Lamellar Aluminophosphate Research Articles

Application of functionalized carboxymethyl cellulose in development of hierarchical lamellar aluminophosphate for the industrial fabrication of wood based panels

Wood adhesives are mostly synthesized from unsustainable and hazardous petrochemical-based formaldehyde. Recently, an inorganic, sustainable and environmentally friendly aluminophosphate adhesive was developed for fabricating various wood-based panels. In order to increase its competitiveness, this study developed an approach for improving the interfacial adhesion of aluminophosphate. Hence, carboxymethyl cellulose was functionalized using 3-aminopropyl triethoxysilane to alter the chemical structures of the adhesive. Thereafter, a face-centered central composite design based on response surface methodology was employed to generate the optimum production conditions for the improved plywood interfaces. Adhesive concentration and hot-press temperature were seen as the significant factors within tested limits. The most appropriate production variables were suggested with a valid predictive model for such conditions. Also, the reaction mechanisms revealed the successful altering of the aluminophosphate properties with a well-uniform adhesive surface. The results indicate that modified adhesives are more thermally stable. Furthermore, the wet bonding strength of the modified adhesive was improved above the minimum threshold (Chinese type II standard ≥0.70 MPa). Therefore, the sustainable (i.e. continuous availability of CMC) approach adopted in this research could be considered as a viable method for improving the properties of aluminophosphate adhesives. • An eco-friendly and low-cost aluminophosphate adhesive was developed via functionalized carboxymethyl cellulose. • The reaction mechanism revealed successful functionalization of carboxymethyl cellulose. • The production conditions of the plywood were optimized using response surface methodology. • The fabricated plywood satisfied the basic requirements for Type II plywood.

Hierarchical Lamellar Aluminophosphate Inorganic Materials for Medium Density Fiberboard with Good Fire Performance

Fire safety issues have attracted much attention since they cause enormous loss of lives and properties. In this study, the sustainable aluminophosphate (AP) adhesive is developed as a fire retardant for improving the fire performance of medium-density fiberboard (MDF). The properties of AP adhesive and AP-based MDF were evaluated based on a scanning electron microscope, thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and cone calorimetry. The thermostability and fire performance of MDF are significantly improved by the deposition of the AP inorganic layer on the wood fibers surface, which could protect wood fibers from further oxidation and take away part of the heat. Compared to control sample (UF sample), the pkHRR (151.7 kW m−2), THR (66.0 MJ m−2), TTI (21 s), and mean EHC (14.6 MJ kg−1) of AP-based MDF was reduced by 52.7%, 39.0%, 41.7%, and 32.8%, respectively. Also, the existence of the AP inorganic layer is beneficial to netting the solid phase and volatile flammable components in char residue of MDF, resulting in large mass loss rate, off-gases (CO and CO2) release and smoke suppression properties. Therefore, AP could improve the fire performance of MDF.

First preparation of microporous AFY-type MeAPOs by topotactic pillaring of lamellar aluminophosphate precursors

Topotactic pillaring of lamellar aluminophosphate (ALPO) layers with zinc cations is used to prepare microporous zincoaluminophosphate (ZnAPO) with an AFY-type framework for the first time.

Hierarchical Lamellar Aluminophosphate Materials with Porosity as Ecofriendly Inorganic Adhesive for Wood-Based Boards

Aluminophosphate inorganic adhesive (APIA), as a binder for wood-based boards (WBB), is synthesized between Al(OH)3 and H3PO4 in solution with hydrothermal treatment in this study. Aluminophosphate compounds with hierarchical lamellar structure are observed on the fibers’ surface. The rheological behavior analysis reveals that the viscosity of APIA varied with its P/Al molar ratio [n(P)/n(Al)]. P–O–Al bridges are formed during the hydrothermal treatment of the APIA. The amounts of hydrogen bonds are formed between APIA and wood fibers, which could explain the improvement in mechanical properties of the WBB. In this study, the optimal n(P)/n(Al) in APIA is found to be 2.8, where the bonding strength, together with an acceptable viscosity are found at 1.83 MPa and 31.3 m Pa·s, respectively. Thermogravimetric analysis indicates that the residual weight of plywood is 44.97% greater than pure wood fibers, indicating the fire resistance of the WBB in the study is improved.

Synthesis of lamellar mesostructure aluminophosphate nanoparticles and their conversion to a highly efficient adsorbent using ultrasound waves for partial template removal

Ultrasound irradiation alters micellar arrangement in lamellar aluminophosphate improving its adsorption capability.

M]-CAL-2: MeAPSO-34-like molecular sieves using a lamellar aluminophosphate as precursor

[M]-CAL-2 (M=Mn, Co and Fe) are metallosilicoaluminophosphates ([M]-APSO) with chabazite-related structure, which are part of the CAL molecular sieves family. They were prepared with a recently developed synthesis based on the use of layered AlPO precursor. The used procedure allowed to obtain high loadings of metal ions and to control the morphology of the crystals. The materials were characterized by structural techniques such as X-ray diffraction, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetry (TGA), and spectroscopic techniques such as UV–Vis and Fourier transformed Infrared (FTIR) with particular attention to the study of their redox functionalities. The results show that [M]-CAL-2 crystals presented rhombohedra morphology and the particles sizes are dependent of the metal concentration in the precursor gel, in addition these particles have a lamellar memory originated from the layered AlPO precursor. The FTIR, UV–Vis and elemental results supported the presence of transition metal ions on the framework of the synthesized materials and allowed to envisage the dependency of the metal and silicon concentrations on a Lowenstein-like ruled substitution mechanism. Finally, the reversible redox behavior of the materials was studied by in situ UV–Vis-NIR spectroscopy. This aspect together with the already shown acidity of CAL samples allowed confirming the acid and redox bifunctionality of the obtained molecular sieves, which can thus be proposed for catalytic applications.

2D Lamellar Aluminophosphate Nanolayers for Enhancing Flame Retardancy and Mechanical Properties of Polymers

2D lamellar aluminophosphate (LAP) is successfully exfoliated into nanolayers in polyurethane (PU) through the combination of organically modification and solution casting method. Morphological studies by XRD and TEM show that the exfoliated LAP nanolayers are dispersed well in the PU matrix. The introduction of small amounts of LAP nanolayers (≤5.0 wt %) results in obvious enhancements in the thermal properties and mechanical performance of PU/LAP nanocomposites. These enhancements are benefiting from the good dispersion and exfoliated morphology of stiff LAP nanolayers and strong interfacial interaction between LAP nanolayers and the matrix. LOI and MCC results indicate that the LAP nanolayers incorporated also improve the flame retardancy of nanocomposites. Detailed flame-retardant mechanism is proposed. Physical barrier effect of LAP nanolayers and the graphitized char formation catalyzed by LAP play key roles in the flame retardancy enhancement.

The intercalation of poly(methyl methacrylate)/aluminophosphate nanocomposites and the properties improvement

Poly(methyl methacrylate) (PMMA)/dodecylamine templated lamellar aluminophosphate (DDA-LAP) intercalated nanocomposites are prepared by in situ bulk polymerization of MMA. The intercalated structure is characterized. With the intercalation of DDA-LAP in PMMA matrix, the glass-transition temperatures of nanocomposites (Tg) are increased. The nanocomposites obtained keep relatively high transparency in optical property and have a significant improvement in mechanical properties and thermal stability. The mechanism for the properties enhancement is investigated. The strong interfacial interaction between the aluminophosphate layers and the PMMA chains, the homogeneously distribution and the graphitized char formation during heating are three key roles for the properties improvement.

Synthesis of single wall carbon nanotubes from a lamellar type aluminophosphate (AlPO4-L)

Single wall carbon nanotubes are synthesized from a lamellar type aluminophosphate, AlPO4-L. The lamellar aluminophosphate was synthesized from hexamethyleneimine template. The latter was calcined at argon atmosphere for 12 h at 600°C. The resulting carbonaceous material was treated with 1 N H2SO4 to remove the aluminophosphate skeleton. Characterization of the resulting carbon revealed to contain single walled nanotubes. These nanotubes are applicable to store more hydrogen.

CAL-4: A SAPO-44 analogue prepared from lamellar aluminophosphate

Normal-butylammonium lamellar aluminophosphate has been used as the source of aluminum and phosphorous atoms in the synthesis of CAL-4, a chabazite-like structure analogous to SAPO-44, in a reaction with silica and using cyclohexylamine as structure directing agent. By using the lamellar reactant, the concentration of organic structure directing agent is diminished to one-third of the value in the literature, without contamination of the product with other phases. The use of such reactant has given particular properties to the solid materials produced, especially in relation to the morphology; the intergrown rhombohedra usually found for SAPO-44 are also observed, however, the presence of the plates on the crystals surface is clear. Monitoring the reaction by physico-chemical techniques has shown that only after 36 h reaction Brönsted acid sites are formed and these protonate the cyclohexylamine and thus the cyclohexylammonium ion is incorporated in the structure in the final stages of the synthesis with the simultaneous intensive formation of structural double six-rings. Although 13C-MAS-NMR and FTIR have shown that n-butylamine and cyclohexylamine are both present in the channels and cavities of the solid, the key molecule in the structure directing complex is the cyclohexylammonium; the n-butylammonium is a part of the organic complex but has no role on the D6R formation or silicon incorporation. In fact, cyclohexylammonium, n-butylammonium and water seem to be involved in the formation of this molecular sieve.

Reaction at Interfaces: The Silicoaluminophosphate Molecular Sieve CAL-1

This work reports on the study to determine the best synthesis conditions for the preparation of CAL-1, a silicoaluminophosphate with a chabazite-like structure, prepared from a lamellar aluminophosphate, ALPO-ntu (herein called ALPO-kanemite), and using hexamethyleneimine (HMI) as the structure directing agent (SDA). These studies showed that optimum reaction conditions to obtain CAL-1 depend on the concentration of silicon desired in the structure. For low silicon concentrations, SiO2/Al2O3 ≤ 0.4, no set of adequate conditions was found; the samples prepared were always contaminated with the starting lamellar materials. At SiO2/Al2O3 molar ratios of 0.8 and 1.2, crystalline samples were obtained after 24 h. For silicon concentrations still larger, an optimum set of reaction conditions could not be determined. The best sample with SiO2/Al2O3 = 1.6 in the gel was obtained with HMI/Al2O3 = 1.5 only after 48 h of reaction time, and even then, the crystallinity of the sample thus prepared was poor. The combi...

Synthesis of a novel lamellar aluminophosphate AIPO4-L

Synthesis of a novel lamellar aluminophosphate AIPO4-L

Mu-7, a New Layered Aluminophosphate [CH3NH3]3[Al3P4O16] with a 4 × 8 Network: Characterization, Structure, and Possible Crystallization Mechanism

The title compound, Mu-7, is a new layered aluminophosphate. It was obtained from a quasi-nonaqueous system involving methylformamide (MF) as solvent in addition to restricted amounts of water. MF is decomposed into methylamine during synthesis and the latter is occluded into the interlayer spacing of the material. The structure was determined by single-crystal X-ray diffraction. The symmetry is triclinic, space group P1̄, a = 8.368(7), b = 11.274(10), c = 11.462(12) Å, α = 72.40(7), β = 89.45(8), and γ = 85.37(7)°. Mu-7 is built from zigzag ladder-type chains connected to form layers containing only four- and eight-membered rings. Mu-7 is the first lamellar aluminophosphate having such a 4 × 8 network. Characterization of the new compound by 13C, 27Al, and 31P solid-state NMR spectroscopy, bulk chemical analysis and TG/DSC is reported. A possible crystallization mechanism based on the condensation between “parent” ([AlP2O8H2]-) and zigzag ladder-type ([Al4P4O20H4]4-) chains is proposed.

Isolation and characterization of a novel lamellar-type aluminophosphate, AlPO4-L, a common precursor for AlPO4 molecular sieves

Several aluminophosphate molecular sieves (AlPO4-5, AlPO4-22, AlPO4-16 and SAPO-35) are formed via a common lamellar aluminophosphate material (AlPO4-L) during hydrothermal synthesis from a gel containing Al2O3, P2O5, SiO2 and hexamethyleneimine (HEM) in aqueous (H2O), or non-aqueous (ethyleneglycol, EG) media. Depending on the concentration of the template HEM, AlPO4-L transforms into AlPO4-5, AlPO4-16 and AlPO4-22, while SAPO-L transforms into SAPO-35. AlPO4-L was isolated in a pure form from H2O as well as EG media and characterized by PXRD, SEM, TG/DTA, TG/MS and FTIR spectroscopic techniques. It is a lamellar aluminophosphate, intercalating HEM and H2O, and is thermally stable up to 250°C. AlPO4-L is believed to form by the rearrangement of macroanionic [3HEMH]3+Al3P4O3−16 sheets formed in the reaction medium.

Phosphate liquid crystals: novel supramolecular template for the synthesis of lamellar aluminophosphates with natural form

The thermal properties ofn-alkylammonium dihydrogenphosphates, [CnH2n+1NH3+ ][H2PO4– ], where 6≤n≤18, have been investigated for the first time. It was discovered that for decylammonium (n=10), the material undergoes several polymorphic phase transitions before ultimately transforming to a smectic liquid crystal mesophase. The crystal to liquid crystal transformation of this phase was studied by in situ variable temperature polarizing optical microscopy and revealed intriguing micron dimension surface patterns. Similar thermal behaviour was observed when the material was dispersed in a polyethylene glycol non-aqueous solvent. The results have direct implications for the growth and form of surface patterned lamellar aluminophosphate morphologies prepared organo-thermally from aluminium oxide, phosphoric acid and n-alkylamines in polyethylene glycol-based solvents. Topological defects present in the precursor alkylammonium phosphate mesophase appear to be responsible for the emergence of surface textured lamellar aluminophosphate replica materials with biomimetic form. Phosphate liquid crystals represent a new class of supramolecular templates for the synthesis of a wide variety of mesostructured metal phosphates.

Synthesis and Al K-Edge Xanes Investigation of Mesostructured Aluminophosphates

AbstractWe report on the synthesis of lamellar mesostructured aluminophosphate composites which contain variable relative amounts of aluminium oxide species in the core regions of the lamellae; this is investigated quantitatively by Al K-edge XANES spectroscopy. Templating is achieved by the utilisation of monododecyl phosphate surfactant. If no phosphorous source (such as H3PO4) is used for the synthesis, the phosphate head groups of the surfactant become incorporated into the inorganic network to form similar lamellar aluminophosphate structures. Thus, the surfactant serves as both template and reactant.

Synthesis and characterization of an unusual lamellar aluminophosphate synthesized from an alcohol system

An unusual lamellar aluminophosphate [Al4P2O11·2C6H13NH2·4H2O]·3H2O was synthesized from a mixture of H3PO4, Al(OPri)3, ethylene glycol and an unbranched primary alcohol. It was characterized by X-ray powder diffraction, scanning electron microscopy, infrared, magic angle spinning NMR spectroscopy, differential thermal and thermogravimetric analysis. It is composed of PO4, AlO4 and AlO6 structural units, and the ratio of octahedral to tetrahedral Al in the as-synthesized compound is about 1:1. This material exhibits a very large weight loss at elevated temperatures. Upon dehydration it possesses a considerable water adsorption capacity. The water adsorption isotherm is linear. Of the seven water molecules in the empirical formula, four are co-ordinated to the Al atoms and the other three are located between adjacent layers.

Lamellar aluminophosphates with surface patterns that mimic diatom and radiolarian microskeletons

ORGANISMS such as diatoms and radiolaria synthesize elaborate biomineral exoskeletons which display hierarchical structures patterned on length scales from less than a micrometre to millimetres. Synthetic materials chemistry, in contrast, has traditionally been able to achieve regular patterning only on microscopic (<10 A) and more recently1–3 mesoscopic (10–103 A) length scales. Here we report the synthesis of crystalline, lamellar aluminophosphate structures that are patterned on the submicrometre-to-millimetre scales found in the living world. As in the syntheses of ordered mesoporous solids1–3, our approach involves templating by self-assembled organic aggregates, and we propose that the larger scale of the patterning here arises from the involvement of vesicle templates rather than the micelle-like or bilayer structures thought to be responsible for mesoscale pattern formation1–3.