Melamine Sponge Research Articles

Preparation and mechanism of hydrophobic modified diatomite coatings for oil-water separation

It remains a significant challenge to separate oil and water in the metallurgical industry. Therefore, there is an urgent need for a low-cost process to prepare hydrophobic and lipophilic materials in order to improve oil-water separation performance. The hydroxyl group on the surface of diatomite was modified by a polysiloxane reaction. The microstructure, chemical composition, and hydrophobicity before and after modification were studied by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Diatomite@POS/EP coating was prepared using the spraying suspension method, to endow various materials with excellent hydrophobic properties (ceramic, sponge, stainless steel, paper, and gauze). The SEM results show that many spherical particles were stacked on the modified diatomite disk, and new elements and structures were observed. The Diatomite@POS floated on the water indicates that the modification was successful. The contact angle between coating on porous diatomite ceramics and water could reach 147.5° when the mass ratio of Diatomite@POS: EP was 7:5. After 0–1000 cm wear test, and soaked in acid and alkali solution for 4 h, the coating could keep hydrophobicity, indicating that it features excellent wear resistance, acid, and alkali resistance. Ceramic sprayed with Diatomite@POS/EP and melamine sponges soaked in Diatomite@POS/EP were capable of effectively separating vacuum pump oil from water, which showed the promising self-cleaning performance of the ceramic surface. Besides, modified diatomite powder had great potential for application in waterproofing, self-cleaning, oil-water separation, and other fields.

Multifunctional and durable graphene-based composite sponge doped with antimonene nanosheets

The development of flexible multifunctional composites is an important topic in the fields of materials engineering, electronics, aerospace and biomedicine. However, there are still major challenges to achieve a variety of functions to meet the requirement for the application. Herein, a flexible multifunctional porous composite is successfully prepared by fabricating both modified graphene and antimonene into a melamine sponge. Compared with the graphene composite sponge, the addition of antimonene improved its electrochemical and sensing performances. The specific capacitance of antimonene/graphene composite sponge was significantly increased, while the capacitance retention rate was 83% under 20,000 charge–discharge cycles. The pressure sensitivity of the prepared flexible multifunctional device assembled was 44% higher than that of the graphene composite sponge. A power supply-integrated sensing system was assembled for monitoring human motion signals. The experimental results show that this system is a promising monitoring device with broad potentials in the fields of biosensing.

Melamine sponge-based copper-organic framework (Cu-CPP) as a multi-functional filter for air purifiers.

COVID-19 has drawn great attention on the necessity for establishing pathogen-free indoor air. This paper offers an insight into the potential application of a multi-purpose filter to remove fine particulates and disinfect pathogens using melamine sponge with a copper-organic framework. In-situ growth dip coating method was applied to coat Cu-based coordination polymer particle (Cu-CPP) on melamine sponge (MS). The integration of Cu-CPPs with high crystallinity and highly active surface area (1,318.1 m2/g) enabled Cu-CPP/MS to have an excellent capture rate (99.66%) and an instant disinfection rate of 99.54% for Escherichia coli. Electrostatic attraction seemed to play a crucial role in capturing negative-charged pathogens effectively by positive charges on Cu-CPP arising from unbalanced copper ions in Cu-CPP. Disinfection of pathogens was mainly attributed to catalytically active Cu2+ sites. Organic ligand played an important role in bridging and maintaining Cu2+ ions within the framework. This study highlights the design of a new capture-and-disinfection (CDS) air filter system for pathogens using Cu-CPP/MS. It can be applied as a substitute for conventional high-efficiency particulate air (HEPA) filters.Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s11814-021-1000-4 and is accessible for authorized users.

Peroxymonosulfate activation by sponge-based FeS material for efficient degradation of tetracycline: The critical role of sponge

The effective control of antibiotic pollution in water has become an important issue in the field of environmental protection. In this study, the composite of iron sulfide and melamine sponge (FeS@MS) was successfully synthesized by in-situ synthesis method and applied to the oxidative removal of tetracycline (TC) in the presence of peroxymonosulfate (PMS). Under optimal conditions ([FeS@MS] = 0.1 g/L and [PMS] = 0.2 mM), 95.7% of TC was degraded in 5 min. The presence of NO3−, SO42−, and Cl− slightly inhibited TC removal, whereas HPO4− had a certain promotion effect in activating PMS to degrade TC. The primary reactive oxygen species (ROS), including SO4−, OH, 1O2, and O2− were identified through electron paramagnetic resonance (EPR) spectroscopy and radical quenching experiments. In addition, Fe3+ in solution could react with FeS to produce Fe2+, which continuously activates PMS to generate radicals for TC degradation. The presence of MS reduced the agglomeration of FeS and played a protective role in the slow release of Fe2+. The degradation performance was further validated in real water matrices. This study provided new insight into fabricating functional material for the remediation of antibiotic wastewater.

Facile one-step fabrication of superhydrophobic melamine sponges by poly(phenol-amine) modification method for effective oil–water separation

Although polydopamine (PDA)-related modification is widely studied in the fabrication of superhydrophobic sponges, the high cost of dopamine limits its widespread application. To imitate PDA modification, a low-cost and facile one-step poly(phenol-amine) modification was performed on melamine sponges in this study. Low-cost catechol and diethylenetriamine (DETA) were used as the monomers, and n-dodecanethiol was used as an additive in the one-step modification. The results confirmed that the poly(phenol-amine) aggregations were successfully anchored on the sponge skeleton surface and that the aggregations were formed via the Schiff base reaction and the Michael addition reaction. Furthermore, the as-prepared sponges still showed excellent mechanical properties after modification. Additionally, the optimally modified sponge (MS-0.5) exhibited superhydrophobic properties with a contact angle value above 150° under various environments, high oil-absorption capacity for various oils and organic solvents, high continuous oil–water separation performance with efficiency greater than 98.8% in 30 cycles, outstanding demulsification performance with 99.52% toward oil-in-water emulsion, and excellent recoverability and long-term stability. Thus, this work provides a feasible facile one-step modification method that can be used in place of PDA-related modification.

Superhydrophobic/superlipophilic interface layer for oil-water separation

Low-cost, stable materials that can be used for oil-water separation have significant industrial applications. A simple two-step immersion approach was used to successfully create a melamine sponge with superhydrophobic/superlipophilic characteristics. The polyphenolamine@ 1 H,1 H,2 H,2 H-perfluorodecyltrichlorosilane sponge (PPA@PF sponge) produced in this study possesses exceptional superhydrophobic and superlipophilic properties. Scanning electron microscopy (SEM), infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS) were used to examine the surface morphology and chemical content of the PPA@PF sponge. The prepared PPA@PF sponge has a static contact angle (SCA) of 156°. More notably, PPA@PF sponge has extremely stable and anti-corrosion properties. After being corroded by acidic solutions, alkaline solutions, and organic solvents, the PPA@PF sponge retains good hydrophobic characteristics on its surface. Finally, the PPA@PF sponge is successfully applied to the rapid oil-water separation.

Superhydrophobic nanohybrid sponges for separation of oil/ water mixtures

The industrial revolution has led to different types of environmental pollution, including frequent leakage of crude oil to marine waters and the contamination of wastewater with immiscible or emulsified oils and organic liquids from various industrial residues. Hence, developing multifunctional materials for oil/water separation is a field of high significance for the remediation of oil-polluted water. Recently, advanced superwetting materials have been employed for oily wastewater treatment. This review summarizes the recent development in fabricating superhydrophobic/superoleophilic nanohybrid polyurethane, melamine, and cellulose sponges for oil/water separation. The use of organic and/or inorganic nanohybrid materials opens the horizon for designing a diverse and wide range of superhydrophobic sponges due to the synergistic effect between the surface roughness and chemical composition. The discussion is organized based on different classes of low surface energy materials including thermoplastics, thermosets, elastomers, fluorinated polymers, conductive polymers, organosilanes, long alkyl chain compounds, and hydrophobic carbon-based materials. Recent examples for the separation of both immiscible and emulsified oil/water mixtures are presented, with a focus on fabrication strategies, separation efficiency, recyclability, mechanical performance, and durability. Currently, most studies did not focus on the mechanical/chemical stability of the fabricated sponges, and hence, future research directions shall address the fabrication of robust and long-term durable superhydrophobic sponges with proper guidelines. Similarly, more research focus is required to design superhydrophobic sponges for the separation of emulsified oil/water mixtures and heavy crude oil samples. Superhydrophobic sponges can be employed for treatment of oily wastewater, emulsion separation, and cleanup of crude oil spills.

Batch sorption and fixed-bed elution for Pd recovery using stable amine-functionalized melamine sponge

Sorption-based techniques have been widely studied for metal recovery. Conventionally, sorption and desorption steps are operated in fixed-bed column system under one-pass mode (FO); however, such sorption requires a large volume of solution passing the bed when the feed concentration is low. In this study, highly stable amine-coated alginate melamine (ML/APG) sponge was prepared and applied in a combined process involving sorption under fixed-bed recirculation mode (FR, simulating batch system) and desorption under FO for Pd(II) concentration. The efficiency was evaluated in terms of both recovery of Pd(II) and utilization of the sponge. Results show that ML/APG sponge is stable in 3 M of nitric acid, sodium hydroxide and sodium chloride after shaking at 300 rpm for 72 h with mass loss less than 0.9%. The maximum sorption capacity obtained by Langmuir model for Pd(II) increases from 9.7 mg g−1 to 134.3 mg g−1 after amine functionalization. The sorption equilibrium could be achieved by a less amount of solution and less time when using FR compared to FO. For example, it only needs 0.7 L of Pd(II) solution with a metal concentration of 20 mg L−1 to achieve the maximum sorption capacity under FR, while the required volume is 1.8 L at flow rate of 1 mL min−1 and more than 5 L at 10 mL min−1 under FO. This means that FR improved the rational use of the sorbent and thus increased sorption efficiency. For elution step, FO only required 40 mL to completely desorb Pd(II) from exhausted sponge, while that needed more than 200 mL under FR. The combined process allows both effective sorption and elution. The reusability of ML/APG sponge and Pd(II) recovery from low-concentration solution were studied by combining FR for sorption step and FO for elution step. Results show that the sorption efficiency maintains more than 96% after 100 min of reaction during 10 cycles. The elution performance is stable with a 100% desorption efficiency by passing 50 mL of acidic thiourea solution. The concentration factor (CF, ratio of metal concentration in the eluate over its concentration in the sorption used for sorption), is above or close to 70 for the first 10 mL-sample and much more than 40 for the second 10 mL-sample.

Enhanced thermal conductivity with ultralow filler loading via constructing branch-type heat transfer network

The rapid growth of modern electronic has put forward higher requirements for the design of thermal management materials. The construction of composites with low filler loading and high thermal conductivity has always been a bottleneck in the research field. Herein, the carbonized melamine sponge (MSC) with in-situ growth carbon nanotubes (CNTs) in MSC@CNTs/EP was prepared to achieve the κ⊥ and κ∥ of 0.51 W/(m K) and 0.48 W/(m K) at ultralow filler loading, respectively. This result showed that the expanded network structure of CNTs converted from ZIF-67 on the MSC maximized isotropic heat transfer efficiency through branch-type thermal conductive pathways. The lightweight structure endowed the skeleton with elasticity and ensured the excellent mechanical properties of the composite. The outstanding performance of the as-obtained composites demonstrates a promising prospect of tackling contemporary electronic devices thermal management issues.

Adsorption of organic dyes on macroporous melamine sponge incorporating conducting polypyrrole nanotubes

AbstractThe macropores of melamine sponge were coated with globular polypyrrole or polypyrrole nanotubes. The resulting materials have been tested for the adsorptive removal of organic dyes from aqueous medium. The nanotubes deposited on the sponge were able to remove Reactive Black 5 dye while the adsorption on analogous polypyrrole globules was marginal. For that reason, the macroporous open‐cell melamine sponge with embedded nanotubes was tested for the adsorption of five anionic and five cationic dyes. The anionic dyes were adsorbed efficiently in the contrast to cationic ones. This can be explained by the electrostatic interaction of anionic dyes with polypyrrole polycation. The fast‐starting adsorption occurred within a few minutes and was followed by a slower process extending for days. The nanotubes deposited on the sponge have always been more efficient adsorbents than free polypyrrole nanotubes or melamine sponge alone. Better organization of polymer chains in the polypyrrole nanotubes and especially those deposited on the melamine sponge is proposed to be responsible for this effect. Cationic dyes were adsorbed even by neat melamine sponge while the adsorption by polypyrrole was negligible. In this case, the indifferent role of polypyrrole can be assigned to the electrostatic repulsion of the dye.

Preparation of Janus melamine sponge suitable for solar evaporation

Preparation of Janus melamine sponge suitable for solar evaporation

Adjusting Ion Diffusion Kinetics of Li Deposition in Porous Melamine Sponge Coated with Silver for Stable Lithium Metal Anode

Adjusting Ion Diffusion Kinetics of Li Deposition in Porous Melamine Sponge Coated with Silver for Stable Lithium Metal Anode

Melamine Sponge Functionalized with Carbon Nanodots: A New Sorbent for the Extraction of PAHs and Musks from Complex Environmental Samples Prior to Their Determination by GC-MS

Melamine Sponge Functionalized with Carbon Nanodots: A New Sorbent for the Extraction of PAHs and Musks from Complex Environmental Samples Prior to Their Determination by GC-MS

Superhydrophobic Nanodiamond-Functionalized Melamine Sponge for Oil/Water Separation

Superhydrophobic Nanodiamond-Functionalized Melamine Sponge for Oil/Water Separation

Reduced graphene oxide modified melamine sponges filling with paraffin for efficient solar-thermal conversion and heat management

A novel type of reduced graphene oxide (rGO) modified melamine sponges (rGS) filling with paraffin (rGS-pf) is developed for efficient solar-thermal conversion and heat management. The microstructures, filling and holding capacity of paraffin in porous rGS, solar-thermal energy conversion and energy harvesting efficiency of the prepared rGS-pf have been investigated systematically. The content of rGO nanosheets coated on the skeletons of rGS-pf is only 0.11%, while the loading content of paraffin in the rGS-pf is as high as 97.53%. Based on the solar-thermal conversion property of rGO nanosheets in the rGS-pf and the heat storage ability of paraffin in the rGS-pf, the proposed rGS-pf provides excellent performance for heat management. The efficiency of solar-thermal conversion could reach up to 92.5%. The thermo-regulation provided by the proposed rGS-pf is real-time, repeatable and long-term stable. The results in this study provide valuable guidance for developing functional materials for efficient solar-thermal conversion and heat management.

A capture and inactivation system against pathogens in indoor air using copper nanoparticle decorated melamine sponge hybrid air filters

Development of a multifunctional and reusable air filter as a capture-and-disinfection system to kill pathogens in a single-pass air flow.

Melamine Sponge Templated Synthesis of Nickel Nanoparticles Encapsulated in B, N Co-Doped Carbon Nanotubes Towards Selective Electrosynthesis of Hydrogen Peroxide

Melamine Sponge Templated Synthesis of Nickel Nanoparticles Encapsulated in B, N Co-Doped Carbon Nanotubes Towards Selective Electrosynthesis of Hydrogen Peroxide

Melamine/Silicone Hybrid Sponges with Controllable Microstructure and Wettability for Efficient Solar-Driven Interfacial Desalination.

Solar-driven interfacial evaporation (SIE) has received extensive attention as a very promising desalination technique to solve the fresh water shortage crisis. However, evaporation rate decline and salt-fouling during long-term SIE seriously hinder applications of solar evaporators. Here, we report the preparation of melamine/silicone (MS) hybrid sponges with controllable microstructure and wettability for efficient SIE by further combination with carbon nanotubes (CNTs). The MS sponges are synthesized by hydrolytic condensation and phase separation of two silanes in the melamine sponge. The microstructure and wettability of the MS sponges are highly controllable by the silanes concentration. The CNTs@MS solar evaporators have a unique three-tier hierarchical macro-/micro-/nanostructure, very low thermal conductivity as well as a superhydrophilic hull and a superhydrophobic nucleus. Consequently, the CNTs@MS solar evaporators show a highly stable evaporation rate of ∼1.75 kg m-2 h-1 without any salt precipitation during a long-term cyclic solar desalination of 3.5 wt % NaCl solution under 1 sun illumination. Furthermore, salt precipitation is completely hindered even during SIE of 20 wt % NaCl solution under 1 sun. The CNTs@MS solar evaporators are very promising for practical SIE because of their excellent performance and simple preparation method.

Superhydrophobic MS@CuO@SA sponge for oil/water separation with excellent durability and reusability

We present a superhydrophobic material based on commercially melamine sponge (MS) with great durability, recyclability, and excellent sorption performance. The fabrication process of this sponge is facile without using toxic reagents or sophisticated equipment and therefore it is simple to scale up. The CuO layer utilized to give a rough surface of the substrate (MS) was successfully prepared in a commercial microwave to seed copper nucleuses in an alkaline medium. Stearic acid (SA) plays a role as the self-assembled monolayer on the surface of the sponge skeletons. Throughout this study, the properties of the modified sponge were fully characterized, and the changes in wettability were carefully examined. Water contact angle (WCA) measurements revealed the excellent superhydrophobicity of the material with high static WCA of 165.1° and low dynamic WCA of 8°. Furthermore, the as-prepared sponge demonstrated high efficiency in separation (over 99.0%) of different oils from water. Notably, several unique properties of as-modified material were found, consisting of ultrafast sorption capacities of up to 32–52 times of its own weight by using 80 mL of each oil, outstanding reusability with good sorption capacity even after 40 cycles. Even under various harsh environments, the novel materials proved its outstanding durability and ultrafast sorption capacity of oils. The durability, recyclability, and superhydrophobic properties of the novel superhydrophobic sponge provide it a solid basis for oil-water separation applications through an ultrafast sorption capacity of oils as well as quick recovery of the oil by easy squeezing process.

Extraction of parabens by melamine sponge with determination by high‐performance liquid chromatography

In the present study, we propose a novel method for the extraction of parabens in personal care products. A new, simple adsorptive material was obtained by combining metal-organic frameworks and melamine sponges using the adhesive property of polyvinylidene fluoride. This new material, metal-organic frameworks/melamine sponges, was found to be particularly suitable for solid-phase extraction. The structural characteristics of metal-organic frameworks/melamine sponges were first analyzed by scanning electron microscopy. Subsequently, solid-phase extraction was performed on sample solutions, and the extracted substances were then analyzed by high-performance liquid chromatography. Following optimization of important experimental conditions, excellent recovery rates were obtained. Our novel method was then applied to the extraction of four parabens (methylparahydroxybenzoates, ethylparahydroxybenzoates, propylparahydroxybenzoates, and butylparahydroxybenzoates) from real samples. The results yielded limits of detection of 0.26-0.41ng/mL. The inter- and intra-day recoveries were 104.0-109.7% and 91.2-98.1%, respectively (relative standard deviation,<13.8%).