Mimicking a Stenocara beetle's back for microcondensation using plasmachemical patterned superhydrophobic-superhydrophilic surfaces

A simple two-step plasmachemical methodology is outlined for the fabrication of microcondensor surfaces. This comprises the creation of a superhydrophobic background followed by pulsed plasma deposition of a hydrophilic polymer array. Microcondensation efficiency has been explored in terms of the chemical nature of the hydrophilic pixels and their dimensions. These results are compared to the hydrophilic-hydrophobic pattern present on the Stenocara beetle's back, which is used by the insect to collect water in the desert. Potential applications include fog harvesting, microfluidics, and biomolecule immobilization.     

Al-doped B80 fullerene as a suitable candidate for H2, CH4, and CO2 adsorption for clean energy applications

Dispersion-corrected density functional theory method was performed to report on a high-performance adsorbent for removal of CO₂ from the precombustion and natural gases. At first, the effect of Al atom impurity on the structural and electronic properties of B₈₀ fullerene is studied. Then, the adsorption geometries and energies of gases (H₂, CH₄, or CO₂) on the B₈₀ and AlB₇₉ (amphoteric adsorbents) are explored. The Al atom enhances reactivity of the cage toward the gases and the adsorption processes are more exothermic with low and high energy barriers for chemisorption of H₂ and CO₂, respectively. Stable chemisorption of CO₂ on the AlB₇₉ is validated by the high adsorption energy and large charge transfer, while the CH₄ is just physically adsorbed on the AlB₇₉. Further, the physisorbed gases can enhance field emission current of the AlB₇₉ and in the continuous capturing of the gases, the magnetic moment of the cage is quenched. Furthermore, dependency of the electronic structure of the adsorbent on the gas adsorption is intensively studied. We suggest that the AlB₇₉ could be a promising material for capture, storage, and separation of the gases and as a novel material for sustainable energy and sweetening process in the petroleum industry.     

Diels-Alder chemistry on alkene functionalized films

A substrate-independent method has been devised for ring formation at solid surfaces. This entails the aminolysis reaction of allylamine with maleic anhydride pulsed plasma polymer films to yield terminal alkene groups at the surface. Subsequent exposure to 1,3-cyclohexadiene leads to a Diels-Alder type (4 + 2) cycloaddition reaction to give a mixture of endo- and exo-bicyclo[2.2.2]oct-2-ene rings.     

Iron‐Mediated Cleavage of C?C Bonds in Vicinal Tricarbonyl Compounds in Water

Drei von einer Sorte : Vicinale Tricarbonyl‐Verbindungen gehen Eisen(III)‐vermittelte C‐C‐Spaltungen ein (siehe Schema). Die Ergebnisse sind relevant für den Aminosäurenachweis durch Ninhydrin und für den Vitamin‐C‐Stoffwechsel.

     

Electroless metallization onto pulsed plasma deposited poly(4-vinylpyridine) surfaces

Pulsed plasma-chemical deposition of poly(4-vinylpyridine) is found to be a highly effective way of functionalizing solid surfaces with pyridine ring centers. These surfaces can be metallized via complexation to Pd2+ ions from solution, followed by autocatalytic electroless deposition of either copper or nickel films.     

An overlooked series of gas phase diatomic metal oxide ions that are long-lived

Although the "Golden" years of spectroscopy and the major studies on ionization processes now are behind us, as with many branches of science, much yet remains to be gleaned from such topics that is both full of interest and of significance to present day research. Presented here is one such overlooked example, an observation that relates to both these fields. An analysis is presented for the periodic table concerning the gas-phase thermochemical nature of MO+ and MO2+ ions. Unexpectedly, a pattern of 18 elements has been identified that exhibit the potential for having long-lived MO+ ions. Normally such molecular ions are expected to decay extremely rapidly by dissociative recombination with electrons, but in particular, 12 of this group behave not like molecules but rather as atomic ions. These are the diatomic oxide ions of Sc, Y, La, Zr, Hf, Ce, Pr, Nd, Pm, Gd, Tb, and Th. In the gas phase, they decay by much slower three-body recombination channels. As may be noted, these elements are located in the first two columns of the transition elements, among the earlier rare earths and an actinide. From all the elements, UO2+ is the only dioxide ion that behaves similarly. These findings now elevate the potential importance of these ions and should facilitate their spectral characterization. Moreover, subsequent comparisons with spectra of well-known isoelectronic and isovalent neutral monoxides and other diatomics will help in the stimulation of further theoretical advances. In addition, once characterized, an ease of spectrally monitoring such ionic states will provide a useful analytical tool.     

Understanding the low-frequency quasilocalized modes in disordered colloidal systems

In disordered colloidal systems, we experimentally measure the normal modes with the covariance matrix method and clarify the origin of low-frequency quasilocalization at the single-particle level. We observe important features from both jamming and glass simulations: There is a plateau in the density of states [D(ω)] which is suppressed upon compression, as predicted by jamming; within the same systems, we also find that the low-frequency quasilocalization originates from the large vibrations of defective structures coupled with transverse excitations, consistent with a recent glass simulation. The coexistence of these features demonstrates an experimental link between jamming and glass. Extensive simulations further show that such a structural origin of quasilocalization is universally valid for various temperatures and volume fractions.