ABSTRACT
The fascinating characteristics of one-dimensional van der Waals crystals (V-VI-VII) enable their wide functionality. In particular, their anisotropic carrier transport and low thermal conductivity are advantageous from a thermoelectric viewpoint. In a quest for the "electron crystal phonon glass" paradigm, the present work investigated the thermoelectric performance of BiSBr. Deep insights were gained into the structural and electronic properties that revealed the synergetic effect of the bonding heterogeneity, lone pair of electrons, and degenerated bands that accelerated favorable transportation. Consequently, a low lattice thermal conductivity (0.225 W m-1 K-1) and considerable power factor (3.471 mW m-1 K-2) and thus a high zT of 2.34 were noted in the x-direction (perpendicular to the chain) at 500 K in the case of the material with 1.5 × 1020 holes per cm3. These observations suggest that BiSBr is a plausible near-room-temperature anisotropic thermoelectric mineral.
ABSTRACT
The pressure induced structural, electronic, transport, and lattice dynamical properties of ZnGa2Te4 were investigated with the combination of density functional theory, Boltzmann transport theory and a modified Debye-Callaway model. The structural transition from I4Ì to I4Ì2m occurs at 12.09 GPa. From the basic observations, ZnGa2Te4 is found to be mechanically as well as thermodynamically stable and ductile up to 12 GPa. The direct band gap of 1.01 eV is inferred from the electronic band structure. The quantitative analysis of electron transport properties shows that ZnGa2Te4 has moderate Seebeck coefficient and electrical conductivity under high pressure, which resulted in a large power factor of 0.63 mW m-1 K-2 (750 K). The ultralow lattice thermal conductivity (â¼1 W m-1 K-1 at 12 GPa) is attributed to the overlapping of acoustic and optical phonon branches. As a result, the optimal figure of merit of 0.77 (750 K) is achieved by applying a pressure of 12 GPa. These findings support that ZnGa2Te4 can be a potential p-type thermoelectric material under high pressure and thus open the door for its experimental exploration.
ABSTRACT
Lumican, an extracellular matrix protein avails wound healing by binding to ALK5 membrane receptor (TGF-beta receptor I). Their interaction enables epithelialization and substantiates rejuvenation of injured tissue. To enrich permanence of ALK5-lumican interaction, we employed graphene and graphene oxide co-factors. Herein, this study explicates concomitancy of graphene and graphene oxide with ALK5-lumican. We performed an in silico approach involving molecular modelling, molecular docking, molecular dynamics for 200 ns, DSSP analysis and MMPBSA calculations. Results of molecular dynamics indicate cofactors influential in altering bioactive site of lumican than ALK5. Similarly, MMPBSA calculations unveiled binding energy of apoenzyme as -108.09 kcal/mol, holoenzyme (G) as -79.20 kcal/mol and holoenzyme (GO) as -114.33 kcal/mol. This concludes graphene oxide lucrative in enhancing binding energy of ALK5-lumican in holoenzyme (GO) via coil formation of Lum C13 domain. In contrast, graphene reduced binding energy of ALK5-lumican in holoenzyme (G) modifying Lum C13 into beta sheets. MMPBSA residual contribution analysis of Lum C13 residues revealed binding energy of -13.9 kcal/mol for apoenzyme, -6.8 kcal/mol for holoenzyme (G) and -19.5 kcal/mol for holoenzyme (GO). This supports coil formation propitious for better ALK5-Lum interaction. Highest SASA energy of -21.05 kcal/mol of holoenzyme (G) assures graphene reasonable for improved ALK5-lumican hydrophobicity. As per the motive of the study, graphene oxide enriches permanence of ALK5-lumican. This provides counsel for plausible exploitation of lumican and graphene oxide as targeted/nano drug delivery system to reinstate acute wounds, chronic wounds, corneal wounds, hypertrophic scars and keloids in near future. Communicated by Ramaswamy H. Sarma.