57%

“…However, the amount of the substance in a thin film is not sufficient to study phase transitions in it with a conventional method of differential scanning calorimetry, DSC, usually used in such studies. On the other hand, it is well known [9,10] that phase transitions in organic substances containing methylene chains always result in considerable changes of almost all IR-spectral bands. So here the IR-spectroscopic analysis allows to reveal for the first time the temperature-dependent changes of molecular and crystal CTAB structure and the phase transitions peculiarities in the thin CTAB films and to make a comparison with the bulk material.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

IR-study of thermotropic phase transitions in cetyltrimethylammonium bromide powder and film

Bezrodna

Puchkovska

Styopkin

et al. 2010

Journal of Molecular Structure

View full text Add to dashboard Cite

Section: Ir-spectramentioning

confidence: 57%

Section: Introductionmentioning

confidence: 99%

IR-study of thermotropic phase transitions in cetyltrimethylammonium bromide powder and film

Bezrodna

Puchkovska

Styopkin

et al. 2010

Journal of Molecular Structure

View full text Add to dashboard Cite

“…Figure 3b and c also shows that a band at ~725 cm -1 appears in the spectra of both organoclays along with the IR bands at ~720 and ~730 cm -1 . This corresponds to the gauche-conformation of the CTAB alkyl chains and is usually observed in spectra of melts of long-chain aliphatic compounds [33,35]. The distinct separation of the absorption envelope in this region enabled these bands to be identified and their spectral parameters to be determined.…”

Section: Introductionmentioning

confidence: 84%

Structure and spectroscopic properties of organoclays doped by multiwall carbon nanotubes

et al. 2011

Self Cite

View full text Add to dashboard Cite

A method to modify a montmorillonite (MMT) clay mineral (CM) surface by surfactant (SA) cations with simultaneous doping by multiwall carbon nanotubes (MWNT) has been proposed. The structure and spectroscopic properties of composites based on MMT from two deposits (Cherkassy and Pyzhevsk, Ukraine) that differ in the inorganic impurity contents and cation-exchange capacities (CEC) have been investigated. Cetyltrimethylammonium bromide (CTAB) was used as the SA. According to x-ray diffraction analysis, CTA + cations intercalated into MMT interplanar spaces expand them significantly whereas MWNTs do not affect the MMT galleries due to the much larger sizes of the former. Studies of the composite materials by IR spectroscopy revealed the mutual influence of the components appearing as the ordering of near-surface layers in the aluminosilicate framework and a change in the modifier methylene chain conformation at the interphase boundary. The majority of CTAB (~90%) is shown to be located inside the MMT galleries, the packing arrangement of which depends on the CEC value and affects the interplanar distances in MMT. The alkyl chains of the CTA + cations on the outer surface of the MMT plates are sorbed by nanotubes, thus providing contact between the organoclay and MWNT surfaces.Introduction. Multi-functional heterosystems consisting of an organic component and multiwall carbon nanotubes (MWNT) are currently under intense scrutiny. The incorporation of small quantities of the latter into an organic medium changes drastically its physical properties such as electrical and thermal conductivity, mechanical and optical characteristics, etc. [1-3]. However, MWNT exhibit a high capability to aggregate. This makes it very difficult to create composites with a uniform distribution of MWNT in the organic matrix because of their lipophobic nature. MWNTs are treated with surfactants (SAs) in order to give their surface a higher affinity for the organic medium [4,5]. Another method for preparing homogeneous composites is to add nanoparticles of organoclays to the organic matrix and MWNT. It was shown [6,7] that these fillers produce a synergistic effect on the mechanical and thermal properties of nanocomposites when added simultaneously to ethylene-vinylacetate copolymer or chitosan (polysaccharide). Furthermore, the effect of adding organoclay particles and MWNT to various polymers on not only the mechanical properties of the resulting composites but also their flammability was investigated [8][9][10][11][12]. It was shown that the ability of such heterocomposites to ignite was sharply reduced even with low (~1%) concentrations of nanofillers owing to the synergistic effect produced in such systems.MWNTs were intercalated into layered clay minerals (CMs) by catalytic decomposition at 700

show abstract

“…The melting and crystallization of pure dodecane can also be followed using ATR-FTIR, as there are specific spectral changes which correlate with conformational changes of the paraffins during the phase transitions (Gnatyuk et al, 2007). Dodecane crystallization is mainly characterized by factor group splitting at 2957 cm À1 and by the appearance of a new band at 716 cm À1 .…”

Section: Solution Properties and Morphology Of The Obtained Structuresmentioning

confidence: 99%

“…Discrepancies between DSC data and FTIR results can be explained because the spectroscopic technique is able to identify conformational changes associated to the crystallization process which are not as easily detectable by DSC. The existence of a unique band at 716 cm À1 for crystalline dodecane indicates that the solid paraffin presents the triclinic structure typical of even numbered nparaffins with n 26 (Gnatyuk et al, 2007).…”

Section: Solution Properties and Morphology Of The Obtained Structuresmentioning

confidence: 99%

Development of zein-based heat-management structures for smart food packaging

2013

View full text Add to dashboard Cite

Polymorphic transformations of C26H54 and C28H58 n-paraffins as typical rotator substances

Cited by 11 publications

References 22 publications

IR-study of thermotropic phase transitions in cetyltrimethylammonium bromide powder and film

IR-study of thermotropic phase transitions in cetyltrimethylammonium bromide powder and film

Structure and spectroscopic properties of organoclays doped by multiwall carbon nanotubes

Development of zein-based heat-management structures for smart food packaging

Contact Info

Product

Resources

About