This work deals with the structural analysis of layered zirconium sulfophenylphosphonates and their intercalates with the use of the classical molecular simulation methods. The inner composition of both fully and partially sulfonated layers was determined in agreement with available experimental data, especially chemical analysis, thermogravimetric measurements and X-ray diffraction. The calculations revealed the positions of the water molecules in the planes of sulfo groups which strongly affect the resultant diffraction pattern. Within the zirconium sulfophenylphosphonate layered structure, the arrangements of intercalated species based on optically active dipyridylamine molecules and cations of sodium, copper and iron were solved with the respect to the agreement with experimental results and values of potential energy. In case of the dipyridylamine molecules and its derivatives, the resultant disordered partially row arrangements of the organic molecules in the interlayer were showed to influence the dipole moment of the intercalate. From this point of view, nitro-derivative has been picked out as the most suitable for potential applications. Regarding the intercalated cations, sodium cations take up the space of water molecules next to the sulfo groups while copper and iron cations are distributed in a...

In dieser Dissertation diskutiere ich theoretische Methoden zur Simulation von Grenzflächen zwischen Metallen und Molekülen auf atomarer Maßstabsebene, die für die Speicherung und Erzeugung "sauberer" Energie von Bedeutung sind, und wende sie an. Wir verwenden die Dichtefunktionaltheorie für das elektronische Subsystem und verschiedene Methoden wie die (quasi-)harmonische Näherung und die Pfadintegral-Molekulardynamik, um die Quanteneigenschaften des nuklearen Subsystems zu berücksichtigen. Wir berechnen den Isotopeneffekt auf die Arbeitsfunktion von Cyclohexan, das an der Rh(111)-Oberfläche adsorbiert wird, ein Effekt, der sich aus der Elektron-Phonon-Kopplung nur dann ergibt, wenn die nuklearen Freiheitsgrade quantenmechanisch behandelt werden. Deuteriertes Cyclohexan C6D12 hat einen größeren Adsorptionsabstand als gewöhnliches Cyclohexan. Pfadintegral-Molekulardynamiksimulationen zeigen auch eine temperaturabhängige Renormierung der elektronischen Zustandsdichte in diesem System. Schließlich befassen wir uns mit Oberflächenreaktionen auf einer geladenen metallischen Oberfläche. Wir stellen unsere Implementierung der Nudged-Elastic-Band-Methode (NEB) im i-PI-Paket vor und diskutieren ihre Leistungsfähigkeit. Anschließend setzen wir die Methode ein, um die Energiebarriere der Wasserspaltungsreaktion auf einer Pd(111)-Oberfläche zu berechnen, die einem elektrischen Feld unterschiedlicher Intensität ausgesetzt ist. Wir zeigen, dass die niedrigste Dissoziationsbarriere auftritt, wenn das Feld eine Stärke erreicht, die eine geometrische Frustration des auf der Oberfläche adsorbierten Wassermoleküls hervorruft, und dass die Nullpunktenergiebeiträge zur Barriere dieser Reaktion über den weiten Bereich der auf das System angelegten elektrischen Feldstärken nahezu konstant bleiben. Wir erklären dies durch eine gegenseitige Aufhebung der Rot- und Blauverschiebungen einzelner Schwingungsmoden zwischen Reaktant und Übergangszustand. / In this thesis, I discuss and apply theoretical methods for simulating interfaces between metals and molecules of relevance to "clean" energy storage and production on an atomistic scale. We use density-functional theory for the electronic subsystem and various methods such as (quasi-)harmonic approximation and path integral molecular dynamics to account for quantum properties of the nuclear subsystem, determining which methods are sufficient to grasp the essential phenomena while remaining computationally affordable. We calculate isotope effect on the work function of cyclohexane adsorbed on Rh(111) surface, an effect that emerges from electron-phonon coupling only when the nuclear degrees of freedom are treated quantum-mechanically. Deuterated cyclohexane C6D12 has larger adsorption distance than ordinary cyclohexane. Path integral molecular dynamics simulations also show a temperature-dependent renormalization of the electronic density of states in this system, induced by both thermal and quantum fluctuations of nuclei. Finally, we address surface reactions on a charged metallic surface. We present our implementation of the nudged elastic band (NEB) method in i-PI package and discuss its performance. We then employ the method to calculate the energy barrier of water splitting reaction on a Pd(111) surface subjected to electric fields of different strengths. We show that the lowest dissociation barrier takes place when the field reaches a strength that induces a geometric frustration of the water molecule adsorbed on the surface, and that the zero-point energy contributions to the barrier of this reaction remain nearly constant across the wide range of electric field strengths applied to the system. We explain this by a mutual cancellation of the red and blue shifts of individual vibrational modes between reactant and transition states.

No description available.

Στην παρούσα διατριβή παρουσιάζονται παράλληλοι αλγόριθμοι και εφαρμογές σε πολυπύρηνες μονάδες επεξεργασίας γραφικών. Πιο συγκεκριμένα, εξετάζονται οι μέθοδοι σχεδίασης ενός παράλληλου αλγορίθμου για την επίλυση τόσο απλών και κοινών προβλημάτων, όπως η ταξινόμηση, όσο και υπολογιστικά απαιτητικών προβλημάτων, έτσι ώστε να εκμεταλλευτούμε πλήρως την τεράστια υπολογιστική δύναμη που προσφέρουν οι σύγχρονες μονάδες επεξεργασίας γραφικών. Πρώτο πρόβλημα που εξετάστηκε είναι η ταξινόμηση, η οποία είναι ένα από τα πιο συνηθισμένα προβλήματα στην επιστήμη των υπολογιστών. Υπάρχει σαν εσωτερικό πρόβλημα σε πολλές εφαρμογές, επομένως πετυχαίνοντας πιο γρήγορη ταξινόμηση πετυχαίνουμε πιο καλή απόδοση γενικότερα. Στο Κεφάλαιο 3 περιγράφονται όλα τα βήματα σχεδιασμού για την εκτέλεση ενός αλγορίθμου ταξινόμησης για ακεραίους, της count sort, σε μια μονάδα επεξεργασίας γραφικών. Σημαντική επίδραση στην απόδοση είχε η αποφυγή του συγχρονισμού των νημάτων στο τελευταίο βήμα του αλγορίθμου. Στη συνέχεια παρουσιάζονται εφαρμογές παράλληλων αλγορίθμων σε υπολογιστικά απαιτητικά προβλήματα. Στο Κεφάλαιο 4, εξετάζεται το πρόβλημα χρονοπρογραμματισμού εξετάσεων Πανεπιστημίων, το οποίο είναι ένα πρόβλημα συνδυαστικής βελτιστοποίησης. Για την επίλυσή του χρησιμοποιείται ένας υβριδικός εξελικτικός αλγόριθμος, ο οποίος εκτελείται εξ' ολοκλήρου στην μονάδα επεξεργασίας γραφικών. Η τεράστια υπολογιστική δύναμη της GPU και ο παράλληλος προγραμματισμός δίνουν τη δυνατότητα χρήσης μεγάλων πληθυσμών έτσι ώστε να εξερευνήσουμε καλύτερα τον χώρο λύσεων και να πάρουμε καλύτερα ποιοτικά αποτελέσματα. Στο επόμενο κεφάλαιο γίνεται επίλυση του προβλήματος σχεδιασμού κίνησης για υποθαλάσσια οχήματα με βραχίονα. Εξετάζεται το πρόβλημα τόσο του ολικού σχεδιασμού όσο και του τοπικού. Στην πρώτη περίπτωση είναι σημαντική η καλή λύση και η ακρίβεια και ο παράλληλος αλγόριθμος που χρησιμοποιείται για την αναπαράσταση του περιβάλλοντος εργασίας σε μια Bump-επιφάνεια βοηθάει προς αυτή την κατεύθυνση. Στη δεύτερη περίπτωση, το πρόβλημα είναι πρόβλημα πραγματικού χρόνου και μας ενδιαφέρει η ταχύτητα εύρεσης της επόμενης θέσης του οχήματος. Ο παράλληλος προγραμματισμός και η GPU βοηθούν σημαντικά σε αυτό. Τελευταία εφαρμογή που εξετάστηκε είναι η μελέτη ενός συστήματος ημιφθοριωμένων αλκανίων με την μοριακή προσομοίωση Monte Carlo. Η παραλληλοποίηση ενός μέρους, του πιο χρονοβόρου, του αλγορίθμου έδωσε τη δυνατότητα εξέτασης ενός πολύ μεγαλύτερου συστήματος σε αποδεκτό χρόνο. Σε γενικές γραμμές, γίνεται φανερό ότι ο παράλληλος προγραμματισμός και οι σύγχρονες πολυπύρηνες αρχιτεκτονικές, όπως οι μονάδες επεξεργασίας γραφικών, δίνουν νέες δυνατότητες στην αντιμετώπιση καθημερινών προβλημάτων, προβλημάτων πραγματικού χρόνου και προβλημάτων συνδυαστικής βελτιστοποίησης. / In this thesis, parallel algorithms and applications in manycore graphics processing units are presented. More specifically, we examine methods of designing a parallel algorithm for solving both simple and common problems such as sorting, and computationally demanding problems, so as to fully exploit the enormous computing power of modern graphics processing units (GPUs). First problem considered is sorting, which is one of the most common problems in computer science. It exists as an internal problem in many applications. Therefore, sorting faster, results in better performance in general. Chapter 3 describes all design options for the implementation of a sorting algorithm for integers, count sort, on a graphics processing unit. The elimination of thread synchronization in the last step of the algorithm had a significant effect on the performance. Chapter 4 addresses the examination timetabling problem for Universities, which is a combinatorial optimization problem. A hybrid evolutionary algorithm, which runs entirely on GPU, was used to solve the problem. The tremendous computing power of GPU and parallel programming enable the use of large populations in order to explore better the solution space and get better quality results. In the next chapter, the problem of motion planning for underwater vehicle manipulator systems is examined. In the gross motion planning problem, it is important to achieve a good solution with high accuracy. The parallel algorithm used for the representation of the working environment in a Bump-surface is a step towards this direction. In the local motion planning problem, which is a real-time problem, the time needed to find the next configuration of the vehicle is crucial. Parallel programming and the GPU greatly assist in this online problem. Last application considered is the atomistic Monte Carlo simulation of semifluorinated alkanes. The parallelization of part of the algorithm, the most time-consuming, enabled the study of a much larger system in an acceptable execution time. In general, it becomes obvious that parallel programming and new novel manycore architectures, such as graphics processing units, give new capabilities for solving everyday problems, real time and combinatorial optimization problems.

There were three main driving forces behind this thesis: global concern over climate change mainly due to uncontrolled carbon dioxide (CO2) emissions, the excitement over the discovery of graphene and its versatile potential, and the potential to design three-dimensional (3D) or two-dimensional (2D) structures, in our case using unique triptycene molecule. We examined two polymeric materials for CO2 adsorption and suggested simple design of disordered carbons suitable for gas adsorption studies. The approach in each task was to examine structural and adsorption properties of materials using detailed atomistic modelling employing Monte Carlo and Molecular Dynamics techniques and where possible provide experimental measurements to validate the simulations. The thesis is presented as a collection of papers and the work can be divided into three independent projects. The aim of the first project is to utilize graphene as an additive in polymer composites in order to increase separation between the polymer chains increasing available surface area. The matrix used is a polymer of intrinsic microporosity (PIM-1), which possess large surface area and narrow nano-sized ( > 2nm) pore distribution attractive for gas separation membrane applications. Adding a filler can reduce aging of the polymer, and enhance permeability across the membrane, often to the expense of loosing selectivity. Therefore, we investigated the packing of PIM-1 chains in presence of discrete 2D graphene platelets and 3D graphene-derived structures and its effect on composite structure and adsorption properties. We found that additives do not alter structural polymer properties at the molecular level preserving the same adsorption capacity and affinity. Potential permeability increase would benefit from the retention of selectivity in the material. Building on design philosophy of materials with intrinsic microporosity we continued further investigation of 3D graphene-derived structures. The idea is that highly concave molecules or polymer chains pack inefficiently creating microporous materials with sufficient surface area for gas adsorption. 3D propeller-like structures were derived from graphene arms connected through the rigid triptycene and other types of cores. The resulting structures created a large amount of micropores and showed similar CO2/CH4 selectivity to activated carbons reported in the literature. It was shown that rigid triptycene core leads to more open structures. The model was also applied to model commercially available activated carbon to predict n- perfluorohexane adsorption. The fitting to experimental structural information proved to be challenging due to trial and error nature of the approach. Nevertheless, the simple packing procedure and diverse structure design have a great potential to serve as a virtual model for porous carbons that possess pore complexity and does not require any previous experimental data to be build on. The last project concerns CO2 adsorption and selectivity over CH4 and N2 in recently reported triptycene-based polymer. The triptycene shape polymer can form a porous 2D network that can be exfoliated into free-standing sheets and potentially used as a membrane. Sheets stack in the bulk material forming anisotropic channel pores. Additionally it contains fluoro- functional groups, which are known to have a high CO2 affinity. We explored pore structure and chemistry of stacked material for gas adsorption and predicted comparable capacity and CO2 selectivity to other microporous covalent materials such as activated carbons and PIMs. The CH4/N2 selectivity was similar to currently most selective material belonging to MOF family. We showed that fluoro-group have a positive effect on CO2 affinity, however predictions are sensitive to the charges of fluorine atoms assigned by different methods.

Les exigences actuelles en terme de lubrification automobile imposent des formulations extrêmement complexes. Parmi tous les additifs présents dans l’huile, on peut noter le dithiocarbamate de molybdène et le dithiophosphate de zinc, additifs à action tribologique à base de soufre et de phosphore. Pour des raisons environnementales, il est important de diminuer voir d’éliminer la présence de ces deux éléments dans les huiles. Les molécules organiques à base de carbone, oxygène et hydrogène semblent être de bons candidats. Le mécanisme de lubrification des acides gras (acides stéarique, oléique et linoléique) est revisité par une approche visant à combiner l’étude expérimentale et la modélisation moléculaire. Tout d’abord, les mécanismes d’adsorption des acides gras sur des surfaces à base de fer sont étudiés par couplage Chimie Quantique et Dynamique Moléculaire (UA-QCMD). L’adsorption des acides gras sur des surfaces à base de fer se fait par la fonction acide. Selon la nature du substrat, la densité du film et l’angle d’inclinaison de la molécule par rapport à la surface, différents mécanismes d’adsorption peuvent avoir lieu (physisorption et chimisorption). Les molécules d’acide stéarique forment une monocouche compacte et bien arrangée alors que les molécules insaturées en sont incapables à cause d’effets stériques induits par les doubles liaisons carbone-carbone. Le frottement favorise la formation de la fonction carboxylate. Ces résultats sont confirmés par des analyses de surface (XPS et PM-IRRAS). Les propriétés tribologiques des acides gras purs, dans la PAO 4 et en mélange dans la PAO 4 sont étudiées par simulation MD et par des tribotests. Un faible frottement et une absence d’usure visible ont été observés pour l’acide stéarique pur et dissous à 1%m dans la PAO 4 à haute température. La présence de molécules insaturées inhibe les propriétés réductrices de frottement de l’acide stéarique, en particulier à 150 °C. Ceci est expliqué par la diffusion des acides gras insaturés bien supérieure à celle de l’acide stéarique dans la PAO 4 à toutes les températures étudiées. / The current requirements in automotive lubrication impose complex formulation. Among all the additives present in oil, the presence of molybdenum dithiocarbamate and zinc dithiophosphate, both tribological additives containing sulfur and phosphorous is found. For environmental reasons, it is important to reduce or eliminate the presence of these two elements contained in oil. Organic molecules based on carbon, oxygen and hydrogen seems to be good candidate. The lubrication mechanism of fatty acids (e.g. stearic, oleic and linoleic acids) is revisited with a new approach combining experimental and computational chemistry studies. First, the adsorption mechanisms of fatty acids on iron-based surfaces are investigated by Ultra-Accelerated Quantum Chemistry Molecular Dynamics simulations. The adsorption of fatty acids on iron oxide surface occurred through the acid group. Depending on the nature of the substrate, on the density of the film and on the tilt angle between the molecule and the surface, different adsorption mechanisms (physisorption and chemisorption) can occur. Stearic acid molecules form a close-packed and well-arranged monolayer whereas unsaturation acids cannot because of steric effects induced by double carbon-carbon bonds. The friction process favors the formation of carboxylate function. Results are confirmed by surface analysis (XPS and PM-IRRAS). Tribological properties of pure fatty acids, blended in PAO 4 and mixture of saturated/unsaturated acids are studied by MD simulations and tribotests. Low friction coefficient with no visible wear is reported for pure stearic acid and single stearic acid blended in PAO 4 at 1%w at high temperature. This lubricating behavior is inhibited in the presence of unsaturated acids, especially at 150 °C. MD simulation results show a faster diffusion toward the surface for unsaturated fatty acids than for stearic acid at all studied temperature.

A Emodina (EMH) é uma das antraquinonas mais abundantes na natureza. Essa molécula vem sendo largamente usada como material de estudo científico por apresentar diversas atividades farmacológicas, tais como antiviral, antitumoral, antifungal, digestiva e outras. É conhecido que a Emodina em solução aquosa alcalina pode sofrer mais de um processo de desprotonação, apresentando-se na forma desprotonada, EM-, após a primeira desprotonação. Nesta tese de doutorado estudamos as propriedades estruturais e eletrônicas da molécula Emodina em meio solvente e em bicamadas lipídicas a fim de caracterizar as propriedades relacionadas à espectroscopia UV-Vis, à reatividade e à termodinâmica dessa molécula nesses ambientes. Realizamos cálculos quânticos com a Emodina em vácuo e em meio solvente, onde consideramos todos os possíveis sítios de desprotonação. Como resultados desses cálculos, identificamos os sítios da primeira, segunda e terceira desprotonação. Calculamos o pKa1 da Emodina em água e o pK*a1 em metanol através de simulações computacionais com o método Monte Carlo e cálculos quânticos, com o solvente descrito com o modelo contínuo polarizável. Nossos melhores valores para o pKa1 da Emodina determinados nesses solventes foram 8.4±0.5 e 10.3±1.5, que estão em boa concordância com os valores experimentais, (pKa1=8.0±0.2 e pK*a1=11.1±0.1) obtidos nesta tese para Emodina em água e metanol, respectivamente. Adicionalmente realizamos simulações com Dinâmica Molecular com as espécies EMH e EM- em bicamada lipídica de DMPC, para investigar a nível atômico as interações dessas espécies com a bicamada e determinar as posições preferenciais dessas espécies nesse ambiente anfifílico. Os resultados dessas simulações mostraram que as espécies EMH e EM- ficam inseridas na bicamada, na região polar dos lipídios, próximos aos gliceróis. Esses resultados corroboram as nossas medidas do espectro de absorção dessas espécies em bicamada lipídica, onde mostramos de forma qualitativa, que ambas as espécies ficam inseridas na bicamada, na região das cabeças polares dos lipídios. A análise das propriedades estruturais da bicamada na vizinhança das espécies da Emodina como área por lipídio e densidade eletrônica dos lipídios, mostrou que o efeito da EM- na estrutura da bicamada lipídica é maior do que o da EMH. Esses resultados corroboram as nossas medidas de DSC(Differential Scanning Calorimetry) das espécies da Emodina na bicamada. / Emodin (EMH) is one of the most abundant anthraquinone derivatives found in nature. This molecule has been used widely as research material, due to its biological and pharmacological activities such as antiviral, anticancer, antifungal, digestive and antibacterial activities. It is known that Emodin in alkaline aqueous solution can undergo more than one deprotonation, leading to the specie EM- in the first deprotonation process. In this PhD thesis, we studied the structural and electronic properties of this molecule in several solvents and lipid bilayers, in order to characterize the properties related to UV-Vis absorption spectroscopy, reactivity and thermodynamics of this molecule in these environments. Performing quantum mechanics (QM) calculations for all possible deprotonation sites and tautomeric isomers of Emodin in vacuum and in water, we identified the sites of the first, second and third deprotonations. We calculated the pKa1 of Emodin in water and pK*a1 in methanol with free energy perturbation method, implemented in the Monte Carlo simulation, and with QM calculations, where the solvent was treated as a polarizable continuum medium. Our best values for pKa1 of Emodin in these solvents were 8.4±0.5 and 10.3±1.5, which are in very good agreement with the experimental values obtained in this thesis pKa1=8.0±0.2 and pK*a1=11.1±0.1, for water and methanol, respectively. Additionally, we performed molecular dynamics simulations of both species in fully hydrated lipid bilayers of DMPC to investigate at atomic detail the molecular mechanism of the interaction of these species with lipid membrane and its preferred positions in this amphiphilic environment. As results of these simulations, we obtained that both species of Emodin have a strong tendency to insert into the lipid bilayer, remaining near the glycerol group of DMPC. These results corroborate our measured absorption spectra of these species in the bilayer, which qualitatively showed that both species are within the bilayer, inserted in the lipid headgroup region. Our results also show that the effect of EM- specie in the lipid bilayer structure is stronger than the EMH, which corroborate our DSC(Differential Scanning Calorimetry) measurements.

A Emodina (EMH) é uma das antraquinonas mais abundantes na natureza. Essa molécula vem sendo largamente usada como material de estudo científico por apresentar diversas atividades farmacológicas, tais como antiviral, antitumoral, antifungal, digestiva e outras. É conhecido que a Emodina em solução aquosa alcalina pode sofrer mais de um processo de desprotonação, apresentando-se na forma desprotonada, EM-, após a primeira desprotonação. Nesta tese de doutorado estudamos as propriedades estruturais e eletrônicas da molécula Emodina em meio solvente e em bicamadas lipídicas a fim de caracterizar as propriedades relacionadas à espectroscopia UV-Vis, à reatividade e à termodinâmica dessa molécula nesses ambientes. Realizamos cálculos quânticos com a Emodina em vácuo e em meio solvente, onde consideramos todos os possíveis sítios de desprotonação. Como resultados desses cálculos, identificamos os sítios da primeira, segunda e terceira desprotonação. Calculamos o pKa1 da Emodina em água e o pK*a1 em metanol através de simulações computacionais com o método Monte Carlo e cálculos quânticos, com o solvente descrito com o modelo contínuo polarizável. Nossos melhores valores para o pKa1 da Emodina determinados nesses solventes foram 8.4±0.5 e 10.3±1.5, que estão em boa concordância com os valores experimentais, (pKa1=8.0±0.2 e pK*a1=11.1±0.1) obtidos nesta tese para Emodina em água e metanol, respectivamente. Adicionalmente realizamos simulações com Dinâmica Molecular com as espécies EMH e EM- em bicamada lipídica de DMPC, para investigar a nível atômico as interações dessas espécies com a bicamada e determinar as posições preferenciais dessas espécies nesse ambiente anfifílico. Os resultados dessas simulações mostraram que as espécies EMH e EM- ficam inseridas na bicamada, na região polar dos lipídios, próximos aos gliceróis. Esses resultados corroboram as nossas medidas do espectro de absorção dessas espécies em bicamada lipídica, onde mostramos de forma qualitativa, que ambas as espécies ficam inseridas na bicamada, na região das cabeças polares dos lipídios. A análise das propriedades estruturais da bicamada na vizinhança das espécies da Emodina como área por lipídio e densidade eletrônica dos lipídios, mostrou que o efeito da EM- na estrutura da bicamada lipídica é maior do que o da EMH. Esses resultados corroboram as nossas medidas de DSC(Differential Scanning Calorimetry) das espécies da Emodina na bicamada. / Emodin (EMH) is one of the most abundant anthraquinone derivatives found in nature. This molecule has been used widely as research material, due to its biological and pharmacological activities such as antiviral, anticancer, antifungal, digestive and antibacterial activities. It is known that Emodin in alkaline aqueous solution can undergo more than one deprotonation, leading to the specie EM- in the first deprotonation process. In this PhD thesis, we studied the structural and electronic properties of this molecule in several solvents and lipid bilayers, in order to characterize the properties related to UV-Vis absorption spectroscopy, reactivity and thermodynamics of this molecule in these environments. Performing quantum mechanics (QM) calculations for all possible deprotonation sites and tautomeric isomers of Emodin in vacuum and in water, we identified the sites of the first, second and third deprotonations. We calculated the pKa1 of Emodin in water and pK*a1 in methanol with free energy perturbation method, implemented in the Monte Carlo simulation, and with QM calculations, where the solvent was treated as a polarizable continuum medium. Our best values for pKa1 of Emodin in these solvents were 8.4±0.5 and 10.3±1.5, which are in very good agreement with the experimental values obtained in this thesis pKa1=8.0±0.2 and pK*a1=11.1±0.1, for water and methanol, respectively. Additionally, we performed molecular dynamics simulations of both species in fully hydrated lipid bilayers of DMPC to investigate at atomic detail the molecular mechanism of the interaction of these species with lipid membrane and its preferred positions in this amphiphilic environment. As results of these simulations, we obtained that both species of Emodin have a strong tendency to insert into the lipid bilayer, remaining near the glycerol group of DMPC. These results corroborate our measured absorption spectra of these species in the bilayer, which qualitatively showed that both species are within the bilayer, inserted in the lipid headgroup region. Our results also show that the effect of EM- specie in the lipid bilayer structure is stronger than the EMH, which corroborate our DSC(Differential Scanning Calorimetry) measurements.