Effect of pH,co-monomer content,and surfactant structure on the swelling behavior of microgel-azobenzene-containing surfactant complex

The contraction/swelling transition of anionic PNIPAM-co-AAA particles can be manipulated by light using interactions with cationic azobenzene-containing surfactant. In this study the influence of pH-buffers and their concentrations, the charge density (AAA content) in microgel particles as well as the spacer length of the surfactant on the complex formation between the microgel and surfactant is investigated. It is shown that the presence of pH buffer can lead to complete blocking of the interactions in such complexes and the resulting microgel contraction/swelling response. There is a clear competition between the buffer ions and the surfactant molecules interacting with microgel particles. When working in pure water solutions with fixed concentration (charge density) of microgel, the contraction/swelling of the particles is controlled only by relative concentration (charge ratio) of the surfactant and AAA groups of the microgel. Furthermore, the particle contraction is more efficient for shorter spacer length of the surfactant. The onset point of the contraction process is not affected by the surfactant hydrophobicity. This work provides new insight into the interaction between microgel particles and photo-sensitive surfactants, which offers high potential in new sensor systems.     

Synthesis and characterization of C60‐based composites of amphiphilic N‐vinylpyrrolidone/triethylene glycol dimethacrylate copolymers

It was found that under mixing of aqueous solutions of copolymers and toluene solutions of C₆₀ two types of polymer composites can be produced with different matrix structure, the fullerene content and an aggregation degree. The dimethacrylate enriched macromolecules migrate to toluene and the VP units enriched copolymer chains remain in water to form copolymer micelles and their aggregates in these media that solubilize and encapsulate the fullerene. The structure and properties of obtained polymer composites were studied by GPC with dual detection (RI and MALLS), FT‐IR, WAXS and SAXS methods. It is shown that in a composite based on N‐vinylpyrrolidone copolymer isolated from toluene the fullerene form larger particles, compare to that isolated from water. According to SAXS, the fullerene particles in a solid copolymer are organized in spherical objects with fine coil‐like structure. The stability of the composites in water, ethanol, and chloroform was shown to depend on the original polymer matrix structure and on copolymer/fullerene ratio. POLYM. COMPOS., 35:1362–1371, 2014. © 2013 Society of Plastics Engineers     

Synthesis and Properties of Hydrazino Amino Acyclic Carbenes of Gold(I), Platinum(II), Palladium(II) and Rhodium(III)

The nucleophilic addition of protected and substituted hydrazine derivatives to isonitrile complexes of gold(I), platinum(II), palladium(II) and rhodium(III) provides the corresponding hydrazino amino acyclic carbene complexes. These are characterized by their spectroscopic data, four different X‐ray single crystal structure analyses and their catalytic activity in the gold(I)‐catalyzed cycloisomerization of N‐propargylcarboxamides to alkylideneoxazolines is investigated.

     

Three-Dimensional Feedforward Neural Networks and Their Realization by Nano-Devices

The three-dimensional (3D) model of a feedforward neural network(NN) based on so called N-hypercube topology isproposed. The N-hypercube is different from theclassical hypercube used in communication theory, and in Booleanalgebra. This new structure has been created based on a novelalgorithm for embedding a binary decision tree and binary decisiondiagram into a N-hypercube. It is shown thatN-hypercube topology is a reasonable solution toimplement NN of threshold gates, in particular, on thesingle-electron devices. The 3D design methodology of feedforwardNN is oriented to technology mapping to nanodevices. Results ofextensive experimental study of feedforward networks consistingof over 3500 N-hypercubes are presented.     

Olfactory coordinated area coverage

This paper proposes an olfaction based methodology to automatically cover an unknown area enabling the decoupled cooperation of a group of floor cleaning mobile robots. This method is based on the utilisation of low cost chemical sensors in cleaning mobile robots, in order to differentiate clean from dirty areas. The experimental results show that the use of olfactory capabilities allows to efficiently cover and clean a certain area, and demonstrate the possibility of coordinating several mobile robots without the need of expensive sensing capabilities, map building or complex algorithms for task scheduling.     

Electronic fingerprints of DNA bases on graphene

We calculate the electronic local density of states (LDOS) of DNA nucleotide bases (A,C,G,T), deposited on graphene. We observe significant base-dependent features in the LDOS in an energy range within a few electronvolts of the Fermi level. These features can serve as electronic fingerprints for the identification of individual bases in scanning tunneling spectroscopy (STS) experiments that perform image and site dependent spectroscopy on biomolecules. Thus the fingerprints of DNA-graphene hybrid structures may provide an alternative route to DNA sequencing using STS.     

A.c.conduction mechanisms in poly(1-ethynylnaphtalene)

Summary The a.c.conduction mechanism in poly(1-ethynylnaphtalene) with various physical and isomeric (cis-cisoidal and trans-cisoidal) structures was investigated over the frequency and temperature ranges of 10–10⁵Hz and 190–373°K respectively.The conduction mechanism depends on the isomeric structure of the polymer,and for the cis-cisoidal polymer supplementary on temperature and frequency.Over the whole frequency range(at 190°K) and above a critical frequency (at higher temperatures),which is temperature dependent,the quantum hopping mechanism is involved in cis-cisoidal polymer.Outside of this range the conduction process takes place by two parallel mechanisms: band and hopping mechanisms.In trans-cisoidal polymer the quantum hopping mechanism is involved over the whole frequency and temperature range considered.     

Dynamics of autowaves in a one-dimensional crystal model

A mechanism of the phase transition between two modulated structures with different wave vectors was proposed and investigated numerically. The phase transition occurs through the mechanism of nucleation and growth of the new phase. The role of the nucleus is played by an unstable domain wall and the domain of a new low energy phase grows due to the motion of autowaves.