Synthesis and application of some novel functional polymers via controlled radical polymerization and click chemistry

The objective of this thesis was to prepare thermoresponsive PEG-based homopolymers and copolymers by combination of cobalt-mediated catalytic chain-transfer polymerization (CCTP) and thiol-ene “click” chemistry and prepare well-defined glycopolymers via “living” polymerization and “click” chemistry. The effect of different catalysts for the nucleophilic mediated thiol-ene reaction was investigated using model compounds, both monomers and oligomers obtained by CCTP. Different catalysts, including pentylamine and hexylamine (primary amines), triethylamine (tertiary amine), and two different phosphines, dimethylphenylphosphine (DMPP) and tris(2-carboxyethyl) phosphine (TCEP), were investigated in the presence of different thiols. The optimum reaction conditions for nucleophile mediated thiol-ene click reactions were investigated. Thermoresponsive PEG-based homopolymers and copolymers of OEGMEMA obtained by CCT were modified using thiol-ene click chemistry with a variety of different functional thiol compounds to yield functional thermoresponsive polymers in high yield. The effect of different solvent systems for based catalyzed thiol-ene reaction was investigated in the presence of different functional thiols. The ATRP polymerization of TMS-PgMA and TIPS-PgMA and ROP polymerization of aliphatic polyester were investigated. A maleimide functional initiator was used in order to achieve post conjugation of nanoparticles for drug delivery. Moreover, the disulfide based bifunctional initiator was introduced into the midpoint of the polymer chain, which could break down to afford the corresponding polymer chain with thiol end group under the reducing condition. The thiol-terminated polymer was also post-functionalized via thiol-ene click chemistry. In addition, the aliphatic polycarbonate is a biocompatible and biodegradable polymer, which is widely used in medical and pharmaceutical applications. The subsequent introduction of sugar moiety to the reactive polymer chain via CuAAC click reaction and then the interactions between glycopolymers and lectins were investigated by Surface Plasmon Resonance (SPR) and Quartz Crystal Microbalance with Dissipation (QCM-D). The controlled SET-LRP polymerization of TMS-PgMA and SET-RAFT polymerization PgMA with the intact alkyne at ambient temperature were investigated. A maleimide functional initiator and CPDB, as the chain transfer agent have been employed. The introduction of maleimide moiety was to allow for post polymerization conjugation to peptides via reaction with cysteines. The subsequent introduction of sugar azides to click with the reactive polymer containing alkyne group and the glycopolymers through CuAAC was also investigated. The glycopolymer has been successfully prepared combining the SET-LRP/SET-RAFT and CuAAc click chemistry at ambient temperature

3-(4-Carb­oxy-5-carboxyl­ato-1H-imidazol-2-yl)pyridin-1-ium monohydrate

In the zwitterionic mol­ecule of the title compound, C10H7N3O4·H2O, one carboxyl group is deprotonated and the pyridine N atom is protonated. The pyridinium and imidazole rings form a dihedral angle of 5.23 (1)°. An intramolecular O—H⋯O hydrogen bond occurs. In the crystal, inter­molecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds link the zwitterions and water mol­ecules into sheets parallel to (102)

Microscopic and self-consistent description for neutron halo in deformed nuclei

A deformed relativistic Hartree-Bogoliubov theory in continuum has been developed for the study of neutron halos in deformed nuclei and the halo phenomenon in deformed weakly bound nuclei is investigated. Magnesium and neon isotopes are studied and some results are presented for the deformed neutron-rich and weakly bound nuclei 44Mg and 36Ne. The core of the former nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed.Comment: 7 pages, 2 figures; invited talk at the XXXV Brazilian Workshop on Nuclear Physics, Sep 2-6, 2012, Maresias, Brazi

Halos in a deformed Relativistic Hartree-Bogoliubov theory in continuum

In this contribution we present some recent results about neutron halos in deformed nuclei. A deformed relativistic Hartree-Bogoliubov theory in continuum has been developed and the halo phenomenon in deformed weakly bound nuclei is investigated. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nuclei 42Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed.Comment: 6 pages, 2 figures; invited talk at the 2nd Int. Conf. on Nuclear Structure & Dynamics (NSD12), Opatija, Croatia, 9-13 July 201

State Estimation for Discrete-Time Fuzzy Cellular Neural Networks with Mixed Time Delays

This paper is concerned with the exponential state estimation problem for a class of discrete-time fuzzy cellular neural networks with mixed time delays. The main purpose is to estimate the neuron states through available output measurements such that the dynamics of the estimation error is globally exponentially stable. By constructing a novel Lyapunov-Krasovskii functional which contains a triple summation term, some sufficient conditions are derived to guarantee the existence of the state estimator. The linear matrix inequality approach is employed for the first time to deal with the fuzzy cellular neural networks in the discrete-time case. Compared with the present conditions in the form of M-matrix, the results obtained in this paper are less conservative and can be checked readily by the MATLAB toolbox. Finally, some numerical examples are given to demonstrate the effectiveness of the proposed results