Mikolaj Pochylski

Adam Mickiewicz University | UAM · Faculty of Physics

Aggregation of the polydopamine (PDA) molecular building blocks at the air/water interface leads to obtaining large surface nanometric-thin films. This mechanism follows two possible pathways, namely, covalent or non-covalent self-assembly, which result in a different degree of structure order and, consequently, different structural properties. Con...

Observation of Fano resonances in various physical phenomena is usually ascribed to the coupling of discrete states with background continuum, as it has already been reported for various physical phenomena. Here, we report on Fano lineshapes of nonthermal GHz phonons generated and observed with pumped Brillouin light scattering in gold-silicon thin...

Hypothesis Polymer particles self-assembled into colloidal crystals have exciting applications in photonics, phononics, templates for nanolithography, and coatings. Cold soldering utilizing polymer plasticization by supercritical fluids enables a novel, low-cost, low-effort, chemical-free means for uniform mechanical strengthening of fragile polyme...

Meibography is becoming an integral part of dry eye diagnosis. Being objective and repeatable this imaging technique is used to guide treatment decisions and determine the disease status. Especially desirable is the possibility of automatic (or semi-automatic) analysis of a meibomian image for quantification of a particular gland’s feature. Recent...

The possible 2D-like arrangement of monomers in polydopamine films obtained by autoxidation of the dopamine at the air/water interface was recently reported. Therefore, the morphological and chemical properties should be controllable by tuning the synthesis conditions. In this work, to optimise the synthesis conditions, films were obtained at the a...

Brillouin spectroscopy (BS) is proceeding toward the hundredth year of its scientific journey with a fascinating chronicle of achievements. So far, the inelastic light scattering from acoustic waves has a plethora of discoveries in condensed matter physics, nonlinear optics, and biomedical engineering. Interestingly, Brillouin light scattering (BLS...

The actuation of micro- and nanostructures controlled by external stimuli remains one of the exciting challenges in nanotechnology due to the wealth of fundamental questions and potential applications in energy harvesting, robotics, sensing, biomedicine, and tunable metamaterials. Photoactuation utilizes the conversion of light into motion through...

Owing to the amphiphilic nature of their constituent molecules, binary mixtures of pure liquid surfactants are usually characterized by enhanced nano-segregation and thus can exhibit interesting transport properties and complex macroscopic behavior. In this ambit it was recently shown by Turco Liveri et al. (J. Mol. Liq. 263 (2018) 274–281) at room...

Colloidal crystals realized by self-assembled polymer nanoparticles have prominent attraction as a platform for various applications from assembling photonic and phononic crystals, acoustic metamaterials to coating applications. However, the fragility of these systems limits their application horizon. In this work the uniform mechanical reinforceme...

In recent years, significant progress has been made in the Meibography technique resulting from the use of advanced image analysis methods allowing a quantitative description of the Meibomian gland structures. Many objective measures of gland distortion were previously proposed allowing for user-independent classification of acquired gland images....

Magnetically-induced birefringence is usually low in molecular liquids owing to the low magnetic energy of molecules with respect to the thermal one. Despite this, it has been found that a mixture of dibutyl phosphate and propylamine at propylamine molar ratio (X) around 0.33 surprisingly gives an intense effect (∆n/λ ≈ −0.1 at 1 Tesla). In this pa...

Brillouin microscopy recently attracted much attention for being a promising tool for all-optical label-free determination of mechanical properties of biological samples. Before its widespread utilization for biomedical applications, numbers of nuances related with this technique need to be recognized. In this article, we discuss the process of str...

Proton conducting materials play an important role in a variety of electrochemical devices. Especially, the class of protic ionic glass-formers with fast water-independent proton transport within the Grotthuss mechanism has been envisioned as promising fuel cell electrolytes. Nevertheless, despite a number of reports on protic ionic glasses the des...

Binary mixtures of liquid surfactants, owing to the amphiphilic nature of the molecules involved, can exhibit nano-segregation and peculiar transport properties. The amphiphilicity, and consequently the resulting self-assembly, can be tuned by changing the length of the alkyl chains and the nature of the polar head group. So, in the present study,...

The ferritin is a protein, which serves as a storage and transportation capsule for iron inside living organisms. Continuous charging protein with iron and releasing it from the ferritin is necessary to assure proper management of this important ions within organism. From other side synthetic ferritin have great potential for biomedical and technol...

In this paper the relaxation dynamics of ionic glass-former acebutolol hydrochloride (ACB-HCl) is studied as a function of temperature and pressure by using dynamic light scattering and broadband dielectric spectroscopy. These unique experimental data provide the first direct evidence that the decoupling between the charge transport and structural...

In this work, we describe new experimental setups for Fluorescence Correlation Spectroscopy (FCS) where a long working distance objective is used. Using these setups, FCS measurements in a broad temperature range for a small sample volume of about 50 µl can be performed. The use of specially designed cells and a dry long working distance objective...

We show the results of magnetically induced birefringence measurements performed in binary mixtures of simple molecular liquids. New excess function was introduced based on experimentally determined values of Cotton-Mouton constant - a quantity directly related to the induced orientation of anisotropic molecules. Concentration dependencies of exces...

Pure surfactant liquids and their binary mixtures, owing to the amphiphilic nature of the molecules involved, can exhibit nano-segregation and peculiar transport properties. The possibility of opportunely choosing the amphiphiles should lead to the formation of anysotropic aggregates which can be oriented by an external factor like a magnetic field...

The shape of the Brillouin light-scattering spectrum recorded from turbid liquids is distinctly distorted compared to that from a transparent sample. The reason for this is the multiple scattering of light within the medium. The usual expression for the Brillouin spectrum does not apply to the multiple scattering situation. In this Letter, we consi...

Recently, the observation of an anomalously large electrorheological effect in the dispersion of nanosized particles of titania in octanoid acid has been reported. Such an enhanced effect was not observed in the similar dispersion of micrometric particles or in more conventional suspensions of silica in silicon oil. It was suggested that this effec...

Electrospray ionization (ESI) is a widely adopted soft ionization method for mass spectroscopy (MS). In spite of the undeniable success of the technique, its mechanisms are difficult to be analytically modelled because the process is characterized by non-equilibrium conditions. The common belief is that the formation of gas-phase ions takes place a...

We have studied the magnetically induced optical birefringence Δn of horse spleen ferritin (HSF) and aqueous suspensions of several different-sized iron oxyhydroxide nanoparticles coated with different polysaccharides mimicking ferritin. The structure and dimensions of the akaganeite mineral core were characterized by XRD and TEM, respectively. The...

When bulk water is cooled down into deeply supercooled state the high-frequency sound velocity exhibit a minimum. This strange behaviour, not observed in any other liquid, can be explained with anomalous temperature dependence of ultrasonic velocity (which decrease with decreasing temperature) and with a presence of the structural relaxation proces...

When a liquid is supercooled, it will return, within a finite time elapsed, to stable thermodynamic equilibrium. The path towards equilibrium begins as a fast process which adiabatically drives the system to solid-liquid coexistence. Only at later stage will solidification proceed with the expected exchange of thermal energy with the external bath,...

Natural ferritin is the iron-storage protein of animals, plants, and bacteria. It is a spherical biomacromolecule of external diameter about 12 nm composed of 24 protein subunits arranged as a hollow sphere of approximately 8 nm in diameter. Inside the sphere, iron is stored in the ferric oxidation state as a complex molecule with a crystallographi...

The influence of interactions between particle surface and host fluids in electrorheological suspensions is explored. It is observed that dispersions of nanosized particles of titania in octanoid acid exhibit an anomalously large electrorheologic effect when compared with a similar dispersion of micrometric particles or with a more conventional collo...

The irreversible return of a supercooled liquid to stable thermodynamic equilibrium often begins as a fast process which adiabatically drives the system to solid-liquid coexistence. Only at a later stage will solidification proceed with the expected exchange of thermal energy with the external bath. In this paper we discuss some aspects of the adiab...

We performed a Brillouin scattering experiment on deeply supercooled water and compared the results with similar literature data obtained both at the same and at higher values of the exchanged wave vector. The whole set of available experimental data can be well reproduced with the use of the generalized hydrodynamic model where all the involved th...

In spite of decades of efforts, the puzzle of understanding the anomalies of liquid water remains unsolved. Several plausible theoretical scenarios have been proposed, but distinguishing among them requires accessing temperatures below the homogeneous nucleation temperature Th, which for bulk water is an experimentally impossible task. A widely ado...

Magnetically induced optical birefringence (δ) was measured for magnetoferritin and horse spleen ferritin aqueous suspensions. The δ for magnetoferritin was described in the frame of the Langevin formalism taking into account distribution of core diameter. The established average magnetic dipole moment and core diameter is equal to about 460 μB and...

This work focuses on the dynamic phenomena emerging in self-assembled transient intermolecular networks formed when two different surfactants are mixed. In particular, the relaxation processes in liquid mixtures composed by bis(2-ethylhexyl)amine (BEEA) and octanoic acid (OA) in the whole composition range has been investigated by dielectric spectr...

Magnetically induced optical birefringence (Δn) was measured for magnetoferritin and horse spleen ferritin aqueous suspensions. The Δn for magnetoferritin was described in the frame of the Langevin formalism taking into account distribution of core diameter. The established average magnetic dipole moment and core diameter is equal to about 460 g�B...

The most familiar approaches used to describe the dynamical structure factor from adiabatic density fluctuations in liquids are based on generalized hydrodynamics and on the memory function, respectively. We show that, contrary to the common belief, the two approaches are not fully equivalent. In particular, models based on the memory function of a...

Magnetically induced optical birefringence (Δn) was measured for magnetoferritin (MFer), horse spleen ferritin (HSF) and nanoscale magnetite aqueous suspensions. The anisotropy of optical polarizability was calculated. The average magnetic dipole moment calculated assuming the Langevin model was about 20,000 and 8500μB per particle, for magnetite n...

Magnetically induced optical birefringence is used to investigate pharmaceutically important iron–sucrose aqueous suspensions. XRD and TEM measurements of the system of oxyhydroxide particles stabilised by sucrose have shown that this system contains iron oxyhydroxide in the form of 2–5nm particles. The mineral form of the iron-core is suggested to...

Some Brillouin scattering experiments on aqueous solution of Polyethylene glycol and Polyethylene glycol dimethyl ether are presented. In all the systems non-Debye relaxation processes have been detected, occurring on the picosecond time scale. The average values of the relaxation time distributions fail to follow simple Arrhenius behaviours. The t...

Magnetically induced optical birefringence (Dn) was measured for magnetoferritin (MFer), horse spleen ferritin (HSF) and nanoscale magnetite aqueous suspensions. The anisotropy of optical polarizability was calculated. The average magnetic dipole moment calculated assuming the Langevin model was about 20,000 and 8500 mB per particle, for magnetite...

Recent phenomenological studies have drawn attention to an appealing effect, observed for the first time in 1893, today known as water-bridge. The phenomenon has been ascribed to unknown properties of water. We report some experimental results showing that, contrary to a widely common belief, the phenomenon is not to be related with water neither w...

It was observed that when polarized by an intense electric field, water is able to self-arrange into macroscopic cylindrical wires that can hang up and remain floating against gravity. This phenomenon is now known as a 'water bridge'. Several attempts have been made to give an explanation of this apparently unusual behaviour of water. A number of e...

The structural relaxation behavior of aqueous solution of poly(ethylene glycol) and methoxy-capped poly(ethylene glycol), both of mean molecular mass 400 g/mol, is investigated by Brillouin scattering experiments. In both cases non-Debye relaxation processes have been detected, proceeding on the picosecond time scale. The average values of the dete...

We present the results of a Brillouin scattering experiment on aqueous mixtures of polyethylene glycol polymer cooled below their crystallization temperature. The shape of the registered spectrum changed considerably when the phase transition occurs. The Brillouin profile consisted of two peaks which has been interpreted as a result of the scatteri...

The paper reports an interferometric method for characterisation of the dynamics of transportation of glucose and urea water solutions through a porous polyethyleneterephthalate membrane. The method is based on measurements of the changes in the light refraction indices of solutions partitioned by the membrane, using a Jamina interferometer. Synthe...

Methods of electric field measurement, based on nonlinear optics phenomena, are an interesting alternative to classical measurement methods. The Kerr effect is one of these phenomena. Liquids characterized by large Kerr constant, have unfortunately high permittivity, which makes them useless in measurement method proposed by authors. An investigati...

Brillouin scattering experiments have been carried out on some mixtures of molecular liquids. From the measurement of the hypersonic velocities we have evaluated the adiabatic compressibility as a function of the volume fraction. We show how the quadratic form of the excess compressibility dependence on the solute volume fraction can be derived by...

Brillouin spectroscopy has been used to examine high-frequency dynamical behavior of aqueous solutions of poly(ethylene glycol) (Mw ≈ 400g/mol) at 298K in the entire concentration region. It was found that a relaxation process takes place in the experimental frequency window that significantly affects the shape of experimentally recorded spectrum o...

Brillouin spectroscopy has been applied to study a synthetic polymer and its solutions in polar and nonpolar solvents. Of particular interest has been the effect of concentration, temperature and polarity of the solvent on the mechanical properties of the mixtures studied. The experimental methods applied permitted investigation of the structural r...

Aqueous solutions of poly(ethylene glycol) (PEG) of mean molecular mass of 600 g/mol (PEG600) are investigated by Brillouin scattering technique. At high PEG content, a relaxation phenomenon is observed, which is related to a local rearrangement of the polymer structure where the interaction, via hydrogen bonding, with the solvent molecules plays a...

The concentration dependence of the hypersonic properties of solutions of poly(ethylene glycol) of mean molecular mass 600 g/mol (PEG600) in benzene and toluene has been investigated by Brillouin scattering. The two solvents are very similar in structure and chemical properties, but while benzene is nonpolar, toluene possess a modest dipole. In bot...

Brillouin spectroscopy was used to study the elastic properties of polyethylene glycol solutions in water, benzene and toluene. It has been shown that the spectroscopic features, characterizing the elastic properties of polymer solutions being under study, strongly depend on both polymer concentration and the kind of solvent. The non-monotonic char...

The article presents an X-ray method of detection of neoplasmic changes in people based on measurements from human blood serum. A new X-ray marker Ωrtg is defined and determined directly from the experimental angular distributions of radiation scattered by human blood serum samples. The numerical values of the marker Ωrtg are related directly to th...

Structural relaxation processes in the solutions of poly(ethylene glycol) of mean molecular mass 600 g/mol in CCl4 were analyzed using Brillouin scattering. It was observed that at high polymer content, the system was dominated by the structure of the polymer, where polymer-polymer interactions, together with excluded volume effects, induce the exi...

Selected dimethacrylates forming multifunctional monomers have been studied using Brillouin spectroscopy. The hypersound wave propagation velocity and adiabatic compressibility of the compounds studied have been determined. It has been revealed that these quantities depend on both temperature and the structure of the molecule chain of the monomer....

Temperature dependence of Brillouin light scattering in selected dimethacrylates has been studied. For the compounds studied, being multifunctional monomers, the values of hypersound speed have been determined. It has been established that with increasing temperature the hypersound speed decreases for all substances studied.