Empirical Correlation and Validation of Lateral Size-Dependent Absorption Coefficient of Graphene Oxides

2017 ◽  
Vol 2 (31) ◽  
pp. 10004-10009 ◽  
Author(s):  
Subrata Pandit ◽  
Mrinmoy De
2020 ◽  
Vol 10 (16) ◽  
pp. 5570
Author(s):  
Bongjin Chung ◽  
Sunghwan Jin ◽  
Junyoung Jeong ◽  
Giyoung Jeon ◽  
Seongwoo Ryu

We report the preparation of a highly-oriented graphene-based film prepared from liquid crystal dispersion of graphene oxides (GOs). We observed that the liquid crystal behavior of GOs is highly affected by the lateral size of GO flakes: the critical concentration for liquid crystal formation decreased with the increase of the lateral size of GO flakes, which is in a good agreement with Onsager’s theory. As a result, we were able to obtain highly-ordered graphene assemblies with large-sized GO flakes (150 ± 29 μm) at relatively low concentrations. By applying the shear force, we were able to obtain highly-oriented films from liquid crystal GO flakes. After hydrogen iodide (HI) reduction, GO films showed excellent mechanical strength and electrical conductivity, which were 278% and 283% higher, respectively, than those of films made from smaller sized GO flakes (28 ± 24 μm).


2013 ◽  
Author(s):  
Manoranjan Ghosh ◽  
Karabi Ghosh ◽  
Seema Shinde ◽  
S. C. Gadkari

2021 ◽  
Author(s):  
◽  
Geoffry Laufersky

<p>Indium phosphide (InP) nanomaterials are attractive for countless technological applications due to their well-placed band gap energies. The quantum confinement of these semiconductors can give rise to size-dependent absorption and emission features throughout the entire visible spectrum. Therefore, InP materials can be employed as low-toxicity fluorophores that can be implemented in high value avenues such as biological probes, lighting applications, and lasing technologies. However, large scale development of these quantum dots (QDs) has been stymied by the lack of affordable and safe phosphorus precursors. Syntheses have largely been restricted to the use of dangerous chemicals such as tris(trimethylsilyl)phosphine ((TMS)₃P), which is costly and highly sensitive to oxygen and water. Recently, less-hazardous tris(dialkylamino)phosphines have been introduced to produce InP QDs on par with those utilizing (TMS)₃P. However, a poor understanding of the reaction mechanics has resulted in difficulties tuning and optimizing this method.  In this work, density functional theory (DFT) is used to identify the mechanism of this aminophosphine precursor conversion. This understanding is then implemented to design an improved InP QD synthesis, allowing for the production of high-quality materials outside of glovebox conditions. Time is spent understanding the impact of different precursor salts on the reaction mechanisms and discerning their subsequent effects on nanoparticle size and quality. The motivation of this work is to formulate safer and less technical indium phosphide quantum dot syntheses to foster non-specialist and industrial implementation of these materials.</p>


2002 ◽  
Vol 2 (6) ◽  
pp. 645-652 ◽  
Author(s):  
D. Nesheva ◽  
Z. Levi ◽  
Z. Aneva ◽  
I. Zrinscak ◽  
C. Main ◽  
...  

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