Optimization of fluid characteristics of 2D materials for inkjet printing

ABSTRACT2D materials have shown to be the next step in semiconductor use and device manufacturing that can allow us to reduce the size of most electronics. One of the novel ways to obtain 2D materials is through liquid exfoliation, in which these materials can be obtained by dispersing the smallest possible particles in different solvents. Once obtained, the solutions can be used to manufacture devices via different processes, one of which is inkjet printing. This process relies in selecting “jettable” fluids, which need to have the necessary combination of viscosity and surface energy or “wettability”. In this work we have modified the viscosities and surface energies of five solvents: IPA (Isopropanol), NMP (N-methyl – 2 pyrrolidone), DMA (Dimethylacetamide), DMF (Dimethylformamide) and a mixture of Cyclohexanone / Terpineol 7:3. We have found an avenue to tailor the viscosity of these solvents though the addition of Ethyl Cellulose (EC), where the viscosity has been increased by up to 15 times at an EC concentration of 6%. For inkjet printing, ideally a viscosity of 4 – 10 cP is recommended, which we have been able to achieve with all of the solvents studied. It has been found that the different solvents present different susceptibilities to the EC addition, with DMA and DMF being the least sensitive to the EC addition. We have also studied the change in the drop dynamics and interactions of the 2D solutions with the substrate. Through this analysis we have found solvents that appear to be attractive for inkjet printing of MoS2 and graphite.

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Vertical Orientation of Liquid Crystal on 4-n-Alkyloxyphenoxymethyl-Substituted Polystyrene Containing Liquid Crystal Precursor

Polymers ◽

10.3390/polym13050736 ◽

2021 ◽

Vol 13 (5) ◽

pp. 736

Author(s):

Kyutae Seo ◽

Hyo Kang

Keyword(s):

Molecular Structure ◽

Liquid Crystal ◽

Surface Energy ◽

Polymer Films ◽

Ultraviolet Irradiation ◽

Molar Fraction ◽

Side Chain ◽

Polymer Modification ◽

Vertical Orientation ◽

Surface Energies

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.

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SURFACE ENERGY ENGINEERING OF Cu SURFACE BY STRAIN: FIRST-PRINCIPLES CALCULATIONS

Surface Review and Letters ◽

10.1142/s0218625x13500546 ◽

2013 ◽

Vol 20 (06) ◽

pp. 1350054 ◽

Cited By ~ 4

Author(s):

L. HE ◽

Y. W. LIU ◽

W. J. TONG ◽

J. G. LIN ◽

X. F. WANG

Keyword(s):

Surface Energy ◽

First Principles ◽

Strain Distribution ◽

First Principles Calculations ◽

Surface Energies ◽

Energy Engineering

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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Surface energies emerging in a microscopic, two-dimensional two-well problem

Proceedings of the Royal Society of Edinburgh Section A Mathematics ◽

10.1017/s0308210516000433 ◽

2017 ◽

Vol 147 (5) ◽

pp. 1041-1089 ◽

Cited By ~ 3

Author(s):

Georgy Kitavtsev ◽

Stephan Luckhaus ◽

Angkana Rüland

Keyword(s):

Surface Energy ◽

Two Dimensional ◽

Direct Control ◽

First Order ◽

Surface Energies ◽

Energy Scaling ◽

Continuous Analogue ◽

Dimensional Shape ◽

Set Up ◽

Microscopic Modelling

In this paper we are interested in the microscopic modelling of a two-dimensional two-well problem that arises from the square-to-rectangular transformation in (two-dimensional) shape-memory materials. In this discrete set-up, we focus on the surface energy scaling regime and further analyse the Hamiltonian that was introduced by Kitavtsev et al. in 2015. It turns out that this class of Hamiltonians allows for a direct control of the discrete second-order gradients and for a one-sided comparison with a two-dimensional spin system. Using this and relying on the ideas of Conti and Schweizer, which were developed for a continuous analogue of the model under consideration, we derive a (first-order) continuum limit. This shows the emergence of surface energy in the form of a sharp-interface limiting model as well the explicit structure of the minimizers to the latter.

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Thermophysical Properties of the Novel 2D Materials Graphene and Silicene: Insights from Ab-initio Calculations

Energy Procedia ◽

10.1016/j.egypro.2014.01.055 ◽

2014 ◽

Vol 45 ◽

pp. 512-517 ◽

Cited By ~ 7

Author(s):

Paola Gori ◽

Olivia Pulci ◽

Roberto de Lieto Vollaro ◽

Claudia Guattari

Keyword(s):

Ab Initio Calculations ◽

Ab Initio ◽

Thermophysical Properties ◽

2D Materials ◽

The Novel

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Liquid exfoliation of graphene oxide nanoribbons using chemical assisted laser ablation

International Journal of Modern Physics B ◽

10.1142/s0217979221400099 ◽

2021 ◽

pp. 2140009

Author(s):

Siddhant Dhongade ◽

Pankaj Koinkar ◽

Akihiro Furube ◽

Satoshi Sugano

Keyword(s):

Graphene Oxide ◽

Laser Ablation ◽

2D Materials ◽

Visible Spectroscopy ◽

Liquid Exfoliation ◽

Graphene Oxide Nanoribbons ◽

Laser Ablation Method ◽

Structural Details ◽

Uv Visible ◽

Optical Applications

The interest toward two-dimensional (2D) materials is gradually increasing because of their structure at nanoscale and great importance for electronic and optical applications. In this study, we show the synthesis of graphene oxide (GO) micro-ribbons fabricated by chemical assisted-laser ablation method. In order to confirm the formation of GO, UV-visible spectroscopy (UV-vis) and Raman spectroscopy are used to observe the surface morphological feature and structural details. In addition, a possible mechanism for the growth of GO nanoribbon is discussed. This work indicates a new method to develop GO nanostructures and related nanomaterials.

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Sono-Assisted Surface Energy Driven Assembly of 2D Materials on Flexible Polymer Substrates: A Green Assembly Method Using Water

ACS Applied Materials & Interfaces ◽

10.1021/acsami.9b10469 ◽

2019 ◽

Vol 11 (36) ◽

pp. 33458-33464 ◽

Cited By ~ 4

Author(s):

Dong Zhou ◽

Ji Hao ◽

Andy Clark ◽

Kyunghoon Kim ◽

Long Zhu ◽

...

Keyword(s):

Surface Energy ◽

2D Materials ◽

Polymer Substrates ◽

Flexible Polymer ◽

Assembly Method

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Use of Contact Angle Hysteresis in Estimating Thin Polymer Film Surface Energy and Wettability

Materials, Nondestructive Evaluation, and Pressure Vessels and Piping ◽

10.1115/imece2006-16173 ◽

2006 ◽

Author(s):

I. S. Bayer ◽

C. M. Megaridis ◽

J. Zhang ◽

D. Gamota

Keyword(s):

Surface Tension ◽

Contact Angle ◽

Surface Energy ◽

Uv Radiation ◽

Contact Angle Hysteresis ◽

Estimation Methods ◽

Thin Polymer Film ◽

Energy Estimation ◽

Surface Energies ◽

Polar Probe

A recent surface energy estimation method [1] interpreting contact angle hysteresis measurements was used to estimate surface energy of various commercially important polymer films including UV radiation cross-linked acrylic based monomer systems. The validity of the method was tested on highly hydrophobic non-polar amorphous fluoro-polymers using a number of polar and low surface tension liquids. Contact angle hysteresis was present on these surfaces even though surface morphology of the solution processed fluoro-polymers is close to ideal. Estimated surface energies using such probe liquids were consistent varying slightly with the probe liquid type. On such highly ordered and non-polar polymer surfaces use of polar and low surface tension liquids results in accurate surface energy estimation. However, use of polar probe liquids commonly employed in surface energy estimation methods, such as, Harmonic mean (HM), Geometric mean (GM) or Lewis Acid-Base method (LWAB) on polar surfaces such as polyester resulted in inconsistent surface energy values. To strengthen this observation, the ASTM surface energy estimation procedure (ASTM D2578 04a) developed for polyethylene and polypropylene surfaces (both non-polar) was employed on a sample polar polyester surface using the ASTM probe liquids. Results showed inconsistent surface energy values supporting the conclusion that care must be exercised during use of polar probe liquids in estimating surface energy on polar polymers with the contact angle hysteresis method. Finally, UV radiation cross-linkable acrylic polymer surface energies were estimated with the hysteresis method. Surface energy results were consistent based on five different probe liquids. It was observed that surface energy of the cross-linked monomer networks decreased slightly with increasing UV curing time.

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Thermodynamics of manganese oxides: Sodium, potassium, and calcium birnessite and cryptomelane

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1620427114 ◽

2017 ◽

Vol 114 (7) ◽

pp. E1046-E1053 ◽

Cited By ~ 24

Author(s):

Nancy Birkner ◽

Alexandra Navrotsky

Keyword(s):

Surface Energy ◽

Surface Area ◽

Oxidation State ◽

Manganese Oxides ◽

Lower Surface ◽

Surface Energies ◽

Surface Areas ◽

Bulk Thermodynamics ◽

Lower Surface Energy

Manganese oxides with layer and tunnel structures occur widely in nature and inspire technological applications. Having variable compositions, these structures often are found as small particles (nanophases). This study explores, using experimental thermochemistry, the role of composition, oxidation state, structure, and surface energy in the their thermodynamic stability. The measured surface energies of cryptomelane, sodium birnessite, potassium birnessite and calcium birnessite are all significantly lower than those of binary manganese oxides (Mn3O4, Mn2O3, and MnO2), consistent with added stabilization of the layer and tunnel structures at the nanoscale. Surface energies generally decrease with decreasing average manganese oxidation state. A stabilizing enthalpy contribution arises from increasing counter-cation content. The formation of cryptomelane from birnessite in contact with aqueous solution is favored by the removal of ions from the layered phase. At large surface area, surface-energy differences make cryptomelane formation thermodynamically less favorable than birnessite formation. In contrast, at small to moderate surface areas, bulk thermodynamics and the energetics of the aqueous phase drive cryptomelane formation from birnessite, perhaps aided by oxidation-state differences. Transformation among birnessite phases of increasing surface area favors compositions with lower surface energy. These quantitative thermodynamic findings explain and support qualitative observations of phase-transformation patterns gathered from natural and synthetic manganese oxides.

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Surface Energy and Wetting Behaviour of Plasma Etched Porous SiCOH Surfaces and Plasma Etch Residue Cleaning Solutions

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.145-146.319 ◽

2009 ◽

Vol 145-146 ◽

pp. 319-322 ◽

Cited By ~ 5

Author(s):

Nicole Ahner ◽

Matthias Schaller ◽

Christin Bartsch ◽

Eugene Baryschpolec ◽

Stefan E. Schulz

Keyword(s):

Surface Energy ◽

Dielectric Materials ◽

Solid Surfaces ◽

Plasma Etch ◽

Surface Energies ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Additional Process ◽

Low K ◽

Etch Residue

The removal of plasma etch residues by wet cleaning is an alternative or additional process to plasma processes, which are known to degrade low-k and ultralow-k dielectric materials. Besides Cu/low-k compatibility wetting is an important issue for wet cleaning. Surface energy of solid and liquid is the key to understand the wetting behaviour. In this study we examined the energetic character of plasma etched/stripped solid surfaces, etch polymers and several cleaning solutions by contact angle measurements. The results show, that variations of the etching process can heavily change the energetic character of the solid. Calculating the surface energies of solid and liquid provides the possibility to make a prediction if a cleaning liquid will wet the surface which has to be cleaned.

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