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Despite its considerable potential, oil palm trunk (OPT) remains underutilized, largely owing to the cyclical replanting process that occurs every 25–30 years. This study aimed to address this issue by developing an eco-friendly oriented strand board (OSB) using vascular bundles (VBs) from oil palm, both in binderless form and with the incorporation of natural adhesives made from sucrose and ammonium dihydrogen phosphate (ADP). The VB was extracted from OPT using a pressure cooker and mixed with a sucrose-ADP solution at various ratios. The mixture was then pressed at temperatures of 180°C and 200°C for 10 min to form boards, which were evaluated based on the Japanese Industrial Standard (JIS) A 5908 for particleboards. Binderless OSB was also manufactured without the use of any adhesive components. Fourier-transform infrared (FTIR) spectroscopy was conducted to evaluate the VB and its board. The results indicated that the mechanical properties of the binderless OSB met the JIS A 5908 Type 8 requirements. Furthermore, the addition of sucrose-ADP improved the physical and mechanical properties of the board, with an optimal sucrose-to-ADP ratio of 85:15. The OSB with the best properties met the JIS A 5908 Type 13 requirements. The FTIR results indicated that carbonyl groups, furan rings, and lignin played important roles in the bonding properties of the OSB. In conclusion, this research demonstrated the potential of VBs as a raw material for producing environmentally friendly OSB, both in binderless form and with the use of sucrose-ADP. [ABSTRACT FROM AUTHOR]

Furfurylated wood exhibits excellent dimensional stability and corrosion resistance, making it a promising material for constructing buildings, but it is highly flammable. Herein, flame-retardant furfurylated poplar wood was produced via a two-step process utilizing boric acid (BA) and ammonium dihydrogen phosphate (ADP) as flame-retardant components, and biomass-derived furfuryl alcohol (FA) as a modifier. The acidity of BA and ADP allowed them to catalyze the polymerization of FA, which formed a cross-linked network that immobilized BA and ADP inside the wood. The addition of BA/ADP substantially delayed the time to ignition from 10 to 385 s and reduced the total heat release and total smoke release by 58.75% and 77.31%, respectively. Analysis of the pyrolysis process showed that the decomposition products of BA and ADP protected the underlying furfurylated wood and diluted combustible gases. This method significantly improved the fire retardancy and smokeless properties of furfurylated wood, providing promising prospects for its application as an engineering material. [ABSTRACT FROM AUTHOR]

Wood densification itself does not, in general, improve the fire-retardant properties sufficiently to reach the standard requirements. The object of this study was to enhance the fire-retardant properties of thermo-mechanically densified wood without any loss of moisture stability and hardness. Scots pine sapwood was pretreated before densification by impregnation with a fire retardant (FR) consisting of ammonium dihydrogen phosphate and urea and then cured in-situ by hot pressing at 150°C or 210°C. Densified specimens without FR were used as a control. Set-recovery, fire retardancy in an open flame test, and Brinell hardness were determined. The set-recovery was slightly reduced as a result of the FR treatment, but the pressing temperature and time had a much greater influence. In the open flame test, specimens without FR-treated ignited within 15−50 s of exposure to the flame, whereas all the FR-treated specimens exhibited ignition resistance over the 10 min duration of the test. Water-soaking cycles had no impact on the ignition resistance in these groups, indicating a strong resistance to water leaching of FR after pressing at 210°C for 60 min. The hardness increased due to the presence of FR after pressing at 210°C, but sharply decreased after water immersion. [ABSTRACT FROM AUTHOR]

Ammonium dihydrogen phosphate (ADP) is a nitrogen-phosphorus-based inorganic flame retardant that is environmentally friendly and non-toxic. Wood treated with ADP has enhanced thermal stability and flame retardancy. Compounding ADP with Acid Red 3R dye further improves the decorative effect of the wood on the basis of excellent flame retardancy, resulting in a kind of dyeing and flame retardant multifunctionalized wood. Single-factor tests were designed to investigate the effects of flame retardant concentration, dye concentration, temperature, and time on three evaluation indexes: dye-uptake, color difference, and oxygen index, respectively. Through SEM and FTIR analysis, it was found that after the wood was simultaneously treated with flame retardant and dye, the two additives were aggregated in the grain pores of the cell wall by a simple physical combination. They did not undergo a chemical reaction. TG analysis showed that fire-retardant dyed wood had good thermal stability, which can delay the thermal degradation of wood and increase the residual charcoal rate of wood. XRD showed that the crystallinity of fire-retardant dyed wood increased compared to untreated wood. Through cone calorimetric test, it is found that flame retardant dyed veneer had excellent flame retardancy.

Epoxy resin was often applied in fiber-reinforced composite materials, adhesives, and encapsulation materials. However, epoxy was easily flammable and limited its usage in certain applications. The study recycled and reused agricultural waste sugarcane bagasse to prepare a halogen-free bio-based intumescent flame retardant and then mixed with epoxy resin to prepare a composite containing polymer with improved thermal properties and flame retardancy of the materials. The work followed the concept of circular economy and sustainability. Bagasse-ammonium dihydrogen phosphate (ADP) flame retardant was added to an epoxy resin to prepare epoxy/bagasse-ADP composites, an effective flame-retarding composite material through hydrothermal method. Adding bagasse-ADP increased the thermal stability and flame retardancy of the composite materials compared with that of pure epoxy. For the material with 30 wt % added bagasse-ADP, the char yield was 32.3 wt%, which was 18.2 wt% higher than that of pure epoxy (14.1 wt%) through thermogravimetric analysis. In addition, the limiting oxygen index increased from 21% to 30%, and the UL-94 classification improved from "Fail" to "V-0." This performance was attributed to the nitrogen, phosphorus, and silicon content of the flame retardant. [ABSTRACT FROM AUTHOR]

To improve the compatibility and flame retardance of kaolinite (Kaol) in polymeric materials, ammonium dihydrogen phosphate (ADP) was intercalated into kaolinite to obtain a novel intercalated kaolinite (K‐ADP) for enhancing thermal stability, flame retardance, smoke suppression, and mechanical performance of epoxy resins (EPs). The results show that the presence of K‐ADP exerts a more positive effect on reducing the heat release and smoke generation of EPs than the same addition of Kaol. Condensed phase analysis shows that EP/K‐ADP composite generates more aromatic cross‐links in the condensed phase to reinforce the compactness and intumescence of char compared to EP/Kaol composite. Especially, 5 wt% K‐ADP confers a 43.7% reduction in peak heat release rate value and a 36.3% reduction in peak smoke production rate value to EP. Toxic gases analysis shows that K‐ADP conduces to inhibiting the release of combustible gases including isocyanates and aromatic volatiles, and generating incombustible gases including ammonia and carbon dioxide to reduce the intensity of EP combustion. The mechanical test shows that K‐ADP imparts less adverse impact on mechanical behavior to EP composites than Kaol due to the good dispersion and compatibility between K‐ADP with EP matrix. [ABSTRACT FROM AUTHOR]

In order to solve the problem of excessive consumption of petrochemical resources and the harm of free formaldehyde release to human health, biomass raw materials, such as sucrose (S) and ammonium dihydrogen phosphate (ADP) can be chemically condensed in a simple route under acidic conditions to produce a formaldehyde free wood adhesive (S-ADP), characterized by good storage stability and water resistance, and higher wet shear strength with respect to petroleum based phenolic resin adhesive. The dry and boiling shear strength of the plywood based on S-ADP adhesive are as high as 1.05 MPa and 1.19 MPa, respectively. Moreover, is Modulus of Elasticity (MOE) is as high as 4910 MPa. Interestingly, the plywood based on the developed S-ADP adhesive exhibited good flame retardancy. After burning for 90 s, its shape remains unchanged. Meanwhile, it can be concluded from thermomechanical analysis (TMA) and thermogravimetric analysis (TGA) that the S-ADP acquired excellent modulus of elasticity (MOE) and good thermal stability. It is thus thought promisingly that the use of S-ADP adhesive as a substitute for PF resin adhesive seems feasible in the near future. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of the amplitude, frequency, and damping of the applied field on the maximal Lyapunov exponents and chaotic dynamics in the bulk antiferroelectric (AFE) system. Numerical simulations are conducted in three parts. First, Wolf’s algorithm calculates the Lyapunov exponents with varying frequencies and a constant amplitude. The second part varies the amplitude while keeping the frequency constant. Two sets of data are generated for small (g = 0.01) and large (g = 0.3) damping values. In the third part, selected parameters produce phase portraits based on the positive and negative Lyapunov exponents using the fourth-order Runge–Kutta method. The results show that the Lyapunov exponent identifies chaotic and periodic regimes with small damping, but this becomes less evident with large damping. The study also demonstrates that manipulating the applied field parameters enables control over chaotic and periodic responses in the bulk AFE system.

This paper studies the chemical and mechanochemical preparation of glauconite with ammonium dihydrogen phosphate (ADP) nanocomposites with a ratio of 9:1 in the vol.% and wt.%, respectively. The methods include X-ray diffraction analysis, scanning electron microscope with energy-dispersive X-ray spectroscopy, transmission electron microscopy, infrared spectroscopy, and differential thermal analysis with a quadruple mass spectrometer. The manufactured nanocomposites keep the flaky glauconite structure. Some glauconite unit structures have been thickened due to minimal nitrogen (ammonium) intercalation into the interlayer space. The globular, granular, or pellet mineral particles of nanocomposites can be preserved via chemical techniques. Globular and micro-aggregate particles in nanocomposites comprise a thin film of adsorbed ADP. The two-step mechanochemical method makes it possible to slightly increase the proportion of adsorbed (up to 3.2%) and intercalated (up to 6.0%) nutrients versus chemical ways. Nanocomposites prepared via chemical methods consist of glauconite (90%), adsorbed (1.8–3.6%), and intercalated (3.0–3.7%) substances of ADP. Through the use of a potassium-containing clay mineral as an inhibitor, nitrogen, phosphorus, and potassium (NPK), nanocomposite fertilisers of controlled action were obtained. Targeted and controlled release of nutrients such as phosphate, ammonium, and potassium are expected due to various forms of nutrients on the surface, in the micropores, and in the interlayer space of glauconite. This is confirmed via the stepwise dynamics of the release of ammonium, nitrate, potassium, and phosphate from their created nanocomposites. These features of nanocomposites contribute to the stimulation of plant growth and development when fertilisers are applied to the soil. [ABSTRACT FROM AUTHOR]

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In order to solve the problem of excessive consumption of petrochemical resources and the harm of free formaldehyde release to human health, biomass raw materials, such as sucrose (S) and ammonium dihydrogen phosphate (ADP) can be chemically condensed in a simple route under acidic conditions to produce a formaldehyde free wood adhesive (S-ADP), characterized by good storage stability and water resistance, and higher wet shear strength with respect to petroleum based phenolic resin adhesive. The dry and boiling shear strength of the plywood based on S-ADP adhesive are as high as 1.05 MPa and 1.19 MPa, respectively. Moreover, is Modulus of Elasticity (MOE) is as high as 4910 MPa. Interestingly, the plywood based on the developed S-ADP adhesive exhibited good flame retardancy. After burning for 90 s, its shape remains unchanged. Meanwhile, it can be concluded from thermomechanical analysis (TMA) and thermogravimetric analysis (TGA) that the S-ADP acquired excellent modulus of elasticity (MOE) and good thermal stability. It is thus thought promisingly that the use of S-ADP adhesive as a substitute for PF resin adhesive seems feasible in the near future.

• NH 4 H 2 PO 4 curbs LDPE deflagration by inhibiting C 2 H 4 generation and consumption. • Species of deflagration products and free radicals were counted using ReaxFF MD. • Traced the production and consumption pathways of the major intermediate C 2 H 4. • Mechanism of NH 4 H 2 PO 4 inhibition of C 100 H 202 deflagration flame spread revealed. In this paper, the inhibition effect of ammonium dihydrogen phosphate (NH 4 H 2 PO 4) on the deflagration of polyethylene dust (C 100 H 202) is studied by combining experimental tests with reaction molecular dynamics simulation (ReaxFF MD). The mechanism by which NH 4 H 2 PO 4 inhibits C 100 H 202 deflagration is revealed at the microscopic level. The experimental results demonstrate that the inhibition effect of NH 4 H 2 PO 4 on C 100 H 202 deflagration is positively correlated with its concentration, and the addition of NH 4 H 2 PO 4 equivalent to 50 % of the mass of C 100 H 202 can completely suppress the deflagration. The apparent activation energies for the decomposition of C 100 H 202 and C 100 H 202 /50 %NH 4 H 2 PO 4 are calculated using ReaxFF MD to be 97.11 kJ/mol and 124.78 kJ/mol, respectively, which are in agreement with the results obtained from thermogravimetric tests. Furthermore, ReaxFF MD is employed to calculate the types and quantities of deflagration products and free radicals before and after the addition of NH 4 H 2 PO 4. The results indicate that the number of the main intermediate C 2 H 4 decreases with the increasing addition of NH 4 H 2 PO 4. Based on this, the generation and consumption pathways of C 2 H 4 are traced. It is found that phosphorous groups such as HOPO and PO 2 scavenge active free radicals like ·O and ·OH, thereby altering the formation and consumption pathways of C 2 H 4 , leading to a reduction in both its formation and consumption. Additionally, H 2 O and inert gases produced by the thermal decomposition of NH 4 H 2 PO 4 also contribute to inhibiting the progression of C 100 H 202 deflagration. [ABSTRACT FROM AUTHOR]

This paper studies the chemical and mechanochemical preparation of glauconite with ammonium dihydrogen phosphate (ADP) nanocomposites with a ratio of 9:1 in the vol.% and wt.%, respectively. The methods include X-ray diffraction analysis, scanning electron microscope with energy-dispersive X-ray spectroscopy, transmission electron microscopy, infrared spectroscopy, and differential thermal analysis with a quadruple mass spectrometer. The manufactured nanocomposites keep the flaky glauconite structure. Some glauconite unit structures have been thickened due to minimal nitrogen (ammonium) intercalation into the interlayer space. The globular, granular, or pellet mineral particles of nanocomposites can be preserved via chemical techniques. Globular and micro-aggregate particles in nanocomposites comprise a thin film of adsorbed ADP. The two-step mechanochemical method makes it possible to slightly increase the proportion of adsorbed (up to 3.2%) and intercalated (up to 6.0%) nutrients versus chemical ways. Nanocomposites prepared via chemical methods consist of glauconite (90%), adsorbed (1.8–3.6%), and intercalated (3.0–3.7%) substances of ADP. Through the use of a potassium-containing clay mineral as an inhibitor, nitrogen, phosphorus, and potassium (NPK), nanocomposite fertilisers of controlled action were obtained. Targeted and controlled release of nutrients such as phosphate, ammonium, and potassium are expected due to various forms of nutrients on the surface, in the micropores, and in the interlayer space of glauconite. This is confirmed via the stepwise dynamics of the release of ammonium, nitrate, potassium, and phosphate from their created nanocomposites. These features of nanocomposites contribute to the stimulation of plant growth and development when fertilisers are applied to the soil.

In this paper, the nonlinear and chaotic responses of bulk antiferroelectrics are elaborated phenomenologically and numerically. The first ordered phase of bulk antiferroelectrics is formulated by applying calculus of variations to Landau free energy density expansions of bulk antiferroelectrics. With applied time-dependent electric field, the antiferroelectrics dynamic responses are obtained by Landau–Khalatnikov equation of motion. The resulting dynamical equations are two nonlinearly-coupled second order differential equations corresponding to two inter-penetrating sub-lattices of antiferroelectrics, and these are solved numerically using forth-order Runge–Kutta methods and ammonium dihydrogen phosphate parameters in its first ordered phase. These calculated results are presented graphically for various frequencies and amplitudes in the applied electric fields.

Aiming at the problem of limited research and slow progress in the determination of barium sulfate content in barite, a new method for the determination of barium sulfate in barite pretreatment is proposed. It uses ammonium dihydrogen phosphate and barite decomposition reaction occurs at 700 °C, then converts water-insoluble and acid-insoluble barium sulfate into acid-soluble barium phosphate salt, and finally obtains the barium content based on the determined phosphorus-to-barium ratio relationship according to the total phosphorus content. The experimental results show that the ratio of the amount of ammonium dihydrogen phosphate to barium sulfate is 2. 0 and high-temperature calcination at 700 °C can completely transform the barium sulfate into barium metaphosphate, and then undergo sodium hydroxide and hydrogen peroxide treatment. It is converted into barium hydrogen orthophosphate and dissolved in hydrochloric acid to form quinoline phosphomolybdate precipitate with quinmolybdenone reagent. According to the quality of the precipitate, the content of barium sulfate in the sample can be accurately calculated. The method is accurate and feasible. This method provides a new idea for determining the content of barium sulfate in barite, which has practical significance. [ABSTRACT FROM AUTHOR]

Maltodextrin is a potential natural adhesive for particleboard because it is reactive and freely soluble in water. However, maltodextrin has a low water resistance and a high melting point that hinder its development as a particleboard adhesive. An addition of ammonium dihydrogen phosphate (ADP) as a catalyst of maltodextrin was expected to overcome its weaknesses. The optimal pressing temperature was expected to be affected due to the addition of catalysts. This research aimed to investigate the effect of maltodextrin/ADP ratios and pressing temperatures on particleboard properties made from Salacca frond. The maltodextrin/ADP ratios used in this research were 100/0, 90/10, and 80/20 wt%, and the pressing temperatures were set at 200 and 220 °C. The combination of an increased ADP ratio in maltodextrin and an increased pressing temperature improved the particleboard properties. The water resistance was also significantly improved by addition of ADP and increased pressing temperature. Thermal analyses showed that the onset temperature of weight reduction of maltodextrin added particles was lowered by addition of ADP. The results suggested that a maltodextrin/ADP mixture could be a promising particleboard binder. [ABSTRACT FROM AUTHOR]

Compound dry powder agent containing Mg(OH)2 is an efficient substitute for halon. Magnesium hydroxide and ammonium dihydrogen phosphate play an important role in chemical fire extinguishing substances. The reaction mechanism and thermal decomposition products of ammonium dihydrogen phosphate and magnesium hydroxide simulated by both molecule and cluster model were theoretically studied. Dense functional theory (DFT) was used to optimize the structure of the samples, and the reaction of the samples with free radicals H·, OH· and CH3· was calculated to prevent the combustion process. A fire extinguishing reaction mechanism that consisted of 13 elementary reactions were proposed. The most kinetically favorable mechanistic pathways in extinguishing reactions were identified. The direct reaction of Mg(OH)2 with H· free radical is the main pathway. Similarly, in the H3PO4 phase, the energy barrier of H3PO4 reacting with free radicals is smaller than that of self‐decomposition and the thermal decomposition of intermediates, indicating that the reaction of H3PO4 with free radicals is also the main route. In addition, the intermediate produced by the reaction will also combine with each other to form new fire extinguishing substances, which accelerates the fire extinguishing process. Therefore, the fire extinguishing effect of composite dry powder containing magnesium hydroxide is higher than the single powder extinguishing agent. [ABSTRACT FROM AUTHOR]

Compound dry powder agent containing Mg(OH)2 is an efficient substitute for halon. Magnesium hydroxide and ammonium dihydrogen phosphate play an important role in chemical fire extinguishing substances. The reaction mechanism and thermal decomposition products of ammonium dihydrogen phosphate and magnesium hydroxide simulated by both molecule and cluster model were theoretically studied. Dense functional theory (DFT) was used to optimize the structure of the samples, and the reaction of the samples with free radicals H·, OH· and CH3· was calculated to prevent the combustion process. A fire extinguishing reaction mechanism that consisted of 13 elementary reactions were proposed. The most kinetically favorable mechanistic pathways in extinguishing reactions were identified. The direct reaction of Mg(OH)2 with H· free radical is the main pathway. Similarly, in the H3PO4 phase, the energy barrier of H3PO4 reacting with free radicals is smaller than that of self‐decomposition and the thermal decomposition of intermediates, indicating that the reaction of H3PO4 with free radicals is also the main route. In addition, the intermediate produced by the reaction will also combine with each other to form new fire extinguishing substances, which accelerates the fire extinguishing process. Therefore, the fire extinguishing effect of composite dry powder containing magnesium hydroxide is higher than the single powder extinguishing agent. [ABSTRACT FROM AUTHOR]

The impurity of Fe3+ in ammonium dihydrogen phosphate (MAP) solution has a significant influence on the morphology and quality of products. The removal of Fe3+ from the MAP solution by Di-(2-ethylhexyl) phosphoric acid (D2EHPA) was investigated in an impact-jet hydraulic cavitation (HC) extractor. The organic phase and aqueous phase can be highly mixed under the action of hydraulic cavitation. The extraction efficiency of 80% can be achieved when the extraction reaction was carried out for only 5 min. It was found that the extraction of Fe3+ with D2EHPA was an exothermic reaction, and the equilibrium equation of extraction was obtained by slope method as follows: Fe(aqu)3++8HD2(org)=FeD3·13HD(org)+3H(aqu)+After the two-stage extraction, the extraction efficiency of up to 96.7% can be reached (only 3.4 ∼ 4 ppm Fe3+ remained in the aqueous phase), and the MAP crystals with regular polyhedral structure, single phase nature, and high optical transmittance were obtained.

This study investigated the effects of adding ammonium dihydrogen phosphate (ADP) on the physical and chemical changes of a water-soluble extract of the inner part of oil palm trunk (OPT) to clarify the bonding mechanism of the binderless particleboard. The extract's effect on ADP-added binderless particleboard was also investigated. OPT particles were treated by hot water at 60 °C for 6 h. Water-soluble extract and treated OPT particles were obtained. ADP was added to the water-soluble extract at 0, 10, and 40 wt%, and the mixtures were heated at 180 °C for 10 min. Furthermore, binderless particleboards using the treated particles were manufactured with similar condition. The 10 wt% ADP mixture changed the water-soluble extract to an insoluble substance, which was twice that of with 0 wt.% ADP addition. Infrared spectroscopy revealed peaks of furan and carbonyl in the insoluble substance. This indicated that the free sugar content in the water-soluble extract would change to furan compounds. Thermal analysis revealed that the resulting insoluble substance had good thermal stability, suggesting a high-molecularweight substance. The insoluble substance would contribute to bonding of the binderless particleboards. In particular, a significant contribution to the water resistance was observed. [ABSTRACT FROM AUTHOR]

A novel bio-based composite, called the ESO-1,6-hexanediamine-ADP-wood (EHAW) composite, was created using epoxy soybean oil (ESO), 1,6-hexanediamine, and ammonium dihydrogen phosphate (ADP) co-condensed resin as matrix and wood powder as aggregate. The cross-linking was achieved through the ring opening polymerization of 1,6-hexanediamine and ESO, which was then esterified and condensed with ADP to form a network structure. The effects of mass ratio of wood powder to soybean oil-hexamethylene diamine-ammonium dihydrogen phosphate (EHA) resin on the performance of the composite were investigated. The mass ratio of wood powder to EHA resin was 0.25, 0.5 and 0.75, respectively. The results revealed that composite with the wood powder/EHA resin of 0.5 (EHAW2) had the best performance indicates by its smooth and uniform distribution under SEM observations. In addition, EHAW2 showed better Brinell hardness, compressive strength, UV resistance as well as water absorption properties than the other two ratios. It also showed better thermal conductivity and flame retardancy. The total heat released during combustion is low, and there are no collapse and shape change during the combustion process, making it an ideal material for building applications. [Display omitted] • Novel bio-based composites based on epoxy soybean oil-based resin and wood chip powder were prepared. • The preparation process is very simple and the materials used is cheap. • The mechanical properties of the composites are good. • The composites also showed superior flame retardancy and water resistance. • The composites have low thermal conductivity that are suitable as building material. [ABSTRACT FROM AUTHOR]

• Solid-liquid phase equilibrium of NH 4 + //SO 4 2−, H 2 PO 4 −–H 2 O system aiming at salt-containing wastewater treatment in lithium-ion batteries industry. • Constructing the Pitzer thermodynamic model of the ternary system. • Calculating solubilities of the ternary system being in good agreement with the experimental results. A tremendous amount of wastewater containing ammonium salts, mainly NH 4 H 2 PO 4 and (NH 4) 2 SO 4 , has been produced in the production of cathode material of lithium iron phosphate (LFP). However, as an important basis for salt separation, the solid–liquid phase equilibrium (SLPE) of these two salts has been investigated by few studies. In this study, SLPE of the ternary system (NH 4 + //SO 4 2−, H 2 PO 4 −–H 2 O) from 313.15 K to 343.15 K at 101.2 kPa were investigated by isothermal dissolution method, and the corresponding physicochemical properties (density, viscosity, and pH) of saturated solution were measured. The phase diagram is composed of one invariant point, two univariant curves, and two single-salt crystallization fields for NH 4 H 2 PO 4 and (NH 4) 2 SO 4. Comparing the phase diagrams from 263.15 K to 343.15 K, it is obvious that two single-salt crystallization fields shrink with increasing temperature. And the area reduction of NH 4 H 2 PO 4 in two salts is more significant. When the temperature drops below 268.15 K, the ice crystallization field would appear. Neither single-salt solid solution, hydrous salt nor double salt was found in the whole temperature range. Furthermore, Pitzer model was successfully applied to describe the SLPE of the ternary system at temperatures from 273.15 K to 343.15 K. The lacking Pitzer-model parameters of mixed electrolytes (θ SO4-H2PO4 and ψ NH4-SO4-H2PO4) were calculated, and the temperature coefficients of model parameters and dissolution equilibrium constant were obtained. The importance of this study is that it supplies basic data and theoretical references for the separation and resource utilization of two ammonium salts from wastewater in the LFP batteries industry. [ABSTRACT FROM AUTHOR]

In this work, the electrochemistry of ammonium dihydrogen phosphate in aqueous solution on Mg and Mg AZ31 alloy (Al 3 wt%, Zn 1 wt%, balanced Mg) electrodes was studied using electrochemical characterization similar to electro-agglomeration and physical characterization to shed some light on the electrochemical mechanism of struvite formation as phosphate precipitation in waste. It was found that the Mg AZ31 alloy exhibited higher corrosion current densities (jcorr), and thus higher Mg dissolution rates and corrosion rates (vcorr) when compared with pure Mg. This finding was confirmed by ion chromatography (IC) analysis. Results also showed a phosphorus removal efficiency (PRem) of 16.8% together with ~53 mL H2 production for pure Mg and 17.2% with ~61 mL H2 production for Mg AZ31 alloy. The precipitates formed on the two Mg electrode materials were physically characterized by SEM, XRD, XPS, and energy-dispersive X-ray spectroscopy, which indicated the formation of struvite (magnesium ammonium phosphate hexahydrate-MgNH4PO4*6H2O). It was found that (i) the thickness of the films was influenced by the applied scan rates, which also had a significant impact on the morphology, and (ii) hydrogen bubble formation influenced the precipitates, whereby the film thicknesses were negatively impacted. [ABSTRACT FROM AUTHOR]

Ammonium dihydrogen phosphate (ADP) crystal utilizes several applications such as Q-switching, electro-optical, and second harmonic generation in nonlinear optics. In the present article, a good-quality single crystal of ADP was grown via Sankaranarayanan–Ramasamy (SR) method for the dimension of 120 mm in length and 12 mm in diameter. The grown ADP crystal is used for diverse characterizations like FTIR spectral study, Vickers microhardness, second harmonic generation, photoluminescence, and chemical etching analysis. The photoacoustic spectroscopy analysis was used to study the thermal diffusivity of the sample. Thermal transport properties of the crystal are required for all types of heat transfer incidences and furthermore used in several applications like acousto-optical, Nd:YAG, and Nd:YLF lasers. A dielectric property was investigated for the grown crystal with dissimilar temperatures, and it was apt for electro-optical and Q-switching applications. [ABSTRACT FROM AUTHOR]

The effect of ammonium dihydrogen phosphate (NH4H2PO4) on the migration and transformation of potassium (K) during rice straw combustion was carried out in a laboratory-scale tube furnace at temperatures of 750 °C, 850 °C, and 950 °C. The characteristics of ashes were analyzed by chemical fractionation, scanning electron microscopy, X-ray fluorescence and X-ray diffraction. Results indicated that with the temperature increasing, the higher PO43−/K molar ratio, the stronger the ability of K-retention. When the molar ratio of PO43−/K was 1:1, the change rate of K retention increased by 4.95%, 23.12% and 47.99% compared to 1:2 molar ratio of PO43−/K at 750 °C, 850 °C and 950 °C, respectively. Water-soluble potassium of RS reacted with PO43− actively and was converted to insoluble potassium, which could avoid potassium migrating into gaseous phase. The addition of NH4H2PO4 can combine with K and Ca to generate the ternary complex salts of Ca–P–K. The compounds are mainly in the form of K2CaP2O7 that has a high melting point, which can improve the ash melting characteristics effectively. [ABSTRACT FROM AUTHOR]

Experimental results of a study of the effect of FeCl3 impurity on the antisolvent crystallization of ammonium dihydrogen phosphate, involving processes of formation of 3D nuclei and growth of these nuclei, from its aqueous solutions saturated at 30 °C and containing different impurity concentrations ci from in situ measurements of temperatures of saturated solutions and pure water as functions of feeding time t of antisolvent ethanol at predefined rates RA are described and discussed. The processes of formation of 3D nuclei and growth of these nuclei are studied in terms of the maximum antisolvent content ΔxmaxN and ΔxmaxG, determined from intervals of temperature difference (Ts−Tw) = ΔT < 0 and ΔT > 0, respectively, obtained from measurements of temperature Ts and Tw of saturated solution, without and with impurity, and pure water. It is found that: 1) the processes of 3D nucleation in antisolvent crystallization from solutions containing impurities can be explained in the framework of theoretical expressions such as a Nývlt‐like relation and an approach based on 3D‐nucleation theory, and 2) adsorption of impurity particles accounts for the increase in the values of antisolvent contents ΔxmaxN and ΔxmaxG of solutions during 3D nucleation and growth of crystallites. [ABSTRACT FROM AUTHOR]

Bamboo is a potential non-wood lignocellulosic material from which to make particleboard. Sucrose-based adhesive is another potential ingredient, but its use in particleboard has been limited. Addition of ammonium dihydrogen phosphate (ADP) can be used to increase the bonding ability of sucrose-based adhesive and to reduce the required pressing temperature. Therefore, this research used different pressing temperatures and sucrose/ammonium dihydrogen phosphate (ADP) composition ratios to optimize the properties of particleboards. The physical and mechanical properties of the boards were analyzed and compared with the JIS A 5908 (2003) standard for particleboard. The results showed that the interaction of the sucrose-ADP composition ratio and the pressing temperature significantly affected the physical and mechanical properties of the particleboards. The particleboard using only sucrose as adhesive had optimum properties at 200 °C; however, after addition of ADP, the intended properties could be achieved at a 160 °C pressing temperature. [ABSTRACT FROM AUTHOR]

A new process is proposed in which citric acid is added during the ammoniation process of wet‐process phosphoric acid (WPA) to chelate metal ions to produce fertilizer ammonium dihydrogen phosphate (MAP) containing medium trace elements. The parameters of the chelation reaction were studied systematically and the results show that the optimal reaction condition is pH 3.0, reaction time 60 minutes, temperature 50.0°C, and citric acid content 1.48%. The XRD patterns show that the water‐insoluble compounds are complex mixtures, and the composition of the water‐insoluble compounds are changed through the addition of citric acid. FTIR and XPS analyes further demonstrate that water‐insoluble compounds are complex mixtures. The XRD patterns of the MAP products indicate that the structure and morphology of the MAP were changed by the addition of citric acid. In addition, the contents of major elements, medium elements, and trace elements in the MAP product are 68.72%, 0.24%, and 0.50%, respectively, which is consistent with the relevant China national standard. [ABSTRACT FROM AUTHOR]

A flame retardant high-performance gelatinized starch (GS)-ammonium dihydrogen phosphate (ADP) wood adhesive, named GS-ADP adhesive was prepared by condensation of GS and ADP under acidic condition. The preparation process of GS-ADP adhesive is very simple by mixing and stirring GS and ADP evenly at room temperature. The results revealed that the GS-ADP adhesive has good storage stability and water resistance, and its wet shear strength is much higher than that of phenolic resin (PF) adhesive. Markedly, the cone calorimeter test results show that G-ADP adhesive has good flame retardancy, and the plywood based on GS-ADP adhesive has good flame retardancy. Meanwhile, it can be seen from dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) that GS-ADP has excellent modulus of elasticity (MOE), high glass transition temperature (Tg) and good thermal stability. The findings suggest that GS-ADP could be a viable substitute for PF resin in structural wood fabrication. [Display omitted] • Thermosetting adhesive with gelatinized starch (GS) and ammonium dihydrogen phosphate (ADP) was prepared. • The preparation method is simple, low cost and the adhesive is environmentally friendly. • Plywood bonded with the adhesive has high shear strength. • It also has good thermal insulation and fire resistance. [ABSTRACT FROM AUTHOR]

Polyacrylic acid (PAA) has high water absorbency but poor salt resistance. Humic acid (HA) extracted from lignite was introduced into the cross-linked copolymer systems of AA to improve the water absorbency and salt-tolerance. A polyacrylic acid-potassium humate (PAA-KHA) coated ammonium dihydrogen phosphate (ADP) fertilizer with water-preserving, salt-resistant and slow-release properties was prepared. The main properties of HA extracted from lignite oxidized by H2O2 were studied. Furthermore, the synthesis process, water absorbency of PAA-KHA in deionized water and in NaCl solution, morphologies of PAA-KHA, and the slow-release performance of the fertilizer (ADP@PAA-KHA) were investigated. The results showed PAA-KHA had a layered interpenetrating network, which can provide sufficient storage space for water and nutrients. The salty water absorbency of PAA-KHA increased by about 3 times compared to PAA. Both the PO43− and NH4+ cumulative release of ADP@PAA-KHA with a coating rate of 10% in deionized water, were less than 20% within 24 h, and were 55.71% and 28.04% after the 15th day, respectively. The weight change of ADP@PAA-KHA before and after absorbing water was about 53 times in deionized water and about 4 times in 1 wt% of NaCl salty water. The results show that ADP@PAA-KHA has excellent properties of water retention, salt resistance and slow-release. This will efficiently improve the utilization of fertilizer and reduce the irrigation water consumption at the same time.

In this study, the co-combustion of Zhundong coal and NH4H2PO4 was investigated in a laboratory-scale tube furnace. The ash fusibility, combustion performance, and ash characteristics were quantified by experimental approaches. This study also used Gibbs free energy theory to analyze the chemical reactions. The results showed that NH4H2PO4 can extend the burning time of coal and reduce combustion intensity. Moreover, NH4H2PO4 significantly changed the composition of ash, which was caused by reactions between alkali/alkaline earth metals and NH4H2PO4, increasing the sodium retention ratio of the formed ash. In addition, the newly formed phosphate crystals (i.e., Mg2P2O7, AlPO4, and Ca3(PO4)2) with higher melting temperatures contributed to the increase in fusion temperature of the formed ash, and the sodium-containing crystals (i.e., Na2CaP2O7 and NaMg4(PO4)3) contributed to the increase in the sodium retention ratio. Furthermore, NH4H2PO4 had a significant effect on the microcosmic structure, with ash showing more rough and sintering being inhibited. [ABSTRACT FROM AUTHOR]

A new type of X‐ray facility, the Beam Expander Testing X‐ray facility (BEaTriX), has been designed and is now under construction at INAF–Osservatorio Astronomico di Brera (Merate, Italy) to perform the acceptance tests of the silicon pore optics modules of the ATHENA X‐ray telescope. Crystals of high perfection and large dimensions are needed in order to obtain a wide beam (20 × 6 cm) with an X‐ray divergence of <0.5′′ and an X‐ray energy purity ΔE/E < 10−5. To generate X‐ray diffracted beams at an X‐ray energy of 1.49 keV, ammonium dihydrogen phosphate (ADP) crystals have been considered among other possible choices, because of their reported crystal quality and because they can be grown at sufficiently large size at a reasonable price. In the present paper, the results of the characterization of crystalline quality and lattice planarity of a 20 × 20 × 2 mm ADP sample are reported. [ABSTRACT FROM AUTHOR]

In order to effectively improve the corrosion resistance of aluminum alloys, anodic oxidation technique was used to generate the oxide film. We investigated the influences of two inorganic corrosion inhibitors (ammonium dihydrogen phosphate and sodium molybdate) on the corrosion resistance of anodic oxidation films on 2024 aluminum alloy, and studied the synergistic effect of two corrosion inhibitors. The corrosion resistance of anodic oxidation film in 3.5wt% NaCl solution was evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves. Results show that, after adding the single ammonium dihydrogen phosphate or sodium molybdate of 0.01 M to oxalic acid electrolyte, inhibition efficiencies of the anodized samples are 10% and 47%, respectively. However, in the presence of two inhibitors with the same concentration of 0.01 M, inhibition efficiency can be as high as 92%. Therefore, we observed the significantly synergistic corrosion inhibition effect of molybdate and phosphate ions for anodic oxidation film formed on 2024 aluminum alloy. [ABSTRACT FROM AUTHOR]

In this study, a further investigation was carried out on the synthesis mechanism, optimal manufacturing conditions, and curing behavior of a sucrose-ammonium dihydrogen phosphate (SADP) adhesive. The results of 13C nuclear magnetic resonance (NMR) spectroscopy confirmed that SADP was composed of 5-hydroxymethylfurfural (5-HMF), deoxyfructosazine (DOF), amino compounds, Schiff base, monosaccharides, and oligosaccharide. The optimal hot-pressing conditions were a hot-pressing temperature of 170 °C, a hot-pressing time of 7 min, and a spread rate of 120 g/m2. The wet shear strength of plywood bonded at optimal manufacturing conditions met the requirements of China National Standard (GB/T 9846-2015). Thermal analysis and insoluble mass proportion measurements showed that the main curing behavior of the SADP adhesive occurred at curing temperatures higher than 145 °C, and more than 50% insoluble mass was formed when the heating time was longer than 5 min. Fourier-transform infrared spectroscopy (FT-IR) indicated that cross-linking of the cured adhesive was promoted by prolonging the heating time. In addition, pyrolysis gas chromatography and mass spectrometry (Py-GC/MS) confirmed that the cured SADP adhesive was composed of furan and nitrogen-containing compounds.

Application of liquid fertilizers can significantly improve the fertilizer utilization efficiency and labor efficiency. Phase equilibrium of various fertilizers in aqueous solution is the basis of manufacturing liquid fertilizers. The solid-liquid phase equilibria of ternary systems NH 4 H 2 PO 4 + CO(NH 2 ) 2 + H 2 O, (NH 4 ) 2 HPO 4 + CO(NH 2 ) 2 + H 2 O, K 2 SO 4 + CO(NH 2 ) 2 + H 2 O, K 2 SO 4 + NH 4 H 2 PO 4 + H 2 O and K 2 SO 4 + (NH 4 ) 2 HPO 4 + H 2 O at 303.2 K were investigated by isothermal solution saturation method. The maximum nutrient content of (NH 4 ) 2 HPO 4 + CO(NH 2 ) 2 + H 2 O solution is 31.78 wt% at the saturated solution of (NH 4 ) 2 HPO 4 , and the mass ratio of N: P 2 O 5 is 1: 2.53. In the solutions of NH 4 H 2 PO 4 + CO(NH 2 ) 2 + H 2 O, K 2 SO 4 + CO(NH 2 ) 2 + H 2 O and K 2 SO 4 + (NH 4 ) 2 HPO 4 + H 2 O, the corresponding maximum of nutrient contents all are obtained at the corresponding invariant points as 33.82 wt%, 27.32 wt% and 32.92 wt% respectively. And the mass ratios of nutrients are N: P 2 O 5 of 2.69: 1, K 2 O: N of 1:15.66 and N: P 2 O 5 : K 2 O of 1.64: 4.15: 1, respectively. The maximal nutrient content in the K 2 SO 4 + NH 4 H 2 PO 4 + H 2 O saturation solution is 25.14 wt% and the corresponding mass ratio of N: P 2 O 5 : K 2 O is 1.26: 6.38: 1. Based on the phase equilibrium diagrams, the species and nutrient contents in liquid fertilizers all are adjustable by choosing different raw materials or modulating the prescription. The results provide fundamental data for the preparation of liquid fertilizers. It is also helpful to optimize the operation parameters in the manufacturing process, storage process or application process to avoid the precipitation of solid. [ABSTRACT FROM AUTHOR]

Highlights • Thermal safety of NH 4 NO 3 -NH 4 H 2 PO 4 mixture was studied. • The decomposition mechanism of NH 4 NO 3 -NH 4 H 2 PO 4 mixture was concluded. • The thermal safety enhancement mechanism of NH 4 NO 3 by NH 4 H 2 PO 4 was investigated. • The thermal sensitivity of NH 4 NO 3 was reduced by the addition of NH 4 H 2 PO 4. Abstract In order to analyze the inhibition effect of the additive on the thermal decomposition characteristics of ammonium nitrate (AN), thermal stability and thermal decomposition behavior of AN and its mixtures with various concentrations of ammonium dihydrogen phosphate (ADP) are systematically investigated by DSC-TG, DSC-TG-QMS and TG-FTIR. Breaking point value of the samples is obtained as an evaluation parameter for thermal safety. Experimental results show that the AN-ADP mixtures show higher onset decomposition temperatures, narrower reaction temperature region and lower enthalpy values than those of pure AN. The main evolved decomposition gases of AN are NH 3 , H 2 O, NO, N 2 O, NO 2 and HNO 3 , while the major gaseous products of the AN mixture with ADP are NH 3 , H 2 O, NO, N 2 O and NO 2. Furthermore, the generation of NO and NO 2 is obviously postponed in the AN mixture. In addition, the breaking point value of AN is markedly improved by ADP. The decomposition mechanism of AN-ADP mixture is concluded and the inhibition mechanism of ADP is proposed. It is concluded that ADP is an effective inhibitor for AN and its thermal stability is effectively enhanced. [ABSTRACT FROM AUTHOR]

We present the case of a 31-year old male with ingestion of fire extinguisher powder in an attempted suicide. After consulting several poison information centres, the intoxication was initially classified as harmless; nevertheless, the patient was admitted to our intensive care unit for cardiopulmonary monitoring. Subsequently, due to the ingestion of ammonium sulphate and ammonium dihydrogen phosphate containing powder the patient developed severe metabolic acidosis with distinct electrolyte imbalance that required temporary haemodialysis. [ABSTRACT FROM AUTHOR]

The solubilities of ammonium dihydrogen phosphate (MAP) were determined by dynamic method in the systems of (NH 4 ) 2 SO 4 + water and NH 4 F + water at the temperatures of 293.2–343.2 K at an atmospheric pressure, and the experimental data was fitted by the modified Apelblat equation. The result showed that the solubilities of MAP increased with temperature and the adding of the NH 4 F, and decreased with the adding of (NH 4 ) 2 SO 4 within the measurement range. The metastable zone width (MSZW) of MAP was measured by the focused beam reflectance measurement (FBRM) during cooling crystallization process. The effects of the (NH 4 ) 2 SO 4 impurity and NH 4 F impurity on the supercooling temperature ΔT max of MAP were studied. The MSZW of MAP were moved and enlarged by the two kinds of impurities mentioned above with different approaches. [ABSTRACT FROM AUTHOR]

Abstract: Measurements of temperatures Tw of water at initial temperature 30 °C and temperature Ts of aqueous ADP solutions saturated at 30 °C against the content x of three alcohols (i.e. methanol, ethanol and n‐butanol) added as antisolvents at different rates reveal regions of constant temperature in the maxima of the Tw(x) plots in water and in the vicinity of occurrence of three‐dimensional (3D) nucleation of the Ts(x) plots in the solutions. These regions of constant temperature, represented by the antisolvent content x, lie between x1 and x2 such that Δx = (x2−x1) > 0. It is found that the antisolvent content range Δx decreases with an increase in the maximum constant temperatures in the Tw(x) and Ts(x) plots. From an analysis of the data of x1 and x2 for different maximum temperatures obtained from the Tw(x) and Ts(x) plots it is argued that the maximum value of Δx is related to the withdrawal of the heat of reactions by the cooling system. However, in the case of ADP solutions, the value of Δx representing the width of the maxima due to 3D nucleation in the Ts(x) plots is also related to the reorganization of crystalline clusters to form stable 3D nuclei during antisolvent crystallization. [ABSTRACT FROM AUTHOR]

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