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Title: Self‐Degrading Molecular Organogels: Self‐Assembled Gels Programmed to Spontaneously Liquefy after a Set Time
Gels are used in the oilfield. For example, during oil recovery, organogels are pumped underground into fractures within oil‐bearing rock, so as to block fluid flow. However, after several days, the gels must be degraded (liquefied) to enable oil extraction through the fractures. To degrade gels, ‘degrading agents’ as well as external stimuli have been examined. Here, a concept is demonstrated that avoids external agents and stimuli:self‐degrading organogelsbased on the self‐assembly of molecular gelators. The gels are a) extremely robust (free standing solids) at timet= 0 and (b) degrade spontaneously into a sol after a set timet=tdegrthat can be minutes, hours, or days. These properties are achieved by combining two readily available molecules — the organogelator (1,3:2,4)‐dibenzylidene sorbitol (DBS) and an acid (e.g., hydrochloric acid, HCl) — in an organic solvent. DBS self‐assembles into nanoscale fibrils, which connect into a 3‐D network, thereby gelling the solvent. The acid type and concentration set the value oftdegrat a given temperature. Degradation occurs because the acid slowly hydrolyzes the acetals on DBS, thereby converting DBS into small molecules that cannot form fibrils. DBS gels with a pre‐programmed “degradation clock” can be made with both polar and non‐polar organic solvents. The concept can be a game‐changer for oil recovery as it promises to make it safer, more efficient, and sustainable.  more » « less
Award ID(s):
2226547 2226533
PAR ID:
10574566
Author(s) / Creator(s):
; ; ; ; ; ;
Publisher / Repository:
Wiley
Date Published:
Journal Name:
Advanced Functional Materials
Volume:
34
Issue:
40
ISSN:
1616-301X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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