Literatura académica sobre el tema "Borophosphates de zinc"

The glasses of the series (1-x)[0.5ZnO-0.1B2O3-0.4P2O5]-xMoO3 with 0 ≤ x ≤ 0.6 were prepared by slow cooling of the melt. These glasses were characterized by the measurements of density, molar volume, chemical durability, glass transition temperature and the thermal expansion coefficient. The density and molar volume of the glasses increase with increasing MoO3 content. All glasses crystallize on heating and their crystallization temperature decreases with increasing MoO3 content. An incorporation of MoO3 into the parent borophosphate glass results in a substantial decrease of their glass transition temperature and also of their chemical durability. The observed changes were ascribed to the gradual replacement of stronger P-O-P bonds by weaker Mo- O-P and Mo-O-Mo bonds. ESR spectra revealed the presence of Mo5+ ions responsible for the blue colour of the glasses and the relative ratio of Mo5+/Mototal decreases with increasing MoO3 content.

The new borophosphates described here were synthesized under mild hydrothermal conditions (170 oC or 220 oC). Powder and single crystal X-ray diffraction were employed to determine and refine the crystal structures. DTA-TG methods were used to analyze the thermal stability. High temperature powder X-ray diffraction (HT-XRD) was applied to study the thermal behavior of products and identify the intermediate phase during the decomposition. Chemical analyses were performed to quantitatively determine the chemical composition. Magnetic properties of the compounds were investigated. 19F MAS NMR was used to check the number of fluorine positions in the crystal structure. The following compounds were prepared and characterized: (C2H10N2)[BPO4F2](C6H14N2){Zn[ZnB2P4O15(OH)2]¡P(C6H13N2)Cl} (zndabcocl) (C3H12N2){Mn[B2P3O12(OH)]} (DAP-Mn) and (C4H12N2){Mn[B2P3O12(OH)]} (PIP-Mn) (C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]}(C3H12N2)2{VIII2VIV3B2P8O38H8} (dapvbpo) K3[B5PO10(OH)3](C2H10N2)[BPO4F2] is the first fluorine-substituted borophosphate and the first borophosphate with crystal structure closely related to the pyroxene type structure. Unbranched zweier single chain {[BPO4F2]2?} represents a new type of borophosphate partial structure. zndabcoclrepresents the first organo-templated zincoborophosphate. The structure contains diaza-bicyclo[2.2.2]-octane (DABCO) which acts in its diprotonated form (H2DABCO)2+ as a pure template and in its monoprotonated form (HDABCO)+ as a ligand to Zn-positions at the borders of ribbons to complete structural motif. This compound is also the first example containing a quaternary Zn-tetrahedron (ZnO2NCl), and can formally be described as an adduct of (C6H14N2)Zn[ZnB2P4O15(OH)2] with diaza-bicyclo[2.2.2]octane-hydrochloride. The thermal behavior of zndabcocl has been studied by HT-XRD and DTA-TG in the temperature range 25?600 oC. The new phase occurring during the decomposition has been identified as HT-NH4[ZnBP2O8].DAP-Mnand PIP-Mn contain identical framework interconnections but difference in the shape of resulting channels, which are due to the different shape of organic templates. The crystal structures are built from the same building units: loop-branched single chains are connected via MnO6-octahedra resulting in a 3-D structure with intersecting channel systems running along [100], [011] and [01], respectively. The different shape of the template controls the shape of the channels, especially channels running along [100], resulting in dramatic shape-differences. The linear (H2DAP)2+ ions make the channels more elongated, while the cyclic (H2PIP)2+ ions give rise to more regular shaped channels. The flexibility of frameworks may be due to the more flexible coordination of Mn-atoms (octahedron and square pyramid).(C3H12N2){FeIII6(H2O)4[B4P8O32(OH)8]} is a new borophosphate with 3-D framework structure, a large size of 10-ring channel (778 ¡Ñ 867 pm2) is occupied by organic templates. The magnetic susceptibility measurements show it to exhibit antiferromagnetic susceptibility at low temperature (TN ?l 14K).dapvbpois the first mixed-valency vanadium borophosphate with a new structure type. Its structure can be considered as an ?intergrowth? of puckered vanadium(III) borophosphate layer (VIIIBPO-layer) and planar vanadium(IV) phosphate layers (VIVPO-layer) stacked and interconnected alternately along [001], which results in a new and unusual building motif. The corner sharing trimers of vanadium octahedra are observed for the first time in vanadium borophosphates. K3[B5PO10(OH)3] has a double unit cell of a twin crystal structure having the same chemical formula. The double b-axis solves the disorder problem of two oxygen positions coordinated to phosphorous. It represents a much more reasonable structure determination.

La spectroscopie par Résonance Magnétique Nucléaire (RMN) à l'état solide est devenue une technique incontournable pour caractériser les matériaux inorganiques oxydes. Ces dernières années, la résolution des spectres RMN a été significativement améliorée par le développement de spectromètres de plus en plus puissants. Dans le contexte Lillois, cette amélioration de la résolution a particulièrement bénéficié aux études sur les matériaux boratés synthétisés par les différentes équipes de recherche de l'université. L'objectif de cette thèse est de soutenir le développement des études par RMN sur les matériaux boratés préparés localement en montrant notamment les apports des techniques de RMN de corrélation. Deux types de matériaux ont ainsi été sélectionnés pour l'étude : les verres de borophosphate de zinc préparés au LASIRE et les systèmes retardateurs de flamme à base de borate de zinc hydraté et de polyphosphate d'ammonium préparés à l'UMET.Les matériaux vitreux étudiés sont des borophosphates de zinc de composition xB2O3 - (50-x/2)ZnO - (50-x/2)P2O5, connus pour leur faible température de transition vitreuse (Tg) et leur bonne durabilité chimique. Les analyses par spectroscopie RMN avancée 11B et 31P 1D/2D ont permis de relier l'effet de formateur mixte observé sur la Tg avec la structure du réseau vitreux.Les systèmes de retardateur de flamme basés sur le borate de zinc hydraté (ZBH) et le polyphosphate d'ammonium (APP) sont couramment utilisés dans l'industrie. Les analyse par RMN 1D/2D de ce travail ont contribué à la compréhension du mécanisme de dégradation thermique de chaque composé dans un premier temps et à la compréhension de la réactivité entre les deux composés dans un second temps
Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy has become an essential technique for characterizing inorganic oxide materials. In recent years, the resolution of NMR spectra has been significantly improved by the development of increasingly powerful spectrometers. In the Lille context, this improvement in resolution has particularly benefited studies on borate materials synthesized by the university's various research teams. The aim of this thesis is to support the development of NMR studies on locally-prepared borate materials, in particular by demonstrating the benefits of correlation NMR techniques. Two types of materials have been selected for study: zinc borophosphate glasses prepared at LASIRE, and flame-retardant systems based on hydrated zinc borate and ammonium polyphosphate prepared at UMET.The glassy materials studied are zinc borophosphates with the composition xB2O3 - (50-x/2)ZnO - (50-x/2)P2O5, known for their low glass transition temperature (Tg) and good chemical durability. Analyses by 11B and 31P 1D/2D advanced NMR spectroscopy linked the mixed-former effect observed on Tg with the structure of the glassy network.Flame retardant systems based on hydrated zinc borate (ZBH) and ammonium polyphosphate (APP) are commonly used in industry. The 1D/2D NMR analyses in this work have contributed to understanding the thermal degradation mechanism of each compound in the first instance, and to understanding the reactivity between the two compounds in the second

碩士
國立聯合大學
材料科學工程學系碩士班
101
In this study, the fluorescent glass which was made up from glass deposited phosphor was produced. The phosphor powder deposited on the glass sheet, and phosphor had sunk into glass by annealing. The phosphor powder used commercially available Y3Al5O12 (YAG) powder, has a yellow fluorescent feature. The fluorescent glasses and blue light InGaN LED can form the white light LED. The selection of glass system is considered with high refractive index and low melting temperature. Because the phosphor powder have high refractive index, similar high refractive index can reduce light scattering. The low temperature make annealing process easier and more efficient. The glass system setected bismuth borophosphate glass system. In the bismuth borophosphate glass system, adding phosphate content , the glass melting temperature decrease, glass crystallization temperature increase, refractive index decrease, transmittance increase, and dissolution rate decrease.Bismuth borophosphate glass has good thermal deposition properties to sink phosphor powder, and the best result is the treatment temperature at 600oC. When the treatment processes different, the florescence emission spectrum does not shift. T he fluorescent glasses’ CIE chromaticity coordinates is (0.35 ,0.62 ) , and it not varies on different annealing processes. The White light CIE chromaticity coordinates is (0.26,0.39).