Wyniki wyszukiwania - BazTech

1

Preparation of Electrospun Composite PEG/PVP Phase-Change Nanofibers and their Application in Cigarette Cooling Filters

Chen Chen, Li Liqun, Qiao Yuemei, Guo Chunsheng, Ye Yajun, Du He

Fibres & Textiles in Eastern Europe

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2023

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Vol. 31, no. 3

9-13

EN

Composite phase-change nanofibers were prepared by electrospinning with polyethylene glycol (PEG) as the phase-change material (PCM) and polyvinylpyrrolidone (PVP) as the carrier matrix. The high PEG content endowed the nanofibers with an excellent cooling effect and significantly reduced the smoke temperature. For PEG70/PVP nanofibers, the smoke temperature can be decreased 45℃ at the 8th puff, and be kept below 45℃. The cooling test proved that the electrospun PEG/PVP phase-change nanofibers exhibited a desirable cooling performance, improving the comfort of cigarette products. And the composite PEG/PVP phase-change nanofibers present great potential as the cooling cigarette filter material for HnB tobacco application.

2

Characterization of SnO2/TiO2 with the Addition of Polyethylene Glycol via Sol-Gel Method for Self-Cleaning Application

Halin Dewi Suriyani Che, Azliza Azani, Razak Kamrosni Abdul, Abdullah Mohd Mustafa Al Bakri, Salleh Mohd Arif Anuar Mohd, Wahab Juyana A, Chobpattana Varistha, Kaczmarek Łukasz, Nabiałek Marcin, Jeż Bartłomiej

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

243--248

EN

TiO2 is one of the most widely used metal oxide semiconductors in the field of photocatalysis for the self-cleaning purpose to withdraw pollutants. Polyethylene glycol (PEG) is recommended as a stabilizer and booster during preparation of water-soluble TiO2. Preparation of SnO2/TiO2 thin film deposition on the surface of ceramic tile was carried out by the sol-gel spin coating method by adding different amount of PEG (0g, 0.2g, 0.4g, 0.6g, 0.8g) during the preparation of the sol precursor. The effects of PEG content and the annealing temperature on the phase composition, crystallite size and the hydrophilic properties of SnO2/TiO2 films were studied. The X-ray diffraction (XRD) spectra revealed different phases existed when the films were annealed at different annealing temperatures of 350°C, 550°C and 750°C with 0.4 g of PEG addition. The crystallite sizes of the films were measured using Scherrer equation. It shows crystallite size was dependent on crystal structure existed in the films. The films with mixed phases of brookite and rutile shows the smallest crystallite size. In order to measure the hydrophilicity properties of films, the water contact angles for each film with different content of PEG were measured. It can be observed that the water contact angle decreased with the increasing of the content of PEG. It shows the superhydrophilicity properties for the films with the 0.8 g of PEG annealed at 750°C. This demonstrates that the annealed temperature and the addition of PEG affect the phase composition and the hydrophilicity properties of the films.

3

Synthesis, electrical and magnetic properties of polymer coated magnetic nanoparticles for application in MEMS/NEMS

Javid Muhammad Arshad, Sajjad Muhammad, Ahmad Saeed, Khan Muhammad Azhar Shahid, Nadeem Khalid, Amin Niama, Mehmood Zahid

Materials Science Poland

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2020

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Vol. 38, No. 4

553--558

EN

In this research work, polymer coated magnetic nanoparticles were prepared by co-precipitation method. The samples were characterized by XRD, SEM, EDS, VSM and two probe DC conductivity measurements. XRD pattern indicated the existence of a sole cubic phase of Fe3O4 with Miller indices (2 2 0), (3 1 1), (5 1 1), (4 4 0). An average size of magnetic nanoparticles was about 22.9 nm and it was reduced to 21.3 nm and 19.4 nm after 1 wt. %. and 2 wt. % coating of PEG-6000, respectively. The morphology and size of the samples were investigated by scanning electron microscope (SEM). EDX spectra confirmed the coating of PEG on magnetic nanoparticles. Magnetic properties were examined by vibrating sample magnetometer (VSM). Saturation magnetization (Ms) decreased as the concentration of PEG increased in the magnetic material. Electrical properties of uncoated and polymer coated Fe3O4 nanoparticles were studied by two-probe conductivity meter. This study concluded that the thermal flow of charge in polymer coated magnetic nanoparticles can be evaluated at micro and nano level.

4

Rheodynamics non-viscous medium in long (cylindrical) pipes: using the Ostwald-De Ville model

Brovatets Oleksandr, Chоvniuk Yuiry, Moskvitina Anna

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

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2020

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Vol. 9, No 2

19--22

EN

While heating the soil in greenhouses, ground heat exchangers are used, as well as when accumulating heat in soil massifs for further use of heat by heat pumps, or when accumulating heat from solar collectors in heat accumulators. In such cases, a coolant moves in the heat exchangers, which will not freeze or boil, most often these are solutions polyethylene/ethylene glycol, which belong to nonlinear viscous fluids. In this work, the nonisothermal motion of a nonlinear-viscous fluid (within the framework of the Ostwald - de Ville model) in a flat channel with a given heat flow on the wall is investigated. A characteristic feature of the flow of such media is their high thermal sensitivity due to phase and structural transformations. Therefore, with a change in temperature, there is a sharp change in rheological properties. For a number of materials, for example, for polyethylene glycol (ethylene glycol) mixtures, for glycerol solutions, these changes can occur in a fairly narrow temperature range. The flow in a channel is considered, the length of which is much greater than the length of the hydrodynamic and thermal initial sections. The case is investigated when the temperature changes along the channel. Channels of arbitrary cross-section (and, in particular, rectangular and circular) are considered. The situation is analyzed when the temperature changes along the channel, and this change is rather weak in relation to the temperature change along the channel walls (in the transverse direction, that is, in the plane of symmetry). To describe the state of the system, the so-called state diagram (dependence of the temperature on the axis of symmetry of the channel on the heat flux).

5

Minimizing the explosion enthalpy of ammonium nitratewith polyethylene glycol and carboxymethyl celluloseto prevent terrorist attacks

Ozan-Gezerma Ahmet

Chemical and Process Engineering

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2020

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Vol. 41, nr 3

183-–195

EN

The use of ammonium nitrate due to its high nitrogen content (>26%) has made it the most utilizedfertilizer in agricultural areas. However, being easily accessible with this feature encouraged its use fordifferent purposes. Ammonium nitrate is usually produced with large tonnage (>50ton/h) and highcost (>$20million) production processes. Therefore, any changes that can be made in the processmust be applied in the process so that the result can be achieved easily without increasing the costin any way. In this study, it is aimed to reduce the explosion sensitivity of ammonium nitrate usedfor explosive purposes in terrorist attacks. Thus, it was aimed to solve the problem by adding variouschemicals to the ammonium nitrate production process so that it can only be used for agriculturalpurposes. For this purpose, the production process was examined by adding carboxymethyl celluloseand polyethylene glycol to the ammonium nitrate production process and the accuracy of the resultswas tested by instrumental analysis methods

6

Zastosowanie glikolu polietylenowego jako domieszki utrudniającej parowanie wody z betonu samozagęszczającego się

Swamy Naga Ratna Giri P., Rajesh Kumar G., Sri Rama Chand M., Rathish Kumar P.

Cement Wapno Beton

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2017

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R. 22/84, nr 1

26--38

PL

Z odkrytych powierzchni betonu zachodzi w sposób ciągły parowanie wody na skutek różnicy ciśnienia pary wodnej w powietrzu i nad wodą na powierzchni betonu. Powoduje to zmniejszenie stosunku w/c w betonie co może powodować niepełną hydratację cementu i pogorszenie jakości betonu. W związku z tym pielęgnacja betonu jest jednym z najważniejszych zabiegów zapewniających dobre właściwości betonu. Samo-pielęgnacja betonu jest jedną z form specjalnego betonu, która zmniejsza wpływ niedostatecznej pielęgnacji spowodowanej źle wyszkoloną kadrą, brakiem wody, lub jej złą jakością. W artykule omówiono zasady stosowania domieszki poli(glikolu etylenowego) o różnej masie cząsteczkowej, dodawanego do mieszanki betonowej, w celu zapewnienia samo-pielęgnacji betonu. Domieszka ta zmniejsza parowanie wody z betonu i poprawia właściwości samozagęszczającego się betonu. Pokazano wpływ tej domieszki na właściwości betonów różnych klas. Porównano tę technologię z pielęgnacją tradycyjną i z brakiem pielęgnacji betonu.

EN

Continuous evaporation of moisture takes place from exposed concrete surfaces due to the potential difference between the vapour and liquid phases. This will reduce the initial water cement ratio resulting in incomplete hydration of cement and thus lowering the quality of concrete. Hence, curing is considered as one of the basic necessities to achieve good performance concrete. Self-curing concrete is one of the special concretes which mitigates insufficient curing due to a variety of reasons including human negligence, scarcity of water, inaccessibility or bad quality of water available for curing. In the present work, polyethylene glycol of different molecular weights are used as self-curing chemicals in self compacting concretes in optimum dosages during the mixing stage. This has ensured reduction in the evaporation of water and enhanced the performance of SCC. This study has clearly brought out the influence of PEG's in different grades of concrete. A comparison was made with conventional curing and concrete without curing.

7

Wpływ dodatku polietylenoglikolu na właściwości użytkowe wyrobów wapienno-piaskowych

Dachowski R., Kostrzewa P.

Materiały Budowlane

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2016

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nr 6

73--74

PL

Celem prowadzonych prac była modyfikacja składu tradycyjnych wyrobów silikatowych polietylenoglikolem, poprawiająca parametry fizyczne i mechaniczne materiału. Przeanalizowano różnice w gęstości objętościowej, wilgotności i wytrzymałości na ściskanie próbek z dodatkiem, w stosunku do próbek tradycyjnych silikatów. Wyniki badań jednoznacznie wskazują pozytywny wpływ substratu na wyroby wapienno-piaskowe. Obniżeniu o 7% uległa gęstość objętościowa, odnotowano również poprawę wytrzymałości na ściskanie o 17% oraz spadek wilgotności o 20%. Na podstawie obrazów z mikroskopu skaningowego określono fazy uwodnionych krzemianów wapnia występujące w badanych próbkach. Przeprowadzono także dyfrakcję rentgenowską XRD.

EN

The aim of this study was to modify the composition of traditional products silicate to performance enhancing physical and mechanical properties of the material. The differences were analyzed in bulk density, moisture content and compressive strength of samples containing polyethylene glycol, relative to the conventional silicate samples. The test results clearly show the positive effect of the addition on the sand-lime products. Reduced 7% was bulk density, also reported improvement in the compressive strength of 15% and a decrease in humidity of 20%. On the basis of images of scanning electron microscopy were determined phase of hydrated calcium silicates present in the test samples. Was performed also X-ray diffraction XRD.

8

Self-curing concrete under sulfate attack

Bashandy A. A.

Archives of Civil Engineering

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2016

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Vol. 62, nr 2

3--18

EN

Self-curing concrete SC is a concrete type that can be cured without using any external curing regimes. It can perform by several methods such as using lightweight aggregate or chemical agents. In this research chemical curing agent is used to produce SC. This paper reports the results of a research study conducted to evaluate the effect of sulfates on the performance of self-curing concrete compared to ordinary concrete. Samples are immersed in sodium sulfate Na2S04 solution of 4% concentration. Results are measured in terms of compressive strength, tensile strength, flexural strength and mass loss. It was found that the rate of strength loss is noticed at ordinary concrete compared to SC concrete. Sulfate resistance is improved when using self-curing concrete. This improvement appears to be dependent on using a chemical curing agent.

PL

Niniejsza praca przedstawia wyniki badania przeprowadzonego w celu ocenienia wpływu siarczanów na beton samoutwardzalny, w porównaniu z betonem zwykłym. Beton samoutwardzalny SC, jest typem betonu, który utwardzany jest bez jakichkolwiek zewnętrznych systemów utwardzania. Można to osiągnąć stosując kilka metod, jak użycie lekkiego kruszywa, czy też środków chemicznych. W tym badaniu, do produkcji SC wykorzystano chemiczny środek utwardzający. Przygotowano dwie mieszanki betonu. Pierwszą mieszanką SC był beton samo-utwardzalny oparty na poprzednich badaniach. Próbki zostały odlane przy wykorzystaniu zwykłego cementu portlandzkiego, zgniecionego dolomitu o maksymalnym rozmiarze nominalnym 12,5 mm, sortowanego piasku ze współczynnikiem delikatności 2,40, pyłem krzemionkowym jako 15% zawartości cementu, super-plastyfikatorem "Addicrete BVF" jako 0,07% zawartości cementu, chemicznym utwardzaczem "Glikolem polietylenowym PEG200" jako 2% składniku cementu oraz z wodą kranową do pierwszej mieszanki betonu. Druga mieszanka betonu CC, jest zwyczajnie utwardzaną mieszanką, o tych samych proporcjach co mieszanka samoutwardzająca, ale bez dodatku chemoutwardzacza "PEG200", aby dać możliwość porównania obu mieszanek. Próbki zostały odlane przy wykorzystaniu dwóch użytych mieszanek, SC i CC. Drugą mieszanką betonu była CC, utwardzana przez 28 dni.

9

Encapsulation of L-ascorbic acid via polycaprolactone-polyethylene glycol-casein bioblends

Ozsagiroglu E., Guvenilir Y. A.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 4

32--36

EN

The aim of this study was to encapsulate, L-ascorbic acid, in biopolymers in order to obtain (i) enhancing its encapsulation efficiency (ii) increasing drug release ratio using different pH mediums. Microparticles based on polycaprolactone, polyethylene glycol and casein are prepared by spray drying technique. Microparticles are in vitro characterized in terms of yield of production, particle size, morphology, encapsulation efficiency, and drug release. In this manner, the importance of the study is producing of a stable and effective drug encapsulation system by PCL-PEG-CS polymer mixture by spray dryer. We achieved minimum 27.540±0.656 μm particle size with 0.512 m2/g surface area, 84.05% maximum drug loading, and 68.92% drug release ratio at pH 9.6. Release profiles are fitted to previously developed kinetic models to differentiate possible release mechanisms. The Korsmeyer–Peppas model is the best described each release scenario, and the drug release is governed by non-Fickian diffusion at pH 9.6. Our study proposed as an alternative or adjuvants for controlling release of L-ascorbic acid.

10

Wpływ dodatku glikolu poli(etylenowego) na właściwości mas lejnych do wytwarzania form ceramicznych na osnowie SiC do zastosowań w odlewnictwie precyzyjnym części turbin lotniczych

Małek M., Wiśniewski P., Matysiak H., Sitek R., Kurzydłowski K. J.

Przetwórstwo Tworzyw

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2014

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[R.] 20, nr 1 (157)

40--49

PL

W artykule przedstawiono wyniki badań właściwości technologicznych mas ceramicznych na osnowie SiC mogących znaleźć zastosowanie do produkcji form odlewniczych do odlewania precyzyjnego części turbin lotniczych. Zawiesiny ceramiczne z SiC o stężeniu 65% otrzymano w mieszadle mechanicznym z dodatkiem 6, 10, 15% wag. glikolu poli(etylenowego) spełniającego rolę spoiwa oraz upłynniacza. Przeprowadzono szereg badań materiałoznawczych dla proszku, polimeru oraz wytworzonych mas lejnych, w tym lepkość względną i dynamiczną, pomiar gęstości, pH oraz zanurzeniowy test płyty mosiężnej. Pomiary prowadzono przez 96 h.

EN

The presented paper relate the application of SiC in manufacturing shell moulds for investment casting of aircraft turbine elements. The tested shell moulds were produced through the „dip and stucco” method. Ceramic slurries with a SiC concentration of 65% wt. were applied. The polyethylene glycol was added at different ranges (6, 10, 15% wt.) as a binder and a flow agent. The characterization of SiC powder was done by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) methods. Properties of ceramic slurries such as: relative and dynamic viscosity, density, pH and plate weight were studied using a range of techniques. The results shows that slurries based on SiC and polyethylene glycol meet the investment casting requirements of aircraft turbine parts and have very promising properties.

11

Influence of polyethylene glycol concentration on morphology of polypropylene membranes

Lenart P., Kotra-Konicka K., Kalbarczyk J.

Challenges of Modern Technology

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2014

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Vol. 5, no. 2

9--14

EN

This work studied the influence of polyethylene glycol (PEG) concentration on the polypropylene membranes morphology. Polypropylene membranes were modified with argon plasma and then immersed in PEG solution with various concentration between 50-80%. Changes of membranes morphology were observed by scanning electron microscope, Fourier transform infrared spectroscopy and contact angle measurements.

12

Self-assembling micelles obtained from PLLA/PEG and PDLA/PEG block copolymers in aqueous solutions

Wu X, Li S.

Engineering of Biomaterials

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2012

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Vol. 15, no. 113

6--8

EN

A series ofpolylactide-poly(ethylene glycol) (PLA- PEG) block copolymers were synthesized by ring-opening polymerization of L- or D-lactide in the presence of mono- or dihydroxyl PEG, using nontoxic zinc lactate as catalyst. Micelles were then prepared by direct dissolution of the obtained copolymers in aqueous medium without heating or using any organic solvents. Aqueous gel permeation chromatography and dynamic light scattering measurements were carried out to characterize the resulting micelles. Generally, mixed micelles containing both PLLA/PEG and PDLA/PEG copolymers appear lager and more compact compared to single ones. However, the size of mixed micelles is smaller than that of single ones which exhibit an anisotropic structure since stereocomplexation disfavors the formation of anisotropic micelles. The copolymer parameters such as structures, molar mass and PEG fraction strongly influence the formation of anisotropic micelles, and thus lead to various micellar sizes.

13

Modyfikacja warstwy wierzchniej fosforanów wapnia polimerami biodegradowalnymi

Szubert M., Adamska K., Voelkel A., Buchwald T., Szybowicz M.

Engineering of Biomaterials

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2012

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Vol. 15, no. 116-117 spec. iss.

29--32

PL

Celem pracy była modyfikacja warstwy wierzchniej biomateriałów ceramicznych należących do grupy fosforanów wapnia-hydroksyapatyt (HA) oraz ß-fosforan trójwapniowy (ß-TCP), a następnie określenie wybranych właściwości biologicznych otrzymanych materiałów. Jako modyfikatory zastosowano dwa polimery biodegradowalne: glikol poli(oksy etylenowy) (PEG) oraz polihydroksymaślan (PHB). Pomyślność procesu modyfikacji potwierdzono za pomocą spektroskopii w podczerwieni (FT-IR; ATR) oraz spektroskopii Ramana. Biomateriały przed modyfikacją oraz po modyfikacji poddano testom określającym ich zdolność do degradacji oraz narastania hydroksyapatytu. Test degradacji przeprowadzono zanurzając materiały w roztworze buforowym tris-HCl przez okres czterech tygodni, w ciągu których dokonywano pomiaru masy w odstępach tygodniowych. W celu zbadania zdolności wzrostu hydroksyapatytu na powierzchni materiałów, próbki inkubowano w płynie symulującym osocze krwi (SBF) w temperaturze 37oC przez miesiąc. Zmiany zachodzące na powierzchni badanych materiałów rejestrowano w odstępach tygodniowych za pomocą skaningowego mikroskopu elektronowego (SEM) oraz spektroskopii w podczerwieni. Na podstawie przeprowadzonych badań stwierdzono, że szybkość procesu degradacji (obliczona na podstawie procentowego ubytku masy) biomateriałów modyfikowanych zwiększyła się w przypadku hydroksyapatytu zarówno modyfikowanego PEG jak i PHB, natomiast w przypadku ß-TCP szybkość ta była na porównywalnym poziomie w porównaniu do materiału wyjściowego. Analiza obrazów wykonanych z wykorzystaniem SEM wykazała widoczne zmiany w morfologii powierzchni modyfikowanych materiałów. Zmiany te mogą świadczyć o właściwościach osteoindukcyjnych tych biomateriałów.

EN

The main aim of this study is surface modification of ceramic biomaterials, belong to calcium phosphates group-hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP)- and furthermore selected biological properties of obtained materials is determined. Polyethylene glycol (PEG) and polyhydroxybutyrate (PHB) are used as modifiers. The process of surface modification of biomaterials is confirmed by means of infrared spectroscopy (FT-IR; ATR) and Raman spectroscopy. In presented study the obtained powder materials are formed on pellets and incubated in SBF (simulated body fluids solution) at body temperature. Formation of apatite layer was evaluated by means of Scanning Electron Microscope (SEM). The degradation behavior was carried out at 37oC for up to 28 days at pH 7.4 using Tris-HCl solution, and is referred to as simulation solution testing. The samples were incubated for 7, 14, and 28 days for the both simulation solution testing, using triplicate samples. The degradation testing of modified HA showed a higher weight loss compared with unmodified HA. In the case of ß-TCP the degradation rate was in similar level before and after modification. SEM images of materials showed visible changes in all of biomaterials surfaces. This changes may suggest the ability to form HA and osteoinductive properties of materials.

14

Adhesion and growth of human osteoblast-like cells on aliphatic polyesters with different chemical composition, surface roughness and modification with hydroxyapatite

Vagaska B., Bacakova L., Pamuła E., Lisa V., Dobrzyński P.

Inżynieria Biomateriałów

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2006

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R. 9, nr 58-60

4-7

EN

In this study we have investigated the effect of three groups of polymeric foils on the behavior of MG 63 osteoblast-like cells. These included (1) poly(L-lactide) (PLLA) compared with newly synthesized copolymer of L-lactide and trimethylene carbonate (PLTMC 50:50), (2) three samples made of glycolide and epsylon-caprolactone copolymer (PGCap) with different surface roughness and topography, and finally (3) copolymer of glycolide with L-lactide (PGLA) compared with its modification with hyroxyapatite deposits. On the 1st and 4th day of cultivation the cell number on all of the samples was lower than on control polystyrene culture dish. However, on day 8 after seeding, the values on the tested samples caught up with the control polystyrene. In the first group the cell number of PLTMC was higher than on polystyrene or PLLA. In the second group, the number of cells on PGCap samples of the lower surface roughness (RRMS 130 and 180 nm) was significantly higher than that on the control polystyrene, whereas on the PGCap samples with the rounghness in micrometers, it was comparable to the value on the polystyrene. Moreover, the surface roughness influenced the cell adhesion area. The cells on the sample with the highest roughness index were roundly shaped and their adhesion area was significantly lower, because the cells were restricted in their spreading by the surface structure of the material. In the last group, the number of cells on day 8 on the polymer with hydroxyapatite deposits was significantly higher than on standard tissue culture polystyrene dish, as well as on unmodified PGLA foil, which suggested that hydroxyapatite supports cell proliferation.