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Conventional pesticides are biosynthetic chemicals that are effectively used for the control of weeds, diseases, and pests worldwide. Among them, glyphosate, one of the most commonly used broad-spectrum herbicides, might cause a series of environmental problems and pose a toxicological risk to aquatic organisms; even though many developed countries currently prohibit its use, it is still commercialized and used in some countries. Alternatively, melamine resins have been used as adsorbents for many substances due to their chemical and physical properties. Hence, this study focuses on determining the capacity of melamine resin derivatives to serve as adsorbents of glyphosate. Melamine resin was synthesized using a condensation reaction between melamine and glyoxal. The reaction product was fully characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, thermogravimetry analysis and molecular dynamics simulations. The ability to remove glyphosate from water was tested, and the adsorption efficiency was evaluated. Furthermore, the kinetics and equilibrium of the adsorption process on the resin were studied with Langmuir isotherms. The maximum adsorption of glyphosate by the synthesized resin was 62.1 mg g−1, which is comparable to that by activated carbon.

Nitrogen-doped transition metal materials display promising potential as bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, Fe/N co-doped three-dimensional (3D) porous graphene (FeN-3D-PG) is prepared via a template method using sodium alginate as the carbon source and low polymerization degree melamine resin as the nitrogen source. The low polymerization degree melamine resin can form complexes with Fe3+ in the aqueous solution and further forms high density Fe-Nx active sites during pyrolysis. Meanwhile, the formed 3D porous structure efficiently promotes the uniform distribution of Fe-Nx active sites. The FeN-3D-PG catalyst exhibits pH-independent ORR activity. For OER, the catalyst possesses a low over potential (370 mV at 10 mA cm−2) in alkaline electrolyte. The Zn-air batteries (ZABs) using FeN-3D-PG as cathode exhibits a power density up to 212 mW cm−2, a high specific capacity of 651 mAh g−1, and the charge-discharge stability of 80 h. This work provides new sight to transition metal materials based ZABs with excellent performance.

The resin melamine cyanurate (MCA) core-shell microcapsules were prepared by surface coatingmodification of halogen-free flame retardant MCA using melamine resin and acrylic resin as wall materials. The influence of different wall materials on the coating effect of halogen-free flame retardant MCA was studied by SEM, particle size analysis, IR, and DSC and TGA methods. The results showed that the melamine resin had a high degree of polymerization and decomposed at about 160°, which had a surface modification effect on MCA and did not affect its flame retardant performance. The surface coating rate of poly(methyl methacrylate) PMMA-MCA core-shell microcapsules was about 80%. Afteradding acrylic acid (AA) as the second monomer the coating effect was significantly improved and the thermal decomposition temperature of the wall material of the microcapsule was reduced.

Transparent intumescent fire-retardant (IFR) coatings are the newest passive fireproofing materials which maintain structural integrity without losing aesthetic appearance of the substrate. In this present paper, effects of three IFR coatings with structurally different epoxy resins, namely aliphatic, cycloaliphatic, and aromatic, on the fire resistance, transparency, and physicomechanical properties were investigated. Different phosphate resin acids (PRA) were prepared by reacting synthesized phosphate ester acid (PEA) with aliphatic, cycloaliphatic, and aromatic epoxy resins. The chemical structures of the above PEA and PRAs were confirmed by Fourier transform infrared spectroscopy (FTIR), 1H-nuclear magnetic resonance spectroscopy (1H-NMR), and 31P-nuclear magnetic resonance spectroscopy (31P-NMR). Subsequently, transparent IFR coatings were prepared by mixing these PRAs with hexamethoxy methyl melamine resin. Transparency of the coatings was confirmed by UV–Vis–NIR spectrophotometeric studies. Fire protection property and char compressive strength were done to investigate the fire protection ability of the coatings, and the quality of the char formed was analyzed by field emission scanning electron microscope. The decomposition process of prepared fire-retardant coatings was studied by thermogravimetric analysis. Results showed that aliphatic epoxy-based transparent coating produced tough and compact char, but the char height was negligible, and aromatic epoxy-based transparent coating produced soft and fluffy char having excellent char height; however, the fluffy char reduced protection for longer duration. Cycloaliphatic epoxy-based transparent coating produced tough and compact char with good char height, thereby reducing heat transfer during combustion, and also showed superior scratch, abrasion, impact, and water resistance compared to other compositions.

Electrolyte uptake and thermal stability of separators are important factors in Li-ion battery application. Here, a poly(vinyl alcohol)/melamine composite nanofiber membrane containing LATP nanocry...

Compressive and tensile strengths were considered for a box connected by dovetail keys under different mortise-and-tenon sizes. Poplar wood modified by melamine resin (MF modified poplar wood) was chosen as the experimental material, and the experimental study was carried out on the box using the concentrated loading method. The results showed that the ratio (T) of hole depth to slope height had a significant effect on the structural strength of the box connected by dovetail keys when other dimensional parameters were the same. When T was equal to 75%, the compression and tensile strength of the box was the highest, and the joint had better recovery and deformation ability. When T` was equal to 50%, the box strength was the worst, and the joint damage was the most serious in both types of loading. In addition, the measurement standard of the displacement was determined through preliminary experimentation. The compression quantity was 8 mm, and the stretching quantity was 5 mm. The latter experiment showed the reliability of the pre-experiment.

Melamine–formaldehyde (MF) resin-based carbon stands out among energy materials due to their superior nitrogen content and intriguing comprehensive properties; however, the inferior rate capability hinders its further application as electrode materials in supercapacitors. In this work, monodisperse melamine–formaldehyde resin microspheres (MMRMs) have been prepared by mild emulsion polymerization, with Pluronic F127 as soft template as well as stable response sites. Triblock copolymer F127 not only regulates the size of the MMRMs, but also enhances its thermal stability owing to strong hydrogen bond forces between resin oligomers and F127. Carbon derived from the subsequent pyrolysis of MMRMs (MFC-0.10-8) has unique lamellar porous architecture and much higher specific surface area (325.75 m2 g−1) compared with that of MFC-0-8 without F127 (82.18 m2 g−1), which is crucial to enhance the electrochemical performances as electrode material. The N content of the carbonized MMRMs is up to 22.0 at%, which brings considerable pseudo-capacitance and rate capability (85.5% capacitance retention from 1 to 10 A g−1). MFC-0.10-8 exhibits high gravimetric capacitance of 311 F g−1 at the current density of 0.5 A g−1 and outstanding capacitance retention with 105% of its initial capacitance after 10000 cycles in 2.0 M H2SO4 electrolyte.

In this research, the effect of melamine resin-impregnated paper waste mixed with industrial wood fibers for medium density fiberboard manufacture was studied. One layer laboratory panel with the resin-impregnated paper of 0/100, 10/90, 20/80, 30/70 percent by weight, press time of 4 and 6 min, and resin content of 8 and 10% to dry weight of fibers, was produced. The physical and mechanical properties of panels including modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), and thickness swelling (TS) were measured. The results showed that resin-impregnated paper waste had a significant effect on MOR, MOE, and IB, where the TS of panels was decreased as resin-impregnated paper waste was increased. Furthermore, the result indicated that press time and resin content had a significant negative effect on the physical and mechanical properties of panels. According to statistical analysis, 20% resin-impregnated paper with 8% resin content and 4 min press time were the best treatments in this study.

The self-healing microcapsules can be buried in the coating to improve the anticorrosive ability. In this paper, self-healing microcapsules of polyurea (PU)/melamine resin (MF) double shell were prepared by in-situ polymerization and interfacial polymerization with isocyanate as the core material. Scanning electron microscope was used to observe the microcapsule morphology. The structures of microcapsules prepared with different chain extenders were characterized by Fourier transform infrared spectroscopy. The micromanipulation system was used to loading–holding, loading–unloading and loading to rupture individual microcapsules, so as to explore the mechanical properties of microcapsules. The Young's modulus corresponding to microcapsules was calculated by mathematical model fitting. The self-healing properties of microcapsule coating were characterized by optical microscope. The experimental results showed that the microcapsule shell prepared under optimized conditions had a complete morphology and good mechanical properties. The microcapsule was in the elastic deformation stage under small deformation, and the plastic deformation stage under large deformation. The Young's modulus range of microcapsules was 9.29–14.51 MPa, and the corresponding Young's modulus could be prepared by adjusting the process. The surface crack of the coating containing microcapsule could heal itself after 48 h in a humid environment.

The microcapsule particles were successfully prepared by means of in-situ copolymerization of layered double hydroxides (LDHs) with the melamine resin monomers, improving the compatibility of inorganic flame retardant LDH with polymer. The electron beam irradiation was introduced into the process to enhance the mechanical properties and thermostability of the flame retardant composite material. The flame-retardant composites were prepared by incorporating the microcapsule LDH into ethylene vinyl acetate (EVA). The compatibility of microcapsule particles with EVA, combustion and thermal behaviors were detected in sequence through SEM, TG analyses, LOI, UL-94 level and mechanical tests. It was shown that the irradiated EVA/LDH@MF composite had showed the best performances of flame retardancy and mechanical properties due to microencapsulation and irradiation processes. The uniform dispersion of microencapsulated LDH in the EVA matrix was due to the good compatibility of MF shell with EVA keeping the mechanical properties of EVA matrix. The irradiated EVA/LDH@MF with 200 kGy dose achieved a limiting oxygen index (LOI) of 25.5% and a UL-94 V-1 rating. When the dose rate was 100 kGy, the EVA/LDH@MF composite had the best mechanical properties of EVA composites. The microencapsulation of LDH with MF shell incorporated into EVA three-dimensioned network through electron beam irradiation induced crosslinking to enhance mechanical properties.

Cathode oxygen reduction reaction (ORR) performance is crucial for power generation of microbial fuel cells (MFCs). The current study provides a novel strategy to prepare Fe/N-doped carbon (Fe/N/C) catalyst for MFCs cathode through high temperature pyrolyzing of biomass capsuling melamine resin polymer. The obtained Fe/N/C can effectively enhance activity, selectivity and stability toward 4 e– ORR in pH neutral solution. Single chamber MFC with Fe/N/C air cathode produces maximum power density of 1166 mW m−2, which is 140% higher than AC cathode. The improved performance of Fe/N/C can be attributed to the involvement of nitrogen and iron species. The excellent stability can be attributed to the preferential structure of the catalyst. The moderate porosity of the catalyst facilitates mass transfer of oxygen and protons and prevents water flooding of triple-phase boundary where ORR occurs. The biomass particles encapsulated in the catalyst act as skeletons, which prevents catalyst collapse and agglomeration.

Low-cost feedstocks and rationally designed structures are the keys to determining the lithium-storage performance and practical applications of Si-based anodes for lithium-ion batteries (LIBs). Herein, we employ low-cost micro-sized kerf-loss silicon (KL-Si) as the cheap feedstock and melamine resin as the carbon source to prepare a hollow-structured Si@void@C composite. The naturally formed SiOx film and the organic layer on the surface of KL-Si during the diamond wire slicing process serve as a natural sacrificial double template to create voids between the Si core and a melamine resin-derived carbon coating. The as-prepared hollow-structured Si@void@C composite anode delivers 1164.4 mA h g−1 at 1 A g−1 after 300 cycles with a retained capacity of 927 mA h g−1 after 500 cycles at 3 A g−1. The full cell with the prelithiated Si@void@C anode and a Li(Ni0.6Co0.2Mn0.2)O2 cathode boasts a high a capacity retention of 81.5% after 150 cycles. This paper presents a straightforward approach to converting low-cost KL-Si waste to value-added LIB anodes, enabling the full utilization of the Si feedstock in the photovoltaic industry.

N-Doped hierarchical porous carbons (HPCs) with tailored pore structures were fabricated via simultaneously foaming and carbonizing resorcinol–formaldehyde–melamine resin under a hypersaline condition using ZnCl2 salt. The obtained carbon aerogels possessed a high surface specific area (700–850 m2 g−1) with uniquely hierarchical porous nanoarchitectures, primarily containing ultramicropores, supermicropores and mesopores, and high residuals of nitrogen heteroatoms (5.36–7.25 wt%), because ZnCl2 acts as the dehydration agent, foaming agent, and porogen collectively. Herein, HPCs, obtained from using ZnCl2 in a proper quantity, exhibited an exceptionally specific capacitance of 423 F g−1 at 1 A g−1, a superior cycling stability after 10 000 cycles at 2 A g−1 and a distinctively high coulombic efficiency (near 100% after 10 000 cycles) as well. In particular, contributions of both double-layer capacitances and pseudocapacitances were determined, where pseudocapacitance accounts for 79% of the total capacitance. The assembled flexible solid state supercapacitor yielded a high energy density of 16.7 W h kg−1 at a power density of 894.0 W kg−1, exhibiting a high cycling stability and flexibility. Our results suggest that a facile and environmentally friendly hypersaline strategy can be utilized to prepare new N-doped HPCs, and moreover their electrochemical performance can be tuned conveniently. Since such HPCs have an exceptional electrochemical property, they have promising potential as carbon substrates in supercapacitive materials or wearable devices.

It has been shown that structural properties of open porous solids, such as the mean pore size, can be derived from gas pressure-dependent thermal conductivity data. However, a reliable prediction of the total thermal conductivity of a porous sample with complex backbone structure from structural data is not possible, because the degree of coupling of gaseous and solid thermal conduction is hard to estimate. To explore the impact of structural effects, the thermal performance of different model structures, generally characteristic for porous solids (necks, dead ends, tortuosity), was theoretically evaluated by means of finite-difference calculations. As a result, we find that dead ends cause the highest amount of thermal coupling. On the other hand, independent experimental investigations were performed to support the theoretical findings. That means, the gas pressure-dependent thermal conductivities of two sample systems in a nitrogen atmosphere were analyzed: At first, thermal conductivity data for three organic, resorcinol–formaldehyde based aerogels with different structural properties were received from hot-wire measurements. Secondly, the regular cell structure of melamine resin foam was systematically changed by uniaxial compression within a guarded hot plate apparatus prior to determining the resulting thermal conductivity in the direction of compression. Overall, the measured gas pressure-dependent thermal conductivities of both systems indicate that the connectivity of the solid network significantly affects the solid–gas coupling term in porous solids. Both the experimental and theoretical results show that the coupling term decreases with increasing connectivity of the backbone material of a porous solid.

In this study, the dimensional stability and mechanical properties of plywood made from untreated and plasma-pretreated beech veneers were compared. The wood veneers used (native and thermally modified) were impregnated with melamine resin in a simple dipping process prior to plywood production. The duration of the impregnation process was adjusted to give the same melamine resin loading for the different veneer types, with the plasma-pretreated veneers requiring only a fraction of the impregnation time compared with non-plasma-pretreated veneers. With comparable melamine loading, testing of the mechanical properties of the plywood for the different specimen collectives showed significant differences in some cases with respect to compressive strength, bending strength and tensile strength (with the associated moduli of elasticity). For example, it was shown that plywood made from plasma-pretreated native beech veneers shows an increase in bending strength of about 8%, and from plasma-pretreated and thermally modified beech veneers, there is an increase of about 10% compared to the reference.

CO2 adsorption in porous carbon materials has attracted great interests for alleviating emission of post-combustion CO2. In this work, a novel nitrogen-doped porous carbon material was fabricated by carbonizing the precursor of melamine-resorcinol-formaldehyde resin/graphene oxide (MR/GO) composites with KOH as the activation agent. Detailed characterization results revealed that the fabricated MR(0.25)/GO-500 porous carbon (0.25 represented the amount of GO added in wt.% and 500 denoted activation temperature in °C) had well-defined pore size distribution, high specific surface area (1264 m2·g−1) and high nitrogen content (6.92 wt.%), which was mainly composed of the pyridinic-N and pyrrolic-N species. Batch adsorption experiments demonstrated that the fabricated MR(0.25)/GO-500 porous carbon delivered excellent CO2 adsorption ability of 5.21 mmol·g−1 at 298.15 K and 500 kPa, and such porous carbon also exhibited fast adsorption kinetics, high selectivity of CO2/N2 and good recyclability. With the inherent microstructure features of high surface area and abundant N adsorption sites species, the MR/GO-derived porous carbon materials offer a potentially promising adsorbent for practical CO2 capture.

Melamine resin sponges have a porous cell structure on the micrometer scale, comparable to the terahertz wavelength. Hydrating the sponge with water introduces a micro-scale rough surface which greatly attenuates the terahertz reflection. When combined with the high absorption of water, the hydrated sponge shows a perfect shielding characteristic by reflecting less than 1% of the light intensity in 0.75-3.5 THz.

The development of high-performance, low-cost bifunctional catalysts with long-term stability for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is one of the most critical challenges for the large-scale application of metal–air batteries. Herein, we report an advanced nitrogen-doped mesoporous carbon (NMC) composite (NiCo2O4/CoNx–NMC) formed from a mixture of Co- and Ni-hydroxide-infiltrated phenolic resin and melamine resin. This composite exhibits superior electrocatalytic activity, stability, and selectivity for the ORR and OER. The activity parameter (ΔE), which is an indicator of the overall catalytic activity of bifunctional catalysts, was 0.76 V for NiCo2O4/CoNx–NMC. Therefore, catalyst outperforms the majority of previously reported non-precious metal-based bifunctional electrocatalysts. The remarkable ultra-high catalytic performance of NiCo2O4/CoNx–NMC for the ORR and OER can be attributed to the presence of different active sites of the CoNx structure and the formation of NiCo2O4 with the spinel structure, which was obtained by a stepwise pyrolysis process. This synthesis strategy opens a new avenue for the rational design of highly active bifunctional electrocatalysts.

In this work, the effect of particle size on the thermal stability and bursting phenomenon of the microcapsules with a melamine resin shell was studied. The heat-induced change process and mechanism of the prepared microcapsules were derived. Firstly, the microcapsules with different particle sizes were prepared and characterized via encapsulation efficiency measurements, optical microscopy, and scanning electron microscopy. The thermogravimetric analysis curves of the samples were calculated, analyzed, and compared with the samples’ particle size and distribution, and the changes and differences in the microcapsules under heating environment were macroscopically studied. Furthermore, thermo-microscopic image analysis of the samples was conducted using a laboratory-combined instrument system, and their dynamic morphology in a temperature-increasing environment was microscopically investigated. On the basis of these data, it was found that the thermal bursting phenomenon occurred when the microcapsule particle size was larger than the “critical dimension.” And as the particle sizes decreased, their heat rupture resistance was improved, and the trend of change was described by an exponential function (y = 133.64 + 94.76 × 0.85x). When the microcapsule size was smaller than the critical dimension, the thermal bursting phenomenon disappeared and the thermal stability was depended on the degradation temperature of the MMF shell.

The aim of the present work was to evaluate the effect of the melamine-resin and Na+-montmorillonite and during the synthesis and deposition of organosilicon hybrid coating on 6063 micro-arc oxidation of aluminum alloy and to analyze how these synthesis parameters affect composition, corrosion performance, friction performance and adhesion of the coating resultant. The results show that the existence of melamine-resin/organosilicon/Na+-montmorillonite composite coating greatly improved the corrosion resistance of aluminium alloy, and the associativity between coating and substrate. What’s more, the obtained coating has superior corrosion resistance and frictional resistance. The surface of the coating forms a smooth and smooth microstructure, and the hydrophobicity of the composite coating is obviously improved. The corrosion experiment result indicates the high stability and better adhesion of melamine/organosilicon /Na+-montmorillonite composite coating. It could be used in corrosion environment for a long time.

Nitrogen-rich sulfur-containing hollow carbon spheres with open macroporous structure and wrinkled surface were fabricated through co-assemble of melamine resin and silica nanospheres by using methionine as catalyst and sulfur source. The obtained materials possessed high nitrogen content (14.16–16.59%) and controllable sulfur doping level (0.06–0.23%). Benefited from the enriched doped heteroatoms and hierarchical porous structure containing micropores, mesopores and macropores, the obtained carbons show high specific capacitance (230 F g−1 at 0.5 A g−1) and excellent rate performance (80% capacitance retention at 10 A g−1). In addition, the carbons investigated by two-electrode system with polyvinyl alcohol/KOH gel electrolyte showed a high capacitance of 208 F g−1 and good long-term stability (94% over 5000 cycles).

WOS:000467904700006 Overall and melamine migration have been determined for 60 samples of melamine resin bowls, which were purchased in various local markets in the area of Bursa, Turkey. The samples were exposed to food simulants 3% acetic acid, 10% ethanol aqueous solutions, and rectified (refined) olive oil at 100 degrees C for 30 min, and 50% ethanol aqueous solutions at 60 degrees C for 30 min. The LOQ value was calculated as 3.3 mg dm(-2) for overall migration and 0.126 mg kg(-1) for melamine migration. Research findings did not exceed the limit of overall migration level (10 mg dm(-2)). Also, melamine levels of all tested items found in the third assays were below the specific migration limit (SML) of 2.5 mg kg(-1) set out in the EU 10/2011 (EU, 2011) and Turkish Food Codex 2013/34 (TFC, 2013a). Some expensive as well as cheap products showed close migration levels. The increased cost of the item did not indicate a higher quality regarding health in this study. Republic of Turkey Ministry of Food, Agriculture and Livestock, General Directorate of Agricultural Research and Policies [TAGEM/HSGYAD/14/A05/P01/48] This study was funded by the Republic of Turkey Ministry of Food, Agriculture and Livestock, General Directorate of Agricultural Research and Policies (Project No: TAGEM/HSGYAD/14/A05/P01/48) and the research was conducted in Central Research Institute of Food and Feed Control (16036 Bursa, Turkey).

The use of UV adsorbers included in composition of a polymer film is a promising way of color protecting against effects of light since application of the polymer to the textile material surface is a universal way of providing the textile materials with necessary special properties. Optical characteristics are the most important indicators of suitability of polymer films for their use in final processing of colored textile materials. The objective of this study consisted in a spectrophotometric determination of optical characteristics of polymer films based on a styrene-acrylic polymer with addition of a cross-linking agent and UV adsorbers for the use in final processing of textile materials for the purpose of their color protection. The polymer matrix is an aqueous dispersion of a thermally linking styrene-acrylic copolymer. Partly esterified melamine resin was used as a cross-linking agent and 2,4-dihydroxybenzophenone, 3,6-dihydroxyacetophenone, salicylic acid phenyl ether, p-methoxy cinnamic acid were used as UV adsorbers. Optical characteristics of polymer films were determined using SF-56 spectrophotometer by constructing spectral curves of absorption and transmission in the range of 200‒800 nm. Based on analysis of spectral curves of absorption in polymer films, UV adsorbers which provide formation of colorless polymer films have been established. Spectral curves of light transmission of the studied polymer films in the visible portion of spectrum have allowed us to determine effect of UV adsorbers on film transparency and light transmission in relation to UV rays in the UV portion of the spectrum. Substances that contribute to reduction of UV radiation transmission through polymeric films and provide light protection properties were established. Based on the multivariate analysis of the results obtained in the study of optical characteristics of polymer films, a composition based on styrene-acrylic polymer, cross-linking agent and UV adsorber was recommended. The found composition is suitable for its use in final processing of colored textile materials in order to form a colorless, transparent coating with light-protective properties.