Τελετή Ορκωμοσίας Τμήματος Επιστήμης και Μηχανικής Υλικών της 26/3/2025
17 Μαρτίου 2025
Δείτε την πρόσκληση της Τελετής Ορκωμοσίας Νέων Αποφοίτων του Τμήματος Επιστήμης και Μηχανικής Υλικών της 26/3/2025.
Παρουσίαση μεταπτυχιακής εργασίας του κ. Β. Τσάμπαλλα
16 Δεκεμβρίου 2024
ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
Τίτλος
«Synthesis and Functionalization of Monodisperse Lignin Nanoparticles»
του Βασιλείου Τσάμπαλλα
μεταπτυχιακού φοιτητή του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης
Επιβλέπουσα Καθηγήτρια: Μαρία Βαμβακάκη
Τρίτη 17 Δεκεμβρίου 2024 Ώρα 16:00
H παρουσίαση θα πραγματοποιηθεί στην αίθουσα
Τηλε-εκπαίδευσης (Ε130), στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών, του Πανεπιστημίου Κρήτης
Abstract
«Lignin, an abundant biopolymer, is a promising yet underutilized resource in the development of sustainable materials. The study aims to overcome challenges associated with lignin's heterogeneous structure by synthesizing monodisperse lignin nanoparticles through a controlled and reproducible process. The synthesis methodology involves precision engineering to achieve uniform particle size distribution, ensuring enhanced properties and reproducibility. Furthermore, the research explores novel avenues for the functionalization of these lignin nanoparticles, imparting them with tailored properties suitable for diverse applications. The functionalization process involves the incorporation of specific chemical moieties, enabling improved compatibility with various matrices and facilitating the design of advanced materials. The thesis seeks to contribute to the expanding field of green materials by providing a comprehensive understanding of the synthesis and functionalization of monodisperse lignin nanoparticles. The resulting nanoparticles hold promise for applications in biocompatible materials, drug delivery systems, and environmentally friendly composites. This research addresses the challenges in lignin utilization and opens new avenues for sustainable materials with diverse functionalities, paving the way for an eco-friendly and resource-efficient future».
Παρουσίαση Μεταπτυχιακής εργασίας του κ. Ιωάννη Σαμψών
16 Δεκεμβρίου 2024
ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
του Ιωάννη Σαμψών
μεταπτυχιακού φοιτητή του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης
Τίτλος
«Liquid-Liquid Phase Separation: From Polyelectrolytes to Proteins Using Quantitative Phase Microscopy and Dynamic Light Scattering»
Επιβλέπουσα: Εμμανουέλα Φιλιππίδη
Τετάρτη 18 Δεκεμβρίου 2024 Ώρα 14:30
H παρουσίαση θα πραγματοποιηθεί στην αίθουσα Τηλε-εκπαίδευσης (Ε130), στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών, του Πανεπιστημίου Κρήτης
Abstract
Understanding the thermodynamic stability of materials allows the prediction of material properties and provides information about energy and entropy changes involved in phase transitions. This thesis focuses on the experimental study of liquid-liquid phase separation of intrinsically disordered proteins and oppositely charged polyelectrolytes, in an effort to provide insights and quantitative thermodynamic measurements relevant to biology.
In particular, this work shows the construction of phase diagrams using quantitative phase microscopy for the disordered protein PGL-3 which participates in condensate formation in the C. elegans embryo and readily undergoes liquid-liquid phase separation in vitro. The control parameters explored are temperature and salt. In addition, first steps are undertaken to examine the multimeric state of the protein upon increasing its concentration. However, since proteins are incredibly complex as they comprise structured and unstructured domains, hydrophobic, hydrophilic, polar and charged amino acids, a parallel study of the coacervation between an oppositely-charged pair of a strong and weak polyelectrolytes was launched. Results from both systems will be presented and similarities and differences will be discussed.
Παρουσίαση διδακτορικής διατριβής του κ. Αλέξανδρου Δελτσίδη
13 Δεκεμβρίου 2024
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής του
κ. Αλέξανδρου Δελτσίδη
Επιβλέπων: κ. Λάππας Αλέξανδρος, Διευθυντής Ερευνών,
Ινστιτούτου Ηλεκτρονικής Δομής και Λέιζερ του Ιδρύματος Τεχνολογίας Έρευνας, Ηράκλειο Κρήτης
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Παρασκευή 20 Δεκεμβρίου 2024 και ώρα 9:30 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής του υποψήφιου διδάκτορα του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Αλέξανδρου Δελτσίδη, με θέμα:
«Electron Correlations in Layered Metal Chalcogenides: Structure and Physical Properties»
Abstract
Intercalation of layered iron chalcogenide superconductors with guest species gives access to a gallery of layered phases with enhanced superconducting properties. In these systems, emerging empirical pictures imply a strong relation of the average and local structure with the magnitude of the superconducting transition temperature . Exploring the puzzling saturation of at large interlayer separations, , (average structure), and the role of the geometry of the basic building FeSe4 block (local structure) in tuning the strength of electronic correlations and spin dynamics in these systems, offers an avenue to parameterize conditions that facilitate high . This thesis focuses on variant phases of the Lix(C5H5N)yFe2-zSe2 system with very large .
High-throughput, time-resolved X-ray total scattering, has been employed to establish conditions that enable the synthesis of phase pure product and simultaneously identify the different length-scales that emerge during the growth of the Lix(C5H5N)yFe2-zSe2 expanded lattice phase. In-situ pair distribution function analysis revealed local distortions, involving swollen FeSe4 edge-sharing units, as a consequence of the electron-donating moieties being accommodated in the interlayer space. These non-trivial local distortions were further explored by element-specific (Fe and Se K-edge) X-ray absorption spectroscopy as a function of temperature and the Li content. The work found progressive softening and stretching of the electronically active Fe-layer with elevated Li content—effects that were associated with the presence of Fe-site vacancies. Annealing Lix(C5H5N)yFe2-zSe2 forms a phase with reduced and somewhat lower —an outcome of the modified metal-ligand environment due to reduced doping level. Local structure insights suggest that empirical local structure metrics for growth may become less relevant when the layers are spaced far away. Instead, other parameters such as electron doping level may come into play to leverage high .
Different aspects of the magnetism of these systems are imprinted in two different time scales. These were probed with X-ray emission spectroscopy and inelastic neutron scattering. The Fe Kβ emission spectra shed light on the evolution of instantaneous spin dynamics (10-15 s) and found evidence of strong localized magnetism in the normal state which, due to strong quantum fluctuations, is severely quenched in the superconducting state. However, Hund's coupling appears to play a key role in mediating the development of local moments when cooling towards the correlated state. Inelastic neutron spectra probed the correlated spin dynamics (10- 12 s) and failed to identify strong resonant signals in the superconducting state—akin to similar unconventional systems—enquiring about the role of electronic correlation strength and doping in dampening the intensity of such signals. Insights on the spin-dynamics suggest that intercalation brings about large spin disorder in the normal state, raising questions about the nature of unconventional pairing interactions in systems with very large .
The outcomes highlight that intercalation by insertion of molecular donors in-between the electronically active iron-layers is a viable tool to develop and design the properties of high- Fe-chalcogenides. The sensitive response of their structure on carrier doping points that when interlayer separation is enhanced, reduces electronic screening that aligns with the concept of Hund’s coupling that is central in modifying the pairing strength and further optimizations of superconductivity.
Call for postgraduate positions Spring Semester 2024-2025
13 Δεκεμβρίου 2024
The Department of Materials Science and Engineering of the University of Crete announces a limited number of postgraduate student positions for enrolment in the spring semester of the academic year 2024-2025.
The aim of the Postgraduate Program in Materials Science and Engineering of the Materials Science and Engineering Department is to prepare MSc students for excellent career prospects in the rapidly growing interdisciplinary field of Materials Science and Engineering. The educational and research activities of the program provide an integrated approach and in-depth training, with emphasis on conducting innovative research in the following cutting-edge fields of Materials Science Engineering and Technology:
- Optoelectronics – Magnetic materials – Nanotechnology
- Polymers – Colloids
- Theoretical – Computational Materials Science
- Synthetic Chemistry of Materials
- Biomaterials – Biomolecules
Successful completion of the Postgraduate Program leads to a Postgraduate Diploma (MSc) after 4 semesters of study that include the mandatory attendance of courses and the preparation and writing of a Master’s Thesis. The program is in English and requires full-time participation. As part of their training, postgraduate students assist in the instruction of undergraduate courses.
Graduates of the first cycle of studies of Greek universities or similar institutions abroad have the right to apply for the program. Knowledge of English is required. There are no tuition fees for students coming from the European Economic Area (EEA). For students coming from countries outside of the EEA, the program’s total tuition fees are 2000 Euro.
The academic criteria that are taken into account for the selection are defined in the Postgraduate Studies Regulations. They include the undergraduate degree, grades in courses related to the subject of the program, the performance in a diploma thesis, if provided in the first cycle of studies, as well as the relevant research or professional activity of the candidate.
Necessary supporting documents
(submitted exclusively in electronic form through the website https://postgrad.cict.uoc.gr )
- Application
- Detailed CV
- Report of interests
- Copy of degree
- Diploma supplement
- Up to three (3) letters of recommendation
- Any other document the candidate considers to substantiate scientific excellence and quality
- Certificate of a good knowledge of the English language (B2 level and above)
Please use the form templates found here: https://mscs.uoc.gr/dmst/?page_id=850
The application must include ane-mail account from which you will be informed about the progress of your application.
Letters of recommendation will be sent directly by the authors to the postgraduate secretariat.
Deadline for submission of the application and supporting documents for the Postgraduate Program is set for January 17th, 2025. The interviews will take place on January 27th, 2025 between 10:00 – 13:00. There is the possibility of a video conference for candidates living outside Crete.
Applications and supporting documents are submitted exclusively online via the website https://postgrad.cict.uoc.gr. Candidates should a) create a user account, b) process their application by filling in the corresponding fields and uploading files for the remaining data, and c) make the final submission before the deadline.
For more information, please contact the Secretariat of the Department of Materials Science and Engineering:
Mr. Ch. Stratigis: tel. +30 2810-394272, stratigis@materials.uoc.gr,
and Ms Sygelaki Fotini: tel. +30 2810394270, fsygelaki@materials.uoc.gr,
or the Director of Postgraduate Studies, Assoc. Prof. D. Papazoglou: postgrad_chair@materials.uoc.gr.
Παρουσίαση διδακτορικής διατριβής της κ. Λέιλας Ζουρίδη
10 Δεκεμβρίου 2024
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής
της κ. Λέιλας Ζουρίδη
Επιβλέπων Καθηγητής: Βασίλειος Μπίνας
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Πέμπτη 19 Δεκεμβρίου 2024 και ώρα 9:00 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής της υποψήφιας διδάκτορος του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Λέιλας Ζουρίδη, με θέμα:
«Development of perovskite oxides as printable solid oxide cell electrodes»
Abstract
The energy transition from fossil fuels to an electrified hydrogen energy economy still faces challenges on the implementation of electrolyzer and fuel electrochemical cells due to complexity of fabrication and materials cost. In this study the investigation of versatile perovskite oxide materials as printed thin-film electrode components for facile manufacturing of solid oxide cells is presented. The implementation of mechanochemical synthesis on the solid-state synthesis of electroceramics directly from salt precursors has been explored for the preparation of easy to handle and abundant titanate and manganite perovskites, followed by the physicochemical characterization of their structural, morphological, elemental, electrical and thermal stability properties in ex-situ and in-situ conditions. The pure perovskite phase was achieved after high temperature annealing solely in the cases where the mechanochemical step was implemented, while other synthetic procedures tested at similar synthetic conditions produced mostly mixed metal oxides, indicating the potential of the solvent-free direct salt precursor mechanochemical synthesis developed in this work. Ink development and study of dispersions based on organic solvents with our synthesized materials was implemented with different processing methods to achieve optimal, inkjet-printable inks, with appropriate shelf-life and print fidelity. The optimized inks were then utilized in an inkjet printing system to study their deposition by altering parameter conditions on the cartridge and platen for consistent drop generation and precision on the deposited patterns. Comparatively, different thick pastes were developed with the perovskite oxides, to be used by two additional additive manufacturing methods, screen printing and direct-ink-writing. Fabrication of electrolyte-supported solid oxide cells was conducted with different designs to explore the extend of applicability of the printing methods. After fabrication of solid oxide cells, the electrochemical evaluation of electrodes on air and hydrogen fuel was conducted illustrating their potential as electrodes for reversible solid oxide cells.
Παρουσίαση διδακτορικής διατριβής της κ. Ελευθερίας Δαριβιανάκη
10 Δεκεμβρίου 2024
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής της
κ. Ελευθερίας Δαριβιανάκη
Επιβλέπων Καθηγητής: Κωνσταντίνος Στούμπος
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την
Τρίτη 17 Δεκεμβρίου 2024 και ώρα
11:00 στην
αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής της υποψήφιας διδάκτορος του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Ελευθερίας Δαριβιανάκη, με θέμα:
«Halide Perovskite Solar Cells and Heterostructures»
Abstract
Halide perovskites semiconductors are in the spotlight of modern research, exceling in many fields of optoelectronics, with the major attention drawn in solar cell applications, due to their exceptional solar cell performance. However, there are several hurdles that the perovskite solar cells need to overcome, such as their limited long-term stability, which constitutes the main obstacle for the commercialization of this promising photovoltaics technology.
In this dissertation, we deal with the fabrication of single-junction perovskite solar cell devices with the aim to improve the stability of photovoltaic devices at ambient conditions. Perovskite solar cells were fabricated using different fabrication thin-film deposition techniques, with a major focus on the two-step immersion method. The optimum perovskite films, achieved under ambient conditions, show an enhancement of the devices towards environmental stability and photostability. However, the photovoltaic conversion efficiency (PCE) of the devices remains low, as a result of interface resistance which limits the photo-generated carriers’ extraction.
Attempting to overcome this barrier, and in order to obtain better charge-transport characteristics, we have switched to an alternative charge-transport layer by introducing GaAs instead of TiO2, used as an ETL layer. Thus, a major part of this work relates to the fabrication of hybrid perovskite/GaAs nanowire heterostructures. In this direction, we have successfully managed to fabricate hybrid perovskite/GaAs nanowire diodes with promising I-V characteristics, following a suitable n+-type doping of the GaAs nanowire ETL layer. These devices showed up a measurable photo-response when illuminated, but did not produce a competitive photocurrent value at this point. We attribute the observed loss of current in the current architecture design, which does not permit the full illumination of the active area of the device. Future directions include the use of Transparent Conducting Oxide (TCO) materials as top electrodes, or the improvement of the structural design of the device to enable effective illumination of the active area of the solar cell.
The present Thesis, represents a new direction in the development of perovskite-based solar cells and draws several important conclusions concerning the interfacing of halide perovskites with non-oxidic based heterojunctions. Since, the vast majority of the experimental work was performed at ambient conditions, the perovskite stability assessment presented here, could be instructive for addressing the long-term stability problem of halide perovskite semiconductors.
Πρόσκληση Τελετής Ορκωμοσίας Τμήματος Επιστήμης και Μηχανικής Υλικών
17 Νοεμβρίου 2024
Ο Πρόεδρος του Τμήματος Επιστήμης και Μηχανικής Υλικών Αναπληρωτής Καθηγητής Δ. Παπάζογλου σας προσκαλεί στην τελετή αποφοίτησης την
Τετάρτη 27 Νοεμβρίου 2024 και ώρα 11:00
στο αμφιθέατρο «Πετρίδης», Κτήριο Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών.
Δείτε την Πρόσκληση Τελετής Αποφοίτησης.
Παρουσίαση Διδακτορικής Διατριβής κ. Βαρβάρας Πλατανιά
01 Νοεμβρίου 2024
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής της
κ. Βαρβάρας Πλατανιά
Επιβλέπουσα Καθηγήτρια: Μαρία Χατζηνικολαΐδου
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Τρίτη 5 Νοεμβρίου 2024 και ώρα 11:00 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής της υποψήφιας διδάκτορος του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Βαρβάρας Πλατανιά, με θέμα:
«3D Bioprinting of Vascularized Bone Grafts Using Human Adult Stem Cells and Cell-Instructive Biomaterials under Mechanical Stimulation»
Περίληψη
Current medical practice still faces significant challenges in treating large bone defects caused by trauma or disease. The main causes of large graft failure are inner graft necrosis and lack of integration with the host tissue due to poor vascularization. Developing bone grafts that can restore vascular function to the regenerating bone tissue has been the most difficult aspect to address. This thesis explores the critical role of vascularization in enhancing bone tissue engineering outcomes.
Acknowledging the potential of 3D bioprinting in bioengineering complex tissues, this study introduces a dual-layered 3D bioprinted vascularized bone model aiming to promote bone regeneration under physiological mechanical loading. The inner layer comprises a vascular-like matrix created from a nanocomposite ink of gellan gum, laponite, and platelet-rich plasma (PRP), with laponite serving as a carrier for the PRP-containing bioactive growth factors, along with Wharton-jelly mesenchymal stem cells. The outer layer features a bone-like matrix containing bone marrow mesenchymal stem cells encapsulated in a photocrosslinkable blend of poly(ethylene glycol) diacrylate (PEGDA), gelatin, and poly(vinyl alcohol). The electrically conductive poly(3,4-ethylenedioxythiophene) (PEDOT) is introduced in the outer layer to enhance the activity of voltage-gated channels, facilitating calcium ion flow across the cell membrane, amplifying the signal triggered by mechanical stimulation.
Dynamic cell cultures performed in the presence of mechanical stimulation within a bioreactor were employed to mimic the physiological environment of native bone tissue. The synergistic cellular and molecular interactions of the dual-layered constructs significantly enhance the osteogenic and angiogenic differentiation due to paracrine signaling. Key markers of osteogenesis and angiogenesis showed significant upregulation in response to mechanical stimulation, particularly in the dynamic cultures. The complex bioprinted constructs demonstrated excellent in vitro biocompatibility, without observing any adverse foreign body reaction following in vivo subcutaneous implantation in mice. The mechanoresponsive biofabricated platform has great potential to promote vascularized bone regeneration.
Παρουσίαση Διδακτορικής Διατριβής του κ. Νικολάου-Αθανασίου Μπούρκερ
30 Οκτωβρίου 2024
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής
του κ. Νικολάου-Αθανασίου Μπούρκερ
Επιβλέπων: Benoit Loppinet
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Τρίτη 5 Νοεμβρίου 2024 και ώρα 14:00 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής του υποψήφιου διδάκτορος του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Νικολάου-Αθανασίου Μπούρκερ, με θέμα:
«Rheology and Μicrorheology at Ηigh Pressures»
Περίληψη
In this dissertation we report experimental investigations of the dynamics, the phase and flow behavior of three systems, Organoclay, Supramolecular organogels, and gelatin. They are gelling dispersions. They form weak solids despite the low volume fraction. Of-ten out of equilibrium, such gels are sensitivity to weak perturbations and show strong dependence on the preparation and environmental conditions or external fields. Their flow behaviors and controls at given environmental conditions (pressure, temperature, humidity etc.) are of broad interest and valuable in multiple applications (energy, food and polymer industry).
We use scattering, rheology and microrheology to probe the dynamics, the linear and non-linear viscoelastic responses. Particular attention is given to high pressure (HP) conditions, as it is not much reported. Light scattering based passive HP-microrheology was developed and used to measure linear viscoelasticity. HP-shear rheology was also used for flow curves. When needed complementary structural characterization was per-formed through spectroscopy techniques and rheo – SAS (light and x-ray).
In organoclay dispersions (Ch. 3,4,5) we explore the effects of preparation treatment and we propose efficient ways to control the rheology and structure (clay exfoliation) through the construction of phase diagrams in clay concentration, homogenization temperature and water content space. We established shear history protocols and effectively tuned their mechanical properties without affecting much the structure. We monitor the evolution of organoclay dispersions and a model oil continuous drilling fluid at different pressures and aging.
We study the linear viscoelastic response and we construct phase diagrams of supramolecular organogels, (EHUT) at pressure, temperature and concentration (Ch. 6,7). We elucidate the effect of pressure and temperature on the linear viscoelasticity and attribute it to small variation in the self-assembly.
We study the effect of pressure (and concentration) on sol-gel transition of gelatin solutions (Ch. 8). We established that the gelation time decreases with increasing pressure, i.e., gelation speeds up. It is governed by the distance to the collagen denaturation temperature, known to increase with pressure by 0.04 K/Mpa.
