Preparation of Millimeter-scale Alumina Hollow Spheres by Oil1-in-water-in-oil2 Emulsions

doi:10.15541/jim20150462

Abstract

Abstract:

To prepare millimeter-scale alumina hollow spheres by oil₁-in-water-in-oil₂ emulsions, the influence factors of formation of precursor and curing process were studied. Composite droplets with paraffin liquid as inner core and alumina sol as outer shell were used as precursor. Results showed that the com-droplets had homogeneous and complete core-shell structure when emulsion generator was designed that inner oil could be injected into water phase with the size of millimeters scale. Thickness and diameter of droplets were adjusted by both controlling the injection speed of oil and water phase in the range of 30-80 μm and 800-2200 μm. In the curing process, the semisolid spheres kept hollow structure and spherical when the speed of rotation between 20 r/min to 60 r/min and the flask being put in horizontal. Finally, the prepared hollow ceramic spheres with wall thickness in micrometer-scale and diameter in millimeter-scale formed complete hollow structure and high sphericity after calcining at 1200 ℃ for 4 h. The surface of sphere was relatively smooth with roughness of about 22 nm. The main crystal of the prepared ceramic hollow spheres was alpha alumina.

Key words: alumina hollow spheres, oil₁-in-water-in-oil₂ emulsion, composite droplets, flow focusing micro-channel

CLC Number:

TQ174

LI Hao-Ting, LIAO Qi-Long, WANG Fu. Preparation of Millimeter-scale Alumina Hollow Spheres by Oil₁-in-water-in-oil₂ Emulsions[J]. Journal of Inorganic Materials, 2016, 31(3): 329-336.

Figures/Tables 9

Fig. 1 Schematic diagram of co-flow micro-emulsion generator

Table 1 Parameters of materials (T=25℃)

Parameters	Alumina sol aged for differeut time/d					Paraffin	Silicone oil
Parameters	1	5	10	15	20	Paraffin	Silicone oil
Density, ρ / (g﹒mL^-1)	1.012	1.024	1.027	1.052	1.073	0.835	0.963
Viscosity, η  (mPa﹒s)	26.56	37.90	48.23	58.44	98.36	35.98	400.00

Fig. 2 Three kinds of composite droplets (model A, model B, model C)

Fig. 3 Diameter and wall thickness of com-droplets at different velocities of water phase (Voil=1 mL·h-1)

Fig. 4 Diameter and wall thickness of com-droplets at different velocities of oil phase (Vwater=6 mL·h-1)

Fig. 5 Schematic of three different rotate types

Fig. 6 Number of intact droplets at different speed after curing (n=10)

Fig. 7 Photographs of com-droplets, semisolid spheres and SEM images of ceramic spheres by model A, B and C

Fig. 8 Characterization of the ceramic sphere(A, B, C): SEM of spheres; (D, E, F): optical images of spheres; (G, H): surface roughness analysis; (I): XRD patterns

References 29

[1]	QI XIAO-BO, GAO CONG, ZHANG ZHAN-WEN, et al. Fabrication and characterization of millimeter-sized glass shells for inertial confinement fusion targets. Chemical Engineering Research and Design, 2013, 91: 2497-2508.
[2]	ZENG YAN, WANG FU, LIAO QI-LONG, et al. Synthesis and characterization of translucent MgO-doped Al2O3 hollow spheres in millimeter-scale. Journal of Alloys and Compounds, 2014, 608: 185-190.
[3]	CHEN JIN-MEI, XU LEI, LI YA-NING, et al. Preparation of nickel-based alloy closed-pore hollow spheres. Rare Metal Materials and Engineering, 2014, 43: 1308-1311.
[4]	LIU RUN-JING, LI YAN-JV, ZHAO HUA, et al. Synthesis and characterization of Al2O3 hollow spheres. Materials Letters, 2008, 62: 2593-2595.
[5]	KANG SHI-ZHAO, YIN DIE-ER, LI XIANG-QING, et al. One-pot template-free preparation of mesoporous TiO2 hollow spheres and their photocatalytic activity. Materials Research Bulletin, 2012, 47: 3065-3069.
[6]	ZHAO WEI-WEI, LIU YANG, LI HU-LIN, et al. Preparation and characterization of hollow Co3O4 spheres. Materials Letters, 2008, 62: 772-774.
[7]	TANG ZHE, LIU YUN-QI, LI GUANG-CI, et al. Ionic liquid assisted hydrothermal fabrication of hierarchically organized γ-AlOOH hollow sphere. Materials Research Bulletin, 2012, 47: 3177-3184.
[8]	WENJEA J TSENG, CHAO PO-SUNG.Synthesis and photocatalysis of TiO2 hollow spheres by a facile template-implantation route.Ceramics International, 2013, 39: 3779-3787.
[9]	LI ZHENG-ZHENG, ZHANG YONG, CHEN ZHI-ZHAN, et al. Synthesis of multi-shelled Mn-doped ZnO hollow spheres. Journal of Inorganic Materials, 2009, 6(24): 1263-1266.
[10]	HUANG YANG-FENG, XIAO HAN-NING, CHEN SHU-GUANG, et al. Preparation and characterization of CuS hollow spheres. Ceramics International, 2013, 35: 905-907.
[11]	WANG CHAO, LE YAO, CHENG BEI.Fabrication of porous ZrO2 hollow sphere and its adsorption performance to Congo red in water.Ceramics International, 2014, 40: 10847-10856.
[12]	YODTHONG BAIMARK, YAOWALAK SRISUWAN.Hollow chitosan microspheres prepared by an oil1-in-water-in-oil2 double emulsion method.Powder Technology, 2013, 249: 436-442.
[13]	WANG HAI-YANG, WANG FU, LIAO QI-LONG, et al. Synthesis of millimeter-scale Al2O3 ceramic hollow spheres by an improved emulsion microencapsulation method. Ceramics International, 2015, 41: 4959-4965.
[14]	LIU HONG-JIANG, NI YONG-HONG, WANG FEI, et al. Fabrication of submicron Cu2O hollow spheres in an O/W/O multiple emulsions. Colloids and Surfaces A: Physicochem. Eng. Aspects, 2004, 235: 79-82.
[15]	GERALD MUSCHIOLIK.Multiple emulsions for food use.Current Opinion in Colloid & Interface Science, 2007, 12: 213-220.
[16]	ISAO KOBAYASHI, MITSYTOSHI NAKAJIMA, SUKEKUNI MUKATAKA.Preparation characteristics of oil-in-water emulsions using differently charged surfactants in straight-through microchannel emulsification.Colloids and Surfaces A: Physicochem. Eng. Aspects, 2003, 229: 33-41.
[17]	LAETITIA OLIVIERI, MONIQUE SEILLER, LEV BROMBERG, et al. Optimization of a thermally reversible W/O/W multiple emulsion for shear-induced drug release. Journal of Controlled Release, 2003, 88: 401-412.
[18]	XU J H, LI S W, WANG Y J, et al. Controllable preparation of monodisperse O/W and W/O emulsions in the same microfluidic device. Langmuir, 2006, 22: 7943-7946.
[19]	MARILYN RAYNER, GUN TRÄGÄRDH, CHRISTIAN TRÄGÄRDH, et al. Using the surface evolver to model droplet formation processes in membrane emulsification. Journal of Colloid and Interface Science, 2004, 279: 175-185.
[20]	MARIJANA M DRAGOSAVAC, RICHARD G HOLDICH, GORAN T VLADISAVLJEVIĆ, ,et al. Stirred cell membrane emulsification for multiple emulsions containing unrefined pumpkin seed oil with uniform droplet size. Journal of Membrane Science. 2012, 392-393: 122-129.
[21]	GALDER CRISTOBAL, JEAN-PHILIPPE BENOIT, MATHIEU JOANICOT, et al. Microfluidic bypass for efficient passive regulation of droplet traffic at a junction. Appllied Physics Letter, 2006, 89: 034104.
[22]	FU TAO-TAO, MA YOU-GUANG, DENIA FUNFSCHILLING, et al. Dynamics of bubble breakup in a microfluidic T-junction divergence. Chemical Engineering Science, 2011, 66: 4184-4195.
[23]	ISAO KOBAYASHI, YOICHI MURAYAMA, TAKASHI KUROIWA, et al. Production of monodisperse water-in-oil emulsions consisting of highly uniform droplets using asymmetric straight-through microchannel arrays. Microfluid Nanofluid, 2009, 7: 107-119.
[24]	KEI NAKAGAWA, SATOSHI IWAMOTO, MITSUTOSHI NAKAJIMA, et al. Microchannel emulsification using gelatin and surfactant-free coacervate microencapsulation. Journal of Colloid and Interface Science, 2004, 278: 198-205.
[25]	CRAMER CARSTEN, FISCHER PETER, WINDHAB ERICH J.Drop formation in a co-flowing ambient fluid.Chemical Engineering Science, 2004, 59: 3045-3058.
[26]	FU TAO-TAO, MA YOU-GUANG, DENIS FUNFSCHILLING, et al. Squeezing-to-dripping transition for bubble formation in a microfluidic T-junction. Chemical Engineering Science, 2010, 65: 3739-3748.
[27]	AMIT GUPTA, HARPEET S MATHAROO, DEVAVRET MAKKAR, et al. Droplet formation via squeezing mechanism in a microfluidic flow-focusing device. Computers & Fluids, 2014, 100: 218-226.
[28]	SCHMIDTS T, DOBLER D, SCHLUPP P, et al. Development of multiple W/O/W emulsions as dermal carrier system for oligonucleotides: Effect of additives on emulsion stability. International Journal of Pharmaceutics, 2010, 398: 107-113.
[29]	WU PING, LUO ZHAO-FENG, LIU ZHI-FENG, et al. Drag-induced breakup mechanism for droplet generation in dripping within flow focusing microfluidics. Chinese Journal of Chemical Engineering, 2015, 23: 7-14.

Preparation of Millimeter-scale Alumina Hollow Spheres by Oil₁-in-water-in-oil₂ Emulsions

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