Thermo-sensitive Microgels Supported Gold Nanoparticles as Temperature-mediated Catalyst
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摘要
Microgels with a thermo-sensitive poly(N-isopropylacrylamide)(polyNIPAm) backbone and bis-imidazolium(VIM) ionic cross-links, denoted as poly(NIPAm-co-VIM), were successfully prepared. The as-synthesized ionic microgels were converted to nanoreactors, denoted as Au@PNI MGs, upon generation and immobilization of gold nanoparticles(Au NPs) of 5–8 nm in size into poly(NIPAm-co-VIM). The content of Au NPs in microgels could be regulated by controlling the 1,6-dibromohexane/vinylimidazole molar ratio in the quaternization reaction. The microgel-based nanoreactors were morphologically spherical and uniform in size, and presented reversible thermo-sensitive behavior with volume phase transition temperatures(VPTTs) at 39–40 °C. The Au@PNI MGs were used for the reduction of 4-nitrophenol, of which the catalytic activity could be modulated by temperature.
Microgels with a thermo-sensitive poly(N-isopropylacrylamide)(polyNIPAm) backbone and bis-imidazolium(VIM) ionic cross-links, denoted as poly(NIPAm-co-VIM), were successfully prepared. The as-synthesized ionic microgels were converted to nanoreactors, denoted as Au@PNI MGs, upon generation and immobilization of gold nanoparticles(Au NPs) of 5–8 nm in size into poly(NIPAm-co-VIM). The content of Au NPs in microgels could be regulated by controlling the 1,6-dibromohexane/vinylimidazole molar ratio in the quaternization reaction. The microgel-based nanoreactors were morphologically spherical and uniform in size, and presented reversible thermo-sensitive behavior with volume phase transition temperatures(VPTTs) at 39–40 °C. The Au@PNI MGs were used for the reduction of 4-nitrophenol, of which the catalytic activity could be modulated by temperature.
Microgels with a thermo-sensitive poly(N-isopropylacrylamide)(polyNIPAm) backbone and bis-imidazolium(VIM) ionic cross-links, denoted as poly(NIPAm-co-VIM), were successfully prepared. The as-synthesized ionic microgels were converted to nanoreactors, denoted as Au@PNI MGs, upon generation and immobilization of gold nanoparticles(Au NPs) of 5–8 nm in size into poly(NIPAm-co-VIM). The content of Au NPs in microgels could be regulated by controlling the 1,6-dibromohexane/vinylimidazole molar ratio in the quaternization reaction. The microgel-based nanoreactors were morphologically spherical and uniform in size, and presented reversible thermo-sensitive behavior with volume phase transition temperatures(VPTTs) at 39–40 °C. The Au@PNI MGs were used for the reduction of 4-nitrophenol, of which the catalytic activity could be modulated by temperature.
引文
1Corma, A.; Serna, P.; Concepcion, P.; Juan Calvino, J. Transforming nonselective into chemoselective metal catalysts for the hydrogenation of substituted nitroaromatics. J. Am. Chem.Soc. 2008, 130, 8748-8753.
2Zhang, J.; Chen, G.; Guay, D.; Chaker, M.; Ma, D. Highly active PtAu alloy nanoparticle catalysts for the reduction of 4-ni-trophenol. Nanoscale 2014, 6, 2125-2130.
3Dong, Z.; Le, X.; Dong, C.; Zhang, W.; Li, X.; Ma, J. Ni@Pd core-shell nanoparticles modified fibrous silica nanospheres as highly efficient and recoverable catalyst for reduction of 4-ni-trophenol and hydrodechlorination of 4-chlorophenol. Appl.Catal. B 2015, 162, 372-380.
4Zhao, P.; Feng, X.; Huang, D.; Yang, G.; Astruc, D. Basic concepts and recent advances in nitrophenol reduction by gold- and other transition metal nanoparticles. Coord. Chem. Rev. 2015,287, 114-136.
5Guo, M.; He, J.; Li, Y.; Ma, S.; Sun, X. One-step synthesis of hollow porous gold nanoparticles with tunable particle size for the reduction of 4-nitrophenol. J. Hazard. Mater. 2016, 310,89-97.
6Chang, Y. C.; Chen, D. H. Catalytic reduction of 4-nitrophenol by magnetically recoverable Au nanocatalyst. J. Hazard. Mater. 2009, 165, 664-669.
7Zhang, W.; Tan, F.; Wang, W.; Qiu, X.; Qiao, X.; Chen, J. Facile, template-free synthesis of silver nanodendrites with high catalytic activity for the reduction of p-nitrophenol. J. Hazard.Mater. 2012, 217, 36-42.
8Ghosh, S. K.; Mandal, M.; Kundu, S.; Nath, S.; Pal, T. Bimetallic Pt-Ni nanoparticles can catalyze reduction of aromatic nitro compounds by sodium borohydride in aqueous solution. Appl.Catal. A 2004, 268, 61-66.
9Behrens, S.; Heyman, A.; Maul, R.; Essig, S.; Steigerwald, S.;Quintilla, A.; Wenzel, W.; Buerck, J.; Dgany, O.; Shoseyov, O.Constrained synthesis and organization of catalytically active metal nanoparticles by self-assembled protein templates. Adv.Mater. 2009, 21, 3515-3519.
10Saha, A.; Ranu, B. Highly chemoselective reduction of aromatic nitro compounds by copper nanoparticles/ammonium formate. J. Org. Chem. 2008, 73, 6867-6870.
11Wu, Y.; Wen, M.; Wu, Q.; Fang, H. Ni/graphene nanostructure and its electron-enhanced catalytic action for hydrogenation reaction of nitrophenol. J. Phys. Chem. C 2014, 118, 6307-6313.
12Dey, R.; Mukherjee, N.; Ahammed, S.; Ranu, B. C. Highly selective reduction of nitroarenes by iron(0) nanoparticles in water. Chem. Commun. 2012, 48, 7982-7984.
13Shen, W.; Qu, Y.; Pei, X.; Li, S.; You, S.; Wang, J.; Zhang, Z.;Zhou, J. Catalytic reduction of 4-nitrophenol using gold nano-particles biosynthesized by cell-free extracts of Aspergillus sp WL-Au. J. Hazard. Mater. 2017, 321, 299-306.
14Wu, S.; Tseng, C.; Lin, Y.; Lin, C.; Hung, Y.; Mou, C. Catalytic nano-rattle of Au@hollow silica: towards a poison-resistant nanocatalyst. J. Mater. Chem. 2011, 21, 789-794.
15Hu, H.; Xin, J. H.; Hu, H.; Wang, X.; Miao, D.; Liu, Y. Synthesis and stabilization of metal nanocatalysts for reduction reactions—a review. J. Mater. Chem. A 2015, 3, 11157-11182.
16Ballarin, B.; Cassani, M. C.; Tonelli, D.; Boanini, E.; Albonetti,S.; Blosi, M.; Gazzano, M. Gold nanoparticle-containing membranes from in situ reduction of a gold(III)-aminoethyli-midazolium aurate salt. J. Phys. Chem. C 2010, 114, 9693-9701.
17Jiang, Z. J.; Liu, C. Y.; Sun, L. W. Catalytic properties of silver nanoparticles supported on silica spheres. J. Phys. Chem. B 2005, 109, 1730-1735.
18Li, M.; Chen, G. Revisiting catalytic model reaction p-nitrophenol/NaBH4 using metallic nanoparticles coated on polymeric spheres. Nanoscale 2013, 5, 11919-11927.
19Plamper, F. A.; Richtering, W. Functional microgels and microgel systems. Acc. Chem. Res. 2017, 50, 131-140.
20Xue, J.; Zhang, Z.; Nie, J.; Du, B. Formation of microgels by utilizing the reactivity of catechols with radicals. Macromolecules 2017, 50, 5285-5292.
21Cao, Q. C.; Wang, X.; Wu, D. C. Controlled cross-linking strategy for formation of hydrogels, microgels and nanogels.Chinese J. Polym. Sci. 2018, 36, 8-17.
22Lyon, L. A.; Fernandez-Nieves, A. The polymer/colloid duality of microgel suspensions. Annu. Rev. Phys. Chem. 2012, 63,25-43.
23Li, Z. B.; Xiang, Y. H.; Zhou, X. J.; Nie, J. J.; Peng, M.; Du, B.Y. Thermo-sensitive poly(DEGMMA-co-MEA) microgels:Synthesis, characterization and interfacial interaction with adsorbed protein layer. Chinese J. Polym. Sci. 2015, 33,1516-1526.
24Deshmukh, O. S.; van den Ende, D.; Stuart, M. C.; Mugele, F.;Duits, M. H. G. Hard and soft colloids at fluid interfaces: Adsorption, interactions, assembly & rheology. Adv. Colloid Interface Sci. 2015, 222, 215-227.
25Hu, W. T.; Yang, H.; Cheng, H.; Hu, H. Q. Morphology evolution of Polystyrene-core/poly(N-isopropylacrylamide)-shell microgel synthesized by one-pot polymerization. Chinese J.Polym. Sci. 2017, 35, 1156-1164.
26Weng, J. Y.; Tang, Z.; Guan, Y.; Zhu, X. X.; Zhang, Y. J. Assembly of highly ordered 2D arrays of silver-PNIPAM hybrid microgels. Chinese J. Polym. Sci. 2017, 35, 1212-1221.
27Zhou, X.; Nie, J.; Du, B. Functionalized ionic microgel sensor array for colorimetric detection and discrimination of metal ions. ACS Appl. Mater. Interfaces 2017, 9, 20913-20921.
28Xue, B.; Kozlovskaya, V.; Kharlampieva, E. Shaped stimuli-responsive hydrogel particles: syntheses, properties and biological responses. J. Mater. Chem. B 2017, 5, 9-35.
29Zhou, X.; Qi, Y.; Zhang, Z.; Nie, J.; Huang, Y.; Du, B. Novel engineered microgels with amphipathic network structures for simultaneous tumor and inflammation depression. ACS Appl.Mater. Interfaces 2018, 10, 10501-10512.
30Zhou, X.; Yang, Q.; Li, J.; Nie, J.; Tang, G.; Du, B. Thermosensitive poly(VCL-4VP-NVP) ionic microgels: synthesis,cytotoxicity, hemocompatibility, and sustained release of anti-inflammatory drugs. Mater. Chem. Front. 2017, 1, 369-379.
31Saunders, B. R.; Vincent, B. Microgel particles as model colloids: theory, properties and applications. Adv. Colloid Interface Sci. 1999, 80, 1-25.
32Zhou, X.; Nie, J.; Xu, J.; Du, B. Thermo-sensitive ionic microgels via post quaternization cross-linking: Fabrication, property, and potential application. Colloid Polym. Sci. 2015, 293,2101-2111.
33Zhou, X.; Zhou, Y.; Nie, J.; Ji, Z.; Xu, J.; Zhang, X.; Du, B.Thermosensitive ionic microgels via surfactant-free emulsion copolymerization and in situ quaternization cross-linking. ACS Appl. Mater. Interfaces 2014, 6, 4498-4513.
34Srivastava, S. K.; Guix, M.; Schmidt, O. G. Wastewater mediated activation of micromotors for efficient water cleaning.Nano Lett. 2016, 16, 817-821.
35Patel, N.; Patton, B.; Zanchetta, C.; Fernandes, R.; Guella, G.;Kale, A.; Miotello, A. Pd-C powder and thin film catalysts for hydrogen production by hydrolysis of sodium borohydride. Int.J. Hydrogen Energy 2008, 33, 287-292.
36Turkevich, J.; Stevenson, P. C.; Hillier, J. A study of the nucleation and growth processes in the synthesis of colloidal gold.Discuss. Faraday Soc. 1951, 55-75.
37Lu, Y.; Mei, Y.; Drechsler, M.; Ballauff, M. Thermosensitive core-shell particles as carriers for Ag nanoparticles: Modulating the catalytic activity by a phase transition in networks. Angew. Chem. Int. Ed. 2006, 45, 813-816.
38Yuan, J.; Wunder, S.; Warmuth, F.; Lu, Y. Spherical polymer brushes with vinylimidazolium-type poly(ionic liquid) chains as support for metallic nanoparticles. Polymer 2012, 53, 43-49.
39Pich, A. Z.; Adler, H. J. P. Composite aqueous microgels: an overview of recent advances in synthesis, characterization and application. Polym. Int. 2007, 56, 291-307.
40Zhou, X.; Nie, J.; Wang, Q.; Du, B. Thermosensitive ionic microgels with pH tunable degradation via in situ quaternization cross-linking. Macromolecules 2015, 48, 3130-3139.
41Benee, L. S.; Snowden, M. J.; Chowdhry, B. Z. Novel gelling behavior of poly(N-isopropylacrylamide-co-vinyl laurate) microgel dispersions. Langmuir 2002, 18, 6025-6030.
42Lu, Y.; Mei, Y.; Walker, R.; Ballauff, M.; Drechsler, M. 'Nano-tree'-type spherical polymer brush particles as templates for metallic nanoparticles. Polymer 2006, 47, 4985-4995.
43Wunder, S.; Lu, Y.; Albrecht, M.; Ballauff, M. Catalytic activity of faceted gold nanoparticles studied by a model reaction:Evidence for substrate-induced surface restructuring. ACS Catal. 2011, 1, 908-916.
44Wei, J.; Wang, H.; Deng, Y.; Sun, Z.; Shi, L.; Tu, B.; Luqman,M.; Zhao, D. Solvent evaporation induced aggregating assembly approach to three-dimensional ordered mesoporous silica with ultralarge accessible mesopores. J. Am. Chem. Soc.2011, 133, 20369-20377.
45Zhang, H.; Yang, X. L. Magnetic polymer microsphere stabilized gold nanocolloids as a facilely recoverable catalyst.Chinese J. Polym. Sci. 2011, 29, 342-351.
46Lu, Y.; Yuan, J.; Polzer, F.; Drechsler, M.; Preussners, J. In situ growth of catalytic active Au-Pt bimetallic nanorods in thermoresponsive core-shell microgels. ACS Nano 2010, 4,7078-7086.
47Bawane, S. P.; Sawant, S. B. Hydrogenation of p-nitrophenol to metol using Raney nickel catalyst: Reaction kinetics. Appl.Catal. A 2005, 293, 162-170.
48Wunder, S.; Polzer, F.; Lu, Y.; Mei, Y.; Ballauff, M. Kinetic analysis of catalytic reduction of 4-nitrophenol by metallic nan-oparticles immobilized in spherical polyelectrolyte brushes. J.Phys. Chem. C 2010, 114, 8814-8820.
49Mei, Y.; Lu, Y.; Polzer, F.; Ballauff, M.; Drechsler, M. Catalytic activity of palladium nanoparticles encapsulated in spherical polyelectrolyte brushes and core-shell microgels. Chem. Mater.2007, 19, 1062-1069.
50Dasog, M.; Hou, W.; Scott, R. W. J. Controlled growth and catalytic activity of gold monolayer protected clusters in presence of borohydride salts. Chem. Commun. 2011, 47,8569-8571.
2Zhang, J.; Chen, G.; Guay, D.; Chaker, M.; Ma, D. Highly active PtAu alloy nanoparticle catalysts for the reduction of 4-ni-trophenol. Nanoscale 2014, 6, 2125-2130.
3Dong, Z.; Le, X.; Dong, C.; Zhang, W.; Li, X.; Ma, J. Ni@Pd core-shell nanoparticles modified fibrous silica nanospheres as highly efficient and recoverable catalyst for reduction of 4-ni-trophenol and hydrodechlorination of 4-chlorophenol. Appl.Catal. B 2015, 162, 372-380.
4Zhao, P.; Feng, X.; Huang, D.; Yang, G.; Astruc, D. Basic concepts and recent advances in nitrophenol reduction by gold- and other transition metal nanoparticles. Coord. Chem. Rev. 2015,287, 114-136.
5Guo, M.; He, J.; Li, Y.; Ma, S.; Sun, X. One-step synthesis of hollow porous gold nanoparticles with tunable particle size for the reduction of 4-nitrophenol. J. Hazard. Mater. 2016, 310,89-97.
6Chang, Y. C.; Chen, D. H. Catalytic reduction of 4-nitrophenol by magnetically recoverable Au nanocatalyst. J. Hazard. Mater. 2009, 165, 664-669.
7Zhang, W.; Tan, F.; Wang, W.; Qiu, X.; Qiao, X.; Chen, J. Facile, template-free synthesis of silver nanodendrites with high catalytic activity for the reduction of p-nitrophenol. J. Hazard.Mater. 2012, 217, 36-42.
8Ghosh, S. K.; Mandal, M.; Kundu, S.; Nath, S.; Pal, T. Bimetallic Pt-Ni nanoparticles can catalyze reduction of aromatic nitro compounds by sodium borohydride in aqueous solution. Appl.Catal. A 2004, 268, 61-66.
9Behrens, S.; Heyman, A.; Maul, R.; Essig, S.; Steigerwald, S.;Quintilla, A.; Wenzel, W.; Buerck, J.; Dgany, O.; Shoseyov, O.Constrained synthesis and organization of catalytically active metal nanoparticles by self-assembled protein templates. Adv.Mater. 2009, 21, 3515-3519.
10Saha, A.; Ranu, B. Highly chemoselective reduction of aromatic nitro compounds by copper nanoparticles/ammonium formate. J. Org. Chem. 2008, 73, 6867-6870.
11Wu, Y.; Wen, M.; Wu, Q.; Fang, H. Ni/graphene nanostructure and its electron-enhanced catalytic action for hydrogenation reaction of nitrophenol. J. Phys. Chem. C 2014, 118, 6307-6313.
12Dey, R.; Mukherjee, N.; Ahammed, S.; Ranu, B. C. Highly selective reduction of nitroarenes by iron(0) nanoparticles in water. Chem. Commun. 2012, 48, 7982-7984.
13Shen, W.; Qu, Y.; Pei, X.; Li, S.; You, S.; Wang, J.; Zhang, Z.;Zhou, J. Catalytic reduction of 4-nitrophenol using gold nano-particles biosynthesized by cell-free extracts of Aspergillus sp WL-Au. J. Hazard. Mater. 2017, 321, 299-306.
14Wu, S.; Tseng, C.; Lin, Y.; Lin, C.; Hung, Y.; Mou, C. Catalytic nano-rattle of Au@hollow silica: towards a poison-resistant nanocatalyst. J. Mater. Chem. 2011, 21, 789-794.
15Hu, H.; Xin, J. H.; Hu, H.; Wang, X.; Miao, D.; Liu, Y. Synthesis and stabilization of metal nanocatalysts for reduction reactions—a review. J. Mater. Chem. A 2015, 3, 11157-11182.
16Ballarin, B.; Cassani, M. C.; Tonelli, D.; Boanini, E.; Albonetti,S.; Blosi, M.; Gazzano, M. Gold nanoparticle-containing membranes from in situ reduction of a gold(III)-aminoethyli-midazolium aurate salt. J. Phys. Chem. C 2010, 114, 9693-9701.
17Jiang, Z. J.; Liu, C. Y.; Sun, L. W. Catalytic properties of silver nanoparticles supported on silica spheres. J. Phys. Chem. B 2005, 109, 1730-1735.
18Li, M.; Chen, G. Revisiting catalytic model reaction p-nitrophenol/NaBH4 using metallic nanoparticles coated on polymeric spheres. Nanoscale 2013, 5, 11919-11927.
19Plamper, F. A.; Richtering, W. Functional microgels and microgel systems. Acc. Chem. Res. 2017, 50, 131-140.
20Xue, J.; Zhang, Z.; Nie, J.; Du, B. Formation of microgels by utilizing the reactivity of catechols with radicals. Macromolecules 2017, 50, 5285-5292.
21Cao, Q. C.; Wang, X.; Wu, D. C. Controlled cross-linking strategy for formation of hydrogels, microgels and nanogels.Chinese J. Polym. Sci. 2018, 36, 8-17.
22Lyon, L. A.; Fernandez-Nieves, A. The polymer/colloid duality of microgel suspensions. Annu. Rev. Phys. Chem. 2012, 63,25-43.
23Li, Z. B.; Xiang, Y. H.; Zhou, X. J.; Nie, J. J.; Peng, M.; Du, B.Y. Thermo-sensitive poly(DEGMMA-co-MEA) microgels:Synthesis, characterization and interfacial interaction with adsorbed protein layer. Chinese J. Polym. Sci. 2015, 33,1516-1526.
24Deshmukh, O. S.; van den Ende, D.; Stuart, M. C.; Mugele, F.;Duits, M. H. G. Hard and soft colloids at fluid interfaces: Adsorption, interactions, assembly & rheology. Adv. Colloid Interface Sci. 2015, 222, 215-227.
25Hu, W. T.; Yang, H.; Cheng, H.; Hu, H. Q. Morphology evolution of Polystyrene-core/poly(N-isopropylacrylamide)-shell microgel synthesized by one-pot polymerization. Chinese J.Polym. Sci. 2017, 35, 1156-1164.
26Weng, J. Y.; Tang, Z.; Guan, Y.; Zhu, X. X.; Zhang, Y. J. Assembly of highly ordered 2D arrays of silver-PNIPAM hybrid microgels. Chinese J. Polym. Sci. 2017, 35, 1212-1221.
27Zhou, X.; Nie, J.; Du, B. Functionalized ionic microgel sensor array for colorimetric detection and discrimination of metal ions. ACS Appl. Mater. Interfaces 2017, 9, 20913-20921.
28Xue, B.; Kozlovskaya, V.; Kharlampieva, E. Shaped stimuli-responsive hydrogel particles: syntheses, properties and biological responses. J. Mater. Chem. B 2017, 5, 9-35.
29Zhou, X.; Qi, Y.; Zhang, Z.; Nie, J.; Huang, Y.; Du, B. Novel engineered microgels with amphipathic network structures for simultaneous tumor and inflammation depression. ACS Appl.Mater. Interfaces 2018, 10, 10501-10512.
30Zhou, X.; Yang, Q.; Li, J.; Nie, J.; Tang, G.; Du, B. Thermosensitive poly(VCL-4VP-NVP) ionic microgels: synthesis,cytotoxicity, hemocompatibility, and sustained release of anti-inflammatory drugs. Mater. Chem. Front. 2017, 1, 369-379.
31Saunders, B. R.; Vincent, B. Microgel particles as model colloids: theory, properties and applications. Adv. Colloid Interface Sci. 1999, 80, 1-25.
32Zhou, X.; Nie, J.; Xu, J.; Du, B. Thermo-sensitive ionic microgels via post quaternization cross-linking: Fabrication, property, and potential application. Colloid Polym. Sci. 2015, 293,2101-2111.
33Zhou, X.; Zhou, Y.; Nie, J.; Ji, Z.; Xu, J.; Zhang, X.; Du, B.Thermosensitive ionic microgels via surfactant-free emulsion copolymerization and in situ quaternization cross-linking. ACS Appl. Mater. Interfaces 2014, 6, 4498-4513.
34Srivastava, S. K.; Guix, M.; Schmidt, O. G. Wastewater mediated activation of micromotors for efficient water cleaning.Nano Lett. 2016, 16, 817-821.
35Patel, N.; Patton, B.; Zanchetta, C.; Fernandes, R.; Guella, G.;Kale, A.; Miotello, A. Pd-C powder and thin film catalysts for hydrogen production by hydrolysis of sodium borohydride. Int.J. Hydrogen Energy 2008, 33, 287-292.
36Turkevich, J.; Stevenson, P. C.; Hillier, J. A study of the nucleation and growth processes in the synthesis of colloidal gold.Discuss. Faraday Soc. 1951, 55-75.
37Lu, Y.; Mei, Y.; Drechsler, M.; Ballauff, M. Thermosensitive core-shell particles as carriers for Ag nanoparticles: Modulating the catalytic activity by a phase transition in networks. Angew. Chem. Int. Ed. 2006, 45, 813-816.
38Yuan, J.; Wunder, S.; Warmuth, F.; Lu, Y. Spherical polymer brushes with vinylimidazolium-type poly(ionic liquid) chains as support for metallic nanoparticles. Polymer 2012, 53, 43-49.
39Pich, A. Z.; Adler, H. J. P. Composite aqueous microgels: an overview of recent advances in synthesis, characterization and application. Polym. Int. 2007, 56, 291-307.
40Zhou, X.; Nie, J.; Wang, Q.; Du, B. Thermosensitive ionic microgels with pH tunable degradation via in situ quaternization cross-linking. Macromolecules 2015, 48, 3130-3139.
41Benee, L. S.; Snowden, M. J.; Chowdhry, B. Z. Novel gelling behavior of poly(N-isopropylacrylamide-co-vinyl laurate) microgel dispersions. Langmuir 2002, 18, 6025-6030.
42Lu, Y.; Mei, Y.; Walker, R.; Ballauff, M.; Drechsler, M. 'Nano-tree'-type spherical polymer brush particles as templates for metallic nanoparticles. Polymer 2006, 47, 4985-4995.
43Wunder, S.; Lu, Y.; Albrecht, M.; Ballauff, M. Catalytic activity of faceted gold nanoparticles studied by a model reaction:Evidence for substrate-induced surface restructuring. ACS Catal. 2011, 1, 908-916.
44Wei, J.; Wang, H.; Deng, Y.; Sun, Z.; Shi, L.; Tu, B.; Luqman,M.; Zhao, D. Solvent evaporation induced aggregating assembly approach to three-dimensional ordered mesoporous silica with ultralarge accessible mesopores. J. Am. Chem. Soc.2011, 133, 20369-20377.
45Zhang, H.; Yang, X. L. Magnetic polymer microsphere stabilized gold nanocolloids as a facilely recoverable catalyst.Chinese J. Polym. Sci. 2011, 29, 342-351.
46Lu, Y.; Yuan, J.; Polzer, F.; Drechsler, M.; Preussners, J. In situ growth of catalytic active Au-Pt bimetallic nanorods in thermoresponsive core-shell microgels. ACS Nano 2010, 4,7078-7086.
47Bawane, S. P.; Sawant, S. B. Hydrogenation of p-nitrophenol to metol using Raney nickel catalyst: Reaction kinetics. Appl.Catal. A 2005, 293, 162-170.
48Wunder, S.; Polzer, F.; Lu, Y.; Mei, Y.; Ballauff, M. Kinetic analysis of catalytic reduction of 4-nitrophenol by metallic nan-oparticles immobilized in spherical polyelectrolyte brushes. J.Phys. Chem. C 2010, 114, 8814-8820.
49Mei, Y.; Lu, Y.; Polzer, F.; Ballauff, M.; Drechsler, M. Catalytic activity of palladium nanoparticles encapsulated in spherical polyelectrolyte brushes and core-shell microgels. Chem. Mater.2007, 19, 1062-1069.
50Dasog, M.; Hou, W.; Scott, R. W. J. Controlled growth and catalytic activity of gold monolayer protected clusters in presence of borohydride salts. Chem. Commun. 2011, 47,8569-8571.