scholarly journals Entropic effects of thermal rippling on van der Waals interactions between monolayer graphene and a rigid substrate

2016 ◽  
Vol 119 (7) ◽  
pp. 074305 ◽  
Author(s):  
Peng Wang ◽  
Wei Gao ◽  
Rui Huang
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Monolayer Graphene ◽  
Rigid Substrate ◽  
Entropic Effects

Snap Transitions of Pressurized Graphene Blisters

2016 ◽  
Vol 83 (7) ◽  
Author(s):  
Peng Wang ◽  
Kenneth M. Liechti ◽  
Rui Huang
Keyword(s):  
Plate Theory ◽  
Numerical Study ◽  
Van Der Waals ◽  
Approximate Solutions ◽  
Interfacial Properties ◽  
Pressure Control ◽  
Van Der Waals Interactions ◽  
Volume Control ◽  
Monolayer Graphene ◽  
Separation Relation

Blister tests are commonly used to determine the mechanical and interfacial properties of thin film materials with recent applications for graphene. This paper presents a numerical study on snap transitions of pressurized graphene blisters. A continuum model is adopted combining a nonlinear plate theory for monolayer graphene with a nonlinear traction–separation relation for van der Waals interactions. Three types of blister configurations are considered. For graphene bubble blisters, snap-through and snap-back transitions between pancake-like and dome-like shapes are predicted under pressure-controlled conditions. For center-island graphene blisters, snap transitions between donut-like and dome-like shapes are predicted under both pressure and volume control. Finally, for the center-hole graphene blisters, growth is stable under volume or N-control but unstable under pressure control. With a finite hole depth, the growth may start with a snap transition under N-control if the hole is relatively deep. The numerical results provide a systematic understanding on the mechanics of graphene blisters, consistent with previously reported experiments. Of particular interest is the relationship between the van der Waals interactions and measurable quantities in corresponding blister tests, with which both the adhesion energy of graphene and the equilibrium separation for the van der Waals interactions may be determined. In comparison with approximate solutions based on membrane analyses, the numerical method offers more accurate solutions that may be used in conjunction with experiments for quantitative characterization of the interfacial properties of graphene and other two-dimensional (2D) membrane materials.

Crystal Structures of Two New Cyclosporin Clathrates

2000 ◽  
Vol 65 (12) ◽  
pp. 1950-1958 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Ivana Císařová ◽  
Alexandr Jegorov
Keyword(s):  
Crystal Structures ◽  
Methyl Ether ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Solvent Molecules ◽  
Butyl Methyl Ether

Two isomorphous clathrates formed by dihydrocyclosporin A or cyclosporin V with tert-butyl methyl ether are reported and compared with the structures of related P21-symmetry cyclosporin clathrates. The cyclosporin molecules in both structures are associated via van der Waals interactions forming cavities occupied by solvent molecules (cyclosporin : tert-butyl methyl ether is 1 : 2).

Van der Waals interactions of the disulfide bond revealed: A microwave spectroscopic study of the diethyl disulfide–argon complex

2021 ◽  
Vol 154 (12) ◽  
pp. 124306
Author(s):  
Tao Lu ◽  
Daniel A. Obenchain ◽  
Jiaqi Zhang ◽  
Jens-Uwe Grabow ◽  
Gang Feng
Keyword(s):  
Spectroscopic Study ◽  
Disulfide Bond ◽  
Van Der Waals ◽  
Van Der Waals Interactions

scholarly journals Microscopic evidence of strong interactions between chemical vapor deposited 2D MoS2 film and SiO2 growth template

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Woonbae Sohn ◽  
Ki Chang Kwon ◽  
Jun Min Suh ◽  
Tae Hyung Lee ◽  
Kwang Chul Roh ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Spherical Aberration ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
Interface Layer ◽  
Van Der Waals Interactions ◽  
Strong Interactions ◽  
Transition Electron Microscopy ◽  
Oxide Substrates

AbstractTwo-dimensional MoS2 film can grow on oxide substrates including Al2O3 and SiO2. However, it cannot grow usually on non-oxide substrates such as a bare Si wafer using chemical vapor deposition. To address this issue, we prepared as-synthesized and transferred MoS2 (AS-MoS2 and TR-MoS2) films on SiO2/Si substrates and studied the effect of the SiO2 layer on the atomic and electronic structure of the MoS2 films using spherical aberration-corrected scanning transition electron microscopy (STEM) and electron energy loss spectroscopy (EELS). The interlayer distance between MoS2 layers film showed a change at the AS-MoS2/SiO2 interface, which is attributed to the formation of S–O chemical bonding at the interface, whereas the TR-MoS2/SiO2 interface showed only van der Waals interactions. Through STEM and EELS studies, we confirmed that there exists a bonding state in addition to the van der Waals force, which is the dominant interaction between MoS2 and SiO2. The formation of S–O bonding at the AS-MoS2/SiO2 interface layer suggests that the sulfur atoms at the termination layer in the MoS2 films are bonded to the oxygen atoms of the SiO2 layer during chemical vapor deposition. Our results indicate that the S–O bonding feature promotes the growth of MoS2 thin films on oxide growth templates.

Concisely modularized assembling of graphene-based thin films with promising electrode performance

2019 ◽  
Vol 3 (7) ◽  
pp. 1462-1470 ◽  
Author(s):  
Weiwei Wei ◽  
Rohit L. Vekariy ◽  
Chuanting You ◽  
Yafei He ◽  
Ping Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Double Layer ◽  
Van Der Waals ◽  
Cellulose Nanofibers ◽  
Van Der Waals Interactions ◽  
Electrode Performance ◽  
Reduced Graphene

Highly dense thin films assembled from cellulose nanofibers and reduced graphene oxide via van der Waals interactions to realize ultrahigh volumetric double-layer capacitances.

A comparison between approaches for the calculation of van der Waals interactions in flotation systems

2021 ◽  
Vol 167 ◽  
pp. 106804
Author(s):  
C. Weber ◽  
P. Knüpfer ◽  
M. Buchmann ◽  
M. Rudolph ◽  
U.A. Peuker
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Interactions

scholarly journals 3-(2,4-Dichlorophenyl)-5-(4-fluorophenyl)-2-phenyl-7-(trifluoromethyl)pyrazolo[1,5-a]pyrimidine

2012 ◽  
Vol 68 (6) ◽  
pp. o1923-o1923
Author(s):  
Ju Liu ◽  
Zhi-Qiang Cai ◽  
Yang Wang ◽  
Yu-Li Sang ◽  
Li-Feng Xu
Keyword(s):  
Dihedral Angle ◽  
Title Compound ◽  
Phenyl Ring ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Compound C ◽  
Benzene Rings ◽  
Planar Systems

In the title compound, C25H13Cl2F4N3, there are four planar systems, viz. three benzene rings and a pyrazolo[1,5-a]pyrimidine system [r.m.s. deviation = 0.002 Å]. The dihedral angle between the dichlorophenyl ring and the unsubstituted phenyl ring is 69.95 (5)°, while that between the fluorophenyl ring and the unsubstituted phenyl ring is 7.97 (10)°. The crystal packing is dominated by van der Waals interactions. A Cl...Cl interaction of 3.475 (3) Å also occurs.

Sign in / Sign up

Export Citation Format

Share Document