Zinc Poly Research Articles

A literature review on various luting cements used in dentistry

The success rate of the given fixed partial denture and the longevity of the fixed partial denture is depend on the tooth preparation and the usage of the luting cement under the fixed partial denture prosthesis. Luting cement plays an important role in maintaining or securing the fixed partial denture prosthesis in the cemented position. Luting cement should be bio compatible, it should be non-irritating to the underlying tooth structure and non-irritating to the pulp, it should maintain the adequate marginal seal. In recent days so many newer luting cements has been introduced in to the dentistry, that are claiming for good as well as better clinical performance from the existing cements in the terms of improved and better characteristic properties. The different cements which can be used as luting cements are glass ionomer cements, zinc phosphate, zinc poly carboxylate, zinc oxide eugenol, newer cements like resin modified glass ionomer cements, compomers and resin cements.

Retraction: Synthesis of a novel type of chiral salen Mn(iii) complex immobilized on crystalline zinc poly(styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPP) as effective catalysts for asymmetric epoxidation of unfunctionalized olefins

Retraction for ‘Synthesis of a novel type of chiral salen Mn(iii) complex immobilized on crystalline zinc poly(styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPP) as effective catalysts for asymmetric epoxidation of unfunctionalized olefins’ by Jing Huang et al., Catal. Sci. Technol., 2011, 1, 1472–1482, DOI: 10.1039/C1CY00285F

Retention of Various Luting Agents Used with Implant-Supported Crowns.

Background:Implant supported crowns can either be screw retained or cement retained. Recent advances in implant dentistry has improved the longevity of the implant restoration and has placed importance on esthetics and function. Cement retained restoration has added advantage of superior esthetics and is preferred by the clinician. However, selecting the ideal type of cement for luting implant supported crown has been a topic of debate.Methodology:A study was conducted at ESIC Dental College & Hospital, Kalaburagi to determine the retentive ability of three different luting agents. 30 samples were divided into three groups and luted with Zinc phosphate, Zinc Polycarboxylate and Glass ionomer cement. The retentive strength was evaluated using universal testing machine.Results:Results proved that zinc poly carboxylate cement had the highest retentive value followed by glass ionomer and zinc phosphate.

Retraction statement: Chiral Jacobsen's catalyst immobilized on zinc poly(styrene‐phenylvinylphosphonate)‐phosphate functionalized by diamine as highly efficient and reusable catalyst for alkene epoxidation

Retraction statement: Chiral Jacobsen's catalyst immobilized on zinc poly(styrene‐phenylvinylphosphonate)‐phosphate functionalized by diamine as highly efficient and reusable catalyst for alkene epoxidation

Nanostructural and barrier property characterization of ZnO/PEDOT:PSS heterojunction by adjusting RF power in the magnetron sputtering deposition technique

Nanostructure and barrier properties of the heterojunction formed at the interface of ZnO/PEDOT:PSS inorganic/organic contact have been investigated. The PEDOT:PSS layer and the zinc oxide nanostructures have been deposited using the spin coating and the radio frequency magnetron sputtering techniques on glass substrates at room temperature, respectively. Particularly, the effects of zinc oxide sputtering power on the nanostructure properties of the deposited layer are investigated. The deposition power varies from 60 to 240 W. AFM results show that increasing the deposition power, results in the grain size and the surface roughness of the zinc oxide layer to increase. The energy gap measured for the zinc oxide layers deposited at the powers of 60, 120, 180 and 240 W was 3.24, 3.23, 3.18, and 3.20 eV, respectively. In order to investigate the heterojunction formed at the interface of zinc oxide and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS), a polymeric layer of thickness of 50 nm is deposited on a 300-nm zinc oxide layer. The dark I–V characteristics indicate that the reverse saturation current density is 5.01 × 10−7, 3.16 × 10−5, 1.96 × 10−7 and 7.98 × 10−7 A/cm2 for the deposition power of 60, 120, 180, and 240 W, respectively. By increasing the deposition power the ideality factor of the resulting Schottky barrier is 3.2, 2.9, 2.3 and 3.6. The effective Schottky barrier heights of 0.76, 0.77, 0.78, and 0.75 eV were obtained for the same order of deposition powers. It was found that the highest optical response could be obtained for the samples prepared at the deposition power of 180 W.

Morphological, optical and electrical properties of spray coated zinc ethyl xanthates for decomposition within a poly(3-hexylthiophene-2,5-diyl) matrix

This work investigates the deposition of hybrid layers, for next generation in energy conversion, via spray coating. Understanding the effect that this deposition procedure has on these layers could lead to the rapid development of these technologies, for both laboratory applications and commercialisation. Synthesised zinc ethyl xanthate and poly(3-hexylthiophene-2,5-diyl) was spray-coated on substrates and heated to a temperature of 160 °C, to the hybrid film. Optical, morphological and conductive properties of these films were investigated and linked to the spray coating duration. It was revealed that shorter-duration spray times led to relatively low conductivity and smoother films, moreover, an increase in spraying duration also led to an increase in conductivity, but with increased roughness, from 6.178 nm to 8.317 nm. As the spray time was further increased factors, including film layering effects, led to a gradual decrease in conductivity accompanied by a decrease in the roughness. Smoother films were shown to result in higher light absorption, characterised by wider band gaps, which could be due to the crystal structure of the inorganic phase. The controllability of this rapid, facile, and inexpensive spray deposition process was then demonstrated in fabrication of prototype photovoltaic devices.

Antibacterial Activity of Zinc Oxide Nanoparticles and Poly (B-hydroxybutyrate)/ZnO Bionanocomposites Against Escherichia coli

Antibacterial Activity of Zinc Oxide Nanoparticles and Poly (B-hydroxybutyrate)/ZnO Bionanocomposites Against Escherichia coli

Enhanced enzymatic degradation in nanocomposites of various organically-modified layered zinc phenylphosphonates and poly (butylene succinate-co-adipate)

In this work, two long-chain alkylamines, dodecylamine (DDA) and octadecylamine (ODA), intercalated with layered zinc phenylphosphonates (PPZns) were prepared using a simple chemical intercalation method. Both biocompatible poly(butylene succinate-co-adipate) (PBSA)/organically-modified PPZn nanocomposites fabricated by a melt-mixing technique have been characterized by wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). These results indicated that the stacking layers of the ODA-PPZn in the PBSA matrix were fully/partially exfoliated and the intercalated PBSA/DDA-PPZn nanocomposites were formed. Enzymatic degradation tests using Lipase from Pseudomonas sp. as the enzyme was investigated. The weight loss of PBSA increases with an increase in the content of organically-modified PPZn. The degradation rate of all samples varied in the order PBSA/ODA-PPZn nanocomposites > PBSA/DDA-PPZn nanocomposites > neat PBSA. This result is probably due to the lowest degree of crystallinity for PBSA/ODA-PPZn nanocomposites. The degradation behavior of the neat PBSA belongs to exo-type hydrolysis activity due to the degradation starts from both ends of the polymer chains.

Enhanced electron transfer ability via coordination in block copolymer/porphyrin/fullerene micelle

Inspired by structures of antenna-reaction centers in photosynthesis, the complex micelle was prepared from zinc tetra-phenyl porphyrin (ZnTPP), fullerene derivative (PyC60) and poly(ethylene glycol)-block-poly(e-caprolactone) (PEG-b-PCL). The core-shell structure made the hydrophobic donor-acceptor system work in aqueous. In micellar core, coordination interaction occurred between ZnTPP and PyC60 molecules which ensured the enhanced energy migration from the donor to the acceptor. The enhanced interaction between porphyrin and fullerene was confirmed by absorption, steady-state fluorescence and transient fluorescence. The generation of singlet oxygen and superoxide radical was detected by iodide method and reduction of nitro blue tetrazolium, respectively, which confirmed that electron transfer reaction in the complex micellar core occurred. Moreover, the complex micelle exhibited effective electron transfer performance in photodebromination of 2,3-dibromo-3-phenylpropionic acid. The complex micellar structure endowed the donor-acceptor system with improved stability under irradiation. This strategy could be helpful for designing new electron transfer platform and artificial photosynthetic system.

Retracted: Chiral Jacobsen's catalyst immobilized on zinc poly(styrene‐phenylvinylphosphonate)‐phosphate functionalized by diamine as highly efficient and reusable catalyst for alkene epoxidation

Chiral Jacobsen's catalyst anchored on zinc poly(styrene‐phenylvinylphosphonate)‐phosphate (ZnPS‐PVPA) functionalized by diamines shows superior catalytic activities (conversion up to 99%; enantiomeric excess up to 99%) in the enantioselective epoxidations of unfunctional olefins with m‐chloroperoxybenzoic acid and NaIO4 as oxidants. The whole chiral salen Mn(III) catalyst, including the ZnPS‐PVPA support and the linker as well as chiral salen Mn ligand together contribute to the chirality of products. The heterogeneous catalyst has the potential for use in industry owing to superior stability (recycling nine times) and activity in large‐scale reactions (such as 200 times).

Mixture of Zinc Oxide Microrod and Poly(3-Dodecylthiophene) with <i>Melastoma malabathricum</i> Dye for Hybrid Solar Cell

A single hybrid solar cell (SHSC) which consist of zinc oxide (ZnO) micro-rod and Poly (3-dodecylthiophene)(P3DDT) materials with nature dye from Melastomamalabathricum fruit (Mm) were fabricated to determine it electrical properties and power conversion efficiency (PCE). The ZnO microrod was growth by thermal method. P3DT was synthesis by oxidation polymerization method. Nature dye was extracted from Mm fruit in purplecolor.The fabrication of a SHSC started with growth ZnO microrodon the Indium Tin Oxide (ITO) in thin filmform, followed with P3DT layers and finally layered with Mm in 5 layers and 10 layers respectively.The SHSC wascharacterized the electrical conductivity and PCE also compared under dark condition and various light intensity. The conductivity of the samples is increase within the increment of light intensity and the efficiency of SHSC increase within the increment of layer of Mm. The highest electrical conductivity was for 10 layers of dye which is 2.678 + 0.002 Scm-1. The power conversion efficiency (PCE) of the ITO/ZnO/P3DDT/10 layers dye achieved was the highest which is 0.0011% under radiation of 200 Wm-2 intensity of light. As a conclusion, it can say that the amount of Mm can affect the performance of hybrid solar cell, where the dye is increased, the electrical conductivity and the PCE also increase. Thus, the Mm is a good dye and can be potential to apply in the solar cell.

Tunable luminescence of pure ZnO nanowires prepared by microwave irradiation in ethanol

In this work, ZnO nanowires were synthesized using zinc acetate, ethanol, and poly (N-vinylpyrrolidone, 40000) (PVP) by microwave irradiation with controllable luminescence properties. This method is very fast, simple and without any doping agent the luminescence of ZnO nanowires is tunable. Effect of variation of PVP/Zn mole ratio on the luminescence properties of the samples has been studied. Structural analysis was performed by means of X-ray diffraction and scanning electron microscopy. The results revealed that microstructure and morphology of the samples does not change significantly with the change of PVP. UV–Vis absorption spectroscopy indicates that with the increase of PVP, the absorption tail increases. Photoluminescence spectroscopy indicated that nanowires emit different colors from blue to yellow just by the increase of PVP. The considerable emission of the deep-level luminescence can be ascribed to the increase in the density of oxygen and zinc interstitials at the surface of ZnO due to successful incorporation of PVP in surface modification of nanowires.

Layered crystalline chiral salen Mn(III) complexes immobilized on organic polymer–inorganic hybrid zinc phosphonate-phosphate as efficient and reusable catalysts for the unfunctionalized olefin epoxidation

Chiral Mn(III) salen complexes grafted on ZnPS-PVPA (zinc poly(styrene-phenylvinyl-phosphonate)-phosphate) upon alkyldiamines through a facile method are evaluated by the asymmetric epoxidation of unfunctionalized olefins. Superior catalytic performances are obtained (conv%, up to >99; ee%, up to >99) whenever with m-CPBA or NaClO or NaIO4 as the oxidant. The additives such as NMO, PPNO as well as imidazole play different roles in the corresponding oxidation system. In addition, the supported catalysts could be reused nine times with the retention of their efficiency. These results highlight the potentiality of ZnPS-PVPA as the support for immobilizing chiral salen Mn(III) to be employed in oxidation reactions.

Ultraviolet Sensor Based on Organic/Inorganic Heterojunction between PEDOT:PSS and ZnO Nanoparticles Thin Films

In this work, the ultraviolet (UV) sensors based on heterojunction between layer of zinc oxide nanoparticles (ZnO NPs) and poly (3,4-ethylenedioxythiophene):poly (styrenesulfonic acid) (PEDOT:PSS) were fabricated, characterized and studied in the electrical response to UV 365 nm. The ZnO NPs layer was solution-based coated on the top of PEDOT:PSS film on the patterned indium tin oxide (ITO) coated on glass. Aluminum was deposited as the top electrode of the device. The current-voltage (I-V) characteristic shows the rectifying behavior in the dark field. With the UV irradiation, the reverse bias current can be found and the forward bias current also highly increases. The current-voltage data fitting with the thermionic emission model shows that the potential barrier height at the heterojunction decreases with illuminating by UV light. Relative high photoresponse of the device exhibits the potential to UV detector application.

Electron paramagnetic resonance (EPR) study of free radicals in irradiated zinc poly methacrylate

Abstract We report the analysis of the X-band EPR spectrum of the free radical species formed in Zn(II) polymethacrylate (Zn(II) PMA), after degradation was induced in this polymer by 60 Co γ- radiation at room temperature. We begin by describing the synthesis and characterization of our samples and its polymerization before applying them several doses to induce degradation. Doses from 10 to 100 kGy in steps of 10 kGy were applied to the samples. At 10 kGy dose, the EPR spectrum shows the superimposed spectra of two species, namely: a typical pattern of an axially symmetrical singlet and a broad symmetric single line. The former can be attributed to peroxide radicals. After applying further doses, the EPR spectra of the samples display a series of superimposed lines on top of the mentioned axial singlet and the broad line. In these spectra, we recognize three sets of lines: a weak doublet, a quartet and quintet in addition to the already detected axially symmetrical line and the broad singlet. These can be assigned to scission radicals trapped in the polymeric matrix.

Syntheses of near infrared absorbed phthalocyanines to utilize photosensitizers

Phthalocyanines have become of major interest as functional colorants for various applications. In order to use various applications especially photosensitizers, the absorption maxima called Q-band of phthalocyanines are required to be shifted to the near infrared region. Substituted phthalocyanine analog alkylbenzopiridoporphyrazins, especially zinc bis(1,4-didecylbenzo)-bis(3,4-pyrido)porphyrazine, and toroidal-shaped phthalocyanines having aminoamine dendric side chains such as toroidal zinc poly(aminoamine)phthalocyanine dendrons were synthesized. Phthalocyanines of two types reportedly use photosensitizers for photodynamic therapy of cancer. The respective efficacies of photodynamic therapy of cancer for zinc bis(1,4-didecylbenzo)-bis(3,4-pyrido)porphyrazine and its regioisomers were estimated using laser-flash photolysis. The capability of using photodynamic therapy for toroidal zinc poly(aminoamine)phthalocyanine dendrons was assessed using a cancer cell culture. Both phthalocyanines were suitable for the use as a photosensitizer as photodynamic therapy of cancer. Then, non-peripheral thioaryl substituted phthalocyanines, 1,4,8,11,15,18,22,25-octakis(thioaryl)phthalocyanines, such as 1,4,8,11,15,18,22,25-octakis(thiophenylmethyl)phthalocyanines, 1,4,8,11,15,18,22,25-octakis(thiophenylmethoxy)phthalocyanines, and 1,4,8,11,15,18,22,25-octakis(thiophenyl tert-butyl)phthalocyanines were also synthesized in order to develop next- generation photovoltaic cells and/or dye-sensitized solar cells. Non-peripheral substituted 1,4,8,11,15,18,22,25-octakis(thioaryl)phthalocyanines exhibited a Q-band in the near infrared region. Electrochemical measurements were performed on the above-mentioned 1,4,8,11,15,18,22,25-octakis(thioaryl)phthalocyanines described above to examine their electron transfer abilities and electrochemical mechanisms. The compounds 1,4,8,11,15,18,22,25-octakis(thioaryl)phthalocyanines are anticipated to be appropriate materials for use in the next generation of photovoltaic cells.

Optical Limiting Analysis of Phthalocyanines in Polymer Thin Films

This paper reports on the effect of embedding twelve phthalocyanines containing In, Ga, Zn and Al as central metals in polymer thin films on their optical limiting abilities. This paper also examines the effect of forming a covalent link between zinc tetraamino phthalocyanine (10) and poly (methyl acrylic acid) (PMAA), and Zn (11) or OHAl (12) octacarboxy phthalocyanines with polyethylenimine (PEI). The average film thickness (for phthalocyanines mixed or linked to polymers) of each Pc/Polymer films on glass was 95 μm. The hyperpolarizability of the twelve phthalocyanines was found to be in the range of 10−26 to 10−24 esu.L. This is significantly higher than the hyperpolarizabilities of these phthalocyanines in solution, which ranged from 10−30 to 10−26 esu.L. Degradation studies seem to indicate that placing a phthalocyanine within a polymer thin film may protect it slightly from photo- and thermal degradation.

A high efficient large-scale asymmetric epoxidation of unfunctionalized olefins employing a novel type of chiral salen Mn(III) immobilized onto layered crystalline aryldiamine modified zinc poly(styrene-phenylvinylphosphonate)-phosphate

A series of chiral salen Mn(III) catalysts immobilized onto aryldiamine modified ZnPS-PVPA with different ratio of phosphonate/phosphate for asymmetric epoxidation were synthesized and characterized by FT-IR, diffusion reflection UV–Vis, AAS, N2 volumetric adsorption, SEM, TEM, XPS, XRD and TG. The supported catalysts displayed superior catalytic activities in the asymmetric epoxidation of α-methylstyrene and indene with m-CPBA and NaIO4 as oxidants. Moreover, the heterogeneous catalysts were relatively stable and could be recycled nine times in the asymmetric epoxidation of α-methylstyrene. Furthermore, this novel type of catalyst could also be validly used in large-scale reactions with superior catalytic disposition being maintained at the same level, which possessed the potentiality for application in industry.

Chiral salen Mn(III) immobilized onto sulfoalkyl-modified zinc poly(styrene-phenylvinylphosphonate)-phosphate as effective catalysts for epoxidation of unfunctionalized olefins

The heterogeneous catalysts 3a–3c immobilized chiral salen Mn(III) onto sulfoalkyl-modified zinc poly(styrene-phenylvinylphosphonate)phosphate (ZnPSPPP) were prepared and used for the enantioselective epoxidation of unfunctionalized olefins. The catalysts were characterized with FT-IR, UV–vis, XRD, SEM, TEM. All the prepared heterogeneous catalysts exhibited much higher chiral induction than the homogeneous Jacobsen’s catalyst did and could be reused six times without significant loss of activity and enantioselectivity. Surprisedly, the conversions and enantiomeric excess (ee) values increased in the absence of axial base N-methylmorpholine N-oxide (NMO), which were different to what most literatures reported. Meanwhile, the role of axial ligand NMO in the asymmetric epoxidation of unfunctional olefin was also discussed here. Furthermore, this novel type of catalyst can also be validly used in large-scale reactions with superior catalytic disposition being maintained at the same level, which possessed the potentiality for application in industry.

Novel organic polymer–inorganic hybrid material zinc poly(styrene-phenylvinylphosphonate)-phosphate prepared with a simple method

A novel type of organic polymer–inorganic hybrid material layered crystalline zinc poly(styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPP) was synthesized under mild conditions in the absence of any template. And the ZnPS-PVPP were characterized by FT-IR, diffusion reflection UV–vis, AAS, N 2 volumetric adsorption, SEM, TEM and TG. Notably, this method was entirely different from the traditional means used for preparing other zinc phosphonate. Moreover, it could be deduced that ZnPS-PVPP possessed the potential applications for catalyst supports. In the initial catalytic tests, the catalysts immobilized onto ZnPS-PVPP showed comparable or higher activity and enantioselectivity with that of catalysts reported by our group in the asymmetric epoxidation of unfunctional olefins.