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1.
Chemistry ; : e202402319, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39155819

RESUMO

Nanoparticles can offer an alternative approach to fabricate phase-change materials. The chemical synthesis of GeTe nanoparticles using organometallic precursors exploits high-boiling solvents and relatively high temperatures (close or even above crystallization temperatures), as reported in the available literature. The aim of this work is the preparation of GeTe nanoparticles by a low-temperature synthetic method exploiting new organometallic precursors and common organic solvents. Indeed, different preparation methods and characterization of GeTe nanoparticles is discussed. The characterization of the prepared nanomaterial was performed on the basis of X-ray diffraction, transmission electron microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, laser ablation time-of-flight mass spectrometry, Raman scattering spectroscopy, and dynamic light scattering. The results show that the low-temperature synthetic route leads to amorphous GeTe nanoparticles. Exploited organometallic precursor is stabilised by neutral ligand which can be isolated after the reaction and repeatedly used for further reactions. Furthermore, GeTe nanoparticle size can be tuned by the conditions of the synthesis.

2.
Int J Mol Sci ; 24(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36675219

RESUMO

Antibacterial coatings on biomedical instruments are of great interest because they can suppress bacterial colonization on these instruments. In this study, antibacterial polymeric thin coatings were deposited on teflon substrates using atmospheric pressure plasma polymerization from a propane-butane mixture. The plasma polymerization was performed by means of surface dielectric barrier discharge burning in nitrogen at atmospheric pressure. The chemical composition of plasma polymerized propane-butane films was studied by energy-dispersive X-ray spectroscopy (EDX) and FTIR. The film surface properties were studied by SEM and by surface energy measurement. The EDX analysis showed that the films consisted of carbon, nitrogen and oxygen from ambient air. The FTIR analysis confirmed, in particular, the presence of alkyl, nitrile, acetylene, imide and amine groups. The deposited films were hydrophilic with a water contact angle in the range of 13-23°. The thin film deposited samples were highly active against both S. aureus and E. coli strains in general. On the other hand, the films were cytocompatible, reaching more than 80% of the cell viability threshold compared to reference polystyrene tissue.


Assuntos
Propano , Staphylococcus aureus , Escherichia coli , Nitrogênio , Pressão Atmosférica , Antibacterianos/farmacologia , Butanos
3.
Int J Mol Sci ; 24(24)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38139283

RESUMO

Poly(2-oxazoline) is a promising new class of polymeric materials due to their antibiofouling properties and good biocompatibility. Poly(2-oxazoline) coatings can be deposited on different substrates via plasma polymerization, which can be more advantageous than other coating methods. The aim of this study is to deposit poly(2-oxazoline) coatings using a surface dielectric barrier discharge burning in nitrogen at atmospheric pressure using 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline vapours as monomers and compare the film properties. For the comparison, the antibacterial and cytocompatibility tests were peformed according to ISO norms. The antibacterial tests showed that all the deposited films were highly active against Staphylococcus aureus and Escherichia coli bacteria. The chemical composition of the films was studied using FTIR and XPS, and the film surface's properties were studied using AFM and surface energy measurement. The cytocompatibility tests showed good cytocompatibility of all the deposited films. However, the films deposited from 2-methyl-2-oxazoline exhibit better cytocompatibility. This difference can be explained by the different chemical compositions and surface morphologies of the films deposited from different monomers.


Assuntos
Antibacterianos , Oxazóis , Polimerização , Oxazóis/farmacologia , Oxazóis/química , Antibacterianos/farmacologia , Escherichia coli
4.
Rapid Commun Mass Spectrom ; 33(7): 719-726, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30710492

RESUMO

RATIONALE: Gallium selenide thin films important for electronics and phase-change materials are prepared via pulsed laser deposition (PLD); however, there are no studies concerning the analysis of gallium selenide clusters formed in the gas phase. Laser desorption ionisation (LDI) combined with time-of-flight mass spectrometry (TOF-MS) has great potential to generate charged Gam Sen clusters, to analyse them and thus to develop new materials. METHODS: LDI of Ga-Se mixtures using a pulsed laser (337 nm nitrogen) was used to generate gallium-selenide clusters. Mass spectra were recorded (in positive and negative ion mode) on a TOF mass spectrometer equipped with a quadrupole ion trap and reflectron mass analyser. RESULTS: Ga-Se mixtures were found to be suitable for laser ablation synthesis (LAS) of gallium selenide clusters, although their composition was strongly dependent on the laser energy. The effect of laser energy on the stoichiometry of the generated clusters was established. In total, over 100 gallium selenide Gam Sen clusters were generated and identified from Ga-Se mixtures. LDI of Ga2 Se3 crystals showed almost the same clusters up to m/z 1000 with lower intensities, whereas no clusters from Ga2 Se3 were observed above m/z 1000. CONCLUSIONS: A family of over 100 gallium selenide clusters, generated and identified for the first time, shows rich and complex chemistry. Some of the clusters represent new compounds that have the potential to be used in the development of advanced materials.

5.
Environ Monit Assess ; 191(3): 181, 2019 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-30798372

RESUMO

Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was applied for the determination of Cd and Zn distributions within the leaves of Cd- and Zn-hyperaccumulating plants, Noccaea caerulescens, N. praecox, and Arabidopsis halleri, in contrast to nonaccumulator species, Thlaspi arvense and A. thaliana. The elemental mapping of the selected leaf area was accomplished via line scans with a 110-µm-diameter laser beam at a 37-µm s-1 scan speed and repetition rate of 10 Hz. The lines were spaced 180 µm apart and ablated at an energy density of 2 J cm-2. The elemental imaging clearly confirmed that Cd was predominantly distributed within the parenchyma of the T. arvense, whereas in the Noccaea spp. and A. halleri, the highest intensity Cd signal was observed in the veins of the leaves. For Zn, higher intensities were observed in the veins for all the plant species except for A. thaliana. Close relationships between Zn and Ca were identified for the Noccaea spp. leaves. These relationships were not confirmed for A. halleri. Significant correlations were also proved between the Cd and Zn distribution in A. halleri, but not for the Noccaea spp. For both T. arvense and A. thaliana, no relevant significant relationship for the interpretation of the results was observed. Thus, the LA-ICP-MS imaging is proved as a relevant technique for the description and understanding of the elements in hyperaccumulating or highly accumulating plant species, although its sensitivity for the natural element contents in nonaccumulator plant species is still insufficient.


Assuntos
Monitoramento Ambiental , Oligoelementos/análise , Arabidopsis/química , Brassicaceae/química , Cádmio , Folhas de Planta/química , Raízes de Plantas , Thlaspi/química , Zinco
6.
Rapid Commun Mass Spectrom ; 32(10): 789-800, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29520912

RESUMO

RATIONALE: Only a few arsenic phosphides are known. A high potential for the generation of new compounds is offered by Laser Ablation Synthesis (LAS) and when Laser Desorption Ionization (LDI) is coupled with simultaneous Time-Of-Flight Mass Spectrometry (TOFMS), immediate identification of the clusters can be achieved. METHODS: LAS was used for the generation of arsenic phosphides via laser ablation of phosphorus-arsenic mixtures while quadrupole ion trap time-of-flight mass spectrometry (QIT-TOFMS) was used to acquire the mass spectra. RESULTS: Many new Asm Pn± clusters (479 binary and 369 mono-elemental) not yet described in the literature were generated in the gas phase and their stoichiometry determined. The likely structures for some of the observed clusters arbitrary selected (20) were computed by density functional theory (DFT) optimization. CONCLUSIONS: LAS is an advantageous approach for the generation of new Asm Pn clusters, while mass spectrometry was found to be an efficient technique for the determination of cluster stoichiometry. The results achieved might inspire the synthesis of new materials.

7.
Chemistry ; 22(32): 11261-8, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27387792

RESUMO

Methods for the rapid construction of new chemical motifs have the potential to accelerate the development of nanoscience. The synthesis of new chemical entities by laser ablation has been systematically demonstrated by using mixtures of gold and selenium. The compounds generated are detected by time-of-flight mass spectrometry and, for selected compounds, the structure is investigated by using density functional theory optimization. In total, 67 new gold selenide clusters have been synthesized, demonstrating an unsuspected richness in gold chemistry. Chemical species generated in the gas phase might inspire new routes for the synthesis of novel compounds in the solid state.

8.
Rapid Commun Mass Spectrom ; 29(11): 1000-8, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-26044266

RESUMO

RATIONALE: Arsenic tellurides have found important applications in various fields of science, but only a few gold-arsenic tellurides have been reported. Laser ablation synthesis (LAS), a suitable method for the generation of new compounds, has been used to generate clusters from As-Te mixtures, an As-Te glass and Au-As-Te nano-composites. METHODS: Chalcogenide glass nano-layers prepared via Physical Vapour Deposition - thermal evaporation were characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). LAS with laser desorption ionisation quadrupole ion trap time-of-flight mass spectrometry (LDI QIT TOFMS) was used for the generation and analysis of new AuxAsmTen clusters. The stoichiometry of the clusters was determined via isotopic envelope modelling. RESULTS: A simple procedure for the preparation of the Au-As-Te nano-composite was developed. From As-Te mixtures only five binary AsmTen clusters were generated, while from a glass layer 10 binary AsmTen clusters were identified, because during the deposition of the glass the elements reacted with each other to form a complex three-dimensional (3D) structure. Using LAS on the Au-As-Te nano-composite leads to the formation of six unary Ten (n = 1-6), 16 binary (AsmTen and AuxTen), and 31 ternary AuxAsmTen clusters. CONCLUSIONS: LAS was demonstrated to be a useful technique for the generation of AuxAsmTen clusters in the gas phase. More AsmTen clusters were generated from the deposited glass layers than from As-Te mixtures. Most of the ternary AuxAsmTen clusters generated from the nano-composite are reported here for the first time.

9.
Rapid Commun Mass Spectrom ; 29(5): 408-14, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26349462

RESUMO

RATIONALE: Ge(x)As(y)Te(z) glasses have a broad window of optical transparency and high refractive index which make them promising for applications in the infrared region. The aim of this work is to reveal structural motifs which could be present during the fabrication of Ge-As-Te thin films by plasma deposition techniques; such knowledge is important for the optimization of thin film growth. METHODS: Mass spectra were acquired using a laser desorption ionization time-of-flight (LDI-TOF) mass spectrometer equipped with a nitrogen laser (337 nm) coupled with a quadrupole ion trap, and recorded in positive and negative ion reflectron modes. XRD, SEM (EDX) and Raman spectroscopy were also used for the characterization of Ge-As-Te bulk or powdered samples. RESULTS: Bulk Ge(x)As(y)Te(z) samples (x = 10-20%, y = 20-60%, z = 30-70%) were synthesized. LDI-MS of Ge-As-Te powders provided evidence for the formation of both positively and negatively charged clusters, whose stoichiometry was determined as Te(n)(+/-) (n = 1-4), Te(5)(+), binary AsTe(n)(+/-) (n = 1-3), GeTe(n)(+/-) (n = 1-3), As(2)Te(+/-), As(2)Te(3)(+), As(3)Te(+), AsTe(4) (+), Ge(2)H(6) (+/-), ternary GeAsTe(+), GeAsTe(2)(+/-), GeAsH5 (+), GeAsH(6)(+), GeAsH(12)(+), and tertiary GeAsTeH(5)(-), GeAsTeH(8)(-), GeAsTe(2)H(3) (+/-). CONCLUSIONS: The local structure of Gex Asy Tez materials is at least partly different from that of species identified in plasma by mass spectrometry, as deduced from Raman scattering spectroscopy analysis. However, LDI-TOFMS was found to be a suitable technique for the partial structure characterization of Ge-As-Te bulk samples and especially for the identification of the structural motifs present in the plasma during the preparation of the corresponding thin films.

10.
Rapid Commun Mass Spectrom ; 28(6): 577-86, 2014 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-24519820

RESUMO

RATIONALE: Currently, a limited number of gold arsenides have been described, some of which have important industrial applications, Laser ablation synthesis (LAS) has been employed in an attempt to generate some novel gold arsenide compounds. METHODS: LAS of gold arsenides was performed using nano-gold (NG) and arsenic as precursors. The clusters formed during laser desorption ionisation (LDI) were analysed by mass spectrometry using a quadrupole ion trap and reflectron time-of-flight analyser to determine the stoichiometry. UV/VIS spectrophotometry was used to follow possible hydrothermal synthesis of gold arsenides. RESULTS: LAS of NG yielded singly charged gold clusters Aum (+(-)) (m = 1-35). LAS of bulk arsenic and nano-arsenic produced Asn (+(-)) clusters with n = 2-10 and n = 2-20, respectively. Laser ablation of Au-As nano-composites or NG-As mixtures generated Aum (+(-)) (m = 1-12), Asn (+(-)) (n = 3-4), and several series of Aum Asn (+(-)) (m = 1-60, n = 1-18) clusters. Over 450 species of gold arsenide clusters and 212 mixed chlorinated Aum Asn Clx clusters were detected and their stoichiometry determined. CONCLUSIONS: Many new gold arsenides were synthesised via LAS for the first time with Au-As composites and NG-As mixtures of different Au:As ratios using mass spectrometry to determine cluster stoichiometry. The resolved stoichiometry of Aum Asn clusters determined in this study could accelerate the development of advanced Au-As nano-materials.

11.
Chemosphere ; 362: 142721, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945226

RESUMO

Arsenic (As) levels in particulate matter (PM) are routinely monitored in cities of developed countries. Despite advances in the knowledge of its inorganic species in PM in urban areas, organic species are often overlooked with no information on their behaviour in urban parks - areas with increased potential for As biomethylation. Therefore, the aim of this study was to characterize As distribution, bioaccessibility, seasonal variation and speciation (AsIII, AsV, MMA, DMA and TMAO) in PMx-PM10 of an urban park. Two sites with different distance from the road were selected for winter and summer sampling. From the PM samples, we gravimetrically determined PM10 concentrations in the air and via ICP-MS the total As content there. To assess the portion of bioaccessible As, water extractable As content was analysed. Simultaneously, the As species in PM10 water extracts were analysed via coupling of HPLC with ICP-MS method. There was no seasonal difference in PM10 concentration in the park, probably due to the increased summer PM load related to recreational activities in the park and park design. Spatial distribution of total As in PM10 and As fractional distribution in PMx suggested that As mostly didn't originate from traffic although highest As content was observed in the fine fraction (PM2.5) related to combustion processes. However, significant winter increase of As (determined by AsIII and AsV) despite the unchanged concentration of PM10 indicated a decisive influence of household heating-related combustion and possibly influence of reduced vegetation density. As present in the PM10 was mostly in bioaccessible form. Seasonal influence of As biomethylation was clearly demonstrated on the TMAO specie during the summer campaign. Except the significant summer TMAO increase, the results also indicated the biomethylation influence on DMA. Therefore, an increased risk of exposure to organic As species in urban parks can be expected during summer.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Arsênio , Monitoramento Ambiental , Material Particulado , Estações do Ano , Material Particulado/análise , Arsênio/análise , Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Parques Recreativos , Cidades
12.
Rapid Commun Mass Spectrom ; 27(14): 1600-6, 2013 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-23754797

RESUMO

RATIONALE: Only a few gold tellurides are known. However, Laser Ablation Synthesis (LAS) using Laser Desorption Ionisation (LDI) time-of-flight mass spectrometry (TOF MS) has high potential for the generation of new compounds. METHODS: LDI of nanogold-Te conjugate using a nitrogen laser 337 nm was applied while the mass spectra were recorded in positive and negative ion modes using a quadrupole ion trap-TOF mass spectrometer equipped with a reflectron. Diffuse coplanar surface barrier discharge was applied for the plasma treatment of glass and silicon surfaces. RESULTS: A form of nanogold-Te conjugate was prepared and found suitable for LAS of gold tellurides. Several new Au(m)Te(n) (m = 1-11; n = 1-4) clusters were identified. An excess of nanogold and chloride or an excess of auric acid caused the formation of mixed Au(m)Te(n)Cl(x) clusters. The nanogold-Te conjugate can be deposited from an aqueous suspension onto glass while the deposition is strongly enhanced if the surface is modified by plasma. CONCLUSIONS: LDI of nanogold-Te conjugate is a suitable procedure for the generation of new gold telluride clusters. Treatment of borosilicate glass with a diffuse coplanar surface barrier discharge strongly enhances the deposition of gold tellurides on glass while limited adsorption on a silicon surface was observed.

13.
J Pharm Biomed Anal ; 209: 114512, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34891005

RESUMO

Correct determination of the instantaneous level and changes of relevant proteins inside individual cells is essential for correct interpretation and understanding of physiological, diagnostic, and therapeutic events. Thus, single-cell analyses are important for quantification of natural cellular heterogeneity, which cannot be evaluated from averaged data of a cell population measurements. Here, we developed an original highly sensitive and selective instrumentation and methodology based on homogeneous single-step bioluminescence assay to quantify caspases and evaluate their heterogeneity in individual cells. Individual suspended cells are selected under microscope and reliably transferred into the 7 µl detection vials by a micromanipulator. The sensitivity of the method is given by implementation of photomultiplying tube with a cooled photocathode working in the photon counting mode. By optimization of our device and methodology, the limits of detection and quantitation were decreased down to 2.1 and 7.0 fg of recombinant caspase-3, respectively. These masses are lower than average amounts of caspase-3/7 in individual apoptotic and even non-apoptotic cells. As a proof of concept, the content of caspase-3/7 in single treated and untreated HeLa cells was determined to be 154 and 25 fg, respectively. Based on these results, we aim to use the technology for investigations of non-apoptotic functions of caspases.


Assuntos
Apoptose , Caspases , Caspase 3 , Células HeLa , Humanos , Tecnologia
14.
Environ Sci Pollut Res Int ; 29(8): 11232-11242, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34532788

RESUMO

Monitoring of pollution in the vicinity of roads connected to winter road maintenance is one of the important tools for optimising winter maintenance technology and reducing its environmental impact. The aim of this study was to determine the relationship between winter road maintenance and the increased concentration of sodium ion to characterise the harm caused by the de-icing agents on selected types of individual components grown in the Norway spruce ecosystem. The model area is located in the immediate vicinity of the D1 motorway connecting Prague and Brno (Czech Republic), at 103 km. The area is thus exposed to long-term contamination from automobile transport, and the monitoring was carried out for 3 consecutive years. A clear effect of the de-icing agents on conifers near the road has been demonstrated by the symptoms of salt damage visually observed in close proximity to the road (at a sampling distance of 5 m). The needles of these spruce trees also showed increased sodium concentrations, regardless of the age of the needles. The study also confirms that sodium accumulates in all selected components of the analysed ecosystem (moos, humus, soil). The sodium concentration has been found to decrease with increasing distance from the road for all of the components.


Assuntos
Florestas , Picea , Efeitos Antropogênicos , República Tcheca , Monitoramento Ambiental , Sais , Sódio , Solo/química , Árvores
15.
ACS Omega ; 6(27): 17483-17491, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34278134

RESUMO

Pulsed UV laser deposition was exploited for the preparation of thin Sn50-x As x Se50 (x = 0, 0.05, 0.5, and 2.5) films with the aim of investigating the influence of low arsenic concentration on the properties of the deposited layers. It was found that the selected deposition method results in growth of a highly (h00) oriented orthorhombic SnSe phase. The thin films were characterized by different techniques such as X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, atomic force microscopy, Raman scattering spectroscopy, and spectroscopic ellipsometry. From the results, it can be concluded that thin films containing 0.5 atom % of As exhibited extreme values regarding crystallite size, unit cell volume, or refractive index that significantly differ from those of other samples. Laser ablation with quadrupole ion trap time-of-flight mass spectrometry was used to identify and compare species present in the plasma originating from the interaction of a laser pulse with solid-state Sn50-x As x Se50 materials in both forms, i.e. parent powders as well as deposited thin films. The mass spectra of both materials were similar; particularly, signals of Sn m Se n + clusters with low m and n values were observed.

16.
Chemosphere ; 249: 126118, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32045757

RESUMO

The enormous tourism boom raises concern about possible negative environmental impacts worldwide. One of the risks posed by tourism may be heavy metal pollution. On the example of the volcanic island of Santorini, a popular tourist destination, pollution of soils categorized according to the tourism load was monitored. Significant anthropogenic contamination by heavy metals, especially Cu, Cr and Pb, was found out. This contamination may constitute a moderate ecological risk to the island ecosystems. Tourism has been shown to be a significant pollution factor as evidenced by the contaminated soils near the airport. Simultaneously, airport traffic has been proved to be an important emitter of Co, Cr and especially Zn. The comparison with other volcanic islands has shown that on Santorini the content of heavy metals in soils is significantly lower, despite frequently higher tourism intensity. On this basis, it can be concluded that in case of volcanic islands the dominant factor determining the content of heavy metals in the soil is the parent rock. Given high and ever-increasing intensity of tourism on the island, it can be assumed that soil contamination will continue to rise rapidly. Therefore, without proper steps reducing tourism, increase in soil degradation, growing negative impacts on local ecosystems as well as on the quality of produced wine can be expected on Santorini.


Assuntos
Poluição Ambiental , Meios de Transporte , Viagem , China , Ecossistema , Monitoramento Ambiental , Ilhas , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise
17.
Polymers (Basel) ; 12(11)2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33202725

RESUMO

Polyoxazoline thin coatings were deposited on glass substrates using atmospheric pressure plasma polymerization from 2-ethyl-2-oxazoline vapours. The plasma polymerization was performed in dielectric barrier discharge burning in nitrogen at atmospheric pressure. The thin films stable in aqueous environments were obtained at the deposition with increased substrate temperature, which was changed from 20 ∘C to 150 ∘C. The thin film deposited samples were highly active against both S. aureus and E. coli strains in general. The chemical composition of polyoxazoline films was studied by FTIR and XPS, the mechanical properties of films were studied by depth sensing indentation technique and by scratch tests. The film surface properties were studied by AFM and by surface energy measurement. After tuning the deposition parameters (i.e., monomer flow rate and substrate temperature), stable films, which resist bacterial biofilm formation and have cell-repellent properties, were achieved. Such antibiofouling polyoxazoline thin films can have many potential biomedical applications.

18.
J Am Soc Mass Spectrom ; 30(4): 634-638, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30648227

RESUMO

The binary system Sb-Se was studied via laser ablation using antimony-selenium mixtures made from powdered elements in various ratios generating new SbmSen clusters. The results show that in addition to Sbm+ (m = 1-8) and Sen+ (n = 2-9) clusters, a series of SbmSen+ clusters such as SbSe1-8+, Sb2Se1-6+, Sb3Se1-5+, Sb4Se1-3+, and Sb5Se1,2+ is generated. In addition, some low intensity oxidized clusters like Se6O2+, Se7O2+, and SbSe2-6O5+ and partially hydroxylated clusters (SbSeO2H7+, SbSe5O4H+) are also formed. In total, 24 new antimony selenide clusters were generated. The knowledge gained can contribute to the elucidation of the structure of SbmSen glasses. Graphical Abstract.

19.
J Am Soc Mass Spectrom ; 30(12): 2756-2761, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31650464

RESUMO

This study compared Sb2Se3 material in the form of commercial polycrystalline bulk, sputtered thin film, and homemade polycrystalline material using laser desorption ionization (LDI) time of flight mass spectrometry with quadrupole ion trap mass spectrometry. It also analyzed the stoichiometry of the SbmSen clusters formed. The results showed that homemade Sb2Se3 bulk was more stable compared to thin film; its mass spectra showed the expected cluster formation. The use of materials for surface-assisted LDI (SALDI), i.e., graphene, graphene oxide, and C60, significantly increased the mass spectra intensity. In total, 19 SbmSen clusters were observed. Six novel, high-mass clusters-Sb4Se4+, Sb5Se3-6+, and Sb7Se4+-were observed for the first time when using paraffin as a protective agent.

20.
Polymers (Basel) ; 11(10)2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31590313

RESUMO

Polymeric surfaces can benefit from functional modifications prior to using them for biological and/or technical applications. Surfaces considered for biocompatibility studies can be modified to gain beneficiary hydrophilic properties. For such modifications, the preparation of highly hydrophilic surfaces by means of plasma polymerization can be a good alternative to classical wet chemistry or plasma activation in simple atomic or molecular gasses. Atmospheric pressure plasma polymerization makes possible rapid, simple, and time-stable hydrophilic surface preparation, regardless of the type and properties of the material whose surface is to be modified. In this work, the surface of polypropylene was coated with a thin nanolayer of plasma-polymer which was prepared from a low-concentration mixture of propane-butane in nitrogen using atmospheric pressure plasma. A deposition time of only 1 second was necessary to achieve satisfactory hydrophilic properties. Highly hydrophilic, stable surfaces were obtained when the deposition time was 10 seconds. The thin layers of the prepared plasma-polymer exhibit highly stable wetting properties, they are smooth, homogeneous, flexible, and have good adhesion to the surface of polypropylene substrates. Moreover, they are constituted from essential elements only (C, H, N, O). This makes the presented modified plasma-polymer surfaces interesting for further studies in biological and/or technical applications.

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