Preparation of graphene-based aerogels by Pickering emulsion method and their performance

Graphene oxide microcapsules (GOMs) have been prepared through Pickering emulsion method by varying the disperse speed to study its effect on the GOM’s size. The GOMs were characterized through phase separation observation, polarized optical microscope (POM), and particle size analyser (PSA). Phase separation observation showed more viscous and cloudy emulsion was produced when the disperse speed was increased. After 24 hours, only 800 rpm emulsion did not show any phase separation. POM characterization depicted that increasing the emulsification energy led to the finer emulsion with the 1200 rpm sample showing the smallest microcapsule size of around 8 ?m. However, PSA analysis suggested that although the disperse speed controls the GOMs size, the amount of GO in the emulsion plays an important role for the microcapsule to maintain its stability. Emulsion produced at 800 rpm possesses satisfactory stability with GOMs diameter of 11.15 ?m. The result also suggested that graphene oxide encapsulated linseed oil may act as a promising candidate for healing microcapsules in a self-healing coating system. ABSTRAK: Mikrokapsul graphene oksida (GOMs) telah dihasilkan melalui kaedah emulsifikasi Pickering dengan memvariasikan tenaga pengemulsi untuk mengkaji kesannya terhadap saiz GOMs. GOMs dicirikan melalui pemerhatian pemisahan fasa, mikroskop optik polarisasi (POM) dan penganalisis saiz zarah (PSA). Pemerhatian pemisahan fasa menunjukkan emulsi yang lebih likat dan keruh dihasilkan apabila kelajuan pengemulsi meningkat. Selepas 24 jam, hanya emulsi 800 rpm tidak menunjukkan pemisahan fasa. Pencirian POM meunjukkan bahawa peningkatan tenaga pengemulsi menghasilkan emulsi yang lebih halus dengan sampel 1200 rpm menunjukkan saiz mikrokapsul terkecil, sekitar 8 ?m. Walau bagaimanapun, analisis PSA mencadangkan bahawa walaupun kelajuan pengemulsi mengawal saiz GOMs, jumlah GO dalam emulsi memainkan peranan penting untuk mengekalkan kestabilan mikrokapsul. Emulsi yang dihasilkan pada 800 rpm mempunyai kestabilan yang memuaskan dengan purata saiz GOMs sekitar 11.15 ?m. Berdasarkan dapatan kajian, graphene oksida yang terkandung minyak biji rami boleh menjadi salah satu mikrokapsul penyembuh dalam sistem cat auto-sembuh.

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Antioxidant and antimicrobial properties of carbohydrate-based films enriched with cinnamon essential oil by Pickering emulsion method

Food Packaging and Shelf Life ◽

10.1016/j.fpsl.2018.12.007 ◽

2019 ◽

Vol 19 ◽

pp. 147-154 ◽

Cited By ~ 20

Author(s):

Hadi Fasihi ◽

Nooshin Noshirvani ◽

Mahdi Hashemi ◽

Mohammad Fazilati ◽

Hossein Salavati ◽

...

Keyword(s):

Essential Oil ◽

Antimicrobial Properties ◽

Pickering Emulsion ◽

Emulsion Method ◽

Cinnamon Essential Oil

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DEVELOPMENT OF MICROSPHERES COVERED WITH HYDROXYAPATITE NANOCRYSTALS AS CELL SCAFFOLD FOR ANGIOGENESIS

Functional Materials Letters ◽

10.1142/s1793604712600107 ◽

2012 ◽

Vol 05 (02) ◽

pp. 1260010 ◽

Cited By ~ 5

Author(s):

TAKASHI IWAMOTO ◽

TAKAHIRO TERADA ◽

YASUMICHI KOGAI ◽

MASAHIRO OKADA ◽

SYUJI FUJII ◽

...

Keyword(s):

Surface Coverage ◽

Pickering Emulsion ◽

Emulsion Method ◽

Cell Scaffolds ◽

Cell Scaffold ◽

Shear Speed ◽

Hydroxyapatite Nanocrystals ◽

Coating Ratio ◽

Scanning Electron ◽

Enhance Cell Adhesion

We prepared poly(L-lactide-co-glycolide) cell scaffolds coated with hydroxyapatite (HAp) nanocrystals with 50–100 nm in diameter via the Pickering emulsion method. Our cell scaffolds were composed of biodegradable polymers and HAp nanocrystals as a core and shell, respectively. The scaffolds were spherical but displayed uneven shapes when altering a shear speed of homogenization during syntheses. The surface coverage of HAp nanocrystals was examined because the HAp-coating ratio for the scaffolds was an important factor as cell scaffolds in order to enhance cell adhesion. On the basis of scanning electron microscopy observations and thermogravimetric analyses, it was found that the cell scaffolds showed distorted morphologies, and the HAp-coating ratio decreased with increasing the shear speed in the synthesis because shear stress influenced shapes of the scaffolds.

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Preparation of Graphene–Polypyrrole Hollow Sphere by Pickering Emulsion Method and Their Electrochemical Performances as Supercapacitor Electrode

NANO ◽

10.1142/s1793292019500565 ◽

2019 ◽

Vol 14 (05) ◽

pp. 1950056

Author(s):

Sai Wu ◽

Jie Tian ◽

Xianglu Yin ◽

Wei Wu

Keyword(s):

Graphene Oxide ◽

Hollow Sphere ◽

Pickering Emulsion ◽

Electrochemical Performances ◽

Test Results ◽

Supercapacitor Electrode ◽

Emulsion Method ◽

Pickering Emulsion Polymerization ◽

First Time ◽

A Current

Graphene–polypyrrole hollow sphere composite was synthesized for the first time via Pickering emulsion polymerization using graphene oxide as Pickering stabilizer. It was found that polypyrrole and graphene were well hybrid and all graphene–polypyrrole composites had a uniform hollow sphere structure, whose diameters gradually decreased as the pyrrole content decreased. The electrochemical properties of the composites as supercapacitor electrode were investigated. The test results displayed that the specific capacitance of the optimal ratio of composite could reach 238[Formula: see text]F/g at a current density of 1[Formula: see text]A/g, and a 90.7% capacitance retention could be achieved after 1500 cycles, which was a significant improvement compared with the 62.2% retention of pure polypyrrole.

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Ultraviolet protection of Bacillus thuringiensis through microencapsulation with Pickering emulsion method

Scientific Reports ◽

10.1038/s41598-020-77721-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Elham Jalali ◽

Shahab Maghsoudi ◽

Ebrahim Noroozian

Keyword(s):

Bacillus Thuringiensis ◽

Olive Oil ◽

Uv Radiation ◽

Protective Efficacy ◽

Pickering Emulsion ◽

Spore Viability ◽

Latex Particles ◽

Emulsion Method ◽

Emulsion Technique ◽

Ultraviolet Protection

AbstractAn encapsulated formulation of Bacillus thuringiensis (Bt) was produced by the Pickering emulsion technique to improve its activity and stability under UV-A radiation. In this technique latex particles, GO nanosheets, olive oil, ethanol, and water were used to encapsulate Bt in colloidosomes. The protective efficacy of this formulation in protecting Bt subsp. Kurstaki against deactivation by UV-A irradiation was measured, so that spore viability and mortality on Ephestia kuehniella (E. kuehniella) Zeller larvae under UV-A radiation are investigated. According to the results of both tests, encapsulated formulation at a concentration of 0.045% has the highest protection of viability. Hence, colloidosome microcapsule formulations successfully provide good protection against UV radiation.

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