The Weak Help the Strong: Low-Molar-Mass Organogelators Harden Bitumen

Abstract

Low-molar-mass organogelators (LMOG) can turn liquids into thermoreversible gels because they self-assemble into a fibrous network. In contrast, using the same kind of low-molar-mass additives to harden materials, which are already solidlike on their own, has been hardly exploited. We show here that simple dicarboxylic acids are very efficient low-molar-mass organogelators (LMOG) for bitumen. Indeed, they increase the range of temperature where bitumen is a solid. Moreover, the hardness and elastic modulus of bitumen at room temperature are also improved. This concept of improving the mechanical properties of a solid with an LMOG can probably be applied to other materials.

Organogel formation rationalized by Hansen solubility parameters: dos and don'ts

“…31,32 They can even be used to improve the mechanical properties of soft solids. 33 To date, a wide range of LMWGs are known, but most of them have been discovered by serendipity. As a matter of fact, it is still difficult to design a gelator de novo to yield a gel in a specific liquid.…”

Large amplitude oscillatory shear of supramolecular materials

“…This is the motivation to modify the relaxation time as a function of network points within a cycle of oscillation as shown in Eqs. (10) and (11) …”

“…It is also known that EHUT does not form these tubular structures in bulky solvents [9]. EHUT has been investigated for applications such as drag reducing agent and hardener for asphalt [10][11][12]. Supramolecular polymers, such as EHUT gels, have been characterized using rheological techniques like steady shear and dynamic oscillatory shear tests [6,[13][14][15].…”

A potential bioactive hard‐stock fat replacer comprised of a molecular gel

“…Organogels comprising "small" molecular gelators (i.e., molecular gels) are thermally reversible, quasi-solid materials comprised mainly of organic liquids that undergo spontaneous formation into self-assembled networks that are often fibrillar in nature (SAFiNs) (George & Weiss, 2006;Mallia, Butler, Sarkar, Holman, & Weiss, 2011;Weiss & Terech, 2006). The contrasting, noncovalent, gelatorgelator and gelator-solvent interactions result in fibrillar aggregates that are, in some cases, capable of structuring fluids, preventing flow, and improving the mechanical properties of solids (Fahrländer, Fuchs, Mülhaupt, & Friedrich, 2003;Isare et al, 2009;Wilder, Hall, Khan, & Spontak, 2003). Specifically, organogels are being widely studied in structuring edible oils to utilize them as hard-stock fat replacers (Bot & Agterof, 2006;Bot, den Adel, & Roijers, 2008;Bot, Veldhuizen, den Adel, & Roijers, 2009;Co & Marangoni, 2012;Da This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.…”