Paper Title:
Advanced Algorithms for PALS Analysis of Self-Assembled Amphiphiles
  Abstract

Self-assembled amphiphile systems are utilized in a wide variety of applications including drug delivery and energy storage. Nano-scale physical and chemical interactions govern the packing of self-assembled amphiphilic molecules, resulting in thermodynamically stable phases of defined geometries. Possible phases include micellar, hexagonal, cubic, lamellar and sponge phases. The internal nano-structure of the amphiphile self-assembly materials plays an important role in the properties of these systems and their application. To date small angle x-ray scattering (SAXS) has been the most common technique used to characterise their structure. We explore positron annihilation lifetime spectroscopy (PALS) as an alternative and/or complementary technique for this purpose, using the phytantriol/water system. While PALS is a well established technique for characterising many materials, the coexistence of aqueous and hydrophobic regions in a soft self-assembled amphiphile material poses a challenge to the analysis and interpretation of the results. In order to alleviate these difficulties we developed a computer program for general-purpose PALS data analysis called PAScual. Amongst the most salient features of this new code are the possibility to perform bounded fits and the option of using advanced algorithms to provide a more robust and unbiased fit: on the one hand, it incorporates a global nonlinear optimisation routine based on the Simulated Annealing algorithm and, on the other hand it gives information on the reliability of the results by means of a Markov Chain Monte-Carlo Bayesian Inference method. In this work we present the newly developed PALS data analysis techniques as well as the results for the phytantriol/water system, comparing them with additional data obtained from complementary techniques.

  Info
Periodical
Edited by
S. J. Wang, Z. Q. Chen, B. Wang and Y. C. Jean
Pages
257-259
DOI
10.4028/www.scientific.net/MSF.607.257
Citation
C. Pascual-Izarra, A. W. Dong, S. J. Pas, B. J. Boyd, C.J. Drummond, A. J. Hill, "Advanced Algorithms for PALS Analysis of Self-Assembled Amphiphiles", Materials Science Forum, Vol. 607, pp. 257-259, 2009
Online since
November 2008
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: M.L. Álvarez, N. Camacho, C. Neipp, A. Márquez, A. Beléndez, I. Pascual
Abstract:The research made in the field of recording materials for holographic applications has yielded to materials of improving quality....
543
Authors: Victoria Corregidor, P.C. Chaves, M.A. Reis, Carlos Pascual Izarra, Eduardo Alves, Nuno P. Barradas
Abstract:Quaternary GaInAsSb films alloys were grown by MOVPE technique on GaSb substrates with different growth conditions such as substrate...
1603
Authors: Dong Sheng Yao, Li Bin Zhao
Chapter 1: Engineering Science for Manufacturing
Abstract:Model updating techniques are used to modify structural model for more accurate predictions of dynamics behavior. A simple survey on the...
140
Authors: Dan Zhou, Hai Yan Gao, Yun Jie Zhang
Chapter 4: Automation, Control and Monitoring Technologies, Software and Information Engineering
Abstract:Nonnegative Matrix Factorization (NMF) is among the most popular subspace methods, widely used in a variety of image processing problems....
858
Authors: Mohd Nizam Ahmad, Wan Mansor Wan Muhamad
Abstract:Structural optimization was important nowadays in getting the optimum design and usage of the material use, where size optimization is part...
309