Low
molecular weight gelators (LMWG) have been extensively explored
in many research fields due to their unique reversible gel–sol
transformation. Intermolecular interactions between LMWG are known
as the main driving force for self-assembly. During this self-assembly
process, individually analyzing the contribution difference between
various intermolecular interactions is crucial to understand the gel
properties. Herein, we report 2,5-bis(hexadecylcarbamoyl)terephthalic
acid (BHTA) as a LMWG, which could efficiently form a
stable organogel with n-hexadecane, diesel, liquid
paraffin, and base lubricant oil at a relatively low concentration.
To investigate the contribution difference of intermolecular interactions,
we first finished FT-IR spectroscopy and XRD experiments. On the basis
of the d-spacing, a crude simulation model was built
and then subjected to molecular dynamics (MD) simulations. Then, we
knocked out the energy contribution of the H-bonding interactions
and π–π stacking, respectively, to evaluate the
intermolecular interactions significantly influencing the stability
of the gel system. MD simulations results suggest that the self-assembly
of the aggregates was mainly driven by dense H-bonding interactions
between carbonyl acid and amide moieties of BHTA, which
is consistent with FT-IR data. Moreover, wave function analysis at
a quantum level suggested these electrostatic interactions located
in the middle of the BHTA molecule were surrounded by
strong dispersion attraction originating from a hydrophobic environment.
Furthermore, we also confirmed that 2 wt % BHTA was able
to form gel lubricant with 150BS. The coefficient of friction (COF)
data show that the gel lubricant has a better tribological performance
than 150BS base lubricant oil. Finally, XPS was performed and offered
valuable information about the lubrication mechanism during the friction.