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Introduction
In our research on covalent and supramolecular polymers, we combine nanobeam X-ray diffraction and nanocalorimetry to explore the correlations between the local-scale structure and thermodynamics of these complex systems. Trying to understand the interplay between the structure formation processes operating at different scales and phase behavior is a very motivating and challenging task.
Additional affiliations
October 2011 - present
March 2005 - present
March 2005 - present
Publications
Publications (286)
We report on the banded polymer morphology of several semicrystalline
commodity polymers such as high-density poly(ethylene), poly(trimethylene
terephthalate), poly(vinylidene fluoride), and poly(3-hydroxybutyrate). The
internal structural organization and 3D shape of the constitutive crystalline
lamellae have been topics of interest in polymer phy...
[3]-Radialene-based dopant CN6-CP studied herein, with its reduction potential of +0.8 versus Fc/Fc+ and the lowest unoccupied molecular orbital level of -5.87 eV, is the strongest molecular p-dopant reported in the open literature, so far. The efficient p-doping of the donor-acceptor dithienyl-diketopyrrolopyrrole-based copolymer having the highes...
The interest toward co-crystals of energetic materials explains by the fact that they can offer better thermodynamic stability and tunable sensitivity and detonation performance. In the present work, a combination of DSC, ultra-fast chip calorimetry, high-resolution X-ray powder diffraction and nano-focus X-ray diffraction was employed to investiga...
The wedge-shaped amphiphiles bearing sulfonate groups at the tip of the wedge are prone to formation of ion nano-channels upon exposure to humid atmosphere. During swelling, the water molecules preferentially accumulate in polar regions of the system resulting in formation of a lyotropic phase. In this work, the
details of the structure formation p...
Charge transport in conjugated polymers is critical to most optoelectronic devices and depends strongly on the polymer structure and conformation in the solid state. Understanding the correlations between charge carrier mobility, energy disorder and molecular assembly is therefore essential to improve device performances. Alkyl side-chains contribu...
This work presents the synthesis and self-organization of the calamitic fluorinated mesogen, 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-4-iodobutoxy)ethanesulfonic acid, a potential model for perfluorosulfonic acid membranes (PFSA). The compound is derived in three steps from 1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoro-2-iodoethoxy)ethanesulfonyl fl...
In this study, the use of anionic polymerization for the synthesis of living poly(dimethylsiloxane) or PDMS-Li+, as well as poly(2-vinylpyridine) or P2VP-Li+ homopolymers, and the subsequent use of chlorosilane chemistry in order for the two blocks to be covalently joined leading to PDMS-b-P2VP copolymers is proposed. High vacuum manipulations enab...
Our lives cannot be imagined without polymer networks, which range widely, from synthetic rubber to biological tissues. Their properties—elasticity, strain-stiffening and stretchability—are controlled by a convolution of chemical composition, strand conformation and network topology. Yet, since the discovery of rubber vulcanization by Charles Goody...
The synthesis of novel thiazolo[5,4-d]thiazole-containing
conjugated polymer was performed by three alternative
methods, namely, by the Stille or Suzuki cross-coupling as
well as microwave-assisted condensation reaction with
carbonyl precursor and dithioxamide. The latter way is
straightforward and efficient for the design of novel materials
with d...
Hot-melt pressure-sensitive adhesives (HMPSAs) are used in applications from office supplies to biomedical adhesives. The major component in HMPSA formulations is thermoplastic elastomers, such as styrene-based block copolymers, that provide both mechanical integrity and moldability. Since neat polymer networks are unable to establish an adhesive b...
Conjugated small molecules are advanced semiconductor materials with attractive physicochemical and optoelectronic properties enabling the development of next-generation electronic devices. The charge carrier mobility of small molecules strongly influences the efficiency of organic and hybrid electronics based on them. Herein, we report the synthes...
The conjugated small molecules (CSMs) are an interesting class of semiconductor materials for thin‐film electronics. Herein, the synthesis of two novel donor–acceptor small molecules BBT‐H and BBT‐F is reported and the impact of morphology rearrangement upon thermal annealing on hole‐transport characteristics of thin films based on them is investig...
The design of new materials for non-contact temperature sensors is an important task for scientists working in the fields of chemistry, physics, and materials science. In the present paper, a novel cholesteric mixture based on a copolymer doped with a highly luminescent europium complex was prepared and studied. It was found that the spectral posit...
We report the synthesis of three (3) linear triblock terpolymers, two (2) of the ABC type and one (1) of the BAC type, where A, B and C correspond to three chemically incompatible blocks such as polystyrene (PS), poly(butadiene) of exclusively (~100% vinyl-type) -1,2 microstructure (PB1,2) and poly(dimethylsiloxane) (PDMS) respectively. Living anio...
Pressure sensitive adhesives (PSAs) are ubiquitous materials within a spectrum that span from office supplies to biomedical devices. Currently, the ability of PSAs to meet the needs of these diverse applications relies on trial-and-error mixing of assorted chemicals and polymers, which inherently entails property imprecision and variance over time...
During ICTAC2020, a workshop was held on “Good laboratory practice in thermal analysis and calorimetry” for young researchers and beginners under the aegis of the Education Committee of ICTAC. Thermal analysis (TA) covers relationship between large number of sample properties and the temperature. Naturally, there is some technique for each property...
Artificial ion-exchange and other charged membranes, such as biomembranes, are self-organizing nanomaterials built from macromolecules. The interactions of fragments of macromolecules results in phase separation and the formation of ion-conducting channels. The properties conditioned by the structure of charged membranes determine their application...
In this study the preparation of hybrid materials based on reduced graphene oxide (rGO) and conjugated copolymers is reported. By tuning the number and arrangement of thiophenes in the main chain (indacenothiophene or indacenothienothiophene) and the nature of the polymer acceptor (difluoro benzothiadiazole or diketopyrrolopyrrole) semiconducting c...
Investigation of hyaluronic acid (HA) morphology and mechanical properties at a single-molecule level is important for the development of HA based biomaterials. We have developed the atomic force microscopy (AFM) based approach for quantitative characterization of conformation of HA molecules. HA molecules adsorbed on a modified graphitic surface f...
This review article discusses the origins of self-assembly behaviour of linear and non-linear block co- and terpolymers and their application towards the fabrication of high-resolution patterns for nanolithography applications. Comparative analysis for the microphase separation in bulk and thin films is provided, to map the fundamentals of various...
Polymeric networks are commonly used for various biomedical applications, from reconstructive surgery to wearable electronics. Some materials may be soft, firm, strong, or damping however, implementing all four properties into a single material to replicate the mechanical properties of tissue has been inaccessible. Herein, we present the A-g-B brus...
The novel phototunable photonic structures based on electrochemically etched silicon filled with four photochromic azobenzene-containing compounds, bent-shaped low molar mass substance and side-chain polymethacrylates and copolyacrylate, were prepared and their photooptical properties were studied. It was found that irradiation of these composites...
The report elucidates for the first time a significant effect of a strong magnetic field combined with thermal treatment on the texture of thin liquid-crystalline films in a smectic state. The metastable texture generated in the magnetic field was arrested via the crystallization of mesogens while they cooled to room temperature. The effect was dem...
Brush-like elastomers with crystallizable side chains hold promise for biomedical applications requiring the presence of two distinct mechanical states below and above body temperature: hard and supersoft. The hard semicrystalline state facilitates piercing of the body whereupon the material softens to match the mechanics of surrounding soft tissue...
Crystalline and liquid-crystalline conjugated small molecules represent a promising family of semiconductor materials for organic electronics applications. The control of the morphology and optoelectronic properties of small molecules allows tuning their charge transport characteristics and hence, improving the performance of electronic devices. He...
A materials’ structure and its evolution due to friction play a crucial role in understanding wear and related processes. So far, structural changes caused by friction are mostly studied using ex situ destructive characterization techniques, such as microscopy of post-mortem the prepared specimen by polishing and etching techniques. In this paper,...
Objective:
The cuticle of human hair has been examined, via a range of analytical methods, in order to reveal previously unknown information about its structure and to deepen understanding of its contribution to fibre properties.
Methods:
Cross sections of hair fibre have been examined with X-ray microdiffraction oriented perpendicular to the su...
Board-shaped polymers form sanidic mesophases: assemblies of parallel lamellae of stacked polymer backbones separated by disordered side chains. Sanidics vary significantly with respect to polymer order inside their lamellae, making them "stepping stones" toward the crystalline state. Therefore, they are potentially interesting for studying crystal...
Cholesteric liquid crystals reflecting circularly polarised light are promising materials for creating flexible and compact polarisers. One of the issues of these systems is the narrow width of the photonic stop band. The range of selective light reflection can be increased by creating a gradient of the cholesteric pitch in the process of photopoly...
Injectable hydrogels are desired in many biomedical applications due to their minimally invasive deployment to the body and their ability to introduce drugs. However, current injectables suffer from mechanical mismatch with tissue, fragility, water expulsion, and high viscosity. To address these issues, we design brush-like macromolecules that conc...
Organic solar cells (OSCs) have attracted considerable attention in the last few decades due to their unique
properties, including lightweight, flexibility, and manufacturing costs. Moreover, OSCs exhibit high performance
under ambient light conditions revealing potential applications of these devices in low power electronics and
Internet of Things...
The influence of the hard segment nature on the crystallization kinetics of multi-block thermoplastic polyurethanes containing poly(butylene adipate) (PBA) as a soft segment was investigated. Using a combination of FTIR spectroscopy, time-domain 1H nuclear magnetic resonance (TD-NMR), differential scanning calorimetry (DSC), fast-scanning calorimet...
An approach to obtaining various nanostructures utilizing a well-studied polystyrene-b-poly(isoprene) or PS-b-PI diblock copolymer system through chemical modification reactions is reported. The complete hydrogenation and partial sulfonation to the susceptible carbon double bonds of the PI segment led to the preparation of [polystyrene-b-poly(ethyl...
Citation: Politakos, N.; Moutsios, I.; Manesi, G.-M.; Moschovas, D.; Abukaev, A.F.; Nikitina, E.A.; Kortaberria, G.; Ivanov, D.A.; Avgeropoulos, A. Synthesis, Characterization and Structure Properties of Biobased Hybrid Copolymers Consisting of Polydiene and Polypeptide Segments. Polymers 2021, 13, 3818. https://doi. Abstract: Novel hybrid material...
A pioneering synthetic approach for the design of novel composite materials is reported. The final products are consisting of high number average molecular weight diblock copolymers which are surface initiated (“grafting from” approach) from either single or multi-wall carbon nanotubes (SWCNTs or MWCNTs respectively). In-situ anionic polymerization...
A combination of in situ nanocalorimetry with simultaneous nanofocus 2D Wide-Angle X-ray Scattering (WAXS) was used to study polymorphic behaviour and structure formation in a single micro-drop of isotactic polypropylene (iPP) with defined thermal history. We were able to generate, detect, and characterize a number of different iPP morphologies usi...
A novel approach to obtaining nanocomposite materials using anionic sequential polymerization and post-synthetic esterification reactions with chemically modified graphene sheets (CMGs) is reported. The anionically synthesized diblock copolymer precursors of the PS-b-PI-OH type were grafted to the chemically modified –COOH groups of the CMGs, givin...
Electron donor-acceptor liquid crystals have been attracting considerable attention due to possible applications in optoelectronics and photonics. The creation of such charge transfer complexes is a powerful and flexible instrument for modifying the structures and properties compared to those of the initial components. In the present work, such an...
The structural evolution of multiblock thermoplastic polyurethane ureas based on two polydiols, poly(1,4-butylene adipate (PBA) and poly-ε-caprolactone (PCL), as soft blocks and two diisocyanites, 2,4-toluylene diisocyanate (TDI) and 1,6-hexamethylene diisocyanate (HMDI), as hard blocks is monitored during in situ deformation by small-and wide-angl...
Graphitic materials including graphene, carbon nanotubes and fullerenes, are promising for use in nanotechnology and biomedicine. Non-covalent functionalization by peptides and other organic molecules allows changing the properties of graphitic surfaces in a controlled manner and represents a big potential for fundamental research and applications....
We report on formation of a bicontinuous double gyroid phase by a wedge-shaped amphiphilic mesogen, pyridinium 4′-[3″,4″,5″-tris-(octyloxy)benzoyloxy]azobenzene-4-sulfonate. It is found that this compound can self-organize in zeolite-like structures adaptive to environmental conditions (e.g., temperature, humidity, solvent vapors). Depending on the...
The use of polarized light for biomedical diagnostics of skin and mucosa has already a long history. Prior studies have shown a contrast enhancement of the polarimetric values and in images of cancerous and healthy zones tissues. In the present study, reflectance-geometry polarization measurements were made with gastrointestinal tissue (GIT) sample...
Linear and non-linear copolymers of the PB-b-PI sequence [PB: polybutadiene of high 1,4-microstructure (~ 92%) and PI: polyisoprene of high 3,4-microstructure (~ 55-60%)] and their corresponding miktoarm star copolymers of...
Planar conjugated molecular backbones are essential for achieving high charge carrier mobilities along molecular -stacking directions but are often concomitant with poor charge transport in other directions. This is particularly...
To the best of our knowledge, this is the very first time that a thorough study of the synthetic procedures, molecular and thermal characterization, followed by structure/properties relationship for symmetric and non-symmetric second generation (2-G) dendritic terpolymers is reported. Actually, the synthesis of the non-symmetric materials is report...
The authors of this article, wondering about science as a completely unique social phenomenon; o note (consider as a objective reality) the crisis of the foundations of modern science; o offer certain principles for creating a new science - «science from scratch»; o reflect on the role of scientific traditions, the specifics, framework and function...
Utilising the AFM nanoindentation technique for the study of hair cross- and longitudinal sections, the mechanical anisotropy of human hair fibres affected by a rare congenital condition, Monilethrix, has been investigated for the first time. Supported by X-ray microdiffraction data, and applying a model based on an ideal composite material consist...
The synthesis of two (2) novel triblock terpolymers of the ABC type and one (1) of the BAC type, where A, B and C are chemically different segments, such as polystyrene (PS), poly(butadiene) (PB1,4) and poly(dimethylsiloxane) (PDMS), is reported; moreover, their corresponding molecular and bulk characterizations were performed. Very low dimensions...
The ability of living species to transition between rigid and flexible shapes represents one of their survival mechanisms, which has been adopted by various human technologies. Such transition is especially desired in medical devices as rigidity facilitates the implantation process, while flexibility and softness favor biocompatibility with surroun...
Softness and firmness are opposing traits that synergistically define the
elastic response of biological systems. Currently, no single class of synthetic materials
including elastomers and gels provides independent control of these mechanical
characteristics, particularly without altering chemical composition. To address this
challenge, we explore...
Here we report on reorganization on heating of a perspective organic semiconductor
poly(3-(2′-ethyl)hexylthiophene) (P3EHT). P3EHT is an analogue of a well-known poly(3-
hexylthiophene) (P3HT), which has comparable optoelectronic properties and the advantage of a lower processing temperature. The processes of structural reorganization during heatin...
Proton-conducting membranes were fabricated from a new short-side chain ionomer
Inion (Russian analogue of Aquivion) by solution casting method. A series of temperature treatment experiments was conducted to show that annealing of Inion membranes at the temperature range from 160 °C to 170 °C leads to a significant increase of specific proton condu...
In the present paper we study the effect of complexation in linear negatively charged
polyelectrolytes with different alkali ions. With combination of IR-spectroscopy, X-ray diffraction and nanocalorimetry, we attempted to explain unusual solubility, crystallinity and thermal stability of these polymers. The increase of thermal stability and insolu...
Sulfonated polyimides (SPIs)/silica composite membranes were prepared via an in situ sol-gel reaction followed by solution casting. SPIs based on 1,4,5,8-naphthalene tetracarboxylic dianhydride, 4,4'-diaminodiphenyl ether-2,2'-disulfonic acid and 4,4'-diaminodiphenyl ether have been chosen for the preparation of composite membranes due to their rel...
Sliding friction causes significant structural transformations in the subsurface layers of interacting materials. These changes are associated with complicated mechanochemical processes which include but not limited to plastic flow, refinement of structure, increase of dislocation density, oxidation, delamination and formation of wear debris. In th...
The synthesis, molecular and morphological characterization of a 3-miktoarm star terpolymer of polystyrene (PS, M n = 61.0 kg/mol), polybutadiene (PB, M n = 38.2 kg/mol) and polyisoprene (PI, M n = 29.2 kg/mol), corresponding to volume fractions (ϕ) of 0.46, 0.31 and 0.23 respectively, was studied. The major difference of the present material from...
A methodology for estimating the entanglement density in the amorphous phase of semicrystalline polyolefins was developed. The method is based on the analysis of the density of physical network junctions in the amorphous phase by 1 H NMR T 2 relaxation experiments. The density of the entanglement network was estimated for melt-and high-pressure-cry...
In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and friction. The setup is particularly suited for testing various friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems rel...
Softness and firmness are seemingly incompatible traits that synergize to create the unique soft-yet-firm tactility of living tissues pursued in soft robotics, wearable electronics, and plastic surgery. This dichotomy is particularly pronounced in tissues such as fat that are known to be both ultrasoft and ultrafirm. However, synthetically replicat...
The synthesis and structural characterization of linear PolyC3 polymers
containing trimethylene-1,1-dicarboxylate structural repeat units, with C6F13 and C8F17
fluorinated side chains is described for the first time, and their properties compared
with the traditional polyvinyl structures that display the fluorinated chain on every
second rather tha...