2001 journal article

Morphological characteristics of 1,3 : 2,4-dibenzylidene sorbitol/poly(propylene glycol) organogels

JOURNAL OF PHYSICAL CHEMISTRY B, 105(11), 2091–2098.

By: D. Mercurio n & R. Spontak n

co-author countries: United States of America 🇺🇸
Source: Web Of Science
Added: August 6, 2018

The organic gelator 1,3:2,4-dibenzylidene sorbitol (DBS) self-organizes to form a 3-D network stabilized by hydrogen bonds at relatively low concentrations in a variety of nonpolar organic solvents and polymers. The resultant network consists of nanofibrils and is responsible for the physical gelation of the matrix component. In this work, the morphological characteristics of organogels composed of DBS and poly(propylene glycol) (PPG) are investigated as functions of DBS concentration, PPG molecular weight, and temperature through the use of polarized light microscopy, transmission electron microscopy, X-ray diffractometry, and spectrophotometry. Polarized light microscopy reveals thermally reversible features that become increasingly more pronounced with increasing DBS concentration. Electron microscopy verifies that these features arise due to the presence of a DBS nanofibrillar network, with nanofibrils measuring ca. 10 nm in diameter. Comparison of X-ray diffraction patterns of pure DBS crystals and DBS networks from which PPG is removed by supercritical fluid extraction reveals that the DBS nanofibrils are crystalline, differing slightly from the structure of pure DBS. Spectrophotometry is used to probe the temperature-dependent development of the molecular network in DBS/PPG organogels.