Pavla Capkova

Pavla Capkova
Jan Evangelista Purkyně University | UJEP · Faculty of Scienece

About

161
Publications
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2,297
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Additional affiliations
January 2011 - present
Jan Evangelista Purkyně University
Position
  • Vice-dean for Research and Foreign affairs

Publications

Publications (161)
Article
Full-text available
Layered crystal structures tend to form flat platelet-like crystallites, and nanofibers having such a structure exhibit strip-like morphology. Crystallographic plane forming the dominant flat surface of the nanofibers can be used for surface modification with catalytically active nanoparticles capable of anchoring to the dominant flat surface. In t...
Article
Electrospun nanofiber membranes for filtration and medical applications are still under rapid development. The common example of membranes - polyamide 6 (PA6) with hydrophilic properties was selected for the conversion to hydrophobic membranes. The fiber diameter in the membrane is about 100 nm. To reach the hydrophobic properties, the hydrophilic...
Article
Present paper shows special benefits of low energy plasma treatment on PVDF electrospun nanofiber membrane, where the plasma power 120W has been applied between two flat electrodes creating homogeneous electric field. This experimental arrangement was crucial for two specific effects: (1) Surface activation took place by the scission of C-H bonds w...
Article
Polyacrylonitrile (PAN) membranes have been prepared using needleless electrospinning with wire electrode and characterized by a series of methods HRSEM, XRD, air permeability and area weight measurements in dependence of high voltage and electrode distance. HRSEM analysis revealed the tendency to longitudinal rolling of strip-shaped PAN fibers for...
Article
Full-text available
Stable antimicrobial nanofibrous membrane for air filtration based on polyamide 6 (hereafter PA6) modified by 1-dodecyltrimethylammonium bromide (DTAB) has been prepared by electrospinning using one-step technology, i.e. with modifying antimicrobial agent dissolved in spinning solution. Stability of antibacterial membrane function has been tested b...
Article
TiCN thin coatings with various different carbon contents were deposited using cathode arc evaporation of pure titanium in a mixture of N2 and C2H2 gasses at a constant pressure of 1.5 Pa. The analyses show a transition from a stoichiometric to a non-stoichiometric coating structure with an increasing C2H2 content. Moreover, the increase in the ace...
Article
Antimicrobial polyvinylidene fluoride (PVDF) membrane modified by dodecyltrimethyl ammonium bromide (DTAB) has been electrospun using simple one-step technology, where the modifying agent DTAB is dissolved in spinning solution. X-ray photoelectron spectroscopy and electrokinetic analysis confirm reliably the presence of DTAB on the nanofibers surfa...
Article
Antibacterial nylon 6 (PA6) nanofibers have been prepared in one-step procedure using Nanospider technology. Chlorhexidine (CHX), 1-dodecyltrimethylamonium bromide (DTAB) and benzyltrimethylamonium bromide (BTAB) have been used as antibacterial agents. Samples were characterized by a series of analytical and testing methods to investigate the surfa...
Article
AlSiN coatings were prepared by the cathodic arc deposition method at a temperature of 400°C and pressure of 2.6 Pa. The chemical composition, determined by SEM/EDS analysis, shows that the AlSiN coating presented here has a stoichiometry structure (Al40Si9N51). XPS and XRD analyses indicated AlN in both cubic and hexagonal modifications in the coa...
Article
Plasma treatment of montmorillonite has been investigated as a prerequisite for design of functional nanostructures, based on clay minerals. The effect of short-term (20 s) plasma treatment on structure and bonding of montmorillonite has been analyzed using combination of X-ray powder diffraction and infrared spectroscopy. Results showed that dehyd...
Article
Novel organic/inorganic hybrid materials with carbosilane fillers were developed. New carbosilane dendrimers of the first (Dm1) and second (Dm2) generations bearing four and eight cationic ammonium groups on their periphery were synthesized first. Their structure was elucidated by NMR spectroscopy and ESI-HRMS whereas their thermal stability was co...
Article
Recently we reported the evidence of solubility of Co in solid C60 found from magnetization of the CoxC60 mixture films (Phys. D: Appl. Phys. 48, 2015, 335002). In the present study we identified the Co solubility limit (xc=2) and specified phase evolution in the CoxC60 mixtures in a wide interval of the Co concentrations (0<x<50) that was carried...
Article
Present paper deals with the effect of gelatin on the structure, phase composition, and morphology of the electrospun chitosan/PEO nanofibers. Special attention is paid to the surface chemistry, surface structure and surface morphology of nanocomposite fibers, as these parameters are crucial for biomedical applications and for eventual subsequent s...
Article
The polypropylene (PP) powder is used for various purposes. However, its good mechanical properties are accompanied by poor wettability. The PP powder was therefore modified by air plasma in fluidized bed reactor (FBR). Several techniques were employed to characterize the treated samples - XPS for the surface chemistry, electrokinetic analysis for...
Article
Polyaniline-montmorillonite nanocomposite was prepared from anilinium sulfate (precursor) and ammonium peroxodisulfate (oxidizing agent) using simple one-step method. The resulting nanocomposite obtained in powder form has been pressed into tablets using various compression pressures (28-400 MPa). Electrical conductivities of tablets in two perpend...
Article
The combination of cobalt with nanocarbons promises hybrid nanostructures that are ideal for the development of memory storage and spin-transfer electronics. Here, we report a dramatic effect of composition on the magnetic properties of the Cox C60 mixtures, whose nanostructure was organized upon simultaneous deposition and sequential exposure to a...
Article
Full-text available
The present work describes the effect of montmorillonite (MMT) particles on the alignment of conducting polyaniline (PANI) chains in a PANI/MMT composite. The composite was prepared both as a powder, pressed into pellets, and as thin films deposited on glass surfaces. For comparison, pure PANI was also prepared in these two forms. A combination of...
Article
Full-text available
Phase composition, morphology and surface properties of nylon-6 nanofibers prepared by Nanospider technology have been studied for dependence on spinning distance using a combination of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrokinetic analysis, and scanning electron and transmission electron microscopy (SEM, TEM). The...
Article
Highly electrically conductive ceramic material based on aluminosilicate/graphene nanocomposite has been prepared by high pressure (400 MPa) compaction of montmorillonite intercalated with polyaniline followed with the high temperature (1400 °C) treatment in argon atmosphere. Tablets pressed from polyaniline/montmorillonite intercalate exhibits str...
Article
Full-text available
Three different methods have been used for the preparation of polyaniline/montmorillonite nanocomposites: (i) two-step process: first intercalation of anilinium into Ca-montmorillonite structure followed with oxidisation; (ii) two-step process: first oxidisation with subsequent addition of Ca-montmorillonite aqueous suspension; (iii) one-step proce...
Article
Kaolinite-TiO2 nanocomposite matrix (KATI) coated with polyaniline (PANI) layer has been prepared in powder form and pressed into tablets. The conductivity was studied in dependence on (1) wt.% of TiO2 in KATI matrix and (2) thermal pre-treatment of KATI matrix. The anisotropy factor alpha, i.e. the ratio of inplane conductivity and conductivity in...
Article
Full-text available
This work is focused on mechanisms that play key role during the polyaniline (PANI) thin film formation on the glass substrate. For the investigation molecular modeling using empirical force fields was performed. Two sets of models were investigated to capture possible influences that may have effect on the PANI thin film formation. Molecular model...
Article
Full-text available
Polyaniline/montmorillonite (PANI/MMT) intercalate pressed into pellets using the pressure 28 MPa has been prepared in order to achieve two-dimensional conductivity which is close to pure PANI, however with improved mechanical and thermal stability (due to the presence of silicate). Structure-conductivity relationship has been investigated using X-...
Article
A simple method for the estimation of the most suitable mutual crystallographic orientations of TiO2 nanoparticles anchored on SiO2 substrate is presented in this work. Number of overlapping titanium and oxygen atoms creating atomic pairs can be used to quantify the structure compatibility. These atomic pairs are obtained directly from non-optimize...
Article
New approach of chemical bath deposition combined with drying of freshly polymerized PANI films in DC high-voltage static electrical field 0.6-2.7 kV/cm has been applied in present work. AFM and SEM microscopy revealed the significant changes of structure and morphology of PANI films, however the most important result of high-voltage treatment was...
Article
Pressed tablets from polyaniline/phyllosilicate nanocomposites have been prepared under various conditions in order to optimize anisotropic conductivity of composite by ordering of flat phyllosilicate particles intercalated with polyaniline (PANI). Powder samples of PANI/phyllosilicate nanocomposites have been prepared using two phyllosilicates, mo...
Article
In order to optimize the technology with respect to maximum conductivity, transmittance and optical homogeneity, the time-controlled chemical bath deposition process was used to prepare polyaniline (PANI) thin films on glass substrate. Two different precursors have been used for PANI thin films preparation: anilinium sulfate and aniline hydrochlori...
Article
The photoactive quartz sand/TiO2 composites were prepared by thermal hydrolysis of the suspension obtained by addition of quartz sand to a titanyl sulfate solution. The required amount of TiO2 in the prepared composites (i.e. 9, 22 and 45 wt.%, respectively) was achieved using a variable titanyl sulfate/quartz ratio. As reference materials, pure Ti...
Article
Full-text available
Polyaniline (PANI) is one of the most studied and applied conducting polymers because of the unique conduction mechanism and high environmental stability. PANI could be synthetized by chemical or electrochemical methods. For this study PANI thin films deposited on glass substrate were prepared by chemical bath deposition from anilinium sulfate (pre...
Article
Full-text available
Present work deals with the study of pellets pressed from polyaniline/montmorillonite (PANI/MMT) nanocomposite. PANI/MMT nanocomposite has been prepared using anilinium sulfate as a precursor and ammonium peroxydisulfate as an oxidizing agent. Prepared powder samples were pressed into pellets at room temperature, without any lubrication and binder....
Article
Full-text available
Electrical conductivity is the well known property of polyaniline (PANI) for which this material is used in wide range of applications. According to the way of its use various forms of PANI, from powder to thin films deposited on different substrates, are prepared. Glass represents one of the often used substrates, mainly due to its chemical stabil...
Article
A simple molecular modeling method for the characterization of polymeric drug carriers is presented. Six biodegradable polymers have been investigated as drug carriers using molecular simulations: L-polylactide, D-polylactide, chitosan, polyglycolic acid, polyethylene glycol and cellulose. Cyclosporine A has been chosen as a model drug substance. C...
Conference Paper
Molecular modeling is nowadays routinely employed in many branches of science and pharmaceutical chemistry is not an exception. This modeling study was focused on behavior of amphiphilic gels mixture serving as a carriers of drug cyclosporine A (CsA) and the main aim was to find whether the contact with small amount of paraffin oil during the produ...
Conference Paper
Full-text available
Structure - electrical conductivity relationship was investigated for the polyaniline (PANI) pressed pellets. PANI powder was prepared from aniline sulfate (precursor) and ammonium peroxodisulfate (oxidizing agent). Pressed pellets were prepared from this powder form of PANI using LECO handpress (applied pressure 28 MPa) at room temperature. Struct...
Conference Paper
Conducting polymers are nowadays in forefront of the interest because of its very good electrical conductivity combined with other beneficial properties. Polyaniline is one of the widely studied conducting polymers due to its light weight, low cost, excellent environmental stability and reversible acid-base switching of its electrical conductivity....
Article
The use of synchrotron X-ray diffraction to study the crystallographic structure of nanostructure polyaniline is reported. It is shown to reveal unprecedented crystallographic information, particularly for early-stage self-assembled intermediate structures that are critical to the formation process. We discuss the new peaks, which are enabled here...
Article
Full-text available
The adhesion of TiO2 (anatase structure) nanoparticles to kaolinite substrate was investigated using molecular modeling. Universal force field computation, density function theory computation, and a combination of both two approaches were used. This study enabled the adhesion energy for the TiO2/kaolinite nanocomposite to be estimated, and revealed...
Conference Paper
Full-text available
Conductive polyaniline (PANI) is nowadays in the forefront of the interest because of its very good electrical conductivity combined with other beneficial properties such as light weight and low cost. Not only PANI in the powder form, but also PANI thin films are widely investigated, because they can be used in wide field of applications, for examp...
Article
Full-text available
The adsorption of methylene blue (MB) on montmorillonite from acid solutions has not yet been studied in detail. In this paper the adsorption of this dye on Ca/SAz montmorillonite from 0.32, 0.80 and 1.60M HCl solutions at ambient temperature and after 2 hours leaching was carefully studied and evaluated. Under the above conditions the MB/SAz inter...
Article
Structure and behavior of amphiphilogel nanoparticles as a drug carriers for cyclosporine A (CsA) have been studied by the molecular modeling using empirical force field. Five atomistic models of a gel-based emulsions (GEM) with various gel compositions have been investigated in order to find a system most similar to a sixth atomistic model of self...
Article
Preparation of nanocomposite kaolinite/TiO(2), using hydrolysis of titanyl sulfate in the presence of kaolin was addressed. A variable (kaolin)/(titanyl sulfate) ratio has been used in order to achieve the desired TiO(2) content in prepared nanocomposites. Calcination of the composites at 600 °C led to the transformation of the kaolinite to metakao...
Article
The reason for the preparation and characterization of the novel antibacterial silver/vermiculites (Ag/V) together with the silver/montmorillonites (Ag/M) was that the information on the vermiculite structure change and stability of Ag/V in water as well as its effect on bacteria are sporadic. The vermiculite (V), (Si(3.02)Al(0.98))(IV) (Mg(2.27)Al...
Article
Adhesion of silver nanoparticles on the montmorillonite substrate was investigated using molecular modeling (force field calculations) and experiment (infrared spectroscopy, high-resolution transmission electron microscopy). Modeling revealed the preferred orientation of silver nanoparticles on the silicate substrate and showed the strong dependenc...
Article
Adhesion of silver nanoparticles on the montmorillonite and kaolinite substrates has been investigated using molecular modeling (force field calculations) that enabled the estimation and comparison of adhesion energies for Ag/montmorillonite and Ag/kaolinite nanocomposites and revealed the preferred orientation of Ag nanoparticles on the silicate s...
Article
We have used atomistic molecular dynamics simulations to consider 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescent probes in a fluid dipalmitoylphosphatidylcholine bilayer with 5 and 20 mol % cholesterol (CHOL). We show that while DPH affects a number of membrane properties, the perturbations induced by DPH depend on the concentration of cholesterol...
Article
The intensity of fluorescence of montmorillonites fully saturated by methylene blue (MB) is very poor due to energy dissipation in MB aggregates. A series of reduced charge montmorillonites (RCM) were prepared from Na-homoionic SWy and Ca homoionic SAz with the aim to decrease the MB aggregation. Fine tuning MB adsorption degree by charge reduction...
Article
Full-text available
The surface area of various types of montmorillonites (MMT) with different values of layer charge plays a very important role in surface arrangement of methylene blue cations (MB). Photoluminescence measurements can be strongly or partially influenced by this surface arrangement of cations. For these reasons and on the basis of our previous results...
Article
Intercalation of 1H-imidazole (IM) and his derivative 2-phenylimidazole (2-PhIM) into the interlayer spaces of both natural Ca(II)-montmorillonite (Ca-MMT) and Cu(II)-montmorillonite (Cu-MMT) was carried out by two ways, solid-state intercalation and intercalation from solution. Only the presented solid-state intercalation gave required results. In...
Chapter
Full-text available
Titanium dioxide (TiO2) is the most studied photocatalyst with application potential in many branches of industry. Building industry represent the sector, where the photoactive TiO2 have been already successfully utilized. Concretes, plasters, paints are building materials where the photoactive TiO2 is widely tested. However the amount of TiO2 in t...
Article
Full-text available
Molecular modeling using empirical force field revealed the differences between the surface and interlayer arrangement of the dye guest molecules in vermiculite intercalated with the divalent methyl viologen cation (MV(2+)). Conformation and anchoring of MV(2+) cations on the silicate layer in the interlayer space of vermiculite host structure is d...
Article
Full-text available
Three procedures (P) were applied to prepare silver nanoparticles on natural Ca-montmorillonite (MT). The intercalation of the montmorillonite with silver nitrate in aqueous solution (P1), the intercalation of the montmorillonite with silver nitrate in glycerol (P2) and the successive combination of both P1 and P2 methods resulted to P3 method. X-r...
Article
Full-text available
Two types of clay minerals-montmorillonite and vermiculite have been chosen as a host matrix for the intercalation of methyl red (MR) in order to investigate a possible fluorescence tuning via dye-clay interactions. The effect of silicate layer charge on the structure and fluorescence of dye-clay intercalated hybrid nanostructures was investigated...
Article
Samples of Mg4Al2 layered double hydroxide (LDH) intercalated with p-methylbenzoate and p-bromobenzoate anions were prepared by reconstruction of calcined LDH. The interlayer arrangement of guests was investigated by molecular modeling combined with X-ray powder diffraction and thermogravimetry. Molecular modeling was carried out in a Cerius2 model...
Article
The ordering of three different sizes of quaternary ammonium salts (QUATs) has been studied with respect to concentration of guests in the host's interlayer gallery. From the modeling, we could verify that small molecules of n-butylammonium salt build a monolayer structure in the vermiculite gallery without reference to concentration. On the other...
Article
Full-text available
The structure of Zn4Al2 Layered Double Hydroxide intercalated with benzencarboxylate (C6H5COO−) was solved using molecular modeling combined with experiment (X-ray powder diffraction, IR spectroscopy, TG measurements). Molecular modeling revealed the arrangement of guest molecules, layer stacking, water content and water location in the interlayer...
Article
The distribution of various aggregates (dimers, trimers, and tetramers) of methylene blue (MB) formed in aqueous solution at various concentrations of dye has been calculated using the equilibrium aggregation constants betaq. Two montmorillonite samples with different cation exchange capacities, surface areas, and interlayer distances d001, Na-SWy,...