Sulfonated Melamine Formaldehyde Research Articles

Application study of seashell powder calcined sludge cement: Effects of different superplasticizer on working properties, mechanical properties and microstructure of materials

Seashell powder calcined sludge cement (SCSC) is a low carbon ternary cement prepared from waste seashells and waste sludge. However, the addition of seashell powder and calcined sludge reduces the working performance of the material and restricts the engineering application of SCSC. To enhance the adoption of SCSC in construction projects, this investigation evaluates the influence of three distinct superplasticizers—Polycarboxylate Ether (PCE), Sulfonated Naphthalene Formaldehyde (SNF), and Sulfonated Melamine Formaldehyde (SMF)—on the workability, mechanical strength, and microstructural properties of SCSC. The effects of superplasticizers on SCSC slurries were analyzed by mechanical property tests and macro-micro property characterization means such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR), hydration thermal analysis and nuclear magnetic resonance (NMR). The results showed that the fluidity of SCSC slurries was increased by 73.3 %, 32 %, and 23.5 %, the initial setting time was extended by 29.6 %, 21.3 %, and 16.6 %, and the compressive strength was increased by 22.7 %, 19.6 %, and 5.7 % for the additions of PCE, SNF, and SMF at an amount of 0.25 %, respectively. The addition of superplasticizers prolonged the hydration induction period of SCSC, optimized the pore size distribution of the material, and reduced the structural porosity. The study shows that PCE has the best suitability for SCSC slurries, and should be preferred in the practical application of SCSC slurries. The results of the study can provide a reference for the application of SCSC slurries in engineering.

Monodisperse sulfonated melamine formaldehyde resin microspheres: Synthesis by dispersion polymerization and light-diffusing performance characterization

The development and characterization of sulfonated melamine formaldehyde resin microspheres (SMF microspheres) as light diffusers in epoxy resin was presented in this paper. The SMF microspheres were prepared through dispersion polymerization with uniform particle size, smooth surface, and a high refractive index. The particle size of the microspheres was controllable within the range from 0.8 to 3.7 µm according to the pH during acidic condensation and the amount of melamine. Compared to traditional MF microspheres, SMF microspheres possessed unique sulfonic acid groups, higher primary amine content, and stronger polarity, which prevent agglomeration when mixed with epoxy resin. The SMF microspheres thus prepared were used as light-diffusing fillers with epoxy resin as matrix. Experimental results and single-particle Mie scattering simulations confirmed that SMF microspheres with a higher refractive index and smaller particle size exhibited higher light-shading efficiency and the haze of EP, demonstrating their outstanding light-diffusing performance. In summary, the significant potential application of SMF microspheres in the field of light diffusers was demonstrated.

DFT and electrochemical studies of new superplasticizers on the corrosion inhibition of 316L stainless steel in neutral medium: A comparative study

In this study, new corrosion inhibitors such as polycarboxylate ether (PCE), sulfonated naphthalene formaldehyde (SNF), modified lignosulphonate (MLS), and sulfonated melamine formaldehyde (SMF) are utilized for 316L stainless steel in a 3.5% NaCl medium. ATR-IR and UV–Vis spectroscopy were used to study the superplasticizers' structural characterization. Based on the ATR-IR and UV–Vis results, all of the spectrum information for PCE, SNF, MLS, and SMF are closely matched to the findings of the significant superplasticizers described in the literature. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) measurements and the weight loss method were used to investigate the corrosion inhibition efficacy of new superplasticizers on 316L stainless steel in a 3.5% NaCl solution. According to the EIS, PDP, and weight loss results, SMF has the highest inhibitory efficiency of all the inhibitors examined. These could be attributed to the presence of additional heteroatoms (N, O, and S) in the SMF than in the other three inhibitors. The inhibition efficiencies were in the order of SMF > MLS > SNF > PCE, with the maximum inhibition efficiency of 88.8% for the SMF inhibitor at 0.00012 mol L−1 concentration. The adsorption of all inhibitors, including PCE, SNF, MLS, and SMF, is well-fitted and follows the Langmuir isotherm model. SEM and EDX analyses were used to study the corrosion mechanism of the adsorbed inhibitor molecules PCE, SNF, MLS, and SMF and their elemental composition on the metal surface. The SEM and EDX result reveals that the SMF inhibitor is substantially adsorbed onto the 316L SS surface as a protective layer. Quantum chemical calculations were utilized to give further evidence of the mechanism of inhibition action of all corrosion inhibitors such as PCE, SNF, MLS, and SMF. All the DFT studies demonstrate that sulfonated melamine formaldehyde (SMF) has outstanding inhibitory capabilities on 316L stainless steel in a 3.5% NaCl solution at room temperature out of the four proficient superplasticizers studied.

Two inorganic shells based on core–shell magnetic sulfonated melamine formaldehyde as sustainable catalysts for the synthesis of biscoumarins

Two inorganic shells based on core–shell magnetic sulfonated melamine formaldehyde as sustainable catalysts for the synthesis of biscoumarins

Boosting the Temperature Adaptability of Lithium Metal Batteries via a Moisture/Acid‐Purified, Ion‐Diffusion Accelerated Separator

AbstractThe reliable operation of Li metal batteries suffers from cathode collapse due to high‐voltage cycling, interfacial reactivity of the Li deposits, self‐discharge at the elevated temperatures, as well as the power output deterioration in low‐temperature scenarios. In contrast to the individual electrode optimization, herein, a hetero‐layered separator with an asymmetric functional coating on polyethylene is proposed in response to the aforementioned issues: On the face‐to‐cathode side, the hybrid layer of the molecular sieve and sulfonated melamine formaldehyde can scavenge the hydrofluoric acid and moisture residues from the carbonate electrolyte, maintaining the cathode robustness in both the high‐voltage cycling or high‐temperature storage scenarios; while the pre‐coated Ag2S layer in situ generates the Li10Ag3‐Li2S composite matrix in contact with the Li foil, promoting interfacial ion diffusion and isotropic Li deposition. The as‐constructed LiNi0.8Co0.1Mn0.1O2/Li pouch cell (3.2 Ah) with the hetero‐layered separator can achieve a high energy density of 400.6 Wh kg−1 on the cell level, as well as a wider temperature adaptability (0–75 °C). This asymmetric separator strategy enables facile energy‐dense cell prototyping with the commercial electrode/electrolyte.

Magnetic Sulfonated Melamine-Formaldehyde Resin as an Efficient Catalyst for the Synthesis of Antioxidant and Antimicrobial Pyrazolone Derivatives

Sulfonated polymer-based materials, among heterogeneous catalysts, are frequently utilized in chemical transformations due to their outstanding chemical and physical durability. In this regard, a magnetic sulfonated melamine–formaldehyde resin (MSMF) catalyst was successfully prepared from a mixture of sulfonated melamine–formaldehyde and Fe3O4 nanoparticles in two steps. MSMF was used as a heterogeneous catalyst for the one-pot, three-component condensation of benzyl pyrazolyl naphthoquinones in water as a green solvent and 4-[(indol-3-yl)-arylmethyl]-1-phenyl-3-methyl-5-pyrazolones. The antimicrobial and antioxidant activities of catalyst, benzyl pyrazolyl naphthoquinones, and 4-[(indol-3-yl)-arylmethyl]-1-phenyl-3-methyl-5-pyrazolones were evaluated using agar disk-diffusion and DPPH assays, respectively. The antioxidant activity of the catalyst and 4-[(indol-3-yl)-arylmethyl]-1-phenyl-3-methyl-5-pyrazolones was found to be 75% and 90%, respectively. Furthermore, catalyst, benzyl pyrazolyl naphthoquinones, and 4-[(indol-3-yl)-arylmethyl]-1-phenyl-3-methyl-5-pyrazolones exhibited antimicrobial activity against Staphylococcus aureus and Escherichia coli. In conclusion, MSMF is a superior catalyst for green chemical processes, owing to its high catalytic activity, stability, and reusability.

Functional polyethylene separator with impurity entrapment and faster Li+ ions transfer for superior lithium-ion batteries

An organic/inorganic hybrid coating consisting of molecular sieve (MS)/sulfonated melamine formaldehyde condensate (SMF) is fabricated on the polyethylene (PE) separator by a simple dip-coating process. The MS/SMF coating with high polarity enhances the electrolyte uptake of PE separator, and therefore favors higher ionic conductivity and Li+ transference number of separators. By regulating the ratio of MS/SMF, much higher Li+ transference number up to 0.5 can be obtained compared with the original PE separator (0.25). The PE separator possesses highest effective Li+ ionic conductivity when the ratio of MS/SMF is 3:1, which promotes more uniform Li+ deposition on the lithium metal surface for excellent lithium plating/stripping cycling stability up to 1000 h without any signs of short-circuit. Moreover, the functional PE separator possesses excellent H2O and HF capturing ability due to strong adsorption of MS and SMF for H2O and the scavenging of SMF for HF. The MS-SMF@PE separator-employed LiCoO2/Li unit cell shows superior C-rates capability and cycling performance, and no obvious lithium dendrite growth is found on the surface of lithium metal anode after cycling.

Water Reducer: A Highly Dispersing Binder for High‐Performance Lithium‐Sulfur Batteries†

Main observation and conclusionSulfur has been paid close attention by the research and manufacturing as a cathode material for lithium‐sulfur batteries (LSB) in recent decade because it has high specific capacity and low cost. But the low utilization of active materials and serious shuttle phenomenon inhibit its commercialization process. In this work, for the first time, water reducers are reported as multifunctional binders to address the above problems to enhance the performance of LSB. Due to the synthetic actions of the water reducer binder, such as highly dispersing effect and good chemical trapping function, commercial sulfur powders are directly used as cathodes, and much better electrochemical performance compared to using the conventional binder polyvinylidene fluoride (PVDF) was obtained, among which the sulfur cathode with sulfonated melamine formaldehyde (SMF) water reducer binder exhibits a high reversible capacity of 625.5 mA·h·g–1 after 200 cycles at 1 C and the cathode with polycarboxylic acid (PC) water reducer binder even demonstrates a high area specific capacity of 5 mA·h·cm–2 at high sulfur loading of 5 mg·cm–2. These low‐cost water reducers are a promising binder for LSB in the future.

Shape-controlled synthesis of sodium zincate mesoporous structures based on sulfonated melamine formaldehyde and their application as catalysts for Biginelli reaction

In the current research, two mesoporous structures of sodium zincate [Na2Zn(OH)4], spheres and aggregated particles, has been synthesized from sulfonation of melamine-formaldehyde (MF) and then bounding [Na2Zn(OH)4] particles onto the surface of sulfonated melamine–formaldehyde (SMF). Furthermore, in the present synthetic methodology the zinc oxide (ZnO) thin films on sulfonated melamine–formaldehyde was formed via the chemical deposition, and thermal treatment techniques of the sodium zincate. Several spectroscopic and analytical methods proved the structural and morphological properties of sodium zincate mesoporous structures based on sulfonated melamine formaldehyde [SMF/Na2Zn(OH)4]. The experimental studies showed that these catalytic systems showed high activity in the Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives and will find recoverable potential application. The obtained results indicated that the synthesized mesoporous structures had a thermal stability near 300 °C, particle-size distribution around of 10–120 nm for spheres and the surface area of 6 and 2 m2/g for spheres and aggregated particles, respectively.

High efficient corrosion inhibitor of water‐soluble polypyrrole–sulfonated melamine formaldehyde nanocomposites for 316 L stainless steel

AbstractIn this work, new water‐soluble polypyrrole–sulfonated melamine formaldehyde nanocomposites (PPy–SMF NCs) were first synthesized by one‐step in‐situ polymerization of pyrrole with FeCl3 in the presence of various mole ratios of sulfonated melamine formaldehyde (SMF). The characterization of the PPy–SMF NCs was investigated via ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray, dynamic light scattering, transmission electron microscopy, X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, and conductivity measurements. The resulting PPy–SMF NCs were proved to improve the solubility, electrical properties, and thermal stability. The anti‐corrosion performance of PPy‐SMF NCs on 316 L stainless steel (316 L SS) was examined using electrochemical impedance spectroscopy, potentiodynamic polarization, and weight‐loss method. The result showed that the PPy–SMF NCs acts as a mixed‐type inhibitor, as well as a protective layer to 316 L SS against corrosion in 3.5% NaCl solution. The Langmuir adsorption isotherm was well fitted and suitable to explain the adsorption behavior of the PPy‐SMF NCs on 316 L SS surface. The inhibition efficiency of PPy‐SMF NCs is 99% by the weight‐loss method which could be attributed to the protective layer formed on 316 L SS surface by the adsorption of PPy‐SMF NCs.

Effect of Added Plasticizers on the Strength Metrics of Molding Plaster

The effect of plasticizers based on sulfonated melamine formaldehyde (Melment F 15 G) and polycarboxylate (Melflux 5581 F, Sika ViscoCrete-G2) on the properties of molding plaster consisting of α-calcium sulfate hemihydrate was studied. The concentrations of additives that increase the strength in compression of molding plaster samples by factor of 1.5 – 2 were determined on the basis of the results of this work.

Preparation and characterization of TFC NF membrane with improved acid resistance behavior

In this study, we prepared the novel acid-resistant thin-film composite (TFC) piperazine(PIP)-based nanofiltration (NF) membrane using melamine (Mel), sulfonated-melamine formaldehyde (SMF), and sulfanilamide (SA) through interfacial polymerization on a polysulfone (PSf) support layer. A long-term acid-resistant experiment for divalent salt was carried out with static immersion tests in a 15 wt% sulfuric acid solution. The divalent rejection of the PIP1-SMF0.3-SA0.05 in a 15 wt% sulfuric acid solution was maintained at over 96% after 10 days, and then slightly decreased to 94% for 20 days, and finally was maintained over 90% for 30 days. The flux was maintained at about 20 GFD even after 30 days of immersion in acid. In order to confirm the degree of hydrolysis in amide, the bond dissociation energy (BDE) was calculated using the density functional theory (DFT). BDE values of PIP-TMC, Mel-TMC, and SA-TMC were 79.34, 83.78, and 93.91 kcal/mol. Consequently, PIP1-SMF0.3-SA0.05 having s-triazine and sulfonyl amide group exhibited acid-stable performance because the C–N bond is more stable and the slow hydrolysis reaction in acid. Our research for preparing high perm-selectivity and long-term acid stability membrane can extend NF technology in many industries, particularly in the recovery of rare metals from acidic solutions.

Influence of the polymeric additives on the process of calcium sulfatedihydrate crystallization

The research is aimed to the clarification of the calcium sulfatedihydrate crystals growth and formation of in the presence of the different polymers based functional additives. The calcium sulfatedihydrate crystals have been synthesized both in the pure form and with the additives. The additives have included a super plasticizer based on a sulfonated melamine-formaldehyde resin (SMF), a methylcellulose (MC) and a redispersible polymer powder based on vinyl acetate, ethylene and vinyl chloride copolymers (VAEVC). The X-ray analysis and the electron microscopy have been applied to identify an influence of the polymer additives over the configuration and size of the calcium sulphate dihydrate crystals. The structural and strength characteristics of the gypsum materials have been also investigated.

Selective ultrasonic assisted synthesis of iron oxide mesoporous structures based on sulfonated melamine formaldehyde and survey of nanorod/sphere, sphere and core/shell on their catalysts properties for the Biginelli reaction.

Sulfonated melamine-formaldehyde including iron oxide nanoparticles were synthesized by sulfonation of melamine-formaldehyde and then Fe3O4 nanoparticles were bounded onto the surface of sulfonated melamine-formaldehyde (SMF). Two different iron oxide nanostructures including nanorods/spheres and nanospheres on sulfonated melamine-formaldehyde (SMF/Fe3O4) were obtained only by modifying the time of radiation from 4 to 8 h in our synthetic method. Furthermore core/shell (Fe3O4@SMF) was prepared by entrapping Fe3O4 magnetic nanoparticles as the core and sulfonated melamine-formaldehyde as the outer shell. The prepared components were characterized via, Fourier transform infrared spectroscopy (FT-IR), titration, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, Barret-Joyner-Halenda (BJH) analysis, vibrating sample magnetometer (VSM), energy-dispersive X-ray (EDX) spectroscopy, and thermal gravimetric analysis (TGA). According to obtained results, the synthesized products had a thermal stability near 180 °C, particle-size distribution around of 20-140 nm and surface area between 6 and 10 m2/g. In this study, vapor was used as a heat source. These effective and magnetically recoverable catalysts were employed for the synthesis of numerous 3,4-dihydropyrimidin-2(1H)-ones by utilizing aldehydes, ethylacetoacetate and urea. Functional easiness, excellent yields, short reaction time, the simplicity of work-up or filter, and thermal stability of these catalysts created them as appropriate heterogeneous systems and acceptable alternative to different heterogeneous catalysts.

Admixtures Used in Self-Compacting Concrete: A Review

Self-compacting concrete or self-consolidated concrete is a highly flowable, non-segregating concrete which spreads into congested reinforcement area and fills the formwork without the use of any vibrators. Self-compacting concrete allows denser reinforcement, optimized concrete section and shapes, and greater degree of freedom. It has the advantages of maintaining the durability and characteristics and meeting expected performance requirements. It has been used ideally in bridges, drilled shaft, and earth-retaining structure, columns and area with high concentration of rebars and pipes. The self-compacting concrete improves constructability, reduces skilled labor and noise level, minimizes the voids in highly reinforced area, gives superior strength and durability and smooth and uniform surface finishing and accelerates the project schedules. In the present study, various mineral admixtures, i.e., ground-granulated blast-furnace slag, limestone powder, silica fume, fly ash and chemical admixtures such as sulfonated melamine formaldehyde condensate, melamine formaldehyde, sulfonated naphthalene formaldehyde condensates and polycarboxylate ether-based superplasticizer, have been studied in the self-compacting concrete. A critical review of the effect of combination of these mineral and chemical admixtures on various rheological, strength and durability properties of the self-compacting concrete is presented in this paper.

Influence of surfactants and experimental variables on the viscosity characteristics of coal water mixtures

To improve the fluidity of a coal water mixture (CWM) having lower viscosity and higher solid concentration, the effects of surfactants (five kinds) and experimental variables such as temperature (5-65 °C), pH (1-11), particle size distribution (PSD) on the viscosity characteristics of two different coals (Shenhua and Kideco Coal) were investigated. Relatively economical surfactants were chosen in this study: sulfonated melamine formaldehyde polymer (SMF-30), naphthalene formaldehyde sulfonate (Sikament-NN), naphthalene sulfonate water reducer (NSWR), naphthalene formaldehyde sulfonate (PC-1000) and poly-carboxylate (PC). The SMF-30, an anionic surfactant, revealed the most significant reduction in viscosity of CWM among the five surfactants since the SMF-30 forms electric double layer on the surface of coal, and the repulsive force of this layer surpasses the aggregation of coal particles. In addition, the viscosity of CWM decreased with increasing pH and temperature, in particular, the increase in OH- on the surface of coals by the addition of NaOH caused the increase in the repulsive force between the negatively charged coal particles. Furthermore, the very fine particles (less than 45 μm) of coals should be removed before making CWMs since it revealed the increase in viscosity of CWMs.

Optimization of superplasticizer in portland pozzolana cement mortar and concrete

Chemical Admixtures are added to concrete at the time of mixing of its constituents to impart workability. The requirement of right workability is the essence of good concrete. It has been found that the use of optimum use of admixtures is very important since low dosage may result in loss of fluidity and over dosage could lead to segregation, bleeding, excessive air entrainment etc in concrete. Hence it is essential to find optimum dosage of superplasticizer for getting good strength and workability. But large number of trial tests are required in the field to find the saturation dosage of superplasticizer in concrete which requires more materials and consume more time. The paper deals with developing a co-relation between the quantity requirements of superplasticiser in mortar to that of cement concrete to get good workability. In this work for preparing mortar and concrete 4 brands of locally available Portland pozzolana cement (PPC) and superplasticizer (SP) belonging to 4 different families namely Polycarboxylate Ether (PCE), Lignosulphate (LS), Sulfonated Naphthalene Formaldehyde (SNF) and Sulfonated Melamine Formaldehyde (SMF) are used. Two different brands of SP’s are taken from each family. Workability study on the superplasticized mortar with cement to sand ratio 1:1.5 and water cement ratio of 0.4 was performed using marsh cone and flow table test and workability study on the concrete with same cement/sand ratio and water cement ratio was done using slump cone and flow table test. Saturation dosage of superplasticizer in mortar and concrete determined experimentally was compared to study the correlation between two. Compressive strength study on concrete cubes were done on concrete mixes with a superplasticizer dosage corresponding to the saturation dosage and a comparative study were done to analyse the improvement in the compressive strength with addition of superplasticizer from different family.

Intercalation of sulfonated melamine formaldehyde polycondensates into a hydrocalumite LDH structure

A series of sulfonated melamine formaldehyde (SMF) polycondensates possessing different anionic charge amounts and molecular weights was synthesized and incorporated into a hydrocalumite type layered double hydroxide structure using the rehydration method. For this purpose, tricalcium aluminate was dispersed in water and hydrated in the presence of these polymers. Defined inorganic–organic hybrid materials were obtained as reaction products. All SMF polymers tested intercalated readily into the hydrocalumite structure, independent of their different molecular weights (chain lengths) and anionic charge amounts. X-ray diffraction revealed typical patterns for weakly ordered, highly polymer loaded LDH materials which was confirmed via elemental analysis and thermogravimetry. IR spectroscopy suggests that the SMF polymers are interleaved between the [Ca2Al(OH)6]+ main sheets via electrostatic interaction, and that no chemical bond between the host matrix and the guest anion is formed. The SMF polymers well ensconced within the LDH structure exhibit significantly slower thermal degradation.

Investigation of Synthesized Sulfonated Melamine Formaldehyde as a Novel Corrosion Inhibitor for Mild Steel in Saline Environment

A water soluble compound named sulfonated melamine formaldehyde (SMF) was synthesized and its corrosion inhibition behavior was studied for carbon steel in 3.5% NaCl solution by polarization measurements and electrochemical impedance spectroscopy (EIS). SMF was characterized with hydrogen nuclear magnetic resonance spectroscopy and then its physical properties and corrosion prevention efficiencies were investigated. The corrosion behavior of SMF was found to be dependent strongly on the electric nature of functional groups which are present in its structure. The decrease in (icorr) and the increase in inhibition efficiency (% IE) with increasing the SMF concentrations proves that it protects C-steel in 3.5% NaCl solution from being corroded and Nyquist diagrams indicate that increasing charge transfer resistance is associated with a decrease in the capacitance and increase in the percentage inhibition efficiency. The decrease in capacitance values could be attributed to the adsorption of the inhibitor molecules at the metal surface by increasing the concentration of inhibitor in the solution the inhibition efficiency increased and the best inhibition was obtained at 1000 ppm inhibitor concentration. The scanning electron microscope was used to investigate the surface morphology of specimens in the absence and presence of inhibitor compound.

Modification of Water Reducer on Desulfurization Gypsum Wall Material

In order to broaden the utilization of desulfurization gypsum in China and achieve the direct usage of desulfurization gypsum, in this paper, Polycarboxylic acid water-reducer (HC), Naphthalene sulfonate formaldehyde polycondensate (NF) and Sulfonated melamine formaldehyde resin (SM) were selected as water reducer to modify desulfurization gypsum. The experiment results are as follows: SM water reducer has little effect on setting time of desulfurization gypsum, although it is helpful to increase the strength of the gypsum-sample, however, compared with HC and NF, it has no obvious effect. About HC water reducer, it has obvious effect on setting time of desulfurization gypsum, so does it to desulfurization gypsum strength, but, higher water using of normal consistency will do adverse effect on the whole with the increase of the dosage. NF water reducer has the similar effect on setting time and sample's strength on desulfurization gypsum with HC, but the dominant changes have no discipline among different mixing amounts with these two water reducer. Lower water using of normal consistency benefits the retention of the sample's strengths.