Stannous Chloride Solution Research Articles

The Antibacterial Effectiveness of Citrullus lanatus-Mediated Stannous Nanoparticles on Streptococcus mutans.

Introduction Dental caries is a prevalent oral health issue caused by the colonization of Streptococcus mutans in the oral cavity. Citrullus lanatus, commonly known as watermelon, is rich in bioactive compounds that possess antibacterial potential. In this study, we aimed to synthesize stannous chloride (SnCl2) nanoparticles (NPs) mediated by Citrullus lanatus extract and investigate their antibacterial effectiveness against Streptococcus mutans. Materials and method Stannous nanoparticles (SnNPs) synthesized by the green method were achieved by using the watermelon extract. Dilute stannous chloride solution was obtained by adding 0.45 gof stannous (Sn) chloride (Cl) powder to 60 mL of water, which was subjected to an orbital shaker with the watermelon extract. The nanoparticles obtained were subjected to characterization using antimicrobial testing, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray (EDAX) analysis, and scanning electron microscopy (SEM). Agar well diffusion method was used against specific strains of S. aureus, S. mutans, and Escherichiacoli. Results The novel nanoparticles demonstrated promising antibacterial activity against S. mutans providing 10 mm of inhibitory action. Conclusion Due to its abundance of naturally occurring bioactive chemicals and improved efficacy against S. mutans, watermelon extract can be utilized to createstannous nanoparticles as opposed to the use of toxic chemicals. They can also be employed as oral administration systems.

One-step synthesis of tin oxide nanoparticles in aqueous solution induced by free radicals

Tin oxide nanoparticles of uniform size with around 5 nm distribution were synthesized in the aqueous solution of stannous chloride under an oxidizing environment. The syntheses were carried out with Cobalt-60 gamma radiation in N2O saturated solution, photoirradiation using 300 nm UV lamps as well as normal chemical route in the presence of H2O2 at room temperature under ambient laboratory conditions. The nanoparticles were characterized by XRD, FTIR and Raman spectroscopy, SEM and HRTEM measurements. The synthesis mechanism was investigated through the electron pulse radiolysis studies. It was established that the formation of tin oxide nanoparticles takes place only through the reactions of oxidizing free radicals like OH• or Cl2•- with Sn2+ ions in aqueous solution. The formation of tin oxide was found follow similar pathways in all the three cases, except that it took a longer time in the case of normal chemical route as compared to the other two routes. The size and shapes of the nanoparticles were found to be identical in all these three cases.

Effect of Precursor Fluorine Concentration Optical and Electrical Properties of Fluorine Doped Tin Oxide thin Films

We have studied effects of Fluorine (F) concentration on the structural, optical and electrical properties of Fluorine Doped Tin Oxide (FTO) thin films. The FTO films were fabricated with homemade spray pyrolysis setup and calcinated for twenty minutes at air environments. The homogeneous solution of Stannous Chloride (SnCl2.2H2O) and Ammonium Fluoride (NH4F) in distilled water was used as a precursor solution. Both the substrate and oven temperature was set to ca. (550 ± 5)℃ during the film synthesis and calcination processes. The films’ optical and electrical properties were investigated from transmittance, reflectance and resistance measurements. The transmittance of FTO film is found to be decreased for increasing F concentration from 0.28 M to1.14 M and increased for 1.14 M to 11.37 M. Also reflectance found to be significantly modulated with varying molar concentration of F. The maximum and minimum of the reflectance (Rmax and Rmin) found to vary from 49 % and 7 %, respectively). However, there was no clear dependency on the dopant F concentration; slightly enhancement may be true which is probably due to the increase in fundamental absorption as photon striking increases. Electrical measurement showed the decrease of resistance of 0.85M FTO film from 138 Ω to 17 Ω.

Randomized in situ trial on the efficacy of Carbopol in enhancing fluoride / stannous anti-erosive properties

ObjectiveTo evaluate if the bioadhesive polymer (Carbopol 980) could potentiate the protective effect of sodium fluoride with stannous chloride (FS) solution on the control of enamel erosive wear. MethodsCylindrical bovine enamel specimens were polished and randomly allocated into three groups (n = 60): FS (500 ppm F- +800 ppm Sn2+ - positive control), FS + Carbopol (0.1% Carbopol), and ultrapure water (negative control). A randomized double-blind cross-over in situ model with three phases was used. In each phase, volunteers (n = 15) used a palatal appliance containing 4 specimens: two were submitted to an erosion model (2 h of pellicle formation; immersion in 1% citric acid, pH 2.3, for 5 min, 4x/day; 1 h intervals of saliva exposure; and treatment with the test solutions for 1 min, 2x/day). Besides erosion, the other two specimens were also subjected to abrasion (2x/day, 15 s) with active electric toothbrush, before the treatment with the solutions. After 5 days, enamel surface loss (μm) was evaluated by profilometry. Data were analyzed by two-way RM-ANOVA and Tukey tests (5%). ResultsThere were significant differences for both challenge and treatment factors. Erosion/abrasion challenge resulted in significantly higher enamel loss than erosion only (p < 0.05). The surface loss values for the erosion/remineralization model were (means ± SL): C = 14.7 ± 5.8b; FS = 9.0 ± 7.5ab; FS + Carbopol = 5.9 ± 3.8a; and for erosion/abrasion: C = 26.6 ± 10.1c; FS = 15.0 ± 8.8b; FS + Carbopol = 12.3 ± 7.9ab. ConclusionThe association of Carbopol to the FS solution significantly protected the enamel against erosive wear, but it was not significantly superior to FS only. Clinical SignificanceUnder highly erosive and abrasive conditions, rinsing with solutions containing sodium fluoride plus stannous chloride, associated or not with the Carbopol polymer, is an effective approach to control enamel erosive wear.

Flexible RFID Tag Metal Antenna on Paper‐Based Substrate by Inkjet Printing Technology

AbstractA reliable and low‐cost solution‐processing procedure to synthesize a highly adhesive flexible metal antenna with low resistivity for radio‐frequency identification device (RFID) tags on paper substrates via inkjet printing combined with surface modification and electroless deposition (ELD) is demonstrated in this paper. Through the surface modification of colloidal solution of hydrolyzed stannous chloride and chitosan solution, the paper‐based substrate is able to reduce the penetration rate of ink and further increase the adsorption amount of silver ions, which could create a catalytic activating layer to catalyze the subsequent ELD of a conductive deposited metal antenna. The resulting metal antenna for RFID tags presents good adhesive strength and low resistivity of 2.58 × 10−8 Ω·m after 40 min of ELD, and maintains a reliable reading range of RFID tags even after over 1000 times of bending and mechanical stress. Consequently, the developed technology proposed allows for cheap, efficient, and massive production of metal antenna for paper‐based RFID tags with excellent mechanical and electrical properties. Furthermore, this process is especially advantageous for the fabrication of next‐generation flexible electronic devices based on paper substrates.

Synthesis, bioevaluation and gamma scintigraphy of 99mTc-N-2-(furylmethyl iminodiacetic acid) complex as a new renal radiopharmaceutical

A ligand of N-2-(furylmethyl iminodiacetic acid) (FMIDA) has been easily labeled by a tetradentate chelating agent of [99mTc]. Factors like a stannous chloride solution as a reducing agent (100 μg), substrate amount (100 μg), pH (7), in vitro stability (8 h) and temperature (37 °C) have been systematically studied to optimize high radiochemical yield (98.0%). The radiochemical conversion was calculated on thin-layer chromatography, paper electrophoresis, and high performance liquid chromatography. Biodistribution study showed that this complex was removed from the kidneys and bladder path way during 1 h post injection. Therefore, [99mTc]FMIDA may be used as renal function radiotracer.

Effects of Concentration of Triethanolamine and Annealing Temperature on Band Gap of Thin Film of Tin Sulphide Prepared by Chemical Bath Deposition Method

&lt;p&gt;Thin films of Tin Sulphide (SnS) were deposited by chemical bath deposition technique using a precursor solution of stannous chloride (SnCl&lt;sub&gt;2&lt;/sub&gt;.2H&lt;sub&gt;2&lt;/sub&gt;O), thioacetamide (TA), triethanolamine (TEA), ammonia (NH&lt;sub&gt;3&lt;/sub&gt;), and distilled water. The effects of concentration of triethanolamine and annealing temperature on the growth of SnS films were studied to optimize the growth conditions. X-ray diffraction study shows the deposited films were polycrystalline in nature and orthorhombic in structure. The optical direct and indirect band gap values of SnS films prepared with 15ml of TEA were found to be 1.76 eV and 0.89 eV respectively. Annealing the sample prepared with 12ml of TEA results increase in band gap from 1.79eV to 3.32eV.&lt;/p&gt;&lt;p&gt;Journal of Nepal Physical Society, 2015, Vol. 3(1): 1-5&lt;/p&gt;

A novel salting-out assisted extraction coupled with HPLC- fluorescence detection for trace determination of vitamin K homologues in human plasma

Recently, new physiological roles of vitamin K homologues have been established in the treatment of rheumatoid arthritis, osteoporosis, hepatocellular carcinoma and leukemia. However, relatively high plasma protein binding, low plasma concentrations and occurrences of interfering lipids make accurate determination of vitamin K homologues a challenging task. Therefore, a sensitive and reliable salting-out assisted liquid/liquid extraction (SALLE) method coupled with HPLC-Fluorescence detection was designed for efficient extraction and quantification of trace levels of vitamin K homologues in human plasma. The investigated vitamin K homologues were phylloquinone (PK, vitamin K1), menaquinone-4 (MK-4) and menaquinone-7 (MK-7). The method employed a new efficient fluorescence derivatization reaction using ethanolic solution of stannous chloride in acidic solution to generate highly fluorescent naphthohydroquinone derivatives. Correlation coefficients were more than 0.998 in the concentration ranges of 0.3–100ngmL−1 with detection limits of 0.1–0.17ngmL−1 in human plasma. The developed HPLC-FL system was successfully applied for sensitive determination of vitamin K homologues in plasma of healthy volunteers. The developed method may provide a valuable tool in the pharmacoinformatic studies concerning the roles of vitamin K homologues.

Preparation and Characterization of Transparent Conductive SnO2-F Thin Film Deposited by Spray Pyrolysis: Relationship between Loading Level and Some Physical Properties

Relationship between loading level and some physical properties of the SnO2-F film has been investigated. SnO2-F thin films were prepared by spray pyrolysis technique using modified respiratory therapist nebulizer at substrate temperature in the range of 400-520̊C. A stannous chloride solution was used as precursor and ammonium fluoride (NH4F) as dopant with 20% [F]/[Sn] ratio. The sheet resistance was found to decrease withthe increasing loading level, and sheet resistancebecame steady after the loading level was greater than0.45mg/cm2. The transmittance was found to decrease with the increase of loading level but the decrease was not significant. The transparent conductive oxide of SnO2-F thin films were obtained, with transmittance was greater than 82.5% and sheet resistance of 21.4Ω/sq. This results are comparable with the reported values (81.9% and 21.8Ω/sq) [1] and this film can be used for efficient support of dye-sensitized solar cells electrode.

Sonochemical growth of SnO2 hollow nanostructures on cellulose acetate flexible substrates

In this paper, we report for the first time tin oxide hollow nanostructures growth on cellulose acetate flexible substrates by sonochemical spin coating. SnO2 particles formed by microwave irradiation of stannous chloride solution in ethylene glycol, used as starting material. Particles were then dissolved in ethanol and ultrasonicated just before ejecting from the spray jet to the substrates placed on the spin coater. The spin rate was maintained at 5000rpm and the process was repeated for several times. All the samples were annealed at 80°C for 2 to 6h and characterized by structural, morphological and optical studies. All the peaks in the X-ray diffractograms are identified and indexed as tetragonal cassiterite structure. AFM and SEM confirm the formation of porous tube- like growth in vertical direction. Strong photoluminescence peak in the visible region makes these structures suitable for flexible optoelectronic applications.

Synthesis of multi-walled carbon nanotube/silver nanocomposite powders by chemical reduction in aqueous solution

Carbon nanotube (CNT)/silver nanocomposite powders with different volume fractions of CNTs 2.5, 5 and 10 vol.% were prepared by chemical reduction in solution. Multi-walled CNTs underwent surface modifications for functionalisations by acid treatments. The acid-treated CNTs were investigated by FT-IR and X-ray photoelectron spectroscopy. The spectroscopic investigations of the acid-functionalised CNTs detected that several kinds of functional groups attached with the graphene structure as well as produced short and de-caped CNTs. Acidic stannous chloride solution was used to sensitise the surface of the functionalised CNTs. Silver was deposited on the surface of sensitised CNTs with chemical reduction reaction of alkaline silver nitrate solution by formaldehyde at room temperature and pH ∼ 9. The morphology of the produced CNT/silver nanocomposite powder was investigated by high-resolution SEM and TEM. It was observed that the produced CNT/silver nanocomposite powders have decorated type of spherical silver particle size 2–5 nm deposited on the surface of CNTs as well as the CNTs were implanted in large spherical silver nanoparticles of particle size ∼200 nm. The chemical analysis of the produced powder indicates that some oxygen content is included in the prepared powders which can be reduced by heat treatment at temperatures between 300°C and 400°C under hydrogen atmosphere.

Preparation of PVP–PVA–exfoliated graphite cross-linked composite hydrogels for the incorporation of small tin nanoparticles

The direct exfoliation of graphite was achieved in water using water-soluble poly(vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA). Prepared wrapped graphene dispersion was employed for the synthesis of chemically cross-linked PVP/PVA/exfoliated graphite (G) composite hydrogels. The swelling behaviour of these hydrogels was studied in aqueous solution of stannous chloride, followed by treatment in a bath of sodium borohydride (NaBH4). The previous PVP/PVA–graphene aqueous dispersion was analyzed by UV–Visible and Raman spectroscopy. The morphology of the composite hydrogels was observed by field-emission scanning electron microscopy (FE-SEM). The successive modifications of the composite hydrogels, in particular the incorporation of tin nanoparticles (SnNPs) were monitored by (FT-IR) Fourier transform-infrared spectroscopy. The size and shape of the incorporated SnNPs were controlled by transmission electron microscopy (TEM).

Radiolabeling and biodistribution studies of polymeric nanoparticles as adjuvants for ocular vaccination against brucellosis

PurposeTo optimize radiolabeling with 99mTc of mannosylated Gantrez® nanoparticles loaded with the Brucella Ovis antigen (Man-NP-HS) and to carry out biodistribution studies in mice after ocular administration of the nanoparticles. Material and MethodsMan-NP-HS nanoparticles were prepared by the solvent displacement method. They were purified, lyophilized and characterized. Then, they were radiolabeled with 74MBq of 99mTcO4− previously reduced with an acidic stannous chloride solution, working in absence of oxygen and at a final pH of 4. Radiolabeling yield was evaluated by TLC. Biodistribution studies were carried out in mice after ocular administration of the formulation and a control of free 99mTcO4−. Thus, animals were humanly killed at 2 and 24h after the ocular administration and activity in organs was measured in a Gamma counter. ResultsRadiolabeling yield obtained was greater than 90%. Biodistribution studies of 99mTc-Man-NP-HS showed radioactivity accumulated at 2 and 24h in nasal and ocular mucosa and gastrointestinal tract, in contrast to biodistribution of free 99mTcO4− that remained concentrated in the skin around the eye and gastrointestinal tract. ConclusionBiodistribution studies of 99mTc-Man-NP-HS after ocular instillation have made it possible to demonstrate its biodistribution in nasal mucosa and gastrointestinal tract. This characteristic is essential as an antigenic delivery system throughout the ocular mucosa. This, together with its elevated immune response, effective protection and intrinsic avirulence make them a suitable anti-Brucella vaccine candidate.

Insitu Raman spectroscopic observation of sequential hydrolysis of stannous chloride to abhurite, hydroromarchite, and romarchite

The sensitive character of tin oxidation and the effect of pH on the solubility of tin species highlight several challenges for further understanding tin speciation within aqueous solutions. Raman spectroscopic monitoring of aqueous stannous chloride solutions over a broad pH range resulted in the observation of several insoluble tin species (e.g. abhurite and hydroromarchite) suspended within the neutral and alkaline solutions. An aqueous tin speciation mechanism was proposed based on semi‐quantitative indirect hard modeling analysis of these solutions. The methods employed in this study demonstrate the usefulness of Raman spectroscopy for the characterization of complex heterogeneous mixtures. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Gas diffusion flow injection determination of thiomersal in vaccines

A new simple gas diffusion flow injection method has been developed for the determination of thiomersal in biological samples. The method is based on cold vapor generation of monoatomic mercury from thiomersal reaction with acidic stannous chloride solution (0.6%) acting as reducing agent. The evolved mercury partially diffuses through a Teflon membrane into an acidic permanganate (2.25×10−4molL−1) acceptor stream, where it is oxidized and re-converted to Hg(II). The resulting decrease in acceptor stream absorbance is sensitively monitored at 528nm. Flow injection variable parameters such as reagents concentrations, injected volume, reactor length, temperature and flow rate were carefully investigated and optimized. The concentration–response relationship was linear over a concentration range of 1–30mgL−1 with a correlation coefficient greater than 0.99 and a good reproducibility (RSD<1.42%, n=6) at 10mgL−1. A detection limit of 0.07mgL−1 (S/N=3) and a sampling frequency of 5samplesh−1 were obtained. The method was successfully applied for the determination of thiomersal in different types of vaccines and gave results in close agreement with those found by previously established HPLC method with no significant interference from vaccines matrices.

The electrocatalytic properties of (Pt/Sn)-CNT hybrids

(Pt/Sn)-CNT hybrids with different Pt/Sn atom ratios were prepared by impregnation using a mixed solution of chloroplatinic acid and stannous chloride using carbon nanotubes(CNTs) as the supporting material,and ethylene glycol and sodium formate as reducing agents.X-ray diffraction and transmission electron microscopy were used to characterize the microstructure of the materials and showed that Pt,Sn particles were highly dispersed on CNTs with a particle size range between 3.5-6.5 nm.Sn existed both in a Pt-Sn alloy and also as SnO2.Cyclic voltammetry analysis indicated that the atomic ratios of Pt/Sn in the materials with the best electro-catalytic activity and anti-toxic abilities were between 2.5∶1 and 3.5∶1.CNTs helped improve the electrocatalytic activity for methanol oxidation.

Preparation SnO2 Nanolayer on Flexible Polyimide Substrates via Direct Ion-Exchange and in situ Oxidation Process

Tin oxide (SnO(2)) nanolayers were formed on flexible polyimide (PI) substrate via direct ion-exchange and in situ oxidation process utilizing pyromellitic dianhydride/4,4'-oxidianiline-based poly(amic acid) films as polyimide precursor. During an ion-exchange process, stannous ions were doped into the precursor by immersion in ethanolic solution of stannous chloride. Subsequent thermal treatment of the tin(II)-containing precursor at a constant heating rate not only imidized poly(amic acid) to PI but also converted stannous ions into SnO(2) clusters, which diffused and aggregated onto the surface of polymer matrix, forming continuous tin oxide layers. Inductively coupled plasma (ICP) was used to investigate the ion-exchange process. Changes in chemical structure of the poly(amic acid) film and the crystal structure of tin oxides were analyzed by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and X-ray diffraction (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to study the microstructure of the PI/SnO(2) nanocomposite films. The nanocomposite film maintained essential mechanical property and thermal stability of pristine PI films.

On the optical properties of SnO2 thin films prepared by sol-gel method

Tin oxide (SnO2) thin films are prepared by spin coating onto well-cleaned glass substrates using stannous chloride and methanol solution as complexing agent. Films of different thicknesses are annealed at 400° C. Optical properties are studied using UV-Visible spectrophotometer. The films are highly transparent in the visible region. It is found that transmission increases in coated glass (∼92%) than uncoated glass. This may find applications in antireflection coating. Energy band gaps obtained are in the range of 4.10–4.12 eV. Refractive index variation with thickness is also studied and is between 1.77–1.91. The thicknesses of the film are of the order 2300, 3500 and 4800 A. These results have been discussed in the light of literature.

Active Stainless Steel/SnO 2-CeO 2 Anodes for Pollutants Oxidation Prepared by Thermal Decomposition

Stainless steel plates were successfully coated with SnO 2 -CeO 2 films (SS/SnO 2 -CeO 2 ) by brush coating with a solution of stannous chloride and cerium trichloride followed by thermal decomposition. It is proven that the properties of SnO 2 films can be evidently improved by Ce doping, and 600°C is the optimum temperature to prepare SS/SnO 2 -CeO 2 anodes. The physicochemical and electrochemical properties as well as the electrocatalytic activity of the electrodes were investigated. It is found that the novel electrodes have compact microstructure, high overpotential for oxygen evolution (1.60 V vs SCE), excellent electrochemical stability, relatively low cost and excellent catalytic activity for oxidizing pollutants. An industrial dye wastewater, which is hard to be purified by using conventional chemical flocculation methods, was oxidated by employing the SS/SnO 2 -CeO 2 anodes, and 83.00% of color and 48.62% of chemical oxygen demand (COD) removal was achieved under the cell voltage of 5 V within only 2 min, and the electricity consumption is only 1.83 kWh for oxidizing 1 m 3 of dye wastewater.

Coir-fiber-based fire retardant nano filler for epoxy composites

Coir-fiber-based fire retardant nano filler has been developed for epoxy resin (ER). At first, the coir fiber was brominated with saturated bromine water and then treated with stannous chloride solution. After drying, it was grinded to nano dimension and mix well with ER for composites preparations. FTIR, DSC, and TG techniques were used to characterize the brominated coir fiber. Gravimetric analysis shows only 10% by mass of bromination on coir fiber. Bromination decreases the thermal stability of the coir fiber, but it does not affect the final stability of the composites. This study concentrates on the thermal, fire retardant, and morphological properties of nanocomposites prepared by direct mixing. The fire retardancy properties (smoke density and limiting oxygen index) of coir–epoxy nanocomposites have increased significantly.