scholarly journals Multi-Level Evaluation of UV Action upon Vitamin D Enhanced, Silver Doped Hydroxyapatite Thin Films Deposited on Titanium Substrate

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 120
Author(s):  
Catalin Constantin Negrila ◽  
Daniela Predoi ◽  
Rodica V. Ghita ◽  
Simona Liliana Iconaru ◽  
Steluta Carmen Ciobanu ◽  
...  
Keyword(s):  
Thin Films ◽  
Uv Irradiation ◽  
Uv Light ◽  
Titanium Substrate ◽  
Degradation Process ◽  
Tissue Reconstruction ◽  
Multi Level ◽  
First Time ◽  
Vacuum Deposition Method ◽  
Ftir Investigation

Hydroxyapatite Ca10(PO4)6(OH)2 (HAp) is an important bioactive material for bone tissue reconstruction, due to its highly thermodynamic stability at a physiological pH without bio-resorption. In the present study, the Ag:HAp and the corresponding Ag:HAp + D3 thin films (~200 nm) coating were obtained by vacuum deposition method on Ti substrate. The obtained samples were exposed to different UV irradiation times, in order to investigate the UV light action upon thin films, before considering this method for the thin film’s decontamination. The effects of UV irradiation upon Ag:Hap + D3 are presented for the first time in the literature, marking a turning point for understanding the effect of UV light on composite biomaterial thin films. The UV irradiation induced an increase in the initial stages of surface roughness of Ag:HAp thin film, correlated with the modifications of XPS and FTIR signals. The characteristics of thin films measured by AFM (RMS) analysis corroborated with XPS and FTIR investigation highlighted a process of recovery of the thin film’s properties (e.g., RMS), suggesting a possible adaptation to UV irradiation. This process has been a stage to a more complicated UVA rapid degradation process. The antifungal assays demonstrated that all the investigated samples exhibited antifungal properties. Moreover, the cytotoxicity assays revealed that the HeLa cells morphology did not show any alterations after 24 h of incubation with the Ag:HAp and Ag:HAp + D3 thin films.

A new method for fabricating high performance polymeric thin films by chemical vapor polymerization

1996 ◽  
Vol 11 (7) ◽  
pp. 1842-1850 ◽  
Author(s):  
Justin F. Gaynor ◽  
J. Jay Senkevich ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
High Performance ◽  
Chemical Vapor ◽  
Polymeric Thin Films ◽  
Copolymer Films ◽  
Initiation Reaction ◽  
First Time ◽  
Rate Limiting ◽  
Vacuum Deposition Method ◽  
General Method

A vacuum deposition method is presented in which copolymer films are grown from a vinylic monomer chosen for desirable properties and paraxylylene. The concentration of paraxylylene in the final copolymer can be negligibly small if proper deposition conditions, presented here for the first time, are employed. Films of paraxylylene with N-phenyl maleimide deposited at 40 °C, for example, showed thermal stability and FTIR spectra nearly identical with homopolymers of poly(N-phenyl maleimide). Different rate-limiting steps are proposed to explain film composition; paraxylylene is under surface reaction control, while the comonomer obeys mass flow control. This results in a deposition environment extremely rich in comonomer. Growth rates and compositions were consistent with predictions. The initiation reaction did not appear different from homopolymerization of paraxylylene. The general method presented here allows fabrication of vapor-deposited thin films with properties limited primarily by the comonomer employed.

scholarly journals Effect of localized UV irradiation on the crystallinity and electrical properties of dip-coated polythiophene thin films

RSC Advances ◽  
2020 ◽  
Vol 10 (56) ◽  
pp. 34130-34136
Author(s):  
So Young Park ◽  
Eun Hye Kwon ◽  
Yeong Don Park
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Uv Irradiation ◽  
Uv Light ◽  
P3ht Film ◽  
Enhanced Crystallinity

When the top part of the solution was irradiated with UV light, the dip-coated P3HT film showed enhanced crystallinity and electrical properties.

scholarly journals Synthesis of Carvedilol–Organotin Complexes and Their Effects on Reducing Photodegradation of Poly(Vinyl Chloride)

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 500 ◽  
Author(s):  
Omar G. Mousa ◽  
Gamal A. El‐Hiti ◽  
Mohammed A. Baashen ◽  
Muna Bufaroosha ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Vinyl Chloride ◽  
Uv Irradiation ◽  
Chemical Structure ◽  
Uv Light ◽  
Poly Vinyl Chloride ◽  
Pvc Film ◽  
Tin Complexes

Poly(vinyl chloride) (PVC) undergoes photodegradation induced by ultraviolet (UV) irradiation; therefore, for outdoor applications, its photostability should be enhanced through the use of additives. Several carvedilol tin complexes were synthesized, characterized and mixed with PVC to produce thin films. These films were irradiated at 25 °C with a UV light (λ = 313 nm) for up to 300 h. The reduction in weight and changes in chemical structure and surface morphology of the PVC films were monitored. The films containing synthesized complexes showed less undesirable changes than the pure PVC film. Organotin with a high content of aromatics was particularly efficient in inhibiting photodegradation of PVC. The carvedilol tin complexes both absorbed UV light and scavenged radicals, hydrochloride, and peroxides and, therefore, photostabilized PVC.

scholarly journals Monitoring the Photodegradation of PVC Thin Films Containing Schiff Base Using FTIR Spectroscopy

2019 ◽  
Vol 4 (1) ◽  
pp. 12-17
Author(s):  
Ali Hassan ◽  
Dina S. Ahmed ◽  
Riyadh Noaman ◽  
Emad Yousif
Keyword(s):  
Thin Films ◽  
Schiff Base ◽  
Light Intensity ◽  
Metal Complexes ◽  
Ftir Spectroscopy ◽  
Uv Irradiation ◽  
Infrared Spectra ◽  
Uv Light ◽  
Base Derivative

Metal complexes of Cu(II), Cd(II), Zn(II), Ni(II) and Sn(II) containing Schiff base derivative (L) as a ligand (ML2) utilized as additives to avoid PVC films photodegradation during UV irradiation (λmax= 313 at a light intensity = 7.75 × 10-7 einstein dm-3 sec-1). Irradiation of PVC films with UV light due to changes in infrared spectra.

Enhancement in Bioactivity of Titanium Substrate with Composite Thin Films

2010 ◽  
Vol 105-106 ◽  
pp. 517-519
Author(s):  
Fei Gao ◽  
Fan Xiao ◽  
Zhi Xian Zhang
Keyword(s):  
Thin Films ◽  
Uv Radiation ◽  
Uv Light ◽  
Irradiation Time ◽  
Titanium Substrate ◽  
Layer By Layer ◽  
Titanium Chloride ◽  
Great Expectation ◽  
Composite Thin Films ◽  
Titanium Substrates

Nanometer TiO2 microcapsule has potential applications in biochemistry, drug Controlled Release, and catalyst. Meanwhile, Ultraviolet (UV) light-induced bioactivity of titanium substrates is attracting more and more attention nowadays. Composite thin films formed by Nano-TiO2 microcapsule prepared by a novel and versatile technique of layer-by-layer (L-b-L) deposition using the Nanometer latex particles of Polystyrene (PS) as the template together with TiO2 films synthesized at low temperature by the hydrolysis of titanium chloride (TiCl4) precursor was successfully deposited on the different titanium substrates after the template was removed. Thus great expectation was placed on whether UV radiation can enhance the bioactivity of the titanium substrates after the composite thin films being deposited on its surface. The apatite-forming ability was evaluated after the UV-irradiated implants being soaked in simulated body fluid (SBF) within different hours by Scanning electron microscopy (SEM), XRD. The vitro results indicated that UV radiation was favored to formation of apatite on titanium substrates. Besides, the effect of different UV- irradiation time on apatite-forming was different.

Photo-assisted crystallization of zirconia thin films prepared using chelate compounds

2007 ◽  
Vol 22 (9) ◽  
pp. 2608-2616 ◽  
Author(s):  
Kaori Nishizawa ◽  
Takeshi Miki ◽  
Kazuyuki Suzuki ◽  
Kazumi Kato
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Uv Irradiation ◽  
Uv Light ◽  
Irradiation Time ◽  
Precursor Solution ◽  
Ultrahigh Pressure ◽  
Molar Ratio ◽  
Zirconium Alkoxide ◽  
Chelate Compounds

A highly crystallized and smooth-surfaced zirconia (ZrO2) thin film was prepared using a precursor solution with 2,4-pentanedione addition (molar ratio of 1:1 for zirconium alkoxide); the film was irradiated with ultraviolet (UV) light using an ultrahigh-pressure mercury lamp. This thin film was compared with another thin film, which prepared using a precursor solution without additives and UV irradiation. The crystallinity of ZrO2 thin films improved with increasing 2,4-pentanedione addition and UV irradiation time and changed according to the type of organic additives. These results occurred presumably because the orientation of polymerization in zirconium alkoxide units and stability of chelate compounds for UV irradiation were controlled under these conditions. In addition, the method was effective for lower-temperature crystallization of highly crystallized, smooth-surfaced thin films.

4 Pattern Recognition for Healing Burns to Compute Evidence: Space Syntax and Machine Learning Analysis of Burns Center Karachi

2013 ◽  
Vol 1 (1) ◽  
pp. 13
Author(s):  
Javaria Manzoor Shaikh ◽  
JaeSeung Park
Keyword(s):  
Pattern Recognition ◽  
Prediction Models ◽  
Uv Light ◽  
Healing Process ◽  
Space Syntax ◽  
Depth Map ◽  
Routine Tasks ◽  
Hyper Plane ◽  
First Time ◽  
Learning Analysis

Usually elongated hospitalization is experienced byBurn patients, and the precise forecast of the placement of patientaccording to the healing acceleration has significant consequenceon healthcare supply administration. Substantial amount ofevidence suggest that sun light is essential to burns healing andcould be exceptionally beneficial for burned patients andworkforce in healthcare building. Satisfactory UV sunlight isfundamental for a calculated amount of burn to heal; this delicaterather complex matrix is achieved by applying patternclassification for the first time on the space syntax map of the floorplan and Browder chart of the burned patient. On the basis of thedata determined from this specific healthcare learning technique,nurse can decide the location of the patient on the floor plan, hencepatient safety first is the priority in the routine tasks by staff inhealthcare settings. Whereas insufficient UV light and vitamin Dcan retard healing process, hence this experiment focuses onmachine learning design in which pattern recognition andtechnology supports patient safety as our primary goal. In thisexperiment we lowered the adverse events from 2012- 2013, andnearly missed errors and prevented medical deaths up to 50%lower, as compared to the data of 2005- 2012 before this techniquewas incorporated.In this research paper, three distinctive phases of clinicalsituations are considered—primarily: admission, secondly: acute,and tertiary: post-treatment according to the burn pattern andhealing rate—and be validated by capable AI- origin forecastingtechniques to hypothesis placement prediction models for eachclinical stage with varying percentage of burn i.e. superficialwound, partial thickness or full thickness deep burn. Conclusivelywe proved that the depth of burn is directly proportionate to thedepth of patient’s placement in terms of window distance. Ourfindings support the hypothesis that the windowed wall is mosthealing wall, here fundamental suggestion is support vectormachines: which is most advantageous hyper plane for linearlydivisible patterns for the burns depth as well as the depth map isused.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

scholarly journals Effect of Water Leaching on Photodegraded Scots Pine and Spruce Timbers Monitored by FTIR Spectroscopy

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 833
Author(s):  
Edina Preklet ◽  
László Tolvaj ◽  
Eszter Visi-Rajczi ◽  
Tamás Hofmann
Keyword(s):  
Ftir Spectroscopy ◽  
Scots Pine ◽  
Uv Irradiation ◽  
Chemical Elements ◽  
Uv Light ◽  
Carbonyl Groups ◽  
Water Leaching ◽  
Absorption Bands ◽  
Chemical Changes ◽  
Absorption Increase

The goal of this research was the systematic study and comparison of the divided individual effects of UV light irradiation and water leaching during artificial weathering. Spruce (Picea abies Karst.) and Scots pine (Pinus sylvestris L.) samples were irradiated by ultraviolet (UV) light. Another sequence of samples was treated with the combination of UV irradiation and water leaching. The total extent of UV treatment was 20 days for both series of samples. Time relation of UV irradiation and water leaching was 2:1. The chemical changes were observed by FTIR spectroscopy. The difference spectrum was used for determination of the chemical changes. Degradation of lignin was greater for the leached samples than for the pure UV treated samples. Scots pine suffered greater lignin degradation than spruce, and produced higher absorption increase on the absorption region of unconjugated carbonyls. The unconjugated carbonyl groups were the most responsive chemical elements to leaching. Spruce was more susceptible to leaching of unconjugated carbonyl groups than Scots pine. Two absorption bands of unconjugated carbonyl groups at 1706 and 1764 cm−1 wavenumbers were produced by photodegradation. The absorption band at 1764 cm−1 was more sensitive to water leaching than the band at 1706 cm−1.

scholarly journals A novel and potentially scalable CVD-based route towards SnO2:Mo thin films as transparent conducting oxides

2021 ◽  
Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Valence States ◽  
3 Omega ◽  
First Time

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract

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