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1.
Heliyon ; 10(8): e29536, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38644888

RESUMO

There has been an ongoing theoretical argument on the role of Academic autonomy (AA) in improving the ability of public universities to develop strategies and enhance their performance. This study aims to investigate whether AA impacts strategy development (SD) and University performance (UP). Moreover, it investigates the effect of SD on UP. The present study uses a resource-based view to demonstrate the links among constructs. This study employed a survey method, and data were collected from 130 leaders of Indian public universities utilising a non-probability purposive sampling technique. Data was analysed using Partial least squares structural equation modelling (PLS-SEM). The results revealed that AA positively and significantly affects SD. Moreover, the results demonstrated that AA directly affects both UP's dimensions: research and teaching performance. The results also showed that SD directly and positively affects both UP's dimensions, research, and teaching performance. In line with these findings, several implications for theory and practices are addressed for university management.

2.
Phys Chem Chem Phys ; 24(41): 25620-25629, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36254769

RESUMO

We report on the synthesis and characterization of NiMoO4 (NMO) nanorods via the hydrothermal method. The High-Resolution Scanning Electron Microscopy (HRSEM) image reveals the nanorod morphology of NMO. The formation of mixed phase α,ß-NMO is confirmed and the crystallite size of the nanorods is measured to be 40 nm from the XRD data. The structural formation of NMO is confirmed by Raman, FTIR, and XPS. The content of Ni, Mo and O was identified from XPS. NMO is optically active in the visible region with the band gap of 3.085 eV. The presence of four oxygen anions in the chemical formula gives the maximum electrical resistivity of 102 Ω m at 313 K and the material exhibits n-type semiconducting nature which is observed through Seebeck measurement and the Hall coefficient. The n-type semiconducting properties are observed due to the material being richer in Mo than Ni. The attained maximum Seebeck value of -159.723 µV K-1 at 513 K is comparable with that of other good thermoelectric materials at low temperatures. A decrease in the value of thermal conductivity was observed as a function of increasing temperature; NMO has the minimum thermal conductivity of 3.851 W m-1 K-1 at 513 K.

3.
Phys Chem Chem Phys ; 23(9): 5607-5614, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33655286

RESUMO

The manifestation of the structural and magnetic properties of Co substituted TiFe2 is investigated using powder X-ray diffraction, magnetization and density functional theory calculations. The alloys TiFe2 and TiFeCo crystallize in the hexagonal structure (P63/mmc) with a reduction in the lattice parameters of TiFeCo (by about 0.51% in a and 0.64% in c) when compared to TiFe2. On the other hand, TiCo2 crystallizes in the cubic structure (Fd3[combining macron]m). A structural transition from hexagonal to cubic is anticipated for a composition with x ∈ [0.5, 1]. The non-collinear antiferromagnetic (AFM) spin structure (formed by 6h Fe atoms) of TiFe2 with Néel temperature TN ∼ 275 K is reported at zero magnetic field H. Meanwhile, a magnetic field-induced collinear antiferromagnetic spin structure is suggested by magnetization measurements and supported by density functional theory calculations. The magnetization of TiFeCo shows a weak-ferromagnetic (FM)-like transition around 204 K, followed by a broad hump at 85.5 K and H = 200 Oe. Ferromagnetic interactions are weakened, causing the hump to disappear due to the possible transfer of electrons between Fe and Co. TiCo2 shows compensated ferrimagnetism with magnetization of the order of 10-5µB f.u.-1 and a linear increase of M with H at 5 K. The presence of a non-collinear AFM spin structure in TiFe2, a reduced magnetic moment in TiFeCo due to the charge transfer between Co and Fe, and compensated ferrimagnetism in TiCo2 promise a rich phase diagram of Ti(Fe1-xCox)2 alloys and the possible potential of these alloys for use in spintronics applications.

4.
J Phys Condens Matter ; 29(13): 13LT01, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28140356

RESUMO

CuAl2O4 is a normal spinel oxide having quantum spin, S = 1/2 for Cu2+. It is a rather unique feature that the Cu2+ ions of CuAl2O4 sit at a tetrahedral position, not like the usual octahedral position for many oxides. At low temperatures, it exhibits all the thermodynamic evidence of a quantum spin glass. For example, the polycrystalline CuAl2O4 shows a cusp centered at ~2 K in the low-field dc magnetization data and a clear frequency dependence in the ac magnetic susceptibility while it displays logarithmic relaxation behavior in a time dependence of the magnetization. At the same time, there is a peak at ~2.3 K in the heat capacity, which shifts towards a higher temperature with magnetic fields. On the other hand, there is no evidence of new superlattice peaks in the high-resolution neutron powder diffraction data when cooled from 40 to 0.4 K. This implies that there is no long-ranged magnetic order down to 0.4 K, thus confirming a spin glass-like ground state for CuAl2O4. Interestingly, there is no sign of structural distortion either although Cu2+ is a Jahn-Teller active ion. Thus, we claim that an orbital liquid state is the most likely ground state in CuAl2O4. Of further interest, it also exhibits a large frustration parameter, f = |θ CW/T m| ~ 67, one of the largest values reported for spinel oxides. Our observations suggest that CuAl2O4 should be a rare example of a frustrated quantum spin glass with a good candidate for an orbital liquid state.

5.
J Nanosci Nanotechnol ; 16(1): 581-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27398491

RESUMO

The PVdF-HFP nanofiber membranes with different molecular weight were prepared by electrospinning technique and were investigated as solid state electrolyte membranes in quasi solid state dye sensitized solar cells (QS-DSSC). The homogeneously distributed and fully interconnected nanofibers were obtained for all of the prepared PVdF-HFP electrospun membranes and the average fiber diameters of fabricated membranes were dependent upon the molecular weight of polymer. The thermal stability of electrospun PVdF-HFP membrane was decreased with a decrement of molecular weight, specifying the high heat transfer area of small diameter nanofibers. The QS-DSSC fabricated with the lower molecular weight PVdF-HFP electrospun nanofiber membrane exhibited the power conversion efficiency of 1 = 5.38%, which is superior over the high molecular weight membranes and is comparable with the liquid electrolyte. Furthermore, the electrospun PVdF-HFP membrane exhibited long-term durability over the liquid electrolyte, owing to the higher adsorption and retention efficiencies of liquid electrolyte in its highly porous and interconnected nanofibers. Thus the proposed electrospun PVdF-HFP membrane effectively tackled the volatilization and leakage of liquid electrolyte and provided good photoconversion efficiency associated with an excellent stability, which constructs the prepared electrospun membranes as credible solid state candidates for the application of QS-DSSCs.

6.
J Nanosci Nanotechnol ; 16(1): 595-600, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27398493

RESUMO

We report on the simple way of obtaining aligned poly(vinylidiene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers by electrospinning process. The collector drum rotation speed was adjusted to prepare well aligned PVDF-HFP nanofibers. The degree of alignment and the orientation of PVDF-HFP nanofibers can be significantly altered by varying the speed of collector drum rotation. The resultant PVDF-HFP nanofibers were systematically characterized. From the scanning electron microscopy data, it was found that the electrospun PVDF-HFP nanofibers were formed with well-aligned nature. The X-ray diffraction results revealed that the electrospun PVDF-HFP nanofibers with ß-phase can be formed by the increased collector drum rotation speed. Overall, the collector rotation speed during the electrospinning process plays an important role in obtaining well-aligned and improved characteristics of PVDF-HFP nanofibers.


Assuntos
Nanofibras/química , Polivinil/química
7.
J Nanosci Nanotechnol ; 16(1): 1033-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27398565

RESUMO

We report on the feasible synthesis of flexible and conductive carbon nanofibers by electrospinning process using polyacrylonitrile (PAN) and phosphoric acid (PA) as precursors. The carbon nanofibers were subsequently obtained by stabilization and carbonization of the electrospun PAN nanofibers. From SEM data, it was found that the electrospun PAN nanofibers showed a smooth surface and had an average diameter of approximately 200 nm. Afterwards, the electrospun PAN nanofibers were stabilized at 250 °C and heated at 900 °C for the carbonization process to obtain the carbon nanofibers. The carbonized PAN nanofibers exhibited a drastic improvement of electrical conduction. From Raman spectroscopy data, it was found that the carbonization at 900 °C gave a decrease of the intensity ratio of D and G peaks, indicating higher graphitic structure.

8.
Environ Monit Assess ; 188(6): 375, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27230427

RESUMO

A simple and sensitive analytical method has been developed and validated for the determination of trace amounts of imidacloprid in/on sugarcane sett, stalk and leaf. The method optimized in the present study requires less volume of organic solvent and time. Hence, this method is suitable for high-throughput analyses involving large number of samples. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.003 and 0.01 mg/kg, respectively. The recovery and relative standard deviation were more than 93 % and less than 4 %, respectively. Thus, it is obvious that the analytical method standardized in this study is more precise and accurate enough to determine the residues of imidacloprid in sugarcane sett, stalk and leaf. The dissipation and translocation of imidacloprid residues from treated cane setts to leaf and stalk were studied by adopting this method. In sugarcane setts, the residues of imidacloprid persisted up to 120 days with half-life of 15.4 days at its recommended dose (70 g a.i./ha). The residues of imidacloprid were found to be translocated from setts to stalk and leaf. The imidacloprid residues were detected up to 105 days in both leaf and stalk. Dipping of sugarcane setts in imidacloprid at its recommended dose may result in better protection of cane setts and established crop because of higher initial deposit (>100 mg/kg) and longer persistence (>120 days).


Assuntos
Monitoramento Ambiental/métodos , Imidazóis/análise , Inseticidas/análise , Nitrocompostos/análise , Resíduos de Praguicidas/análise , Saccharum/química , Cromatografia Líquida de Alta Pressão/métodos , Meia-Vida , Índia , Limite de Detecção , Neonicotinoides , Folhas de Planta/química , Clima Tropical
9.
Mater Sci Eng C Mater Biol Appl ; 64: 11-19, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27127023

RESUMO

Gelatin nanofiber fabricated by electrospinning process is found to mimic the complex structural and functional properties of natural extracellular matrix for tissue regeneration. In order to improve the physico-chemical and biological properties of the nanofibers, graphene oxide is incorporated in the gelatin to form graphene oxide decorated gelatin nanofibers. The current research effort is focussed on the fabrication and evaluation of physico-chemical and biological properties of graphene oxide-gelatin composite nanofibers. The presence of graphene oxide in the nanofibers was established by transmission electron microscopy (TEM). We report the effect of incorporation of graphene oxide on the mechanical, thermal and biological performance of the gelatin nanofibers. The tensile strength of gelatin nanofibers was increased from 8.29±0.53MPa to 21±2.03MPa after the incorporation of GO. In order to improve the water resistance of nanofibers, natural based cross-linking agent, namely, dextran aldehyde was employed. The cross-linked composite nanofibers showed further increase in the tensile strength up to 56.4±2.03MPa. Graphene oxide incorporated gelatin nanofibers are evaluated for bacterial activity against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria and cyto compatibility using mouse fibroblast cells (L-929 cells). The results indicate that the graphene oxide incorporated gelatin nanofibers do not prevent bacterial growth, nevertheless support the L-929 cell adhesion and proliferation.


Assuntos
Proliferação de Células , Fibroblastos/metabolismo , Gelatina/química , Grafite/química , Teste de Materiais , Nanofibras/química , Animais , Adesão Celular , Linhagem Celular , Escherichia coli/crescimento & desenvolvimento , Fibroblastos/citologia , Camundongos , Staphylococcus aureus/crescimento & desenvolvimento , Resistência à Tração
10.
Carbohydr Polym ; 136: 1098-107, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26572452

RESUMO

Coaxial electrospinning is an upcoming technology that has emerged from the conventional electrospinning process in order to realize the production of nanofibers of less spinnable materials with potential applications. The present work focuses on the production of chitosan nanofibers in a benign route, using natural polymer as core template, mild solvent system and naturally derived cross-linkers. Nanofibers with chitosan as shell are fabricated by coaxial electrospinning with highly spinnable gelatin as core using aqueous acetic acid as solvent. For maintaining the biocompatibility and structural integrity of the core-shell nanofibers, cross-linking is carried out using naturally derived cross-linking agents, dextran aldehyde and sucrose aldehyde. The biological evaluation of gelatin/chitosan mat is carried out using human osteoblast like cells. The results show that the cross-linked core-shell nanofibers are excellent matrices for cell adhesion and proliferation.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Quitosana/química , Eletricidade , Gelatina/química , Nanofibras/química , Nanotecnologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Dextranos/química , Glutaral/química , Humanos , Fenômenos Mecânicos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Oxirredução , Solventes/química , Sacarose/química , Temperatura , Alicerces Teciduais/química
11.
Environ Monit Assess ; 188(1): 33, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26670042

RESUMO

Chlorantraniliprole 0.4 % GR has been in use for managing early shoot borer and top borer of sugarcane. Persistence and dissipation kinetics of granular formulation of chlorantraniliprole were studied in the soil of tropical sugarcane ecosystem by employing simple and sensitive analytical method. Limit of quantification of the method was 0.01 mg/kg and the recovery of chlorantraniliprole was in the range of 92.3-99.7 % with RSD of 1.14-3.0 %. The initial deposit of chlorantraniliprole in the soil was 0.513 and 1.031 mg/kg for the recommended (75 g a.i./ha) and double the recommended (150 g a.i./ha) doses, respectively. The residues were quantified up to 30 days after treatment irrespective of the doses applied. Half-life (t 1/2) was 6.60 and 6.73 days, respectively, for recommended and double the recommended doses of chlorantraniliprole.


Assuntos
Inseticidas/análise , Resíduos de Praguicidas/análise , Solo/química , ortoaminobenzoatos/análise , Ecossistema , Monitoramento Ambiental , Meia-Vida , Inseticidas/química , Cinética , Resíduos de Praguicidas/química , Saccharum , Poluentes do Solo/análise , Poluentes do Solo/química , ortoaminobenzoatos/química
12.
J Nanosci Nanotechnol ; 15(6): 4653-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26369093

RESUMO

In this study, we report the preparation and comparison of the rosin based thin films and electrospun fibers in terms of their formation and characterizations. Rosin in the form of thin films and fibers can be obtained via wet casting method and electrospinning process, respectively. Systematic experiments were performed to study the morphology, structure and thermal properties of the rosin thin films and electrospun fibers. Finally, in order to understand the accurate mass values of rosin in the different morphologies, we performed matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) spectroscopy. The rosin thin film prepared via wet casting method exhibited very smooth surfaces whereas the electrospun fibers were continuous without any beads over long distances. The MALDI-TOF data revealed that the most intense peak in the molecular weight of rosin components is about 302 for the rosin powder, thin film and fibers. On the other hand, some of the higher molecular component can also be observed for electrospun rosin fibers owing to the structural morphology. The present study demonstrated that the full structural characterization of the molecular species present in these different forms of rosin.

13.
J Nanosci Nanotechnol ; 15(8): 5718-22, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26369144

RESUMO

In this paper, we report on the structural and electrical properties of graphene oxide (GO) incorporated Nylon66 (N66) composite nanofibers prepared via electrospinning technique. Different types of composite nanofibers were electrospun by varying the weight percentage of GO in the polymer solution. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy, as well as current-voltage (I-V) measurements were used to characterize the N66/GO composite nanofibers. The morphology of the N66/GO composite nanofibers exhibited densely arranged mesh-like ultrafine nanofibers which were strongly bound in between the main fibers. The I-V characteristics of the N66/GO composite nanofibers demonstrated that the blending of GO in to N66 nanofibers led to a dramatic improvement of the electrical conduction compared to that of pristine N66 nanofibers which can be utilized for the various technological applications.

14.
Int J Biol Macromol ; 73: 270-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25478965

RESUMO

Gelatin nanofibers were fabricated via electrospinning with minimal toxicity from solvents and cross-linking agents. Electrospinning was carried out using a solvent system based on water and acetic acid (8:2, v/v). Acetic acid concentration was kept as minimum as possible to reduce the toxic effects. Electrospun gelatin nanofibers were cross-linked with oxidized sucrose. Sucrose was oxidized by periodate oxidation to introduce aldehyde functionality. Cross-linking with oxidized sucrose could be achieved without compromising the nanofibrous architecture. Cross-linked gelatin nanofibers maintained the fibrous morphology even after keeping in contact with aqueous medium. The morphology of the cross-linked nanofibrous mats was examined by scanning electron microscopy (SEM). Oxidized sucrose cross-linked gelatin nanofibers exhibited improved thermal and mechanical properties. The nanofibrous mats were evaluated for cytotoxicity and cell viability using L-929 fibroblast cells. The results confirmed that oxidized sucrose cross-linked gelatin nanofibers were non-cytotoxic towards L-929 cells with good cell viability.


Assuntos
Gelatina/química , Nanofibras/química , Materiais Biocompatíveis/química , Linhagem Celular , Sobrevivência Celular , Humanos , Fenômenos Mecânicos , Nanofibras/ultraestrutura , Oxirredução , Espectroscopia de Infravermelho com Transformada de Fourier , Sacarose/química
15.
Biomark Res ; 2: 17, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25285214

RESUMO

BACKGROUND: Exact sample annotation in expression microarray datasets is essential for any type of pharmacogenomics research. RESULTS: Candidate markers were explored through the application of Hartigans' dip test statistics to a publically available human whole genome microarray dataset. The marker performance was tested on 188 serial samples from 53 donors and of variable tissue origin from five public microarray datasets. A qualified transcript marker panel consisting of three probe sets for human leukocyte antigens HLA-DQA1 (2 probe sets) and HLA-DRB4 identified sample donor identifier inconsistencies in six of the 188 test samples. About 3% of the test samples require root-cause analysis due to unresolvable inaccuracies. CONCLUSIONS: The transcript marker panel consisting of HLA-DQA1 and HLA-DRB4 represents a robust, tissue-independent composite marker to assist control donor annotation concordance at the transcript level. Allele-selectivity of HLA genes renders them good candidates for "fingerprinting" with donor specific expression pattern.

16.
Carbohydr Polym ; 114: 467-475, 2014 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-25263915

RESUMO

Electrospun gelatin nanofibres attract attention of bioengineering arena because of its excellent biocompatibility and structural resemblance with native extracellular matrix. In this study, we have developed gelatin nanofibres using an innovative cross-linking approach to minimize cytotoxic effects. Gelatin was dissolved in water:acetic acid (8:2, v/v) solution and electrospun to form nanofibres with diameter in the range of 156 ± 30 nm. The nanofibres were cross-linked with a modified polysaccharide, namely, dextran aldehyde (DA). Cross-linking with DA could be achieved without compromising the fibrous architecture. DA cross-linked gelatin nanofibres maintained the fibrous morphology in aqueous medium. These mats exhibit improved mechanical properties and gradual degradation behaviour. The nanofibres were evaluated for cytotoxicity, cell adhesion, viability, morphology and proliferation using L-929 fibroblast cells. The results confirmed that DA cross-linked mats were non cytotoxic towards L-929 cells with good cell adhesion, spreading and proliferation.


Assuntos
Dextranos/química , Gelatina/química , Nanofibras/química
17.
J Nanosci Nanotechnol ; 14(3): 2299-306, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24745225

RESUMO

An efficient method to degrade 4-nitrophenol (4-NP) using cadmium sulphide nanoparticles (CdS NPs) prepared by a novel method as a photocatalyst in the presence of H2O2 as a free radical generator was developed. To investigate the degradation mechanism, the interaction between the substrate (4-NP) and the catalyst (CdS NPs) was studied using UV-visible absorption and emission spectral techniques. Investigation on the effect of pH of the medium on the degradability of 4-NP revealed that neither the acidic (pH 4) nor alkaline (pH 9) is as suitable as pH 6 due to the desorption of 4-NP from the catalyst surface at the former condition and the existence of 4-NP in its most stable quinonoid form at the latter pH. Similarly, the effect of ratio between the photocatalyst (CdS NPs) and the substrate (4-NP) was also investigated to achieve higher efficiency in the photocatalytic reaction.


Assuntos
Compostos de Cádmio/química , Nanopartículas/química , Nitrofenóis/análise , Compostos Orgânicos/análise , Sulfetos/química , Poluentes Químicos da Água/análise , Absorção , Animais , Catálise , Casca de Ovo , Radicais Livres , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Fotoquímica , Fotólise , Espectrofotometria Ultravioleta , Fatores de Tempo
18.
J Nanosci Nanotechnol ; 13(7): 4686-93, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23901491

RESUMO

We report on the preparation and characterization of polyurethane (PU) nanofibers containing silver (Ag) nanoparticles were synthesized by using electrospinning. Two different approaches were adopted to incorporate the Ag nanoparticles in to PU nanofibers. In the first approach, a homogeneous solution of 10 wt% PU containing silver nitrate was electrospun to obtain PU-Ag composite nanofibers. And in the second approach, the pristine PU nanofibers were initially electrospun and then Ag nanoparticles were coated via wet casting method. The surface morphology, structure, bonding configuration, optical and thermal properties of the resultant products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, UV-vis spectroscopy and thermogravimetric analysis. The antibacterial activity was tested against four common food borne pathogenic bacteria, namely, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae by minimum inhibitory concentration (MIC) method. Our results demonstrated that no bactericidal activity was detected for the pristine PU nanofibers. Further on, antibacterial activity was observed to be more pronounced for the composite nanofibers which were attributed to the presence of Ag nanoparticles in the composite nanofibers. Overall, this study demonstrates the fabrication of cheap, stable and effective nanofiber mats with excellent antimicrobial activity that can be utilized to inhibit the microbial growth associated with food stuff.


Assuntos
Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Poliuretanos/química , Prata/química , Prata/farmacologia , Antibacterianos/farmacologia , Eletroquímica/métodos , Teste de Materiais , Rotação
19.
J Colloid Interface Sci ; 397: 65-72, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23453708

RESUMO

Semiconductor nanoparticles incorporated highly aligned electrospun polyacrylonitrile (PAN) composite nanofibers were obtained via a simple, scalable and low-cost dip coating technique at room temperature. The resultant PAN nanofibers exhibited good incorporation of CdS, ZnS and CoS semiconductor nanoparticles. The detailed characterizations of these composite nanofibers were investigated. The incorporation of semiconductor nanoparticles on the surfaces of PAN nanofibers were confirmed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction analysis. The current-voltage (I-V) characteristics revealed that the electrical conductivity of these composite nanofibers were higher than that of the pristine PAN nanofibers. Overall, the feasibility of obtaining uniformly dispersed semiconductor nanoparticles on PAN nanofibers can be utilized for the realization of various nanotechnological device applications.

20.
Colloids Surf B Biointerfaces ; 104: 262-7, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23333914

RESUMO

In this study, we describe the influence of antimicrobial additives on the formation of rosin fibers by using electrospinning technique. Systematic experiments were performed to fabricate the rosin fibers via electrospinning and we tried to reduce the size of the fibers by mixing some additives such as triethylbenzylammonium chloride (TEBAC), chitosan and silver nitrate in the rosin polymer solution. The morphology, structure and thermal properties of the electrospun rosin fibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy and thermogravimetry (TGA). Rosin fibers with a diameter of the order of nanoscale were achieved by the use of TEBAC additive. The antimicrobial activity of the resultant fibers was checked by the antimicrobial disc diffusion test. All the rosin fibers showed excellent antibacterial activity against the gram negative bacteria and feeble activity against the gram positive bacteria. The present study demonstrated that the electrospun rosin fibers can be utilized for potential antimicrobial products.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Nanofibras/química , Resinas Vegetais/química , Salmonella typhimurium/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-Atividade , Difração de Raios X
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