Poly Melamine-formaldehyde Research Articles

Preparation of highly active and stable magnetically separable Pd NPs encapsulated in mesoporous polymelamine formaldehyde Yolk-Shell nanoreactor for the Mizoroki–Heck cross-coupling reaction

Preparation of highly active and stable magnetically separable Pd NPs encapsulated in mesoporous polymelamine formaldehyde Yolk-Shell nanoreactor for the Mizoroki–Heck cross-coupling reaction

Removal of basic dyes from aqueous medium using high-sulfonated polymelamine formaldehyde magnetic nanoparticles

Removal of basic dyes from aqueous medium using high-sulfonated polymelamine formaldehyde magnetic nanoparticles

Flexible electrochemical sensor for highly sensitive and selective non-enzymatic detection of creatinine via electrodeposited copper over polymelamine formaldehyde.

A non-enzymatic electrochemical biosensor was developed for highly sensitive detection of creatinine using copper nanoparticles supported over polymelamine formaldehyde. The synergy between the electrodeposited copper nanoparticles over the highly porous polymer (eCu-PMF) provided a greener platform to boost up the electron transport at the electrode electrolyte interface by eliminating the role of redox species as well as interference of major interferents like glucose, dopamine, and ascorbic acid in physiological media 0.1 M PBS (pH 7.4). The proposed sensor exhibited a wide detection range of 100 fM-60 mM with high sensitivities of 0.320 mA nM-1 cm-2 and 3.8 mA nM-1 cm-2. Moreover, the sensor was applied to real samples of serum creatinine and recoveries of 97 to 114% were found. Additionally, a paper-based flexible screen-printed electrode was fabricated which displayed an excellent activity with the same detection range of 100 fM-60 mM and long-term storage stability of 15 days.

Polymelamine Formaldehyde-Coated MIL-101 as an Efficient Dual-Functional Core-Shell Composite to Catalyze the Deacetalization-Knoevenagel Tandem Reaction.

Porous organic polymer (POP) coated on a metal-organic framework (MOF) has the functions and advantages of MOF and POP at the same time and has excellent catalytic ability. In this study, an efficient dual-functional core-shell composite MOF@POP with Lewis acid and Brønsted base sites was synthesized using the impregnation method in which MIL-101(Cr) was the core component and polymelamine formaldehyde (PMF) was the shell component. Most importantly, the obtained MIL-101(Cr)@PMF showed perfect catalytic activity in the deacetalization-Knoevenagel tandem reaction. In addition, it could still maintain ultrahigh physical and chemical stability.

Synthesis of Mesoporous Fe/N/C Electrocatalyst for Improved Oxygen Reduction Reaction Activity Through CO2‐Assisted Pyrolysis

AbstractFe/Nx/C electrocatalysts have appeared as one of the promising non‐platinum group metal (non‐PGM) electrocatalysts for oxygen reduction reaction (ORR) in energy conversion devices. These non‐PGM electrocatalysts Fe/N/C need structural tuning of pores to improve the surface area for high‐performance ORR in proton exchange membrane fuel cells. In this report, the specific surface area of poly‐melamine‐formaldehyde (PMF)‐based Fe/N/C electrocatalysts was enhanced without using a template through simple CO2‐assisted pyrolysis. The highly porous electrocatalyst exhibited an onion‐like graphitic structure and an efficient catalytic activity for ORR, comparable to Pt/C electrocatalyst. At 0.95 VRHE, the mass activity of the PMF‐based PMF−Fe/N/C‐CO2/Ar electrocatalyst was 63 % that of a commercial Pt/C electrocatalyst. Moreover, the devised fabrication process for the PMF−Fe/N/C electrocatalysts with a high specific surface area can be readily scaled up.

Selective and sensitive determination of capsaicin using polymelamine formaldehyde decorated over carbon nanotubes

An electrochemical biosensor based on polymelamine formaldehyde (PMF) supported over oxygen functionalised carbon nanotubes (OCNTs) was designed for selective and sensitive determination of capsaicin.

Solid-phase synthesis of arylidene and alkylidene malonates, as versatile intermediates, catalyzed using mesoporous poly-melamine–formaldehyde as a nitrogen-rich porous organic polymer (POP)

An efficient solid/slurry-state synthesis of arylidene and alkylidene malonates as versatile intermediates is developed in the presence of mesoporous poly-melamine–formaldehyde. The condensation reaction was conducted through a ball milling process as a non-conventional procedure and a greener methodology at room temperature under solvent-free conditions. The mesoporous heterogeneous catalyst could be recovered and reused ten times, and the results showed a negligible loss of catalytic activity. Various aryl- and heteroarylidene malonates, as well as dimethyl (cyclohexylidene)malonate, were isolated in good to high yields under optimal conditions. The use of hazardous reagents and solvents were minimized in the current method, and separation of catalyst and products, as well as the recovery and reusing of catalyst, were performed by cost-effective procedures. This work revealed that the synergistic effect of numerous Lewis base sites together with acceptor-donner hydrogen bonding functional groups in porous organic polymer (POP), and its high porosity plays a vital role to promote the carbon–carbon coupling reaction in the solid phase synthesis.

A New Nanocomposite Based on Pt‐rGO Embedded Polymelamine Formaldehyde Nanocomposite for Reduction of Carbon Dioxide

AbstractHere, polymelamine formaldehyde was decorated on the surface of reduced graphene oxide whose surface was then electrodeposited with a sub‐monolayer of platinum nanoparticles. The nanocomposite thus prepared was characterized using several spectroscopic methods. Using the nanocomposite as a potential electrocatalyst for carbon dioxide reduction, the products were detected by Raman spectroscopy, gas chromatography, 13C‐NMR spectroscopy, and gas chromatography‐mass spectrometry. The analytical results identified methanol as the main product of CO2 reduction. Moreover, analysis of the liquid products confirmed methanol as the predominant product with a current density of 0.4 mA/cm and a Faradaic efficiency of 93 %.

Poly(melamine-formaldehyde-silica) Composite Hydrogel for Methylene Blue Removal

In this work, we presented the synthesis and characterization of poly-melamine-formaldehyde-silica (PMF‑Si) composite from poly-melamine-formaldehyde (PMF) and previously purified commercial sodium silicate used as a precursor of silica nanoparticles (Si‑NPs). The materials were characterized by several physicochemical techniques such as XRD, FTIR, SEM, TEM, AFM, TGA, and DTG analysis to access their properties. We also studied hydrogel dehydration, rehydration, the potential of zero charge (PZC), and the adsorption capacity of the dye methylene blue (MB) in the hydrogel. From XRD analysis, PMF and PMF‑Si materials presented amorphous profiles. AFM, SEM, and TEM images revealed a fibrous PMF structure and homogeneous dispersion of Si-NPs through the PMF-Si composite. The Si‑NPs exhibited an average diameter between 10 to 15 nm. The first PMF-Si hydration reached 93% after synthesis, and complete rehydration is possible up to 70% of dehydration. PMF-Si has the PZC at pH = 1.22 and, at superior values of pH, the composite exhibits superior adsorption rates of MB. The adsorption tests performed to remove MB dye using PMF-Si hydrogel showed a qmax of 140 mg/g, which is superior to other materials routinely used for MB dye removal.

Palladium (II) anchored on a magnetic mesoporous polymelamine–formaldehyde as new catalyst for Heck coupling reaction: optimization of reaction using response surface methodology

The paper describes synthesis of a novel mesoporous and magnetically regenerated heterogeneous nanocatalyst with high catalytic activity. The synthesis strategy includes a one-step polycondensation reaction of melamine, formaldehyde and FeCl3·6H2O in a simple and sustainable manner and followed by immobilization of Pd(II) on it. Formation and properties of nanocomposite were characterized by different techniques; the results were illustrated good surface area and a well-defined mesopore structure. Also the palladium-catalyzed C–C bond formation between aryl halides and olefins was selected to survey the activity of the synthesized nanocatalyst. Central Composite Design (CCD) strategy was used to predict the optimum synthesis conditions and identify the remarkable and effective factors including temperature, period of the reaction and amount of catalyst. These results were also verified experimentally. In order to minimize systematic error, the experimental runs as a randomized fashion were accomplished.

One-pot synthesis of propargylamines using magnetic mesoporous polymelamine formaldehyde/zinc oxide nanocomposite as highly efficient, eco-friendly and durable nanocatalyst: optimization by DOE approach.

Magnetic mesoporous polymelamine formaldehyde nanocomposite-incorporating ZnO nanoparticles were successfully synthesized using solvothermal and sol-gel methods. Fourier-transform infrared spectrometry (FT-IR), X-ray diffraction, Brunauer-Emmett-Teller, vibrating sample magnetometer, thermogravimetric analysis, elemental analysis, transmission electron microscopy and field emission scanning electron microscopy techniques were then utilized for evaluation of nanocomposites. The as-prepared nanocomposite can be used as heterogeneous nanocatalyst with remarkable performance for A3 coupling reaction toward one-pot synthesis of propargylamine and its derivatives under solvent-less condition. In order to maximize the product yield, the variables, i.e., reaction time, temperature and catalyst amount, were optimized by using a statistical approach. The synthesized nanocomposite can be easily separated from the reaction medium and reused over and over, without significant changes in its catalytic activity.

Magnetic mesoporous poly-melamine–formaldehyde: an efficient and recyclable catalyst for straightforward one-pot synthesis of imidazo[1,2-a]pyridines

Magnetically separable mesoporous poly-melamine–formaldehyde nanocomposite (Fe3O4@mPMF) has been synthesized and characterized by FTIR spectroscopy, SEM, XRD spectroscopy and EDS. The magnetically separable Fe3O4@mPMF catalyst had excellent efficiency for the synthesis a wide diversity of imidazo[1,2-a]pyridines by a three-component reaction of a 2-aminopyridine, aldehyde and isocyanide in good-to-excellent yields within a short reaction time, through an environmental friendliness and straightforward procedure. The nanocomposite that is easily recoverable and also found to be reusable can be recovered and reused when the reaction is completed for several times without distinct deterioration in catalytic activity.

Synthesis of nanoporous poly-melamine-formaldehyde (PMF) based on Schiff base chemistry as a highly efficient adsorbent.

This study proposes the construction of nanoporous poly-melamine-formaldehyde (PMF) through the Schiff base condensation reaction of paraformaldehyde and melamine. The PMF nanoparticles showed a good adsorption capability to some benzene-ring-containing dyes including acid fuchsine, nigrosine, and methyl orange. Moreover, the as-prepared PMF nanoparticles were employed as the coating adsorbent for the solid-phase microextraction (SPME) of seven volatile fatty acids (VFAs) with high enrichment factors. A PMF-assisted SPME method was established for the enrichment of VFAs from environmental water samples with satisfactory recoveries (88.5%-102.0%) and acceptable precisions (relative standard deviations <10.9%). This contribution might furnish an advanced benchmark for the exploitation of new porous organic polymers as the effective adsorbents for SPME or other fields of utilization.

Hierarchical porous metallized poly-melamine-formaldehyde (PMF) as a low-cost and high-efficiency catalyst for cyclic carbonate synthesis from CO2 and epoxides

We report a metalized hierarchical porous poly-melamine-formaldehyde catalyst having excellent catalytic activity and low cost.

CdS nanoparticles loaded on porous poly-melamine–formaldehyde polymer for photocatalytic dye degradation

CdS nanoparticles were loaded on a highly porous polymer of poly-melamine–formaldehyde (PMF) by a simple co-precipitation approach. Benefiting from the high specific surface area of PMF of 943 m2 g−1, the obtained CdS/PMF composite can adsorb dye molecules efficiently, which favors the subsequent photocatalytic dye degradation process. Typically, 99% of Rhodamine B could be degraded over the optimized CdS/PMF sample after 3 h visible light irradiation. Moreover, the CdS/PMF sample displays reasonable stability during the recycle runs, indicating its potential application for organic pollutants removal by photocatalysis.

Anionic and cationic dyes adsorption on porous poly-melamine-formaldehyde polymer

Liquid phase adsorption is one of the most effective approaches for dye removal from colorant effulent. In this study, we investigated the adsorption behaviors of cationc and anionic dyes on a highly porous adsorbent of poly-melamine-formaldehyde (PMF). Both micropores and mesopores were found in PMF, which supported high specific surface area and pore volume. The maxmium adsorption capaities for methylene blue (MB), methyl violet 2B (MV), methyl orange (MO), orange II sodium salt (OS) and congo red (CR) were 80.8, 113.9, 81.2, 89.3 and 87.5mgg−1, respectively. Isotherm study showed that the experimental data can be well fitted by Langmuir adsorption model. Kinetic study indicated that the adsorption process followed pseudo-second order kinetic model and both external and intra-particle diffusion were rate-determining steps. Furthermore, dye-exhausted PMF can be regenerated by sulfate radical based advanced oxidation process. After 6 runs, the dye removal percentages for MV and OS were 87.6% and 99.4%, respectively, indicating good stability and reusability of PMF. The main factor contributed to the high adsorption capacity of PMF should be ascribed to its high specific surface area and large pore volume. The advantages of high adsorption capacity and stability made PMF a promising adsorbent for colorant effluent treatment.

Direct oxidative esterification of alcohols and hydration of nitriles catalyzed by a reusable silver nanoparticle grafted onto mesoporous polymelamine formaldehyde (AgNPs@mPMF)

Oxidative esterification and hydration of nitriles are catalyzed by a newly synthesized AgNPs@mPMF. The catalyst is well characterized and reusable.