CaltechAUTHORS
  A Caltech Library Service

Conformational Disorder Binds n-Alkanes into Surface Monolayers above the Normal Freezing Point

Colussi, A. J. and Hoffmann, M. R. and Tang, Y. (2000) Conformational Disorder Binds n-Alkanes into Surface Monolayers above the Normal Freezing Point. Langmuir, 16 (12). pp. 5213-5217. ISSN 0743-7463. https://resolver.caltech.edu/CaltechAUTHORS:20150623-154759488

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20150623-154759488

Abstract

The monolayer arrays formed on liquid n-alkanes within ΔT ≈ 3 K of the normal freezing point T_F are but the two-dimensional termini of a series of disordered solid phases. An enthalpy/entropy of fusion correlation shows that the arrays approach the melting behavior of molecules lacking internal rotors; i.e., liquid n-alkanes bind into monolayers with slight conformational entropy losses. Therefore, organized surface phases persist above T_F because their end-chain torsional barriers are lowered from solid-phase values at such modest energy cost that net stabilization accrues from extra conformational disorder. The reported ΔT vs n diagram is consistent with about n/2 end-chain monolayer internal rotors gaining the ΔS = 5.3 J K^(-1) mol^(-1) entropy increase associated with a reduction of the gauche/trans energy barrier from V_o = 17 kJ mol^(-1) (as in packed, infinite polyethylene chains) to V_o < 6 kJ mol^(-1) (cf. with V_o = 3.4 kJ mol^(-1) in liquid n-alkanes) at a cost of about 1.6 kJ mol^(-1).


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/la9912141DOIArticle
http://pubs.acs.org/doi/abs/10.1021/la9912141PublisherArticle
ORCID:
AuthorORCID
Colussi, A. J.0000-0002-3400-4101
Hoffmann, M. R.0000-0001-6495-1946
Additional Information:© 2000 American Chemical Society. Received September 14, 1999. In Final Form: March 27, 2000.
Issue or Number:12
Record Number:CaltechAUTHORS:20150623-154759488
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20150623-154759488
Official Citation:Conformational Disorder Binds n-Alkanes into Surface Monolayers above the Normal Freezing Point A. J. Colussi, M. R. Hoffmann, and Y. Tang Langmuir 2000 16 (12), 5213-5217 DOI: 10.1021/la9912141
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:58490
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:28 Jul 2015 19:56
Last Modified:03 Mar 2020 13:01

Repository Staff Only: item control page