© The Institution of Engineering and Technology
A facile and flexible technique is described for the fabrication of silica/titania microcapsules from stable miniemulsion droplets. Bis (2,4-pentanedionato)-bis (2-propanolato) titanium (IV) (PDPT), tetraethoxysilane (TEOS) and γ–(trimethoxysilyl) propyl methacrylate and/are restricted in miniemulsion microreactor droplets via a miniemulsification process, are stabilised by cetyltrimethylammonium bromide and hexadecane. After the addition of triethylamine, silica/titania shells are formed in situ by the hydrolysis–condensation at the interfaces of miniemulsion droplets because of the dramatical decrease of the original TEOS and PDPT volume. The mesoporous silica/titania microcapsules are about 1 μm with average pore size of 5.2 nm and the Brunauer–Emmett–Teller surface area is 312.0 cm2/g. The biocompatible and mesoporous nature of microcapsules promises an ideal vehicle for catalyst and drug delivery.
References
-
-
1)
-
9. Cui, Y., Liu, L., Li, B., Zhou, X., Xu, N.: ‘Fabrication of tunable core−shell structured TiO2 mesoporous microspheres using linear polymer polyethylene glycol as templates’, J. Phys. Chem. C, 2010, 114, (6), pp. 2434–2439 (doi: 10.1021/jp908613u).
-
2)
-
16. Hong, S.S., Lee, M.S., Park, S.S., Lee, G.D.: ‘Synthesis of nanosized TiO2/SiO2 particles in the microemulsion and their photocatalytic activity on the decomposition of p-nitrophenol’, Catalysis Today, 2003, 87, (1), pp. 99–105 (doi: 10.1016/j.cattod.2003.10.012).
-
3)
-
13. Landfester, K.: ‘Miniemulsion polymerization and the structure of polymer and hybrid nanoparticles’, Angew. Chem. Int. Ed., 2009, 48, (25), pp. 4488–4507 (doi: 10.1002/anie.200900723).
-
4)
-
12. Guo, C.W., Cao, Y., Xie, S.H., Dai, W.L., Fan, K.N.: ‘Fabrication of mesoporous core-shell structured titania microspheres with hollow interiors’, Chem. Commun., 2003, 2003, pp. 700–701 (doi: 10.1039/b212845d).
-
5)
-
10. Fan, X., Niu, L., Xia, Z.: ‘Preparation of raspberry-like silica microcapsules via sulfonated polystyrene template and aniline medium assembly method’, Colloid Polym. Sci., 2014, 292, (12), pp. 3251–3259 (doi: 10.1007/s00396-014-3377-7).
-
6)
-
2. Zhu, Y.F., Shi, J.L., Shen, W.H., et al: ‘Stimuli-responsive controlled drug release from a hollow mesoporous silica sphere/polyelectrolyte multilayer core-shell structure’, Angew. Chem. Int. Ed., 2005, 44, pp. 5083–5087 (doi: 10.1002/anie.200501500).
-
7)
-
17. Lei, J.F., Du, K., Wei, R.H., Ni, J., Zhang, S.F.: ‘Controllable synthesis of anatase TiO2 with nano-carved surface morphologies’, Mater. Lett., 2014, 134, pp. 1–4 (doi: 10.1016/j.matlet.2014.07.018).
-
8)
-
5. Varghese, O.K., Gong, D., Paulose, M., Ong, K.G., Dickey, E.C., Grimes, C.A.: ‘Extreme changes in the electrical resistance of titania nanotubes with hydrogen exposure’, Adv. Mater., 2003, 15, pp. 624–627 (doi: 10.1002/adma.200304586).
-
9)
-
8. Yamada, Y., Mizutani, M., Nakamura, T., Yano, K.: ‘Mesoporous microcapsules with decorated inner surface: fabrication and photocatalytic activity’, Chem. Mater., 2010, 22, (5), pp. 1695–1703 (doi: 10.1021/cm9031072).
-
10)
-
14. Zhang, J.A., Yang, J.J., Wu, Q.Y., et al: ‘SiO2/polymer hybrid hollow microspheres via double in situ miniemulsion polymerization’, Macromolecules, 2010, 43, (3), pp. 1188–1190 (doi: 10.1021/ma902435w).
-
11)
-
11. Fujiwara, M., Shiokawa, K., Tanaka, Y., Nakahara, Y.: ‘Preparation and formation mechanism of silica microcapsules (hollow sphere) by water/oil/water interfacial reaction’, Chem. Mater., 2004, 16, (25), pp. 5420–5426 (doi: 10.1021/cm048804r).
-
12)
-
3. Martins, I.M., Barreiro, M.F., Coelho, M., Rodrigues, A.E.: ‘Microencapsulation of essential oils with biodegradable polymeric carriers for cosmetic applications’, Chem. Eng. J., 2014, 245, pp. 191–200 (doi: 10.1016/j.cej.2014.02.024).
-
13)
-
7. An, K., Hyeon, T.: ‘Synthesis and biomedical applications of hollow nanostructures’, Nano Today, 2009, 4, (4), pp. 359–373 (doi: 10.1016/j.nantod.2009.06.013).
-
14)
-
15. Zhang, J.A., Qiu, S.L., Zhu, Y.L., et al: ‘Facile fabrication of Janus magnetic microcapsules via double in situ miniemulsion polymerization’, Polym. Chem., 2013, 4, (5), pp. 1459–1466 (doi: 10.1039/C2PY20863F).
-
15)
-
6. Varghese, O.K., Gong, D., Paulose, M., Ong, K.G., Grimes, C.A.: ‘Hydrogen sensing using titania nanotubes’, Sens. Actuators B Chem., 2003, 93, pp. 338–344 (doi: 10.1016/S0925-4005(03)00222-3).
-
16)
-
4. Huang, Z.B., Tang, F.Q.: ‘Preparation, structure and magnetic properties of mesoporous magnetite hollow spheres’, J. Colloid Interface Sci., 2005, 281, pp. 432–436 (doi: 10.1016/j.jcis.2004.08.121).
-
17)
-
1. Wei, W., Ma, G.H., Hu, G., et al: ‘Preparation of hierarchical hollow CaCO3 particles and the application as anticancer drug carrier’, J. Am. Chem. Soc., 2008, 130, (47), pp. 15808–15810 (doi: 10.1021/ja8039585).
http://iet.metastore.ingenta.com/content/journals/10.1049/mnl.2015.0024
Related content
content/journals/10.1049/mnl.2015.0024
pub_keyword,iet_inspecKeyword,pub_concept
6
6