Abstract The chemical characteristics of spent wash, an effluent from the distillation of ethanol from molasses, can vary, depending on the initial feed stock and the operations of the factory. Spent wash from Australia contained large quantities of dissolved organic carbon (DOC), K, N and Cl with moderate to low concentrations of Ca, Mg, Na, and S, and small amounts of trace elements (Fe, Al, Mn, Cu, Zn). Spent wash from Thailand was obtained from whisky distillation and generally had similar chemical attributes to the spent wash from ethanol production, although the Zn concentration was much higher (399-974 mg Zn L-1). Large differences in EC and pH were found between Australian (pH: 4.08-4.49; EC: 40.4-42.2 dS m-1) and Thai spent wash (pH: 7.86-9.20; EC: 11.3-82.4 dS m-1). However, the high concentration of K in spent wash from both manufacturing processes indicates the unique chemical characteristic of wastewater produced from molasses-based distillation. While chemical characterisations of spent wash have shown its potential value as a fertilizer, its utility needs to be more practical than by direct application. This is due to its dilute nature, associated with the presence of organic carbon (OC) and nutrients in soluble form, thus making direct application susceptible to leaching losses of nutrients, especially in soils of low cation exchange capacity (CEC). It was hypothesized that capturing OC and nutrients on a high activity exchanger would overcome this problem. Since the charge on organic components in spent wash is important to the capturing process, pH manipulation is one of the major factors affecting the efficiency of this capture. The study of the influence of pH on development of charge on organic components in spent wash was undertaken using potentiometric titration. The potentiometric titration, and derived pH buffer curve, showed that the organic components in spent wash comprised a wide range of ionizable organic functional groups behaving like a mix of weak acids. While the inflection point (s) could not be obtained from the potentriometric titration, the absorbance of spent wash in the UV waveband (250 to 400 nm) confirmed the presence of phenolic groups in spent wash. The charge on organic components in spent wash was strongly pH dependent, and highest in the pH range of 4.0-5.0. The manipulation of pH and salt concentration (EC) was shown to have an effect on flocculation/dispersion and it is inferred that this was due to changes in the molecular arrangement of organic components in spent wash. A coiled configuration is suggested at acidic pH, whereas a linear flexible configuration and macromolecular structure tending to occur at neutral and alkaline pH respectively. Ca-saturated bentonite, originally sourced from Mantuan Downs, Central Queensland, was used in an investigation of the capture of OC and nutrients from Sarina spent wash at different pH values (4.5, 6.0, 8.0). This study demonstrated that manipulation of pH and electrolyte concentration had a small effect on adsorption of OC by the clay, probably the result of effects on the charge characteristics of both clay mineral surfaces and organic molecules and also on molecular sizes of the dissolved organic matter (DOM). The highest absorption of OC was only 28% for dewatered spent wash, suggesting Ca-saturated bentonite may not be a strong sorbent for DOM from a wastewater of high EC and which contains high concentration of DOC of the composition found in spent wash. The study of the adsorption of K by bentonite in a pure inorganic system (without DOM) indicated sufficiently high concentrations of K can compete with divalent Ca2+ for exchange sites on the clay surface. The adsorption of K in an organic system (the DOM component in spent wash) showed that DOM had a positive influence on adsorption of inorganic ions (e.g. K+). Characterisation of the spent wash/ clay mixture demonstrated its potential to be used as a soil ameliorant on the basis of the large quantity of OC and nutrients it contained (especially N and K). Wet and dry organic clays were produced and assessed as ameliorants in a glasshouse trial using forage oat (Avena sativa var. Coolobah) as test species. This pot study indicated a positive influence of application of either wet or dry organic clay on crop biomass at the high application rate (equivalent to 40 tonnes ha-1). The high proportional K recovery from this high application rate application suggests that organic clays can be used as K fertilizer. The crop nutrient uptake data also indicated its use as a source of S and Mn.

Made available in DSpace on 2014-07-29T15:07:11Z (GMT). No. of bitstreams: 1 Dissertacao_Jose_Sousa_Junior.pdf: 1029134 bytes, checksum: fbc7b3b1f9f5739dfceb85efc46fbb23 (MD5) Previous issue date: 2009-04-24 / We present the structural study, by x-rays diffraction, of two forms on the crystalline and molecular structures of the metal-organic single-crystal compounds Dicloro[N- benzoyl-N´-(4-methylphenyl)-N´´-(2-pyridinyl)-guanidine)]copper(II). Such compound is known for the phenol oxidative catalictic bioactivity. The compound is a copper(II)-guanidine de- rivative complex. The main motivation of the present work is the polimorphism observed on such complex when the crystallization conditions are changed. The structures were sol- ved using the Direct Methods method and the structural parameters were refined with full matrix least-squares method. The copper(II) complex C19H22Cl2CuN4O crystallizes in the triclinic system in the P¯1 space group, with a single molecule in the assymetric unit and unit cell parameters: a = 8.616 (3) °A, b = 9.288 (3) °A, c = 13.623 (2) °A, α = 106.96 (2)o, β = 96.02 (3)o, γ = 100.60 (2)o, with volume 1010.3 (5) °A3 and calculated density of 1.528 Mgm−3. The same compound also crystallizes in the monoclinic system in the P21/n space group and unit cell parameters: a = 7.937 (2) °A, b = 18.727 (2) °A, c = 13.993 (2) °A, β = 102.03 (2)o, with volume 2034.2 (6) °A3 and calculated density 1.518 Mgm−3. The two isomeric molecules showed different conformations from one crystal packing to the other, due to the different intermolecular interactions. Given the different crystal packing and intermolecular interactions, we performed electronic structure calculations using the Density Functional Theory in order to derive the energetic differences, including calculations of dimers linked by hydrogen bonds, for evaluating the crystal packing influence on the complex stability in their crystal structures. / Apresentamos um estudo estrutural, por difra¸c ao de raios X, das estruturas cris- talinas e moleculares de um composto metalorg anico no estado monocristalino Dicloro [N- benzoil-N´-(4-metilfenil)-N´´-(2-piridinil)-guanidina)] Cobre(II). O qual apresenta atividade biol´ogica de cat´alise do processo de oxida¸c ao de fen´ois. O complexo ´e de cobre(II) com um derivado do grupo qu´ımico org anico guanidina. A motiva¸c ao ao exposto nesta disserta¸c ao foi a ocorr encia de duas formas polim´orficas do complexo supracitado variando-se as condi¸c oes de cristaliza¸c ao. As estruturas foram resolvidas utilizando o M´etodo Direto e para o re- finamento dos par ametros t´ermicos usou-se o m´etodo dos m´ınimos quadrados de matriz completa. O complexo de cobre(II) C19H22Cl2CuN4O foi cristalizado no sistema cristalino tricl´ınico, no grupo espacial P¯1, com uma mol´ecula independente por unidade assim´etrica e par ametros de cela: a = 8,616 (3) °A, b = 9,288 (3) °A, c = 13,623 (2) °A, α = 106,96 (2)o, β = 96,02 (3)o, γ = 100,60 (2)o com volume de 1010,3 (5) °A3 e a densidade calculada 1,528 Mgm−3. O mesmo composto cristalizou-se no sistema cristalino monocl´ınico, no grupo espacial P21/n, em que foi observada uma mol´ecula por unidade assim´etrica com par ametros cela unit´aria: a = 7,937 (2) °A, b = 18,727 (2) °A, c = 13,993 (2) °A, β = 102,03 (2)o, volume 2034,2 (6) °A3, densidade calculada 1,518 Mgm−3. Estruturalmente id enticas as mol´eculas apresentaram diferentes conforma¸c oes moleculares e seus dois empacotamento apresentaram intera¸c oes intermoleculares bastante distintas. Em fun¸c ao dos diferentes arranjos cristalinos e das diferentes intera¸c oes intermoleculares, foram feitos c´alculos de estrutura eletr onica com a Teoria do Funcional Densidade para inferir as diferen¸cas energ´eticas, incluindo d´ımeros que interagem por pontes de hidrog enio, com o objetivo de avaliar a influ encia do empacotamento cristalino na estabilidade do complexo nas estruturas cristalinas.

Durant les 15 dernières années, le couplage fort lumière-matière avec des matériaux organiques a attiré un intérêt croissant, notamment à cause des valeurs extrêmes que peut atteindre l'écart énergétique entre les modes couplés dans ces systèmes. Ces modes couplés sont des hybrides lumière-matière, aussi appelés états polaritons et notés habituellement P+ et P-. La valeur de I' écart énergétique entre les modes couplés, également appelé énergie de Rabi-splitting, est provoqué par une transition efficace de dipôle moments entre des molécules et aussi par des cavités ou des plasmons en surface de petits volumes en mode de micro-Fabry-Pérot métalliques (FP) qui sont utilisés dans ces études. Rabi-splittings - 1eV représente souvent une fraction importante de l'énergie de transition électronique, dans ce cas, le système est appelé dans le régime de couplage ultra-forte. Dans ce régime, la physico-chimie des molécules ou des propriétés des matériaux du système couplé peuvent être modifié. En effet, d'effet a déjà été montré sur les voies de relaxation dans le système couplé, les taux de réactions photochimiques, le travail d'extraction et de la conductivité des semi-conducteurs organiques dans l'obscurité, entre autres choses. Une étude récente a pu montrer que l'énergie de l'état non-excité dans une étude thermodynamique peut également être décalée dans le régime de couplage ultra-fort. De plus, le couplage fort ne se limite pas à des transitions électroniques, mais peut aussi être utilisé pour perturber les vibrations de l'état non-excité de molécules dans la région infrarouge. Tous ces résultats montrent que le couplage fort en lumière-molécule a beaucoup de potentiel pour le matériel et la science moléculaire et mérite donc une étude plus approfondie. / Over the past 15 years, light-matter strong coupling involving organic materials has been of increasing interest due to the very large energy splitting such systems exhibit between the two hybrid light-matter states, also known as the polaritonic states typically denoted P+ and P-. The large energy splitting, so-called Rabi splitting, is the result of the high transition dipole moments of the molecules and the small mode volumes of micro-metallic Fabry-Pérot (FP) cavities or surface plasmons used in these studies. Rabi-splittings -1 eV have been observed, often representing a significant fraction of the electronic transition energy in which case the system is said to be in the ultra-strong coupling regime. ln this regime the physical chemistry of molecules or the properties of materials of the coupied system should be modified. lndeed, it has already been shown to affect the relaxation pathways in the coupled system, the rates of photochemical reactions, thework-function and conductivity of organic-semiconductors in the dark, among other things. A recent thermodynamic study demonstrated that the ground state energy can also be shifted in theultra-strong coupling regime. Moreover, the strong coupling is not limited to electronic transitions, but also can be used to perturb the ground-state vibrations of molecules in the infrared region. Ali these results suggest that light-molecule strong coupling has much potential for material and molecular science and therefore merits further study.

Membrane transport processes underlie many purification technologies. The efficiency of a membrane separation process depends upon material throughput (flux), and the degree to which the membrane discriminates amongst species in the feed stock (selectivity). In a supported liquid membrane, flux may be enhanced by carrier molecules, which act as catalysts of translocation. Carrier molecules also confer selectivity, via differential molecular recognition of the substances in the feed stock. The effect of electrical potential on the flux and selectivity of carrier-containing supported liquid membranes is not well documented. We elected to study the effect of electrical potential on supported liquid membranes containing valinomycin, a potassium ionophore, and a calixarene ester, a sodium ionophore. In these systems, the open circuit membrane potential could be made positive or negative by the choice of anion. With both of these carriers, we observed that selectivity for potassium or sodium salts was dependent on the open circuit membrane potential. To confirm that electrical potential was responsible for the observed selectivity variance, we applied a potential across the membrane using a potentiostat. The applied potential created conditions for carrier-mediated electrodialysis, where oxidation and reduction reactions on either side of the membrane act as the driving force for transmembrane flux of charged species. In chronoamperometry experiments, we found that selectivity for potassium or sodium ion was dependent on the applied electrical potential. Subject to some constraints, selectivity and flux could be controlled by the application of positive or negative electrical potentials. Linear sweep voltammetry experiments allowed for the rapid prediction of the potential that must be applied to achieve optimal selectivity. We also found that membrane potential measurements, as well as the magnitude of current that flows in chronoamperometry experiments, could be interpreted to predict Eisenman and Hofmeister sequences. These results are novel, and await a convincing theoretical justification. The results also suggest that a separation technology could be developed around the idea of modulating selectivity with electrical potential. In this regard, carrier-mediated electrodialysis may be suitable for the sequestration of toxic or radioactive heavy metals, and a large number of carrier molecules for metal ions are currently known. The technique may also be suitable for separating organic molecules, such as high-value chiral pharmaceuticals. Supported liquid membranes are a useful research tool, but industrial applications may require a more stable membrane architecture. / Graduate

A coupling-limited approach for the Ullmann reaction-like on-surface synthesis of a two-dimensional covalent organic network starting from a halogenated metallo-porphyrin is demonstrated. Copper-octabromo-tetraphenylporphyrin molecules can diffuse and self-assemble when adsorbed on the inert Au(111) surface. Splitting-off of bromine atoms bonded at the macrocyclic core of the porphyrin starts at room temperature after the deposition and is monitored by X-ray photoelectron spectroscopy for different annealing steps. Direct coupling between the reactive carbon sites of the molecules is, however, hindered by the molecular shape. This leads initially to an ordered non-covalently interconnected supramolecular structure. Further heating to 300 °C and an additional hydrogen dissociation step is required to link the molecular macrocycles via a phenyl group and form large ordered polymeric networks. This approach leads to a close-packed covalently bonded network of overall good quality. The structures are characterized using scanning tunneling microscopy. Different kinds of lattice defects and, furthermore, the impact of polymerization on the HOMO–LUMO gap are discussed. Density functional theory calculations corroborate the interpretations and give further insight into the adsorption of the debrominated molecule on the surface and the geometry and coupling reaction of the polymeric structure. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

This work presents applications of an ab-initio molecular dynamics method, the so-called nonadiabatic quantum molecular dynamics (NA-QMD), for various molecular systems with many electronic and nuclear degrees of freedom. Thereby, the nuclei will be treated classically and the electrons with time-dependent density functional theory (TD-DFT) in basis expansion. Depending on the actual system and physical process, well suited basis sets for the Kohn-Sham orbitals has to be chosen. For the ionization process a novel absorber acting in the energy space as well as additional basis functions will be used depending on the laser frequency. In the first part of the applications, a large variety of different laser-induced molecular processes will be investigated. This concerns, the orientation dependence of the ionization of multielectronic diatomics (N2, O2), the isomerization of organic molecules (N2H2) and the giant excitation of the breathing mode in fullerenes (C60). In the second part, fullerene-fullerene collisions are investigated, for the first time in the whole range of relevant impact velocities concerning the vibrational and electronic energy transfer (\"stopping~power\"). For low energetic (adiabatic) collisions, it is surprisingly found, that a two-dimensional, phenomenological collision model can reproduce (even quantitatively) the basic features of fusion and scattering observed in the fully microscopic calculations as well as in the experiment. For high energetic (nonadiabatic) collisions, the electronic and vibrational excitation regimes are predicted, leading to multifragmentation up to complete atomization.

科学研究費補助金 研究種目:基盤研究(A)(2) 課題番号:15206012 研究代表者:後藤 俊夫 研究期間:2003-2004年度

No description available.

This work presents applications of an ab-initio molecular dynamics method, the so-called nonadiabatic quantum molecular dynamics (NA-QMD), for various molecular systems with many electronic and nuclear degrees of freedom. Thereby, the nuclei will be treated classically and the electrons with time-dependent density functional theory (TD-DFT) in basis expansion. Depending on the actual system and physical process, well suited basis sets for the Kohn-Sham orbitals has to be chosen. For the ionization process a novel absorber acting in the energy space as well as additional basis functions will be used depending on the laser frequency. In the first part of the applications, a large variety of different laser-induced molecular processes will be investigated. This concerns, the orientation dependence of the ionization of multielectronic diatomics (N2, O2), the isomerization of organic molecules (N2H2) and the giant excitation of the breathing mode in fullerenes (C60). In the second part, fullerene-fullerene collisions are investigated, for the first time in the whole range of relevant impact velocities concerning the vibrational and electronic energy transfer (\"stopping~power\"). For low energetic (adiabatic) collisions, it is surprisingly found, that a two-dimensional, phenomenological collision model can reproduce (even quantitatively) the basic features of fusion and scattering observed in the fully microscopic calculations as well as in the experiment. For high energetic (nonadiabatic) collisions, the electronic and vibrational excitation regimes are predicted, leading to multifragmentation up to complete atomization.

Das Hauptthema dieser Dissertation ist die Untersuchung der Selbstorganisation organischer Moleküle an der Flüssig-Fest-Grenzfläche (LSI). Besondere Betonung liegt auf der Kontrolle der Selbstassemblierung durch geeignete Parameter: die Substrattemperatur während der Abscheidung, die Konzentration der gelösten Moleküle, und die chemische Natur der gelösten Stoffe und Lösungsmittel. Die Untersuchungen wurden unter Verwendung der Rastertunnelmikroskopie (STM) durchgeführt. Der erste Schwerpunkt dieser Arbeit ist die systematische Untersuchung der Auswirkung erhöhter Substrattemperatur während der Abscheidung aus der Lösung auf die Selbstorganisation komplexer molekularer Architekturen an der LSI. Diese Untersuchungen wurden mit dem planaren Molekül Trimesinsäure (TMA), sowie dem nicht-planaren Molekül Benzen-1,3,5-triphosphonsäure (BTP) durchgeführt. Es wird gezeigt, dass der Polymorphismus der Adsorbatstrukturen von TMA und BTP durch die Substrattemperatur während der Abscheidung der Moleküle aus der Lösung für verschiedene Lösungsmitteln unterschiedlicher Polarität, wie Phenyloctan, Octansäure und Undecanol, kontrolliert werden kann. Durch die Erhöhung der Temperatur des vorgeheiztem Graphitsubstrates kann die spezifische 2D supramolekulare Struktur and die entsprechende Packungsdichte der Moleküle in der Adsorbatschicht für jedes der untersuchten Lösungsmittel präzise eingestellt werden. Weiterhin wird der Einfluss der Konzentration auf die resultierende Anordnung der TMA Moleküle an der LSI durch ein weiteres Experiment abgeschätzt, bei welchem Rühren (von 0 h bis 40 h) der Lösungen mit verschiedenen Lösungsmitteln eingesetzt wurde. Diese Ergebnisse zeigen, dass die verschiedenen Präparationsmethoden (Erhöhung der Abscheidetemperatur oder Rühren) zu derselben Tendenz der Änderung der geordneten Strukturen sowie der Packungsdichte führt, weswegen man schlussfolgern kann, dass die Erhöhung der Konzentration an der LSI bei erhöhter Abscheidetemperatur ebenso der Hauptgrund für die beobachteten Änderungen ist. Der zweite Schwerpunkt dieser Dissertation ist die Untersuchung von chemischen Reaktionen der selbstassemblierenden Moleküle. Eine Veresterungsreaktion von TMA mit Undecanol wurde gefunden. Weiterhin wurde, als ein erster Schritt zur Untersuchung der Zwillingspolymerisation, die Oligomerisation des Zwillingsmonomers 2,2’-spirobi [4H-1,3,2-benzo-dioxasiline] (SBS) mit STM an der Grenzfläche zwischen der SBS-Undecanol-Lösung und einer Graphitoberfläche untersucht. Erstens wurde durch Ultraschallbehandlung der SBS Lösung in Undecanol für verschieden lange Zeiten die Oligomerisation der SBS Monomere ohne einen Katalysator an der LSI beobachtet. Zweitens konnte die Oligomerisation auch durch Erhöhung der Substrattemperatur während der Abscheidung der Moleküle aus der Lösung initiiert werden. Durch die schrittweise Erhöhung der Temperatur des vorgeheizten Substrates konnten mehrere, verschiedene, periodische Anordnungen von Phenol‒Dimeren, ‒Trimeren, und –Pentameren u.s.w. gefunden werden. Weiterhin wird die Auswirkung der Abscheidetemperatur auf die Selbstorganisation an der LSI nur der Lösungsmittelmoleküle aus dem reinen Lösungsmittel beschrieben. Dies ist wichtig, da die Undecanol‒Moleküle stets mit den gelösten, in dieser Arbeit verwendeten Stoffen (TMA, BTP, SBS) koadsorbieren und lineare Muster bilden. / The main aim of this thesis is to study the self-assembly of organic molecules at the liquid-solid interface (LSI). Special emphasis is given to controlling the process of self-assembly via suitable parameters such as: the substrate temperature during the initial deposition, the concentration of dissolved molecules, or the chemical nature of solutes and solvents. The investigations are performed using scanning tunneling microscopy (STM). The first focus of this work is the systematic investigation of the effect of the substrate temperature during the deposition out of the solution on the self-assembly of complex molecular architectures at the LSI. These investigations have been done with the planar molecule trimesic acid (TMA), and the non-planar molecule benzene 1,3,5-triphosphonic acid (BTP). We show that the polymorphism of the adsorbate structures of TMA (also with BTP) can be controlled by the substrate temperature during the deposition of the molecules out of the solution for various solvents of different polarity such as phenyloctane, octanoic acid, and undecanol. By increasing the temperature of the pre-heated graphite substrate, the specific 2D supramolecular structure and the corresponding packing density in the adsorbate layer can be precisely tuned for each kind of the solvents studied. Furthermore, the influence of the concentration on the resulting self-assembly of TMA molecules at the LSI is estimated by another experiment using stirring (from 0 h to 40 h) of the solutions of different kinds of solvents. These results demonstrate that choosing different preparation methods (increasing deposition temperatures or stirring) lead to the same tendency in the change of the self-assembled structures as well as the tuning of the packing density from which it can also be concluded that the increase of the concentration at increased deposition temperatures is also the main reason for the observed changes. The second focus of this work is the investigation of chemical reactions of self-assembling molecules. The esterification of TMA with undecanol was observed. Moreover as a first step to study twin polymerization, the oligomerization of the twin monomer 2,2’-spirobi [4H-1,3,2-benzo-dioxasiline] (SBS) was investigated by STM at the SBS-undecanol solution/graphite interface. Firstly, by ultrasonicating the solution of SBS in undecanol for different times the oligomerization of SBS monomer without any catalyst has been observed at the LSI. Secondly, the oligomerization of SBS monomer can also be initiated by the substrate temperature during the deposition of the molecules out of the solution. By stepwise increasing the temperature of the pre-heated substrate, various periodic assemblies of phenolic dimer, trimer, pentamer resin, and so on were observed. Furthermore, the effect of deposition temperature on the self-assembly of solely solvent molecules from the pure liquid at the LSI is described, which is important because the undecanol solvent molecules are always co-adsorbed with the solutes used in this work (TMA, BTP, SBS) to form linear patterns.