Absolute surface energies of wurtzite (10 1¯1) surfaces and the instability of the cation-adsorbed surfaces of II–VI semiconductors

2021 ◽  
Vol 119 (20) ◽  
pp. 201603
Author(s):  
Wentao Jin ◽  
Guangde Chen ◽  
Xiangyang Duan ◽  
C. Moyses Araujo ◽  
Xubo Jia ◽  
...  
Keyword(s):  
1992 ◽  
Vol 62 (9) ◽  
pp. 535-546 ◽  
Author(s):  
Philip E. Slade ◽  
Debra N. Hild

The surface energies of spin finishes adsorbed onto synthetic fibers are a major factor in determining the processing capabilities of these fibers. They also play a key role in determining how wettable the fibers are by other materials that may be applied to yarn or fabrics in later stages of processing, such as dyes, sizes, or anti-soiling agents. We have applied several homologous series of nonionic surfactants, which can be used as spin finish emulsifiers, to nylon 66 fibers and determined the polar, dispersion, and total surface energies of these adsorbed materials. We also propose a relationship between the measured surface energies and the calculated Hansen fractional solubility parameters.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 736
Author(s):  
Kyutae Seo ◽  
Hyo Kang

We synthesized a series of polystyrene derivatives that were modified with precursors of liquid crystal (LC) molecules, such as 4-ethyloxyphenol (homopolymer PEOP and copolymer PEOP#; # = 20, 40, 60, and 80, where # indicates the molar fraction of 4-ethyloxyphenoxymethyl in the side chain), 4-n-butyloxyphenol (PBOP), 4-n-hexyloxyphenol (PHOP), and 4-n-octyloxyphenol (POOP), via polymer modification reaction to investigate the orientation of LC molecules on polymer films, exhibiting part of the LC molecular structure. LC molecules showed a stable and uniform vertical orientation in LC cells fabricated with polymers that have 4-ethyloxyphenoxymethyl in the range of 40–100 mol%. In addition, similar results were obtained in LC cells fabricated with homopolymers of PEOP, PBOP, PHOP, and POOP. The vertical orientation of LC molecules in LC cells fabricated with polymer films correlated to the surface energy of polymer films. For example, vertical LC orientation was observed when the total surface energies of the polymer films were lower than approximately 43.2 mJ/m2. Good alignment stabilities were observed at 150 °C and 20 J/cm2 of ultraviolet irradiation for LC cells fabricated with PEOP film.


2020 ◽  
Vol 193 ◽  
pp. 338-349
Author(s):  
Yotam Hirsh ◽  
Semën Gorfman ◽  
Dov Sherman
Keyword(s):  

1996 ◽  
Vol 465 ◽  
Author(s):  
Robert J. Finch

ABSTRACTGibbs free energies of formation (ΔG°ƒ) for several structurally related U(VI) minerals are estimated by summing the Gibbs energy contributions from component oxides. The estimated ΔG°f values are used to construct activity-activity (stability) diagrams, and the predicted stability fields are compared with observed mineral occurrences and reaction pathways. With some exceptions, natural occurrences agree well with the mineral stability fields estimated for the systems Sio2-Cao-Uo3-UOH2O and Co2-caO-UO3-H2O providing confidence in the estimated thermodynamic values. Activity-activity diagrams are sensitive to small differences in ΔG°f values, and mineral compositions must be known accurately, including structurally bound H2O. The estimated ΔG°f values are not considered reliable for a few minerals for two major reasons: (1) the structures of the minerals in question are not closely similar to those used to estimate the ΔG°f* values of the component oxides, and/or (2) the minerals in question are exceptionally fine grained, leading to large surface energies that increase the effective mineral solubilities.


2020 ◽  
Vol 20 (4) ◽  
pp. 783-794
Author(s):  
Andrea Braides ◽  
Margherita Solci

AbstractWe consider energies on a periodic set {\mathcal{L}} of the form {\sum_{i,j\in\mathcal{L}}a^{\varepsilon}_{ij}\lvert u_{i}-u_{j}\rvert}, defined on spin functions {u_{i}\in\{0,1\}}, and we suppose that the typical range of the interactions is {R_{\varepsilon}} with {R_{\varepsilon}\to+\infty}, i.e., if {\lvert i-j\rvert\leq R_{\varepsilon}}, then {a^{\varepsilon}_{ij}\geq c>0}. In a discrete-to-continuum analysis, we prove that the overall behavior as {\varepsilon\to 0} of such functionals is that of an interfacial energy. The proof is performed using a coarse-graining procedure which associates to scaled functions defined on {\varepsilon\mathcal{L}} with equibounded energy a family of sets with equibounded perimeter. This agrees with the case of equibounded {R_{\varepsilon}} and can be seen as an extension of coerciveness result for short-range interactions, but is different from that of other long-range interaction energies, whose limit exits the class of surface energies. A computation of the limit energy is performed in the case {\mathcal{L}=\mathbb{Z}^{d}}.


2013 ◽  
Vol 20 (06) ◽  
pp. 1350054 ◽  
Author(s):  
L. HE ◽  
Y. W. LIU ◽  
W. J. TONG ◽  
J. G. LIN ◽  
X. F. WANG

Surface energies of strained Cu surfaces were studied systematically using first-principles methods. Results showed that the strain-stabilization of Cu surface was anisotropic and strongly related to the strain distribution. This strain-induced approach could be used as an effective way to engineer the surface energies of metals.


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