Preparation of uniform micrometer-sized polymer particles with closed-cell porous architecture made by limited coalescence of a double emulsion

Nair, Mridula; Lusignan, Charles P.; Boris, David C.

doi:10.1016/j.colsurfa.2013.11.037

Cited by 9 publications

(8 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…11,12 Polymerization of HIPEs has previously been utilized for developing toner particles for electrophotographic printing. 13,14 However, this technology has not been applied earlier to development of heat storage materials. In addition, thermal properties of the bulk and microscale polyols are extensively characterized here using differential scanning calorimetry (DSC).…”

Section: Introductionmentioning

confidence: 99%

Novel microstructured polyol–polystyrene composites for seasonal heat storage

et al. 2016

View full text Add to dashboard Cite

We propose a robust route to prepare supercooling microstructured phase change materials (PCMs) suitable for long-term heat storage or thermal protection applications. The new preparation method is based on polymerization of high internal phase emulsion (HIPE). Two promising polyols, erythritol and xylitol, are successfully prepared as new type microencapsulated PCM-polystyrene composites with PCM mass fractions of 62w-% and 67 w-%, respectively, and average void diameter of ~50 µm. Thermal properties of polyol-polystyrene composites and bulk polyols are studied thoroughly with differential scanning calorimetry (DSC). Microscale engineering has a significant impact on the thermal properties of polyols. Crystallization of the microscale erythritol is accelerated as compared to the crystallization of bulk PCM due to high fraction of solid surfaces in the polymer-polyol composites. Furthermore, crystallization properties of the microstructured erythritol are preserved similar in the cycling experiments. Crystallization of the bulk erythritol is found to strongly depend on the cooling rate, thermal history of the sample and surface roughness of the crucible, whereas these factors have only little impact on the crystallization of microstructured erythritol. In addition, microstructured polyolpolystyrene composites show anomalous enhancement in the specific heat as compared to bulk polyols. This enhancement may be originated from the strong polyol-surfactant interactions occurring in the composites.

show abstract

Section: Introductionmentioning

confidence: 99%

Novel microstructured polyol–polystyrene composites for seasonal heat storage

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The nanoparticles were obtained as a suspension in a mixture of ethanol and water, and were approximately 4–20 nm in diameter. Multicompartment microparticles containing the palladium nanoparticles were prepared using a double emulsion technique as reported earlier except that the first emulsion (W 1 /O) was prepared in the presence of a nonionic PCL containing block copolymer emulsifier as follows. An aqueous phase, W 1 , containing Pd nanoparticles dispersed in a solution of sodium carboxymethyl cellulose, was emulsified in an ethyl acetate solution of polycaprolactone with a small amount of methoxy(polyethylene oxide)‐ b ‐polycaprolactone copolymer.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, researchers at Kodak devised a scalable method for producing highly porous uniform polymer microparticles (Figure ) containing closed‐cell pores via water‐in‐oil‐in‐water (W 1 /O/W 2 ) double emulsions in combination with the evaporative limited coalescence (ELC) process. This method provides simultaneous control of micrometer‐ and submicrometer‐sized features of the microparticles, has been scaled to make kilogram quantities in manufacturing, and is amenable to the incorporation of addenda in closed multicompartments . Although this technology was initially developed to provide tailored electrophotographic toner, such multicompartment microparticles can be useful for a variety of applications.…”

Section: Introductionmentioning

confidence: 99%

“…This catalyst carrier scheme presents many advantages: Rapid reactions because the high surface area of the microparticles facilitates diffusion of reactants to and products from the catalysts. Uniform diffusion rates for all particles because of the relatively narrow particle size distribution of the microparticle and their compartments. A primarily aqueous process. Easy recovery and reuse of expensive catalysts. Adaptability to flow reactors. Demonstrated scalability of multicompartment microparticle synthesis from laboratory to manufacturing scale A simple process using conventional equipment and inexpensive materials (other than the catalysts). Many different polymers can be used as binders More than one kind of catalyst, or functional materials other than catalysts, can be encapsulated in different particles, or even in separate compartments within the same particle …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Micron‐sized membrane reactors: Multicompartment semipermeable polymer particles containing palladium nanoparticles

Robello

Mis

Nair

2015

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

Multicompartment polymer microparticles are prepared encapsulating palladium nanoparticles within closed-shell compartments, using a double-emulsion (W 1 /O/W 2 ), evaporative limited coalescence process. The encapsulation efficiency in some cases is as high as 99%, and very little Pd leaches from the particles. The Pd nanoparticles dispersed in an aqueous environment within the closed-shell compartments of the microparticles catalyze hydrogenation reactions of low molar mass substrates in water at substantial rates. The microparticle walls serve as semipermeable membranes, permitting diffusion of small molecules into the compartments while retaining the larger metal nanoparticles. The microparticles can be reused after simple filtration. The catalytic activity increases on recycling, possibly because of plasticization of polymer walls by the reactant and products, resulting in increased diffusion. In a second demonstration of catalytic activity, the microparticles efficiently decompose hydrogen peroxide. These nanoparticle-containing microparticles serve as convenient, reusable catalyst carriers, and prevent inadvertent human and environmental contact with nanoparticles.

show abstract

“…Figure shows the macropore size distributions of the EC microspheres with different EC/EA mass ratios. The mercury was first pumped into the pores among the particles and then increasing pressure facilitated the mercury into the inner space of the particles . Thus, the distribution curve of the spherical microspheres shows typical bimodal distribution.…”

Section: Resultsmentioning

confidence: 99%

A physical route to porous ethyl cellulose microspheres loaded with TiO₂ nanoparticles

Cai

Han

et al. 2014

J of Applied Polymer Sci

View full text Add to dashboard Cite

Porous ethyl cellulose (EC) microspheres were prepared via a physical method in oil‐in‐water (O/W) emulsions. The morphologies and pore structures of the resulting porous microspheres were investigated by scanning electron microscopy (SEM), mercury porosimeter and spectrometer equipped with an integrating sphere. The increase of EC amount in oil phase will increase the size of the microspheres. All the microspheres possess open macropores in the shell and interconnected pores inside the microspheres by means of phase separation. The saturation of the Ethyl acetate (EA) in external phase has an effect on the morphology of the EC particles obtained. Using EA unsaturated aqueous solution as the external water phase in the emulsion process results in the formation of porous EC particles with irregular shape. The loaded TiO2 nanoparticles uniformly disperse in EC matrix, and slightly deceases the size and volume of interconnected pores inside the microspheres. The addition of TiO2 nanoparticles is also proved to increase the light‐scattering power of the porous EC microspheres. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40822.

show abstract

Preparation of uniform micrometer-sized polymer particles with closed-cell porous architecture made by limited coalescence of a double emulsion

Cited by 9 publications

References 31 publications

Novel microstructured polyol–polystyrene composites for seasonal heat storage

Novel microstructured polyol–polystyrene composites for seasonal heat storage

Micron‐sized membrane reactors: Multicompartment semipermeable polymer particles containing palladium nanoparticles

A physical route to porous ethyl cellulose microspheres loaded with TiO₂ nanoparticles

Contact Info

Product

Resources

About

Preparation of uniform micrometer-sized polymer particles with closed-cell porous architecture made by limited coalescence of a double emulsion

Cited by 9 publications

References 31 publications

Novel microstructured polyol–polystyrene composites for seasonal heat storage

Novel microstructured polyol–polystyrene composites for seasonal heat storage

Micron‐sized membrane reactors: Multicompartment semipermeable polymer particles containing palladium nanoparticles

A physical route to porous ethyl cellulose microspheres loaded with TiO2 nanoparticles

Contact Info

Product

Resources

About

A physical route to porous ethyl cellulose microspheres loaded with TiO₂ nanoparticles