Theses supervised by Prof. Dr. Şefik Süzer
12 theses · İhsan Doğramacı Bilkent University
Elektrolit olarak iyonik sıvı karışımı içeren cihazlardaki iyon dinamiklerinin elektriksel modülasyon altında X-ışını fotoelektron spektroskopisi ile incelenmesi
X-ray Photoelectron Spectroscopy (XPS) has long been used to investigate surface composition, chemical states, and electronic environments in materials. In this study, XPS is employed not only for these traditional roles but also to extract local electrical potential profiles by monitoring shifts in core-level binding energies under applied DC and/or AC biases. Two complementary device architectures are utilized to achieve this objective: (i) platinum–platinum (Pt–Pt) coplanar capacitors, which are well-suited for investigating frequency-dependent charge screening, potential drop across the ionic liquid (IL) layer, and circuit modeling under square-wave excitation; and (ii) multilayer graphene–multilayer graphene (MLG–MLG) devices, which are employed to explore electrosorption dynamics, open-circuit potential (OCP) effects, and residual charge behavior after shorting. A Square Wave (SQW) AC signal with varying frequencies was employed to resolve dynamic charging and discharging processes in these systems. The co-planar capacitor configuration used was featuring a polyethylene membrane (PEM) coated with either the ionic liquid N,N-Diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide (DEME-TFSI) alone, or a ~1:1 volume mixture of DEME-TFSI and N,N-Diethyl-2-methoxy-N-methylethanaminium tetrafluoroborate (DEME-BF4). The measurements were conducted under operando conditions, allowing simultaneous acquisition of XPS spectra and current data. Although ionic liquids offer advantages such as wide electrochemical windows and thermal stability, their high viscosity and cost can hinder ionic mobility and conductivity. A promising approach to address these limitations involves mixing different ILs to tailor their properties; for example, adjusting the ratio of DEME-TFSI and DEME-BF4 alters electrolyte characteristics. The pronounced size difference between the TFSI and BF4 anions provides an opportunity for detailed investigation via XPS. Additionally, a DEME-TFSI system containing ~10% rubidium bis(trifluoromethanesulfonyl)imide (Rb-TFSI) was explored to assess the influence of a small, mobile alkali cation (Rb⁺) on surface composition and charge storage. XPS revealed polarity-sensitive surface accumulation of Rb⁺, correlating with a sharp increase in currents. Overall, this non-invasive methodology, leveraging both Pt–Pt and MLG–MLG architectures, demonstrates that XPS is a powerful tool for probing local electrochemical processes. The technique offers valuable insights that can contribute to the development of next-generation energy harvesting and storage systems.
Aygıtların elektriksel ve kimyasal analizleri için X-ışını fotoelektron spektroskopisinin sıvı/katı arayüzeyleri de kapsayacak şekilde genişletilmesi
Understanding of electrical and electrochemical devices in operating conditions is vital for development of new technologies. Many important characteristics that determine the performance of such devices lie on their surfaces and interfaces which significantly deviate from the bulk properties. However, particularly for the liquid based devices, carrying out surface analysis is challenging and requires highly sophisticated instrumentation. In this PhD. thesis, we aim to unravel the potential development on liquids, dielectrics as well as the liquid/solid interfaces during AC and DC excitation in a chemically resolved fashion using the UHV compatible non-aqueous liquids in a basic electrowetting on dielectrics configuration within X-Ray Photoelectron Spectroscopy (XPS) chamber. Low molecular weight Polyethylene glycol (PEG) and a particular ionic liquid Diethylmethyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide [DEME][TFSI] are used to represent two extreme cases as being non-ionic and fully-ionic liquids. Application of external electrical bias to these devices either from the top or the bottom electrode during data acquisition enabled us to investigate the electrowetting phenomenon, in a chemically addressed fashion In the first part of the thesis, geometrical changes that the drop undergoes during electrowetting have been monitored both by steady state areal maps and by dynamic XPS point analysis where the potential was altered periodically. In the second part, we have focused only on the DC electrowetting of liquids. We probed the potential developments in the dielectric layer and on the liquid by monitoring the changes in the binding energy of the representative XPS peaks with respect to the applied potential. We showed that the conductivity of the liquid has no influence on the potential and the entire potential drop occurs at the liquid/dielectric interface. Dielectric breakdown and its effect on the potential developments were also investigated in this part. In the third part, we have tried to understand the frequency dependent potential developments of the ionic liquid and the polyethylene glycol based EWOD devices by AC electrowetting. Our time dependent XPS measurements under AC excitation with sweeping frequency have demonstrated that EWOD devices exhibit two different behaviors separated by a critical frequency, which is dependent on the AC resistance (impedance) or ionic content of the liquid and also the electrical characteristics of the dielectric layer. Below the critical frequency, XPS spectra are mainly affected by the capacitive component of the dielectric, hence the liquid completely screens the applied electrical field. However, for frequencies above the critical, the resistive component of the liquid dominates and the drop behaves like a resistive strip, resulting in the formation of equipotential surface contours which are shown experimentally for the first time in this study. In the last part of the thesis, an equivalent circuit model was developed to electrically describe the electrowetting behavior of PEG on dielectric and also to generate a solid-state mimicking device to produce the same XPS spectral observations.
HQ yardımıyla fotobozunan PVC polimerinin mekanizması
ABSTRACT THE MECHANISM OF HYDROQUINONE ASSISTED PHOTODEGRADATION OF PVC SİNAN BALCI M. S. in Chemistry Supervisor: Prof. Dr. Şefik Süzer August 2002 Pure poly(vinyl chloride) (PVC) degrades upon exposure of UV radiation (k <300 nm) by the loss of HC1 and formation of long conjugated structures known as polyenes. The mechanism of this process is fully understood and known as the zip mechanism, firstly involving the elimination of chlorine radical from the PVC backbone and then the formation of HC1. Addition of chromophores (light absorbing units) into the matrix of the PVC increases the wavelength absorption of the matrix. One of these compounds is Hydroquinone (HQ), which sensitizes the photodehydrochlorination of PVC at 312 nm. The purpose of this thesis is to shed light into the mechanism of HQ assisted photodehydrochlorination of PVC at 312 nm. Accordingly, the effect of (i) the minimum concentration of HQ, (ii) the temperature of the medium on the rate of PVC photodegradation, (iii) the viscosity of the PVC, (iv) the flux of the irradiation, and (v) the hydroquinone-benzoquinone composition on the rate of PVC photodegradation are investigated. Various sensitizers and quenchers are also used to compare the HQ's sensitisation ability and to investigate the effect of the triplet-state of HQ in the mechanism of the HQ sensitized PVC photodegradation. UV-Visible, IR, and XPS spectroscopic techniques are used to determine the effect of the mentioned parameters. IVIn the light of all the findings, a mechanism of the HQ assisted (sensitized) photodegradation is proposed to involve mostly formation of a triplet state of HQ followed by effective transfer of this energy to the PVC matrix for dehydrochlorination. Keywords: Polyvinyl chloride), hydroquinone, methyl violet, polyaniline, sensitization, quenching, photodegradation, UV-Visible, IR and XPS. V
Politetrafloroetilenin silikon oksit ve polimer yüzeylere tribolojik transferi
The main objective of this study is to understand the nature of tribological transfer of polytetrafluoroethylene (PTFE) onto counter thermally-oxidized silicon, polystyrene (PS), polyvinylchloride (PVC) and poly(methyl methacrylate) (PMMA) surfaces, as well as investigating the possible formation of chemical bonds arising at polymer-semiconductor and polymer-polymer interfaces, while or after tribological material transfer. Tuning the wettability characteristics of PTFE transferred surfaces is also aimed. Within these purposes, first part of the research focused on the preparation of silicon oxide and polymer substrates and the utilization of tribological transfer method in order to form desired PTFE patterns on these surfaces. The realization of this transfer was provided by the design of a simple rig to bring about a friction between the surfaces via sliding a piece of PTFE on silicon oxide and polymer specimens. In order to monitor the tribological interaction in a gradual manner as a function of increasing contact force, a very mild inclination (∼0.5◦) along the sliding motion was also employed in some specimens mounted on the inclined aluminum supports. In addition, procedures used to explore the stability of specimens against time and washing / cleaning practices using various organic solvents and boiling water are given within this part. In the second part of the work, characterization of PTFE-contacted silicon oxide and polymer surfaces was carried out using X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy and Atomic Force Microscopy (AFM). XPS results were obtained, which revealed that PTFE was faithfully transferred onto the silicon oxide and polymer surfaces upon even at the slightest contact; SEM and AFM images reinforced that stable morphological changes could be imparted onto the counter silicon oxide surfaces. In experiments where the inclined aluminum supports were used to create gradual tribological transfer of PTFE onto counter silicon oxide surfaces, use of relation between the increase in contact force with respect to transferred amount of PTFE helped us to estimate the minimum apparent contact pressure needed to realize the PTFE transfer, which was found to be about 5 kPa. Stability of the patterns imparted towards time and various chemical washing processes lead us to postulate that the interaction was most likely occurred with formation of chemical bonds. Contact angle measurements, which were carried out to monitor the wettability of the silicon oxide surface, showed that upon PTFE transfer the hydrophobicity of the SiO2 surface could be significantly enhanced, depending on the pattern sketched onto the surface. All of these findings show that tribological transfer of PTFE onto various counter surfaces is possible by a simple procedure, which has both academical and commercial importance.
İyonik sıvılı elektrokimyasal aygıtların elektronik özelliklerinin X-ışını fotoelektron spektroskopisiyle incelenmesi
Attention towards electrochemical energy storage devices assembled with innovative solvent-free electrolytes 'ionic liquids' (ILs) has been progressively rising over the last two decades. In order to design a particular electrochemical device it becomes crucial to understand the structure of interfacial region and the electrical response of ILs. Accordingly, this thesis focuses on X ray Photoelectron Spectroscopic (XPS) investigations of electrochemical devices containing ILs, that is compatible with ultra high vacuum condition needed for XPS. Towards better understanding the fundamental aspects of certain electrochemical issues, electrochemical devices consisting of two metal electrodes, which contains N,N – Diethyl -N- methyl -N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) imide, (DEME-TFSI) IL-electrolyte between them, have been investigated by XPS under external electrical stimuli control, as a novel analytical tool for elucidating; (i) charging/ discharging phenomena, (ii) electrical double layer (EDL) formation and (iii) electrochemical reaction products. In the first part, a co-planar electrochemical device, with two gold electrodes on porous polyethylene membrane (PEM) plus DEME-TFSI impregnated between the electrodes, has been studied using external DC bias, for recording the position dependent electrical potential variations. In addition, AC bias is used to harvest temporal behavior. For the AC bias a square wave excitation is used, for which two frequencies are adopted corresponding to slow (10 mHz) and fast (1 kHz) time scales, for probing the response of the system at infinite- and zero-time onset, respectively. In all cases XP spectra have been recorded at different lateral positions. As a result of these DC and AC applications a new understanding has surfaced. Accordingly, although at the metal-electrolyte interface the EDL formation is limited to lateral dimensions at the nanometer scale, its visualization through the analysis of the XPS-probed voltage transients can be extended to very large distances from the interface, in the millimeters scale. These responses have also been modeled using a simple equivalent circuit with two oppositely polarized electrodes and an ionic conducting medium in between. In the second part, re-arrangement of the DEME-TFSI's ionic constituents at the Au electrode/IL-electrolyte interface has been monitored by the dynamic-XPS approach under application of electrical pulses in the form of a slow (1 mHz) triangular wave with an amplitude of 5V, while recording the intensity fluctuations of the two N1s peaks corresponding to the anionic and the cationic fragments. In the last part, the externally bias XPS analysis has been used for in situ and in-vacuo monitoring of anodically triggered electrochemical preparation and characterization of Au NPs in both a co-planar and also in a wire-plane electrode electrochemical geometries. The small sized Au NPs' formation within the DEME-TFSI medium has been confirmed by the characteristic peak around 470 nm in the Visible spectrum and with the spherical and well-dispersed (~4 nm) particles in TEM images
FT-IR,XRD,Raman tekniklerini kullanarak sıcaklık değişikliğine bağlı olarak polipropilen filmlerinde kristallinite ve yönteminin incelenmesi
ABSTRACTINVESTIGATION OF THE CRYSTALLINITY AND ORIENTATION OFPOLYPROPYLENE WITH RESPECT TO TEMPERATURE CHANGESUSING FT-IR, XRD, AND RAMAN TECHNIQUESHARUN NEZİH TÜRKÇÜM.S. in ChemistrySupervisor: Prof.Dr. Şefik SüzerAugust 2004Having good mechanical and barrier properties, polypropylene films are widely usedin food-packing industry. The relation of crystallinity and orientation ofpolypropylene with these properties are well known. Temperature increase has animportant effect on the crystallinity and orientation of polypropylene. The purpose ofthis study is to understand better crystallinity and orientation changes of the cast andbi-axially oriented polypropylene films with respect to temperature effect. Thesechanges were investigated using especially in-situ FT-IR and dichroism as well asXRD and Raman spectroscopy.For this purpose, an in-situ variable temperature set-up is developed and adapted forFT-IR studies. Accordingly, the changes in the peaks related to the amorphous andcrystalline contents of the films as well as the peaks reflecting the orientation of thefilms were investigated over the temperature range from 120-170oC. Temperaturecycle was also applied. Moreover, the films were investigated after application ofadditional stress at 120oC for various durations.The crystallinity and orientation of the films are affected significantly when the filmswere analyzed at higher temperature (>150oC). The crystallinity content of the filmIIIrecovers after returning back to room temperature whereas orientational loss arepermenant.Keywords: Polypropylene, FT-IR, Dichroism, XRD, Raman Spectroscopy,Phase Transition, and Temperature EffectIV
İnce PS/PMMA polimer filmlerinin elektriksel özelliklerinin dinamik XPS ile incelenmesi
İnce-kaplama methoduyla hazırlanmış saf polistiren (PS), poli(metil metakrilat) (PMMA), ve karışım PS/PMMA polimer filmlerinin elektriksel özellikleri X-ışını fotoelektron spektroskopisi (XPS) ile dışarıdan doğrusal voltaj ve dinamik(kare dalga) uygulanarak incelenmiştir.PS ve PMMA farklı yüklenme özellikleri olmasından yola çıkılarak, karışım PS/PMMA polimer filmi yüzeyindeki saf PS ve PMMA bölgelerinin birbirilerine göre farklı yüklenme özellikleri olduğundan yük ayrışımı ve/veya faz ayrışımı açık bir şekilde XPS?e dışarıdan doğrusal voltaj uygulamasıyla ölçülmüştür.10-3 - 103 Hz frekans aralığında dışarıdan uygulanan kare dalga ile ince-kaplama PS ve PMMA polimer filmlerinin eletriksel parametreleri dinamik XPS ile incelenmiştir. Geliştirilen bir modelle etkin direnç ve kapasite değerleri her bir ince-kaplama ile hazırlanmış polimer filmleri için saptanmıştır. XPS ölçümlerini modelleyebildiğimiz method ile ince polimerik filmlerin etkin direnç ve kapasite değerleri saptanmıştır. Ayrıca aynı method ile bu filmlerin zaman sabitleri ve bükülme frekanları hesaplanmıştır. Bunun yanında, polimer film kalınlıklarının yüklenme ve diğer elektriksel parametrelere olan etkileri incelenmiştir. Son olarak, modelin geçerliliğini denemek ve polimerik filmlerin dışardan doğrusal voltaj ve kare dalga uygulamalarındaki dielektiksel davranışlarını simüle edebilmek için, değerleri bilinen ve dışarından paralel bağlanmış direnç ve kapasite içeren devre elemanı ile iletken bir grafit numunesinde de ölçümler yapılmıştır.
Bimetalik ve çekirdek-kabuk Au-Ag nanoparçacıkların spektroskopik karakterizasyonu ve yüklenme/yük boşalması özellikleri
The purpose of this work, is to control and manipulate optical and electrical properties of bimetallic alloy and core-shell Au and Ag nanoparticles by optical spectroscopy and XPS respectively. Several objectives have been pursued in achievement of the goal. First goal is to investigate the tunability of optical properties of bimetallic Au and Ag alloy and core-shell nanoparticles due to changes in composition and geometry, and later on, to study the possibility of charge-storage on single metal particles, especially on gold and silver, and bimetallic alloy forms of the corresponding nanoparticles in solution. Within this framework, bimetallic silver-gold alloy and core-shell particles are synthesized, then their electron-storage capacities in aqueous media by introduction of borohydride is followed by spectral shifts in their surface plasmon resonance bands. Moreover, the parameters like composition, geometry, affecting the charging ability of particles are reported by means of optical spectroscopy as well. In addition, electron storing/releasing capacities of Au and Ag nanoparticles and their kinetics are investigated.In the second part, main focus is to control and manipulate optical and electric properties by surface modification with incorporating Au and Ag nanoparticles within dielectric shell (silica and titania). Therefore, small Au@SiO2, Ag@SiO2, and Ag@TiO2 core-shell nanoparticles with the metal core size ca. 5-7.5 nm and the shell size ca. 3-7.5 nm are synthesized and optical properties of these nanoparticles are investigated. These nanoparticles are also analyzed by XPS under external biasing to get further understanding of their charging capacities. Additionally, we investigated incorporating the metal nanoparticles within titania shell to provide enhanced photocatalytic activity through the metal core by means of increased charging capacity.
Katman-katman kaplama yöntemiyle Au ve Ag nanoparçacıkları içeren ultra-ince filmlerin hazırlanması ve karakterizasyonu
The main objective of this thesis is to investigate the layer-by-layer deposited polyelectrolyte and polyelectrolyte/metal nanoparticle films by using X-ray Photoelectron (XPS) and Optical Spectroscopy (UV-Vis).Within this purpose, in the first part of the study, layer-by-layer deposited single and oppositely charged bilayered films are investigated by XPS. To extract additional information in the molecular level, the samples are analyzed while applying an external voltage bias. It is shown that applying external electrical stimuli to a single polyelectrolyte layer coated Si/SiO2 system responds to the change in the polarity by molecular rearrangements, evidenced by the changes only in the intensity of the corresponding ?N+(1s) peak.In the second part of the study, metal nanoparticle (Au and/or Ag) incorporated polyelectrolyte films are investigated by optical spectroscopy. Within this frame, multilayer gold and silver nanaoparticle/polyelectrolyte films are prepared both separately and in bimetallic form. In order to get further understanding about the optical responses of single type of metal nanoparticle incorporated systems, several experimental approaches are followed. These approaches also enable us to control and manipulate the optical properties of these compact structures.The last part focuses on incorporation of metallic ions into layer-by-layer assembled polyelectrolyte matrices through ion-exchange method. It is shown that metal ions can be incorporated and subsequently reduced within this polymer matrix by UV or X-ray irradiation and can also form nanoparticles.
Altın nanoparçacığı içeren polimer kompozitlerinin hazırlanması ve karakterizasyonu
In this study, light-assisted synthesis of gold nanoparticles in polymer films is demonstratedand characterization of gold nanoparticle-polymer composites using various techniques isshown. There are various methods introduced for the synthesis of gold nanoparticles insolution and their integration to the polymer films afterwards. However, synthesizing goldnanoparticles directly inside the polymer matrix is more advantageous for the production ofpolymer-nanoparticle composites.An advantage of synthesizing gold nanoparticles within polymer films is the opportunity ofphoto-patterning. Films having patterns made of regions with and without gold nanoparticlescan be produced, using masks designed to cut off the radiation at desired places. Suchpatterned films were investigated with scanning electron microscope (SEM) and dark regionsbetween irradiated regions and masked regions were observed. These dark regions are shownto be ?ion depleted regions?, where gold ions diffuse through irradiated regions during theirradiation. These regions of about 10 ? m width, suggests a very large distance for gold ionsto diffuse through a rigid matrix like Poly(methyl methacrylate)(PMMA), which is veryinteresting. Supporting evidence for the existence of these regions was obtained fromfluorescence studies with Rhodamine 6G molecule and x-ray electron spectroscopy (XPS).The observations made through the formation of ion depleted regions can be used to estimatethe diffusion constant of gold ions inside the PMMA matrix. Also the presence of iondepleted regions indicate the stability of photo-patterns created on the polymer film againstsmearing during light exposure after the production, by setting an upper limit to the criticalfeature size.During the characterization of gold nanoparticle-polymer composites, the electrical propertiesof PMMA with and without gold nanoparticles were investigated using charge resolved XPS,while applying external bias to the films with and without gold nanoparticles to probe thecharging properties of the films. An enhancement of conductivity of PMMA films containinggold nanoparticles was observed using this technique. Additionally charge resolved XPStechnique was also used to determine the charge storage characteristics of the polymersurfaces, which is important for the identification of charging mechanisms during contact andother electrification processes. It was shown that the PMMA surface is very susceptible tonegative charging and even native negative charges on the PMMA surface can be observedprior to any treatment. Also when the surface is charged carbon and oxygen atoms of thecarbonyl and methoxy groups of PMMA were observed to behave differently from thebackbone of the polymer, which shows the chemical specificity of the charge accumulatingspots on the surface.
Işık altında yarıiletken malzemelerin üzerinde oluşan voltaj yüklenmelerinin foto-dinamik XPS ile incelenmesi
The main motivation of this Ph.D. study is investigation of the photoinduced voltage changes in semiconductive materials with X-ray Photoelectron Spectroscopy (XPS). For this purpose, we have developed a technique for recording the shifts in the positions of the XPS peaks in response to different waveforms of electrical and/or optical stimuli for tracing dynamics of the developed potentials originating from intrinsic or extrinsic factors of the semiconductive materials such as charging/discharging, photoconductivity, surface photovoltage, band-bending/flattening/inversion, etc.Within this purpose, the surface photovoltage behaviors of n- and p-type doped Si and GaN samples are examined with the photo-dynamic XPS, to follow the behavior of the band-bending under photoillumination in both static and dynamic fashions. The band inversion effects are clearly observed on the n- and p-Si samples in the presence of a dielectric silica overlayer and on the p-GaN sample due to variation of the illuminating laser energies. Moreover, the extent of the dopant dependent XPS peak shifts of the n- and p-Si samples are assessed after correction of their surface photovoltage values.A laser patterned silicon wafer with a high-power near infrared fiber laser is also investigated. While the patterned silica domains have identical chemical composition with the non-patterned regions, an investigation with dynamic XPS clearly reveals distinct dielectric characteristics of the patterned domains.Electrical parameters of CdS thin film are extracted by dynamic XPS with and without photoillumination. The photo-dynamic XPS technique has also provided useful information by disentanglement of processes; charging/discharging, photoconductivity, and surface photovoltage. Furthermore, location (space) dependent resistance and chemical profile of a CdS based Light Dependent Resistor (LDR) is also probed during realistic operational conditions, by utilizing spatially resolved XPS analysis (in the area mapping mode). In addition, with the XPS mapping analysis defects and malfunctioning sites/domains have been located under various experimental and preparation conditions.
Antibakteriyel uygulamalar için gümüş-bakır nanoalaşımlar içeren ve katman-katman-kaplama yöntemi ile hazırlanan ultra ince filmlerin hazırlanması ve karakterizasyonu
The main objective of this master thesis is to explore the preparation, characterization and antibacterial applications of Layer-by-Layer (LbL) assembled ultra thin films containing AgCu nanoalloys. Within this purpose, first part of the research mainly focused on the preparation of Ag nanoparticles and AgCu nanoalloys in order to prevent the oxidation of copper to copper oxide and the formation of polyelectrolyte-AgCu nanoalloy films by Layer-by-Layer assembly. Accordingly, Ag nanoparticles and AgCu nanoalloys were synthesized by the chemical reduction of silver and copper salts in aqueous solution with the help of strong reducing agents sodium borohydride or hydrazine hydrate in the presence of complexing agent and stabilizer, then ultra thin polyelectrolyte layers containing pre-prepared AgCu nanoalloys were constructed by Layer-by-Layer deposition technique in different combinations. Also the stability of these nano sized binary alloys in solution phase were prolonged in the presence of third metal zinc as a sacrificial anode. In the second part of the study, characterization of LbL assembled ultra thin polyelectrolyte and metal nanoparticle thin films using Optical (UV-visible) and X-ray Photoelectron Spectroscopy (XPS) was studied. In order to get further information on the optical response of single and bimetallic nanoparticles, Ag nanoparticle and AgCu nanoalloy incorporated ultra thin polyelectrolyte films were investigated by optical spectroscopy. In addition the LbL films were analyzed by Static XPS to extract atomic level chemical information due to elemental and chemical state analysis. In order to get further understanding at the molecular level, samples were analyzed under external bias application by Dynamic XPS and it was shown that Ag and Cu respond in the same way to applying external electrical stimuli when both are in the same environment as a result of alloy formation, as reflected by the same shifts in Ag3d and Cu2p binding energy positions. Lastly, in the third part of the study detailed antibacterial analysis of synthesized monometallic and multimetallic nanoparticle solutions and the organized ultra thin polyelectrolyte layers containing Ag and AgCu nanoclusters against Escherichia coli strain was performed. These approaches enabled us to show the better antibacterial behavior of AgCu nanoalloys as a result of successful synthesis of AgCu nanoalloy without any copper oxide formation as the end product.