Zinc Phosphates Research Articles

Zinc in ammoniated phosphate fertilizers: Solid‐phase speciation, solubility, and use of barrier coatings to enhance zinc availability

AbstractZinc (Zn) is the micronutrient commonly found deficient in agricultural soils worldwide, limiting crop yield and reducing food quality. Zinc‐enriched fertilizers have been successfully used to tackle crop Zn deficiency. However, Zn solubility is reduced after addition to phosphate fertilizers due to the formation of sparingly soluble precipitates, decreasing Zn availability to crops. We hypothesized that the availability of Zn in the fertilizer to plants is related to its speciation in the fertilizer. We evaluated a range of ammonium phosphate fertilizers using X‐ray absorption near‐edge structure and assessed the water‐solubility of Zn in the formulations. Four Zn species were identified in these fertilizers, with zinc ammonium phosphate the most abundant one. The speciation of Zn in the fertilizer had little relationship with the water solubility of Zn in the final product. Zinc solubility was driven by fertilizer pH, with lower pH resulting in higher solubility. We concluded that added Zn reacts with the fertilizer matrix to form mainly zinc (ammonium) phosphates, and when the fertilizer is dissolved in water, hopeite controls the solubility. Based on these findings, we tested whether a barrier coating between the P granule and the Zn compound could prevent reaction between Zn and P and thus enhance Zn availability. Indeed, higher Zn uptake was observed in an isotopically labeled fertilizer growth trial when a barrier coating physically separated Zn and P in the fertilizer. In summary, Zn availability to crops can be maximized by decreasing fertilizer pH and separating P and Zn in the granule.

Improving the rate and cycle performance of V-based cathodes through regulation of the Zn2+ desolvation process

The large-scale application of vanadium in AZIBs has been hampered by its inferior rate performance and cycling stability, arising from the desolvation penalty of Zn2+ and the dissolution of vanadium. To address this issue, hydroxymethyl zinc phosphates Zn(O3PCH2OH) (ZnOPC) have been innovatively employed as a cathode electrolyte interphase (CEI) material to enhance the electrochemical performance of V2O5·nH2O (VO) cathode. The organized path structure of ZnOPC, coupled with its numerous hydroxyl groups, significantly reduces the desolvation penalty of Zn[H2O]62+ by forming new hydrogen bonds with the solvent-shell water molecules. More importantly, ZnOPC effectively mitigates vanadium dissolution by immobilizing free H2O which comes from the desolvation of Zn[H2O]62+. Consequently, the modified VO cathode exhibits superior rate performance and extraordinary cycling life, maintaining a specific capacity of 202.7 mAh/g after 7000 cycles at 10 A/g and 238.1 mAh/g at the high current of 20 A/g. These results offer a new prospect for designing high electrochemical performance vanadium-based cathode for AZIBs.

Flame retardancy in isotactic polypropylene modified with crystalline coordination polymers based on calcium, zinc or aluminum dimethyl phosphates

A novel variety of metal organophosphates (MOPs) coordination polymers: calcium bis(dimethyl phosphate) (CaDMP), zinc bis(dimethyl phosphate) (ZnDMP) and aluminum tris(dimethyl phosphate) was examined for the first time to act as potential flame retardants in isotactic polypropylene (iPP) materials and their flame-retarding activity compared with widely used commercial flame retarder ammonium polyphosphate (APP). All iPP composites containing 20 wt. % of MOPs as with APP achieve V-2 in the UL-94 test and LOI values even higher (25.5 vol. % for iPP/20 %CaDMP) than determined for APP-containing material accompanied by maintaining or slightly degrading mechanical properties. Also in mass loss calorimeter test (MLC) the MOPs demonstrated a positive effect on the fire response of the obtained composites leading to a reduced, in the case of ZnDMP, the peak of heat release rate (pHRR), total heat evolved (THE), average effective heat of combustion (avEHC), fire growth rate (FIGRA) by 57 %, 35 %, 29 %, 63 % respectively when compared with pure iPP. Moreover the detailed analysis of the solid and liquid pyrolysis products of MOPs was done via FTIR. The FTIR spectra and PRXD studies of the char residues after combustion indicated the formation of a solid, inorganic condensed phosphates and release of trimethyl phosphate (TMP) into the gas phase. Finally, the flame retardancy mechanism of MOPs was proposed based on results of MLC test and of the pyrolysis experiment. The gas phase activity of all three MOPs was confirmed by the decrease of avEHC most probably due to release of trimethyl phosphate (TMP) into flame, whereas, in particular ZnDMP acted strongly in the condensed phase by forming a intumescent, protective layer.

Exploring the potential of silica mixed zinc phosphate bioactive glasses for bone regeneration: In vitro bioactivity and antibacterial activity analysis

Biomaterials development is currently the main active research area in the field of bone tissue engineering. In the present study, the bioactive glasses with different chemical compositions (mol %) of zinc oxide, silica, calcium oxide, sodium oxide, and phosphates were synthesized by the melt-quench technique. We studied the thermal, physical, and other structural characteristics of the glasses to know the structural stability and potentiality to use as implant material. The in-vitro studies were performed to test the apatite forming ability and biocompatible nature of the prepared bioglass samples by immersing in simulated body fluid (SBF) solution with ion concentrations nearly equal to those in human blood plasma (pH =7.4 at 37 °C). All glass samples showed the formation of a clear layer of hydroxyapatite (HAP) on their surfaces after 14, and 21 days of immersion in SBF and the crystallization phases, morphology and functional groups of the hydroxyapatite layer (HAP) were confirmed by the characterizations of X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared (FTIR) analyses respectively. The antimicrobial studies of the silica containing phosphate bioglasses against Escherichia coli (E. coli), carried out for 24 h confirmed their potential antibacterial activity. The overall obtained results of the as developed silica containing phosphate bioglasses with enhanced properties suggested to use as potential bone regenerative implant material in the field of biomedicine.

Engineered baicalein-decorated zinc phosphates for synergistic alleviation of inflammatory bowel disease by repairing the mucosal barrier and relieving oxidative stress.

Orally administered baicalein-decorated zinc phosphates (ZnBM) were engineered for mucosal barrier improvement and intestinal inflammation relief. ZnBM with a size of 1.78 μm comprised 5.58 wt% baicalein and 13.17 wt% zinc. The incorporation of baicalein endowed ZnBM with excellent radical scavenging activities. ZnBM exhibited good stability with negligible zinc release in PBS solution for 2 days, and 32.82% of the zinc could reach the gut. In addition, ZnBM polarized macrophages into the anti-inflammatory M2 type and effectively scavenged intracellular reactive oxygen species (ROS) of lipopolysaccharide (LPS)-treated RAW264.7. Meanwhile, ZnBM effectively scavenged intracellular ROS of phorbol 12-myristate 13-acetate (PMA)-induced Caco-2 cells and exerted a reparative effect on the LPS-damaged Caco-2 monolayer, causing an obvious improvement of the barrier function. Reduced systemic exposure to FITC-dextran was observed to illustrate barrier restoration by ZnBM, which was achieved through upregulation of tight junction protein expression. Notably, the commonly used clinical drug 5-aminosalicylic acid is toxic to the liver and kidneys, and commercial ZnO caused the death of mice during treatment. Apparently, the therapeutic effect of ZnBM was significantly better than that of baicalein alone in chronic colitis. Overall, ZnBM exhibited outstanding therapeutic efficacy and is expected to treat colitis due to its effectiveness, biosecurity, facile preparation, and easy storage.

Mineralization of Lipase from Thermomyces lanuginosus Immobilized on Methacrylate Beads Bearing Octadecyl Groups to Improve Enzyme Features

Lipase from Thermomyces lanuginosus (TLL) has been immobilized on Purolite Lifetech® ECR8806F (viz. methacrylate macroporous resin containing octadecyl groups, designated as Purolite C18-TLL), and the enzyme performance has been compared to that of the enzyme immobilized on octyl-agarose, designated as agarose C8-TLL. The hydrolytic activity versus p-nitrophenol butyrate decreased significantly, and to a lower extent versus S-methyl mandelate (more than twofold), while versus triacetin and R-methyl mandelate, the enzyme activity was higher for the biocatalyst prepared using Purolite C18 (up to almost five-fold). Regarding the enzyme stability, Purolite C18-TLL was significantly more stable than the agarose C8-TLL. Next, the biocatalysts were mineralized using zinc, copper or cobalt phosphates. Mineralization increased the hydrolytic activity of Purolite C18-TLL versus triacetin and R-methyl mandelate, while this activity decreased very significantly versus the S-isomer, while the effects using agarose C8-TLL were more diverse (hydrolytic activity increase or decrease was dependent on the metal and substrate). The zinc salt treatment increased the stability of both biocatalysts, but with a lower impact for Purolite C18-TLL than for agarose-C8-TLL. On the contrary, the copper and cobalt salt treatments decreased enzyme stability, but more intensively using Purolite C18-TLL. The results show that even using enzymes immobilized following the same strategy, the differences in the enzyme conformation cause mineralization to have diverse effects on enzyme stability, hydrolytic activity, and specificity.

Multiphase zinc and magnesium mono-substituted calcium phosphates derived from cuttlefish bone: A multifunctional biomaterials

Biomimetic calcium phosphate (CaP) systems mono-substituted with zinc (Zn2+) and magnesium (Mg2+) ions were prepared from a biogenic source (cuttlefish bone) by wet precipitation method. The results revealed that the as-prepared powders were composed of calcium-deficient carbonated hydroxyapatite (HAp), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP), while the heat-treated powders consisted of HAp, α-tricalcium phosphate (α-TCP), and β-tricalcium phosphate (β-TCP). In addition to Zn2+ and Mg2+ ions, the presence of CO32−, Sr2+ and Na + ions was detected with elemental analysis, which can be attributed to the use of cuttlefish bone as a natural precursor of Ca2+ ions. The data obtained by XRD study demonstrated the decrease in lattice parameters in the OCP and β-TCP phases for Zn-substitution and Mg-substitution in the HAp, OCP, and β-TCP phases. Zn2+ occupies the Ca(1,3,4,6,7,8) sites in OCP and Ca(1,2,3,4) sites in β-TCP, while Mg2+ occupies the Ca(2) sites in HAp and the Ca(4,5) sites in β-TCP. Phase transformation study under simulated physiological conditions for 7 days showed the transformation of OCP and ACP into the thermodynamically more stable HAp. Characterization of the zeta-potential showed positively charged populations for all prepared CaP powders, while all samples showed high bovine serum albumin adsorption capacity. The culture of human embryonic kidney cells showed that the prepared CaPs are non-cytotoxic and that viability of the cells increases during the culture period. All powders obtained showed antibacterial activity towards Gram-negative Escherichia coli and low antibacterial effect against Gram-positive Staphylococcus aureus, as determined by viability analysis during 48 h. Inhibition zone analysis and observation of the morphology after 24 h showed no antibacterial properties.

Tuning Immobilized Commercial Lipase Preparations Features by Simple Treatment with Metallic Phosphate Salts.

Four commercial immobilized lipases biocatalysts have been submitted to modifications with different metal (zinc, cobalt or copper) phosphates to check the effects of this modification on enzyme features. The lipase preparations were Lipozyme®TL (TLL-IM) (lipase from Thermomyces lanuginose), Lipozyme®435 (L435) (lipase B from Candida antarctica), Lipozyme®RM (RML-IM), and LipuraSelect (LS-IM) (both from lipase from Rhizomucor miehei). The modifications greatly altered enzyme specificity, increasing the activity versus some substrates (e.g., TLL-IM modified with zinc phosphate in hydrolysis of triacetin) while decreasing the activity versus other substrates (the same preparation in activity versus R- or S- methyl mandelate). Enantiospecificity was also drastically altered after these modifications, e.g., LS-IM increased the activity versus the R isomer while decreasing the activity versus the S isomer when treated with copper phosphate. Regarding the enzyme stability, it was significantly improved using octyl-agarose-lipases. Using all these commercial biocatalysts, no significant positive effects were found; in fact, a decrease in enzyme stability was usually detected. The results point towards the possibility of a battery of biocatalysts, including many different metal phosphates and immobilization protocols, being a good opportunity to tune enzyme features, increasing the possibilities of having biocatalysts that may be suitable for a specific process.

Improvement of Flame Retardancy and Antidripping Properties of Intumescent Polybutylene Succinate Combining Piperazine Pyrophosphate and Zinc Borate

Developing flame-retarded polybutylene succinate (PBS) is a challenging task owing to its high flammability, noncharring, and melt-dripping during burning. In this work, based on the synergistic combination between piperazine pyrophosphate (PAPP) and zinc borate (ZnB), a promising intumescent PBS system was developed as an efficient strategy to impart PBS with improved flame retardancy and antidripping properties. The results showed that PBS/PAPP15%/ZnB5% passed V-0 rating in the UL-94 vertical burning test (3 mm), while only a V-2 rating was achieved for PBS/PAPP20%. Compared to PBS/PAPP20%, the combination of PAPP and zinc borate (ratio of 15:5) led to significant reductions in the peak heat release rate (pHRR, −55%), fire growth rate index (FIGRA, −40%), and maximum average rate of heat emission (MARHE, −47%) evaluated by mass loss cone calorimetry. Meanwhile, the flame retardancy index of PBS/PAPP15%/ZnB5% reached up to 5.18 and the flameout time significantly increased to 1049 s. Fourier transform infrared and solid-state nuclear magnetic resonance analyses were employed to gain insight into the reaction-to-fire mechanism in the condensed phase. The results confirmed the fact that the formation of a crack-free protective intumescent char layer, reinforced by thermally stable inorganic species (boron–zinc phosphates), effectively restricted the heat and fuel transfer between condensed and gas phases, hence resulting in the excellent enhancement in flame retardancy.

Modified phosphate coatings applied to steel by cold method

The deposition of phosphate coatings occurs on the surface of the product when it is immersed in a solution containing phosphoric acid. The formation of a film on the metal surface occurs during the deposition of insoluble two- and three-substituted phosphates of iron, manganese, and zinc from a solution. To speed up the process and conduct phosphating at low temperatures, nitrates, nitrites, and fluorides of active metals are introduced into the solution. Organic compounds, such as glucose, glycerin, Trilon A, and Trilon B, are buffer additives to maintain the pH of phosphating solutions in the range of 2.6-3.2. It was found that 10-15 minutes at a process temperature of 20-25 °C are sufficient for the formation of a protective phosphate coating from solutions containing modifiers. The content of zinc phosphates in the modified phosphate coatings is increased. Additives in cold phosphating solutions have a positive effect on the quality and protective properties of the resulting phosphate films. Modified phosphate coatings obtained by the cold method have a fine-crystalline structure, a smooth surface and low porosity.

MODIFICATION OF NATURAL ZEOLITE FOR ANTICORROSIVE PAINT PREPARATION

Metal surface coating occupies an important place in industry. The most important external factor on metal surfaces is corrosion. Corrosion is a natural process that occurs because of chemical reaction between the metal surfaces and the medium. It causes degradation of metals. There are three methods that used for the prevent corrosion. These methods are cathodic protection, anodic protection, and barrier coatings. In this study, it was aimed to develop environmentally friendly corrosion resistant paint for the barrier coatings, by using zeolite material which has natural characteristic of corrosion resistant. In other words, it was aimed to gain the anticorrosive effect to the production of corrosion resistant paint by adding modified natural zeolite in paint. Micro scale zeolite was modified by using lanthanum (III) nitrate, zinc acetate and magnesium chloride solutions. The best results were obtained with a zeolite size of 0.8869 μm and using a 60% zeolite / solution volume ratio. It can be said from the results of the experiments that; thin zeolite film applications are very successful for corrosion resistance paint production. Modified natural zeolite coatings show very good ability to protect surfaces from corrosion. Results of these procedures are positive and promising. The best result is obtained by zeolite with size reduction and 60% zeolite/solution by volume ratio. The amount of zinc phosphate was greatly reduced. High and low content of zinc phosphates have almost the same anticorrosive effect with zeolite modified paint formulations. As a result, cation-exchanged zeolites can be considered as a safe and efficient alternative to traditional hazardous pigments in protecting steel surfaces.

Impacts of lubricating oil and its formulations on diesel engine particle characteristics

Lubricating oil-related engine emission reduction is now a key path to further control the engine-out emission level and to meet the restrict regulations, especially in the manner of particulate number emission. This work experimentally studied the contribution of lubricating oil and its key constituents to the particle emission via monitoring the combustion process and analyzing the particle physic-chemical characteristics. Two sets of experiments were conducted to understand how the lubricating oil alters the regular combustion cycles and to study the effects of oil sulfur and metallic-ash constituents on the particle chemical characteristics, respectively. Details of the surface oxygenated functional groups and carbon chemical state on the particle surface were analyzed by XPS, while the FTIR was employed to characterize the possible functional groups in the bulk particle samples and the bonding patterns of the sulfur element. The effects on the particle morphology and elemental compositions were analyzed by SEM-EDS. Results show that the lubricating oil could shorten the ignition-delay phase combustion effectively, for instance, by 20% when 1wt% oil is burned along with diesel. Furthermore, more oxygenated surface functional groups and relatively more sp3 hybridization carbon shows up in the oil-derived particles. The sulfur element in the oil increases the oxygenated functional groups and lowers the aliphatic CH group by forming –SH radical. On the contrary, the metallic-ash fraction reduces the amount of oxygenated functional groups because the inorganic sulfates/phosphates occupy some oxygen atoms during the combustion reaction. Both the sulfur and ash tend to generate more un-substituted and meta-disubstituted benzene instead of the mono-disubstituted benzene structure, which is popular in diesel fuel-related particles mainly. Last but not the least, the sulfur and ash content significantly increase the concentration of the sulfates and phosphates of Iron, Calcium, and Zinc in the particles.

Phosphate dental cements aged in vivo up to 25 years

ABSTRACT Phosphates particularly zinc phosphates is a family of conventional dental cements that was developed a century ago and has been in use until today despite the fact that a number of new resin composite cements have been introduced in the market through the years. A close inspection of the in vivo aged samples provides insides to the margins and to the micro-leakage thus would sharpen the understanding and inspire the future development of the cements and cementation interfaces between the dental restorations and the natural tooth or implant abutment. This study highlights the cementation interface and its structural change during in vivo aging. Besides the focused studies on phosphate cements, limited investigation has also been performed on resin composite cements as references.

A Simple Synthesis, Characterization, Kinetics and Thermodynamics of Zinc Ammonium Phosphate, ZnNH4PO4

Zinc ammonium phosphate (ZnNH4PO4) was synthesized via a simple precipitation method at room temperature. Thermal decomposition of ZnNH4PO4 occurred through five stages related to the deamination (1st and 2nd steps) and deprotonated hydrogen phosphate (3rd, 4th, 5th steps) reactions and its final decomposed product at above 600 °C was zinc pyrophosphate (to γ-Zn2P2O7). ZnNH4PO4 and γ-Zn2P2O7 samples were analyzed by XRF, XRD, FT-IR and SEM techniques, which are significant for the further treatments. Kinetic parameters (Ea, A) and thermodynamic functions (ΔH*, ΔS* and ΔG*) calculated on well-known equations have been used to support for five thermal transformation processes, reported for the first time. The kinetic results indicate that the intramolecular dehydration of the protonated hydrogen phosphate groups (3rd, 4th, 5th steps) need higher-energy pathways than the deammonium reactions (1st and 2nd steps) because of harder reactions, more difficulties and lower rates. Additionally, thermodynamic results reveal that all thermal reactions are endothermic and non-spontaneous processes. The obtained data may be useful for industrialists and academicians to apply these zinc phosphates for large roles in industrial applications.

Sorption properties of modifiers of piezoquartz resonators based on 3d-elements

Transition metals are complexing substances, that is why being incorporated into the sensor modifiers, they can improve detection discrimination. The method of piezoelectric microweighting was used to study the sorption characteristics of the films based on partially soluble phosphates of 3d-elements (manganese (II), iron (II and III), nickel, copper, zinc, chromium) and coatings bearing partially soluble ferrous salts (hydrated oxide, fluoride, carbonate, sulfide, phosphate). The salts were created immediately prior to analysis, with bee glue as a filming agent. The method of immersion sensors in suspension of the filming agent and partially soluble salt, that was kept homogeneous by ultrasonic bath, was recognized the best way of film formation. Sorption characteristics of the composed coatings of piezoelectric resonator were estimated by the area under sorption kinetic curve and by peak value of sensor oscillation frequency drop during analysis of equilibrium gaseous form received over pure substances (water, phenol, isopropanol, isobutanol, acetous acid, chloroform, benzene, toluene, acetone, ethyl acetate, ammonia, diethyl amine, triethylamine, tert-butylamine, benzylamine). It was possible to determine the identifying variables Aij, minimax values of those allow to detect individual substances in the mixed vapour. Modifier application of piezoelectric resonators of phosphates of different 3d-elements is more efficient than use of different salts of one element. The shortcoming of the proposed modifiers is temporarily stable amine (ammonia) complexation. Those analytes desorption from the films proceeds slowly, it is determined by the bond strength of complexes and takes from 2 to 6 hours. However, array of seven sensors, modified by phosphates of transition metals of group IV, allows to detect oxygen- and nitrogen-based compounds vapours in the mixed vapour as well as to detect ammonia, diethyl amine and triethylamine individually.)

Thermodynamic assessment of the CaO–P2O5–SiO2–ZnO system with special emphasis on the addition of ZnO to the Ca2SiO4–Ca3P2O8 phase

The CaO–P2O5–SiO2–ZnO system including all binary and ternary sub-systems has been thermodynamically assessed using all available experimental data. Particular attention was given to the phase C2S–C3P which forms a complete solid solution with end-members α-Ca2SiO4 and α′-Ca3P2O8. In addition, the present modelling of the phase C2S–C3P allows the inclusion of experimentally determined solubility values of zinc oxide in both end-members of the phase C2S–C3P. The mutual solubility between different crystallographic modifications of calcium and zinc phosphates is also described in this work using available experimental data. 24 phospates as stoichiometric phases have also been included in the database.

Thermodinamical Analyse the Formation of Phosphates Copper, Zinc and Cobalt on the Base Double Superphosphate and Sulphates of Copper, Zinc and Cobalt

In this article the relationship between the entropies of crystalline calcium compounds and copper, zinc and cobalt compounds were analyzed. Thermal capacity dependence of temperature for acidic phosphates of copper, zinc and cobalt, determining value of enthalpy and entropy of copper, zinc and cobalt phosphates have been determined and the possibility to conduct thermodynamic analysis of reactions for their formation were established. Accordingly the data of thermodynamic analysis of temperature conditions for obtaining double superphosphate, the most formation of monosubstituted phosphates of copper, zinc and cobalt, and possibility of formation disubstituted of copper phosphates.

The structure and properties of bioactive multilayer coatings applied by a low-energy electron beam on the implant surface

The composition of a multilayer coating on the basis of Mg + Ca + P2O5, applied to the surface of an intramedullary implant to initiate the growth of bone tissue, has been proposed and justified. The possibility of etidronate and polymethylsilsesquioxane deposition (PMSQ) by an electron beam is first established during the research process. The efficiency of using the PMSQ coating system as a separate layer has been evaluated. It is shown that the exchange processes between the multilayer system and the buffer solution are responsible for the destruction of the cross-linked organosilicone layer. For this reason, using PMSQ as a layer, which initiates HA nucleation, is ineffective. The formation of calcium and zinc phosphates has been established in etidronate and phosphorus (V) oxide interaction with the corresponding metals. The multilayer system Mg + Ca + etidronate + P2O5 + Zn + P2O5, heat-treated at 200°С, is shown to be highly resistant to abrasion. The layer system transforms into HA in the SBF buffer solution. The effect of heat treatment is manifested in an increase in the structural ordering of individual layers.

Synthesis of condensed cobalt (II)-zinc phosphate with the concrete anionic composition

Сondensed cobalt(II)-zinc phosphates with the concrete anionic composition (with а linear structure of anion with = 2–8 of the general formula (Co1-хZnх)(n+2)2PnO3n+1, 0<х<1.00, and a cyclic with = 4 – (Со1-xZnx)2P4O12, 0<x<1.0) were synthesized by heat treatment in the isothermal conditions of crystallohydrates of composition Со1-хZnх(H2PO4)2·2H2O (0<x<1.00).
 The heat treatment of Со1-хZnх(H2PO4)2·2H2O (0<x<1.00) was carried out in the air in the range of 100–350 °C (± 5 °). The sample was maintained at a predetermined temperature for 0.5, 1.5, 3.0, 5.0 and 7.0 hours. Heat treatment products were identified using a set of analytical methods: chemical, X-ray, IR spectroscopy, quantitative chromatography on paper.
 It has been determined that the formation of condensed phosphates in products of heat treatment Со1-хZnх(H2PO4)2·2H2O (0<x<1.00) at 100 °C for 0.5–3.0 h does not occur. The processes of anionic condensation begin under the heat treatment for 5.0–7.0 h at 100 °C and deepen for further temperature rise.
 With the increase in the duration of heat treatment at 150 °C to 3.0–7.0 h, the formation of condensed phosphates with a linear structure of anion with a degree of polycondensation = 2–5 of the general formula (Со1-хZnх)(n+2)2PnO3n+1. is recorded. The degree of conversion of monophosphate anion to polyphosphate is 61-73%, respectively. Similar changes in the composition of heat treatment products are realized with the destruction of the structure and complete amorphization of the solid phase. The formation of a new crystalline lattice is recorded at 225 °C.
 The sample, which lasts 0.5 h, is a crystalline phase identified as Со1-хZnхH2P2О7 with an admixture of Со1-хZnхP2О7. The maximum amount of diphosphate (52.9 % of the total content of P2O5) is formed during the firing of Со1-хZnх(H2PO4)2·2H2O for 1.5 h at 225 °C. The amount of diphosphate is reduced by almost 2 times during heat treatment for 7.0 hours. Similar changes in the composition of linear condensed phosphates are observed at 275 °C: with the increase in the duration of heat treatment the number of low-molecular phosphates with = 2–4 decreases, the high-molecular with = 5–8 of the general formula (Со1-хZnх)(n+2)2PnO3n+1 increases . Fosted condensed phosphate with a cyclic structure of the anion with = 4 – cyclotetraphosphate of the composition (Со1-хZnх)2Р4O12 . It increases the temperature to 350 °C and becomes the only heat treatment product.
 Quantitative dependences of the content of condensed phosphates with different anion structure and phosphate acids, which released as intermediate products, on the temperature regime and roasting duration were established.
 The influence of cation nature on the conditions of synthesis and quantitative composition of the condensed phosphates of cobalt(II)-zinc with concrete anionic composition (with а linear structure of anion with = 2–8 of the general formula (Co1-хZnх)(n+2)2PnO3n+1, 0<х<1.00, and a cyclic with = 4 – (Со1-xZnx)2P4O12, 0<x<1.0) is shown.

The effects of different dimensional organic amines on synthetic zinc phosphites/phosphates

Three different dimensional zinc phosphites and zinc phosphates, [C7H18N]2[Zn(HPO3)2] (1), [C6H9N2][Zn2(PO4)(HPO3)] (2), and [C6H14N2][Zn2(PO4)2] (3) were hydro(solvo)thermally synthesized from organic amines with the same number of nonhydrogen atoms and different dimensionalities and sizes. Structural analysis indicates that compound 1 shows a one-dimensional (1D) chain structure; compound 2 is an inorganic–organic hybrid two-dimensional (2D) material; compound 3 is a three-dimensional (3D) open-framework zinc phosphate EDI zeolite. The mechanisms of 1D chain-like n-heptamine, 2D planar 3-aminomethylpyridine, and 3D triethylenediamine on the synthetic process were analyzed. The n-heptamine has only one function: a protonated template in compound 1, while 3-aminomethylpyridine has two functions: a protonated template and binding ligand in the synthesis of compound 2. The triethylenediamine has three functions in compound 3: a protonated template, space-filling agent, and structure-directing agent. Thus, the three organic amines play different roles in the three compounds. They were analyzed by XRD, SEM, TGA, FT-IR, ICP, and CHN analyses.