Structure–dynamics relationship during the amorphous to smectic transition of a main chain liquid crystalline polymer

Ezquerra, Tiberio A.; Martínez‐Gómez, Aránzazu; Álvarez, Celedonio M.; Alonso, Elena O.; Sanz, Alejandro; García-Gutiérrez, Mari Cruz; Bello, A.; Pérez, Ernesto; Funari, Sérgio S.; Dommach, M.

doi:10.1016/j.jnoncrysol.2005.03.073

Cited by 6 publications

(10 citation statements)

References 8 publications

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“…Several studies have examined the dielectric behavior of either MCLCPs or side chain liquid crystalline polymers (SCLCPs) [5][6][7][8][9][10][11][12][13], but few studies have been conducted on smectic C A MCLCP [11,14,15]. These investigations have demonstrated that LCPs exhibit multiple relaxations in both the glassy and liquid crystalline state(s).…”

Section: Introductionmentioning

confidence: 99%

Dynamics of main-chain liquid crystalline polysiloxanes containing p-phenyleneterephthalate mesogens

Masser

Patil

Hedden

et al. 2010

Journal of Non-Crystalline Solids

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Section: Introductionmentioning

confidence: 99%

Dynamics of main-chain liquid crystalline polysiloxanes containing p-phenyleneterephthalate mesogens

Masser

Patil

Hedden

et al. 2010

Journal of Non-Crystalline Solids

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“…A very slow second stage that involves only a minor dielectric strength change is followed, and it is related to the improvement of the smectic order. 8 Finally, the high pressure dielectric study of PTEMeB revealed that the fast pressure increase induces a fast mesophase formation. It seems that, at high pressures, the methyl lateral substituent is not enough to inhibit a comparatively fast transformation into the liquid crystal.…”

Section: Discussionmentioning

confidence: 99%

“…Simultaneous dielectric and X-ray diffraction experiments of a similar system have shown that the first stage (fast) is related to the smectic layer formation and the second one to the increase of order within smectic domains. 8,32 Equation 1 can be used to fit all the isochrones considering the following constraints. For the first curve, only one HN was used to describe the α iso mode, whereas for longer times, two HN functions describe the competitive α iso and α LC processes; the peaks of the final isochrones can be also described with only one broad HN function.…”

Section: Dielectric Relaxation Studymentioning

confidence: 99%

“…21 Depending on whether each repetitive unit has one or two methyl lateral substituents, the polymer forms smectic C or nematic mesophases. Ezquerra et al have recently studied 8 one of these copolymers using dielectric relaxation spectroscopy, DR. They found that the copolymer shows an isosbestic frequency, previously described in SCLCPs as they are realigned in electric fields and for long side chain methacrylates during crystallization.…”

Section: Introductionmentioning

confidence: 99%

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X-ray Diffraction, Calorimetric, and Dielectric Relaxation Study of the Amorphous and Smectic States of a Main Chain Liquid Crystalline Polymer

et al. 2012

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Liquid crystalline polymers (LCPs) are complex systems that include features of both orientationally ordered mesophases and amorphous polymers. Frequently, the isotropic amorphous state cannot be studied due to the rapid mesophase formation. Here, a new main chain LCP, poly(triethyleneglycol methyl p,p′-bibenzoate), PTEMeB, has been synthesized. It shows a rather slow mesophase formation making possible to study independently both the amorphous and the liquid crystalline states. The structure and phase transitions of PTEMeB have been investigated by calorimetry, variable-temperature MAXS/WAXS employing synchrotron radiation, and X-ray diffraction in oriented fibers. These experiments have pointed out the presence of two glass transitions, related to the amorphous or to the liquid crystal phases. Additionally, the mesophase seems to be a coexistence of orthogonal and tilted smectic phases. A dielectric relaxation study of PTEMeB over broad ranges of temperature and pressure has been performed. The dynamic glass transition turns out to be slower for the amorphous state than for the liquid crystal. Monitoring of the α relaxation has allowed us to follow the isothermal mesophase formation at atmospheric pressure. Additionally, the dynamical behavior at high pressures has pointed out the fast formation of the mesophase induced by sudden pressure changes.

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“…Each component has its characteristic signal region; therefore, X-ray diffraction works as a fingerprint identification. In the same way, it is possible to determine in addition to the morphology of biopolymers its stability, observing changes in the ranges and intensity of the signals with respect to time, using this technique for periods after the analysis in an initial time [27].…”

Section: X-ray Diffraction (Xrd)mentioning

confidence: 99%

Biofunctionalized Polymer Nanomaterials: Implications on Shapes and Sizes

Razura-Carmona¹,

Prado-Guzmán²,

Pérez-Larios³

et al. 2020

Nanomaterials - Toxicity, Human Health and Environment

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Nanotechnology has been one of the most widely used tools in various industries such as pharmaceutical, food, and chemistry, among others, for the encapsulation of compounds or even microorganisms. However, an analysis of the methodologies or polymer matrices to be used is rarely generated, and these in turn contribute to the objective of the product that is intended to be designed. In addition to the evaluation of its physicochemical, optical, and rheological characteristics, and others, are a set of technological tools that allow predicting the stability of a colloid, however, some of the factors that have less importance as the effect of the synthesis process on the shape and size that a structure may have, studies have been carried out to evaluate this phenomenon, which has become a determining factor in the design of any nanoscale material.

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Structure–dynamics relationship during the amorphous to smectic transition of a main chain liquid crystalline polymer

Cited by 6 publications

References 8 publications

Dynamics of main-chain liquid crystalline polysiloxanes containing p-phenyleneterephthalate mesogens

Dynamics of main-chain liquid crystalline polysiloxanes containing p-phenyleneterephthalate mesogens

X-ray Diffraction, Calorimetric, and Dielectric Relaxation Study of the Amorphous and Smectic States of a Main Chain Liquid Crystalline Polymer

Biofunctionalized Polymer Nanomaterials: Implications on Shapes and Sizes

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