Intermolecular hydrogen bonds are formed through the electrostatic attraction between the hydrogen nucleus on a strong polar bond and high electronegative atom with an unshared pair of electrons and a partial negative charge. It affects the physical and chemical properties of substances. Based on this, we presented a physical method to modulate intermolecular hydrogen bonds for not changing the physical-chemical properties of materials. The graphite and graphene is added into the glycerol respectively by being used as a viscosity reducer in this paper. The samples are characterized by Raman and ¹H-NMR. Results show that intermolecular hydrogen bonds are adjusted by graphite or graphene. The rheology of glycerol is reduced to varying degrees. TEM and computer simulation show that the spatial limiting action of graphite or graphene is the main cause of breaking the intermolecular hydrogen bond network structure. We hope this work reveals the potential interplay between nanomaterials and hydroxyl liquids, which will contribute to the field of solid-liquid coupling lubrication.

Figure 1. Raman spectrum of graphite and graphene in glycerol. Figure 1a is the Raman spectrum peak of graphite and infiltrated graphite. Figure 1b is the Raman spectrum peak of graphene and infiltrated graphene. They were analyzed by HORIBA LABRAM_HR800 Raman spectrometer in the State Key Laboratory of tribology, Tsinghua University. The laser wavelength is 633 nm, Liquid nitrogen cooled InGaAs detector and Equipped with XYZ automatic platform. The accuracy is 0.1um. Graphite nanoparticles and graphene are purchased from Nanjing XFNANO Materials Tech Co., Ltd and The Six Element Inc., respectively. The test data were processed and plotted by originpro 8.5.1 software.

Figure 2. ¹H-NMR of samples. Figure 2a is the ¹H-NMR spectrum peak of graphite and glycerol mixture. Figure 2b is the ¹H-NMR spectrum peak of graphene and glycerol mixture. ¹H-NMR was carried out using dimethyl sulfoxide-d6 as solvent and configuring 0.5mol/L detection solution concentration. It was analyzed by JNM-ECA600 nuclear magnetic resonance spectrometer, which was performed at Tsinghua University. The test data were processed and plotted by originpro 8.5.1 software.

Figure 3. Rheological curves of samples. Figure 3a is the Rheological behavior of graphite and glycerol mixtures. Figure 3b is the Rheological behavior of graphene and glycerol mixtures. The mixtures were analyzed by Anton Paar Physica MCR301 in the State Key Laboratory of tribology, Tsinghua University. The air-bearing torque of 0.002 μNm to 200 mNm and the detection temperature was 25±1°C. The test data were processed and plotted by originpro 8.5.1 software.

Figure 4. TEM images of infiltrated graphite and graphene. Figure 4a is the distribution of graphite in glycerol before shearing. Figure 4b is the distribution of graphite in glycerol after shearing. Figure 4c is the distribution of graphene in glycerol. They were carried out by JEM-2100 TEM, which was performed at Tsinghua University. Lanthanum hexaborate filament. Accelerating voltage is 80-200kv. The point resolution is 0.23nm.The lattice resolution is 0.19nm.

Figure 5, Figure 6, Figure 7 are the results of computer simulation. And Figure 8 is a mechanism analysis diagram based on the simulation results. All of these are calculated by Materials Studio 8.0 in the State Key Laboratory of tribology, Tsinghua University. The construction parameters of periodic single layer graphene is that its supercell range was (6, 6, 1). Its lengths (Å) were a=12.6, b=14.8 and c=6.8. Its angles were α=β=γ=90°.

(1) The adsorption simulation in Figure 5 was carried out by using the adsorption locator module in MS software.

(2) The differential charge density simulation of adsorption system in Figure 6 was based on PBE functional in GGA by Castep model in MS software.

(3) Figure 7 shows the measurement of the bond length of glycerol before and after adsorption.

The .rar file contains the original data of all calculation simulations. All data are operated by Materials Studio software, the version of which is Materials Studio v8.0.0.843. When viewing the original data, you only need to open the .stp type file through Materials Studio software. The two folders in the .rar file are the root data storage locations of the two .stp file.