Journal of Physical and Theoretical Chemistry
Volume:7 Issue: 2, Summer 2010

Biological materials. recently. are the building blocks of several self-assembling peptide and protein systems.The main challenge In molecular self-assembly is to design molecular building blocks that can undergospontaneous organization. These cyche peptides were produced by an alternating fl'ell number of D- and Laminoacids.which interact through non-covalent interactions co an array of selfassembleil nanotubes.Physicochemical properties of structure of some peptide nanodngs in couple form. with the support of abiocompatible and biodegradable polylactic acid. (PLA) have been calculated by quantum mechanicalcalculations within the Onsager self-consistent reaction field (SCRI) model using a Hartree-Fock method(RHF) at the RH tiSTO-30 (5D-7F) level in water medium at 310 K. Four rings, Cycle g(D-Gly-L-Glyhj (A),Cyclo (D-Gly-L-Ala)3] (B). Cyclo [-(D-Gly-L-aminoGly)s (C). Cycle [-(D-Oly-L-hydroxyGly)3] (0). aredesigned in a couple form and geometrically optimized near by the 1.3 and 6 polylactic acid. (PLA) support,with non-covalent interaction. Analyzing the geometncal position of polylactic acid chain, around the couplednano system, results the PLA is preferred to stand in the distance of 4 A of AA, 2-5 A for AB and 12 A or bothBC and Al'. The stability of some systems, could not be affected in the wide range of distances such as. AC inI-10 A, BB in 3-12 A. CC in 4-12 A and both CD and DO in the 2-12 A. DO nano system presents the best inall conditions where CC. BD and AD couples stand in the second rank BC and AC stand after. The stability ofAA, AB and BB are less. Although no effect in behavior of nano systems are seen, increasing the number ofsupports make them more stable. Conung near and go far, the PLA aflbcts the dipole moment of system, deeply,

The effect or temperature on the behavior of Cu(II) Mr electrode based on bis(N-sahcylidenc-3.3'-4iaminodiphenyl) sulfune(BSDDS) was studied. This electrode showed a good Nemstian response in the temperaturerange of 20-50 C. Also, the behavior of the synthesized electrode was inngigated in the mixed solvents'ethanol+water" and "dioxane +water'.

The present study deals with the decolorization of CI Acid Red SR (ARAN as a model contaminant from textileindustry using sawdust as an adsorbent. The effects of initial AR88 concentration, adsorbent dosage, pH. c not acttime and ',riming rah: wcrg studied in a batch mode. The variation of pH from 3 to 10 showed no considerablechange in decolorization rate. The desired conditions for decolorization or 84.46% were obtained to be 20 minof contact time, stirring rate of 400 rpm with 30 g L."' of adsorbent. Freundlich, Redlich-Peterson and Langmuiradsorption models were used for the mathematical description of the equilibrium data and the equilibriumprocess confirmed well with all the models attaining corn:611On Csaciduittnts 0.970, 0.96V and 0.958.respectively. The results also revealed that the adsorption kinetics obeys pseudo-second order and it wasconcluded that intra-particle diffusion model is not the rate determining step.

Interaction of Pb(II) ion with modified banana shell (MBS) and banana shell (BS) during adsorption fromaqueous solution were investigated. Batch experiments were carried out to investigate the effect of contact time,pH, and IDMID ion concentration on adsorption efficiency. The favorable pll for maxim= Pb(II) adsorptionwas at 5.0. For the investigated IMOI) concentrations (10-80 mph), maximum adsorption vacs were achievedalmost in the 100 min of contact. Lanpnuir, Freundlich, and Redlich-Peterson were fitted to equilibrium datamodels. According to values of error functions and correlation coefficient, the Langmuir and Redlich-Petersonmodels were mon: appropriate to describe the adsorption of Pb(II) ions on MRS and BS. The monolayermaximum adsorption capacity of Pb(II) ions was determined as 104.2 and 453 mgig for MRS and BS.respectively. Results indicated that theSc adsorbents had a great potential for removing of Pb(11) ions as an ecofriendlyprocess

The CuNiCA nanopanicles have been synthesized by sol-gel auto-combusson. microwave and co-precipitationtechniques. Then, the results of the three techniques were compared. In the vol-ael auto-combustion synthesiswas used glycine as a fuel. At first, sol was prepared. Then, gel was achieved from drying so'. The prepared gelwas burnt at 350°C. In the noicrowavc technique, gel was prepared. Then, the final nanoparticles were producedon influence of microwave irradiation. The CuNiO2 nanoparticles 'ere prepared by co-pAcipitation methodinvolved metal sulfates The temperature of calcmations was 620T. These minoparticles were investigated byX-ray diffraction (XRD) and Scanning Plectmn Microscopy (SEM) techniques. The XRD results show that thenangeryssil eon tat iis various phases. stnictures and the average size of MilliThIMCIIMA CuNi0: cry stallities wascalculated by Scherer equation. Scanning Electron Microscopy was also used to characterize the microstnic tareand morphology.

In lb is research, adsorption of some amino acids and their complenation with manganese (II) ion on carbonnanotube (MWCNT) by using of four relations Langmuir, Freundlich. Temkin and Harkins -Jura imitherms wasinvestigated. From this relations. Freudlich and Temkin relations predict good equilibrium diagram in, isothermcondition. we could compute the theoretical constants by excel software. Hy considering these constants, it isclear that among amino acids used and also amino acids %yam formed complex. L-phenylalanme and LusaWinein comparison with other showed the most adsorption on carbon nanotube.

Polyaniline and polyamide (nylon 6,6) nanocomposites with Silva were prepared by in-situ oxidativepolymerization of aniline monomers in the presence of Ag salt Nano particles of silver (NPs) were symthesieedby controlled reduction of Ag+ ions kith sodium borohydride at room temperature. Nylon 6,6 wax loaded withAg nanoparfieles by erdrapment of Ag+ ions into the polymer network, followed by reduction. Thenanocomposiles were characterized by scanning electron microscopy (SEN) UN—Vis spectroscopy and FT-IR spectroscopy

In this research. CO gas molthules were approached to single-wall carbon nanotube (SWNT) and (6,0) CNTsurface from carbon side and oxygen side in three states (top, bridge, centre) and two shapes ( erlica I.horizontal), then adsorption energies were calculated by B3TYP/6-310 B3LYPI3-216" and Hge3-210"methods after that they were compared m order to obtain the most stable adsorption state. OFT and IIF methodswere compared and the better method was selected. Also two basis sets were compared. Besides, the bondlength of gas molecule was changed by CAUSSIAN 03 program and was calculated by B3LYP with the bansset of 3-2I G" for the nanumbe and gas molecules. Next CO, NO. H2 CO: molecules were passed through thenanotube with different intervals and the adsorption energies for SWNT and NO. CO, H1 and (:01 moleculeswere compared and then calculated using B3LY P /6-310 So the same process was repealed for CO moleculesusing basis set 3-21 CS and adsorption energies on the inside and outside surface of the nanotuhe werecompared.

A new hydroxylamine sensor has been fabricated by immobilizing oxadiazol denvative at the surface ol aglassy carbon electrode (GCE) modified by multi-wall carbon nanotube (MIVCNT). The adsorbed thin Illms oroxadiazol derivative on the MWCNT modified GCE show a pair of peaks with surface confined characierisnus.The oxadiazol derivative MWCNI (OMWCNT) modified GCE shows highly catalytic activity togurdelectrooxidation of hydroxylamine. The results show that the peak potential of hydroxylamine at OMWCNTmodified GCE surface shifted by about 331 and 346 my toward nevative values compared with those orMIVCNT and activated OCE surface. respectively. In addition. the sensitivity of hydroxylamine determinationis improved remarkably by OMWCNT modified electrode. The kinetic parameters, such as the electron transfercoefficient, a. the standard heterogencouq rate constant, kg and exchange current. i0, for oxidation orhydroxylamtne at the OMWCNT modified GCE (041WCH1-GCE) were determined by cyclic voltainmcirymeasurements. Also &fusion coefficient of hydroxylamine was determined as 4.05 g l0 ctn2 s I by usiagchronoamperometry technique. Furthermore, the linear dynamic range (2 0-600.0 pM), sensitivity and detectionlimit (0.61 pM) for hydroxylamine determination was evaluated using differential pulse voltammary. Excellentelectrochemical reverkibility of the redox couple. technical simplicity, good electrocatalytic activity forhydros ylamine and good reproducibility are the advantages of this modified electrode. ginally. the activi” ofOAIWCNT-UCE ...as also investigated for hydroxylamine determinatm on in two natural water samples.

The X-ray charge density analysis of a hydroxynaphthoquinnne derivative was obtained by multipolar Hansen-Coppens formalism refinement through high resolution X-ray diffraction data at 100(1) K. The molecularproperties of the title compound resulted from the combined experimental and the quantum theory of atoms inmolecules (QTAIM) studies. The topological properties of the covalent bonds and of the hydrogen bonds havebeen investigated.