A New Versatile Water‐Soluble Iniferter Platform for the Preparation of Molecularly Imprinted Nanoparticles by Photopolymerisation in Aqueous Media

The multi‐step synthesis of a new water‐soluble dithiocarbamate iniferter platform for the preparation of nanoparticles and ‐gels in aqueous solvents by photoinduced living‐radical polymerisation is described herein. The water solubility of the dithiocarbamate iniferter was achieved by incorporating two unprotected glucose units into the iniferter structure by copper(I)‐catalysed azide–alkyne cycloaddition (“click chemistry”). Molecularly imprinted nanoparticles (MIPs) specific for 2,4‐dichlorophenoxyacetic acid and the corresponding non‐imprinted particles (NIPs) were prepared in pure water by using the prepared iniferter as photoinitiator. Radioligand binding tests confirmed a high imprinting factor, and the living character of the iniferter was demonstrated by re‐initiating a second photochemical polymerisation on the NIP nanoparticles in water by using ethylene glycol methacrylate phosphate. Our newly synthesised structure is a promising tool for iniferter‐mediated photopolymerisations in aqueous media for the preparation of biocompatible nanomaterials with high potential for biomedical applications in a bottom‐up fashion.     

Study of Cu,Cu-Ni and Rh-modified Cu porous layers as electrode materials for the electroanalysis of nitrate and nitrite ions

Journal of Solid State Electrochemistry - Three porous materials (Cu, a Cu-Ni alloy with 70 at.% Cu and Rh-modified Cu) have been tested as electrodes for the electroanalysis of nitrate...     

Path-integral solution of the one-dimensional Dirac quantum cellular automaton

Quantum cellular automata, which describe the discrete and exactly causal unitary evolution of a lattice of quantum systems, have been recently considered as a fundamental approach to quantum field theory and a linear automaton for the Dirac equation in one dimension has been derived. In the linear case a quantum cellular automaton is isomorphic to a quantum walk and its evolution is conveniently formulated in terms of transition matrices. The semigroup structure of the matrices leads to a new kind of discrete path-integral, different from the well known Feynman checkerboard one, that is solved analytically in terms of Jacobi polynomials of the arbitrary mass parameter.     

DNS Scrutiny of the <Emphasis Type="Italic">ζ</Emphasis>-<Emphasis Type="Italic">f</Emphasis> Elliptic-Relaxation Eddy-Viscosity Model in Channel Flows with a Moving Wall

In this paper we present a Direct Numerical Simulations (DNS) of channel flow with stationary and moving walls. Three cases, Poiseuille-type with U_W/U_b = 0.75, intermediate-type with U_W/U_b = 1.215, and Couette-type with U_W/U_b = 1.5 (U_W and U_b are the wall and the bulk velocity), were compared with the pure Poiseuille U_W/U_b = 0, at a bulk Reynolds number equal to 4,800 corresponding to Re _\uptau = 288_{\uptau} =288. The DNS results were used to scrutinize the capabilities of ζ-f eddy viscosity model (based on the elliptic relaxation concept) in reproducing the near-wall turbulence in non conventional flows where the shear stress structures are strongly different with respect to the cases used for models calibration. The ζ-f model (also in its basic formulation) demonstrated to have good prospects to reproduce the main phenomenology of such class of flows due to its built-in capabilities to account separately for the different (and opposite) near wall effects on turbulence: the damping due to viscosity and pressure reflection. The results of the computations demonstrated that standard ζ-f model can reasonably reproduce the phenomenology of these flows in terms of velocity and turbulent kinetic energy profiles and budgets.     

Boundary-layer receptivity to external disturbances using multiple scales

Non-homogeneous multiple scales are introduced to solve the resonant problem of non-parallel boundary-layer receptivity originating from the quadratic mixing of environmental disturbances. The resulting algorithm is computationally inexpensive and can be efficiently included in industrial codes for transition prediction. The mutual interactions between acoustic wave, vorticity wave, wall vibration and wall roughness are discussed in detail and the receptivity coefficient, which relates the amplitude of the excited wave to the amplitude of the exciting sources, is computed. The largest effect is found for the interaction between acoustic waves and wall roughness perturbations. Other coupling mechanisms are less effective. By comparing parallel and non-parallel results, it is found that flow non-parallelism can play a non-negligible role even in Blasius’ boundary layer, although the largest effects are evident for the three-dimensional boundary layer over an infinite swept wing. For the particular case of wall roughness—wall vibration mixing, the velocity disturbance is shown to be exactly equal to the velocity perturbation induced by wall roughness alone on a wall vibrating in the normal direction.     

Spin adducts of group IVB organometallic radicals with Thioketones. an esr study

The radical adducts resulting from the reaction between group IVB organometallic radicals MR₃ (M = Si, Ge, Sn; R = alkyl or aryl) and a number of thioketones of the chromone and flavone series have been investigated by ESR spectroscopy. The spectral parameters obtained for these species have been compared with those of similar adducts of the corresponding ketones. Both classes of radicals adopt an orthogonal conformation, and the differences between the former and the latter paramagnetic species can be accounted for by the different electronegativity of oxygen and sulphur. the effects of substitution of the heterocyclic oxygen with a sulphur or selenium atom on the spin density distribution are likewise explained. INDO calculations have been carried out on the model systems CH₂XSiH₃ (X = O, S).     

Activation of chlorobenzene as phenylating agent by means of a dinitrogen-molybdenum complex

Bis(dinitrogen)bis[1,2-bis(diphenylphosphino)ethane]molybdenum reacts with chlorobenzene to form molybdenum chloro complexes and phenylated organic products. Benzene, biphenyl, o-, m-, p-chlorobiphenyl, a dihydro derivative of o-chlorobiphenyl, triphenylphosphine and diphenylvinylphosphine were formed. The isomer distribution of the chlorobiphenyls is close to that obtained by decomposition of 0.02 M benzoyl peroxide in chlorobenzene under dinitrogen. The cleavage of the PhCl bond induced by the molybdenum-dinitrogen complex appears to give rise to the same homolytic reaction pattern. Phenylation of anisole and of triethyl phosphite has also been achieved with the same reagent.