Amino acid-based surfactants were used as the main surfactants to prepare new lyotropic mixtures presenting three nematic phases. One of them is biaxial (NB), and the two others are uniaxial, discotic (ND) and calamitic (NC). These surfactants were the non-chiral molecules, potassium N-dodecanoyl-DL-alaninate (DL-KDDA), potassium N-dodecanoyl-DL-serinate (DL-KDDS), disodium N-dodecanoyl-DL-aspa...

In this work, a study of the nematic (N)-isotropic (I) phase transition has been made in a series of odd non-symmetric liquid crystal dimers, the α-(4-cyanobiphenyl-4'-yloxy)-ω-(1-pyrenimine-benzylidene-4'-oxy) alkanes, by means of accurate calorimetric and dielectric measurements. These materials are potential candidates to present the elusive biaxial nematic (NB) phase, as they exhibit both m...

We have performed a comprehensive first-principles study of the electronic and magnetic properties of two-dimensional (2D) transition-metal dichalcogenide (TMD) heterobilayers MX2/MoS2 (M = Mo, Cr, W, Fe, V; X = S, Se). For M = Mo, Cr, W; X = S, Se, all heterobilayers show semiconducting characteristics with an indirect bandgap with the exception of the WSe2/MoS2 heterobilayer which retains the...

Abstract The modification of the nature and size bandgaps for III-V semiconductors is strong interest optoelectronic applications. Strain can be used to systematically tune bandgap over a wide range values induce indirect-to-direct transition (IDT), direct-to-indirect (DIT), other changes in nature. Here, we establish predictive first-principles approach, based on density functional theory, ana...

The existence of a new two dimensional CN2 structure was predicted using ab-initio molecular dynamics (AIMD) and density-functional theory calculations. It consists tetragonal hexagonal rings with C-N N-N bonds arranged in buckling plane, isostructural to tetrahex-carbon allotrope. is thermodynamically kinetically stable suggested by its phonon spectrum AIMD. This nanosheet has high concentrati...

The optical behavior of gradient biaxial dielectrics has not been widely explored in the literature due to their complicated nature, but the extra degrees of freedom in the index tensor have the potential of yielding useful optical instruments which are otherwise unachievable. In this work, a design method is described in detail which allows one to combine the behavior of up to four totally ind...

Several unique optical properties have been obtained from freestanding films of a bent-core compound. Our experimental results indicate the existence of the antiferroelectric biaxial smectic-A (Sm A) phase. The critical exponent associated with the biaxiality through the uniaxial-antiferroelectric biaxial Sm A transition has been measured to be 0.82+/-0.04 , which is in good agreement with our ...

wileyonlinelibrary.com determined by the deformation mechanisms of the ligaments, which buckle under compression at relatively low values of strain. In elasto-plastic porous materials buckling of the beam-like ligaments results in collapse bands that progress at relatively constant stress, providing an efficient energy absorbing mechanism. [ 8–12 ] However, this deformation process cannot be ex...

Pyramidal truss sandwich cores with relative densities 4q in the range 1–10% have been made from carbon fiber reinforced polymer laminates using a snap-fitting method. The measured quasi-static uniaxial compressive strength increased with increasing 4q from 1 to 11 MPa over the relative density range investigated here. A robust face-sheet/ truss joint design was developed to suppress truss– fac...