Statistical thermodynamics of flexible‐chain surfactants in monolayer films: Mixtures of different chain lengths

1989 ◽  
Vol 91 (10) ◽  
pp. 6306-6317 ◽  
Author(s):  
Robert S. Cantor
Keyword(s):  
Statistical Thermodynamics ◽  
Monolayer Films ◽  
Flexible Chain ◽  
Chain Lengths

scholarly journals Design and Self-Assembling Behaviour of Calamitic Reactive Mesogens with Lateral Methyl and Methoxy Substituents and Vinyl Terminal Group

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2156
Author(s):  
Alexej Bubnov ◽  
Martin Cigl ◽  
Deyvid Penkov ◽  
Marek Otruba ◽  
Damian Pociecha ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Liquid Crystalline ◽  
Terminal Group ◽  
X Ray Diffraction ◽  
Flexible Chain ◽  
X Ray ◽  
Self Assembling ◽  
Methoxy Groups ◽  
Chain Lengths ◽  
Reactive Mesogens

Smart self-organising systems attract considerable attention in the scientific community. In order to control and stabilise the liquid crystalline behaviour, and hence the self-organisation, the polymerisation process can be effectively used. Mesogenic units incorporated into the backbones as functional side chains of weakly cross-linked macromolecules can become orientationally ordered. Several new calamitic reactive mesogens possessing the vinyl terminal group with varying flexible chain lengths and with/without lateral substitution by the methyl (methoxy) groups have been designed and studied. Depending on the molecular structure, namely, the type and position of the lateral substituents, the resulting materials form the nematic, the orthogonal SmA and the tilted SmC phases in a reasonably broad temperature range, and the structure of the mesophases was confirmed by X-ray diffraction experiments. The main objective of this work is to contribute to better understanding of the molecular structure–mesomorphic property relationship for new functional reactive mesogens, aiming at further design of smart self-assembling macromolecular materials for novel sensor systems.

Statistical Thermodynamics of Phase Transitions in Surfactant Monolayer Films

1989 ◽  
Vol 177 ◽  
Author(s):  
Robert S. Cantor
Keyword(s):  
Chain Length ◽  
High Surface ◽  
Mean Field ◽  
Mechanical Method ◽  
Monolayer Films ◽  
Ideal Behavior ◽  
Ideal Mixing ◽  
Statistical Mechanical ◽  
The Difference ◽  
Chain Lengths

ABSTRACTA lattice statistical mechanical method has recently been developed and used to predict structural and thermodynamic properties of fluid phases of surfactant monolayer films of uniform chain length. This mean-field approach is extended here to examine films of mixed chain length. As in the earlier work, a fluid-fluid (LC-LE) phase transition is predicted to occur at high surface densities. This transition is found to exhibit non-ideal mixing behavior, ranging from positive azeotropy to phase separation (in the LC phase) as the difference in chain lengths increases. In contrast, the phase diagram in the liquid-gas (LEG) transition region is predicted to exhibit almost ideal behavior, with a nearly linear bubble-point curve.

Possibility of Organic Monolayer Films as Lubricants for Disk Drives: Comparative Study of PFPE and Organosilane

2003 ◽  
Vol 125 (4) ◽  
pp. 850-853 ◽  
Author(s):  
Junho Choi ◽  
Masahiro Kawaguchi ◽  
Takahisa Kato
Keyword(s):  
Hard Disk ◽  
Disk Drive ◽  
Monolayer Films ◽  
Organic Monolayer ◽  
Pfpe Lubricant ◽  
Coated Surface ◽  
Carbon Overcoats ◽  
Drive Systems ◽  
Magnetic Hard Disk ◽  
Chain Lengths

Organosilane monolayer of 1H,1H,2H,2H-perfluorodecyltrichlorosilane and PFPE lubricant films were deposited on magnetic hard disk surfaces protected with amorphous carbon overcoats, and their frictional properties were investigated by a ball-on-flat tribotester. The thickness of PFPE films having only an immobile layer or both immobile and mobile layers was varied from about 0.6 nm to 4 nm. The friction coefficient of the organosilane monolayer coated surface is comparable to that of the PFPE coated surface with a 1.0 nm thick immobile layer and lower than that of the PFPE coated surface with a 0.6 nm thick immobile layer. The thickness of the lubricant has to decrease to less than 1 nm to further increase recording density. In that case, the mobile portion of PFPE lubricant is negligible. This study suggests that organosilane monolayers (with shorter chain lengths) may be used as an alternate lubricant in hard disk drive systems.

Equilibrium and Non-Equilibrium Statistical Thermodynamics

2004 ◽  
Author(s):  
Michel Le Bellac ◽  
Fabrice Mortessagne ◽  
G. George Batrouni
Keyword(s):  
Statistical Thermodynamics ◽  
Non Equilibrium
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