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Journal ArticleDOI: 10.1039/D0SM01902J

Fabrication of hydrophobic NiFe2O4@poly(DVB–LMA) sponge via a Pickering emulsion template method for oil/water separation

04 Mar 2021-Soft Matter (The Royal Society of Chemistry)-Vol. 17, Iss: 8, pp 2327-2339
Abstract: Super-hydrophobic porous absorbents are convenient, low-cost, efficient and environment-friendly materials in the treatment of oil spills. In this work, a simple Pickering emulsion template method was employed to fabricate an interconnected porous poly(DVB-LMA) sponge. A new co-Pickering stabilization system of Span 80 and NiFe2O4 nanoparticles was used to prepare ultra-concentrated internal phase water-in-oil (W/O) emulsions. After further polymerization, the resulting sponges were generated, which exhibited excellent adsorption selectivity due to the super-hydrophobicity and super-lipophilicity. Furthermore, the characterization results indicated that the composites had superior thermal stability, low density, high porosity and a flexible three-dimensional porous structure. Besides, the addition of nickel ferrite nanoparticles provided the materials with extra magnetic operability. High oil adsorption capacity (up to 36.9-84.2 g g-1), high oil retention, fast adsorption rate and superior reusability allowed the materials to be applied in the treatment of oily water.

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Topics: Pickering emulsion (63%), Adsorption (52%), Thermal stability (50%)
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5 results found


Open accessJournal ArticleDOI: 10.1039/D1SM00441G
07 Jul 2021-Soft Matter
Abstract: A task-specific design of biodegradable and processable porous polymers is one of the primary requisite for their efficient day-to-day use to minimize polymer waste Herein, a surfactant (or additive)-free method is reported for the synthesis of a processable and degradable aliphatic open-pore porous polyelectrolyte monolith for the removal of gaseous pollutants such as iodine and CO2 This is achieved via a colloidal templating method In the 1st stage, cationic colloidal nanoparticles containing reactive amines and acrylamide groups were formed via the phase separation of hyperbranched polyaminoamides in water (sol) These cationic nanoparticles (which acted as both templates and macromers) further reacted to form a gel, which upon freeze-drying leads to the formation of a polymer monolith with an open-pore porous morphology and hierarchical porosity throughout its structure During gelation, the shape of the monolith can be controlled using suitable templates and a similar strategy was used to prepare porous thin films The monolith has shown excellent iodine adsorption ability (5000 mg g−1 in the vapor phase and 2663 mg g−1 in the solution phase) with good reusability and CO2 adsorption ability (60 mg g−1), with CO2/CH4 and CO2/N2 selectivities of 185 and 67, respectively The degradability of the materials was studied in detail at different pH, confirming their easy degradability in aqueous solutions and a higher degradability at basic pH

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Topics: Monolith (57%), Polyelectrolyte (53%), Adsorption (53%) ... read more

1 Citations


Journal ArticleDOI: 10.1039/D1SM00831E
Jintao Lu1, Guohong Gao, Riping Liu1, Chen Cheng1  +3 moreInstitutions (1)
03 Nov 2021-Soft Matter
Abstract: Macroporous materials templated using high internal phase emulsions (HIPEs) are promising for various applications. To date, new strategies to create emulsion-templated porous materials and to tune their properties (especially wetting properties) are still highly required. Here, we report the fabrication of macroporous polymers from oil-in-water HIPEs, bereft of conventional monomers and crosslinking monomers, by simultaneous ring-opening polymerization and interface-catalyzed condensation, without heating or removal of oxygen. The resulting macroporous polymers showed drying condition-dependent wetting properties (e.g., hydrophilicity–oleophilicity from freezing drying, hydrophilicity–oleophobicity from vacuum drying, and amphiphobicity from heat drying), densities (from 0.019 to 0.350 g cc−1), and compressive properties. Hydrophilic–oleophilic and amphiphobic porous polymers turned hydrophilic–oleophobic simply by heating and protonation, respectively. The hydrophilic–oleophobic porous polymers could remove a small amount of water from oil–water mixtures (including surfactant-stabilized water-in-oil emulsions) by selective absorption and could remove water-soluble dyes from oil–water mixtures. Moreover, the transition in wetting properties enabled the removal of water and dyes in a controlled manner. The feature that combines simply preparation, tunable wetting properties and densities, robust compression, high absorption capacity (rate) and controllable absorption makes the porous polymers to be excellent candidates for the removal of water and water-soluble dyes from oil–water mixtures.

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Topics: Polymer (54%), Wetting (54%), Porous medium (51%)



Journal ArticleDOI: 10.1039/D1SM01061A
27 Oct 2021-Soft Matter
Abstract: Hydrophobic/oleophilic sponges are excellent absorbent materials for oil contaminant removal. However, the application is limited in dealing with surfactant stabilized O/W emulsions. The water in the emulsion isolates the contact between the sponge and oil droplets. Consequently, the oil absorption efficiency is not ideal. Herein, to improve the oil absorption efficiency from anionic surfactant stabilized O/W emulsions, water responsive hybrid sponges were reported. To prepare such sponges, water soluble poly(N,N-dimethylaminoethylmethacrylate) (PDMAEMA) was introduced into polydimethylsiloxane (PDMS) sponges using table salt as a template and multi-walled carbon nanotubes (MWCNTs) as mechanical reinforcement in a one-pot method. Upon contact with an O/W emulsion, the water soluble PDMAEMA chain rose to the surface of the sponge, turning the hydrophobic surface into hydrophilic. Next, the tertiary amine groups in PDMAEMA ionized in water and carried positive charges which would cause the coagulation of oil droplets. Finally, the coagulated oil droplets were absorbed immediately by the oleophilic inner part of the sponge through the wicking effect. As a result, a Janus interface was generated in situ and sustained. Such material design synergistically contributed to a satisfactory hexadecane (HD) absorption efficiency of 178 ± 4% in 25 min. In contrast, the PDMS-MWCNT1.0% sponge could only absorb 9.8 ± 0.2% HD. Moreover, these sponges also presented robust mechanical performance and reusability, offering a new route for oil/water separation and oil pollution remediation in open water.

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Topics: Emulsion (53%), Tertiary amine (53%), Pulmonary surfactant (50%)
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64 results found


Journal ArticleDOI: 10.1007/BF00655236
Abstract: The formation of the interconnected morphology of open-cell styrene/divinylbenzene (DVB) PolyHIPE copolymers has been studied by scanning electron microscopy on frozen HIPE samples at different stages of polymerisation, a technique known as cryo-SEM. The transition from discrete emulsion droplets to interconnected cells was observed to occur around the gelpoint of the polymerising system. This would suggest that the formation of holes between adjacent cells is due to the contraction of the thin monomeric films on conversion of monomer to polymer, as a result of the higher density of the latter.

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Topics: Divinylbenzene (59%), Copolymer (53%), Styrene (52%)

214 Citations


Open accessJournal ArticleDOI: 10.1039/C5EM00070J
Abstract: Crude oil and petroleum products are widespread water and soil pollutants resulting from marine and terrestrial spillages. International statistics of oil spill sizes for all incidents indicate that the majority of oil spills are small (less than 7 tonnes). The major accidents that happen in the oil industry contribute only a small fraction of the total oil which enters the environment. However, the nature of accidental releases is that they highly pollute small areas and have the potential to devastate the biota locally. There are several routes by which oil can get back to humans from accidental spills, e.g. through accumulation in fish and shellfish, through consumption of contaminated groundwater. Although advances have been made in the prevention of accidents, this does not apply in all countries, and by the random nature of oil spill events, total prevention is not feasible. Therefore, considerable world-wide effort has gone into strategies for minimising accidental spills and the design of new remedial technologies. This paper summarizes new knowledge as well as research and technology gaps essential for developing appropriate decision-making tools in actual spill scenarios. Since oil exploration is being driven into deeper waters and more remote, fragile environments, the risk of future accidents becomes much higher. The innovative safety and accident prevention approaches summarized in this paper are currently important for a range of stakeholders, including the oil industry, the scientific community and the public. Ultimately an integrated approach to prevention and remediation that accelerates an early warning protocol in the event of a spill would get the most appropriate technology selected and implemented as early as possible – the first few hours after a spill are crucial to the outcome of the remedial effort. A particular focus is made on bioremediation as environmentally harmless, cost-effective and relatively inexpensive technology. Greater penetration into the remedial technologies market depends on the harmonization of environment legislation and the application of modern laboratory techniques, e.g. ecogenomics, to improve the predictability of bioremediation.

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Topics: Petroleum industry (57%), Petroleum (56%)

193 Citations


Journal ArticleDOI: 10.1016/J.POLYMER.2005.05.022
08 Aug 2005-Polymer
Abstract: Typical polyHIPE (porous polymers from high internal phase emulsions) have a cellular structure with volume fractions from 0.2 to 0.04, cell diameters from 15 to 25 μm and intercellular pore diameters from 0.5 to 10 μm. Unique interpenetrating polymer networks synthesized within the polyHIPE exhibited enhanced mechanical properties and an extended temperature range for damping. Hybrid polyHIPE that combine an inorganic polysilsesquioxane network with an organic polystyrene network exhibited superior high temperature mechanical properties and enhanced thermal stability. A nanoscale porosity in the cell walls, produced through the addition of a porogen to the HIPE, reduced the density and significantly enhanced the specific surface area. Porous silica monoliths with silica volume fractions of as low as 0.02 were produced through the pyrolysis of hybrid polyHIPE. PolyHIPE coated with an intrinsically conducting polymer exhibited reversible and repeatable changes in conductivity on exposure to acetone vapor, demonstrating their potential as sensor materials.

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139 Citations


Journal ArticleDOI: 10.1016/J.CEJ.2016.08.085
Tao Zhang1, Liying Kong1, Dai Yuting1, Xuejie Yue1  +3 moreInstitutions (1)
Abstract: The severe environmental and ecological problems, derived from oil spills and organic solvents leakage, have occurred in many parts of the world. It is urgent to seek appropriate ways to resolve oily wastewater and organic solvent pollution. A versatile oil-absorbing material which can separate the oily wastewater effectively and quickly is in high demanded for this issue. In this work, we report a facile and inexpensive to fabricate an effective and recyclable oil-absorbent, namely MnO2 nanowires/polyurethane (PU) foam composites, using a PU sponge as a porous substrate and MnO2 nanowires as modifiers. The hydrothermal method is employed to synthesize MnO2 nanowires and then foaming technology is used to fabricate MnO2 nanowires/PU foam composites. In order to enhance the hydrophobic and oleophilic properties, the surfaces of MnO2 nanowires are chemically modified using silane coupling agent (KH 570). The present MnO2 nanowires/PU foam composites not only effectively separate oils from water as expected, but also possess a very high absorption capacity for the removal of organic solvents from water up to 40.15 times its own weight. More importantly, the obtained MnO2 nanowires/PU foam composites is demonstrated to have excellent oil recoverability and absorbent regenerability, making them versatile and comprehensive absorbents to satisfy various practical oily wastewater and organic solvent separation requirements.

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138 Citations


Journal ArticleDOI: 10.1002/MASY.200651004
Angelika Menner1, Alexander Bismarck1Institutions (1)
Abstract: We present new evidence that the formation of pore throats (windows) or pore interconnects in polymerised High Internal Phase Emulsions (polyHIPEs) is most likely due to a mechanical action exerted during the post-synthesis processing of the porous polymer monolith. We would like to invite researchers interested in this field to reopen the discussion on the mechanism which lead to the formation of pore throats during the polymerisation of concentrated emulsion templates.

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127 Citations