氢化酶 1.ppt

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1、Group Meeting 2010.03.21Facile molecular design of hybrid functional assemblies with controllable transport properties:mesoporous films meet polyelectrolyte brushesChem.Commun.,2009,25532555Alejandra Calvo,a Basit Yameen,b Federico J.Williams,cd Omar Azzaroni*e and Galo J.A.A.Soler-Illia*aPolystyren

2、e sulfonate The precursor solution was prepared using 0.8 TEOS:0.2 APTES:0.005 F127:24 EtOH:5.2 H2O:0.28 HCl.This solution was used to produce films by dip-coating on ITO under 40-50%relative humidity at 298 K(1-2 mm s-1 withdrawing speed).Freshly deposited films were submitted to 50%relative humidi

3、ty chamber for 24 hours followed by a stabilizing thermal treatment of two successive 24 hours steps at 60 C and 130 C,and a final 2 hours step at 200 C.The template was removed by extraction in 0.01 mol dm-3 HCl in ethanol for three days under stirring.This experimental protocol led to the formatio

4、n of thin mesoporous displaying highly organized pore arrays(Fig.1(a)with cubic-derived mesostructure(Im3m)and pore openings in the range 69 nm,10 as indicated by transmission electron microscopy(TEM)and small angle X-ray scattering with two-dimensional detection(SAXS-2D).Fig.1 Schematic depiction c

5、orresponding to the inner environment of the mesoporous amino-silica thin film prior to(a)and after(b)the surface-initiated atom transfer radical polymerization of poly(styrene sulfonate)brushes.In the figure are also described the different chemical entities present in the pore surface during the s

6、equential modifications.Fig.1 DRIFT spectra of amino-silica mesoporous films prior to(A)and after the surface-initiated polymerization(B).Fig.2(A)N 1s XP spectra corresponding to:(a)mesoporous aminosilica thin film,(b)PSS brush-modified mesoporous silica film obtained by the procedure described in F

7、ig.1.The red trace indicates the raw data whereas the blue trace describes the signal contribution originated from the amide bonds(BE=402.1 eV)(B)S 2p XP spectra corresponding to:(a).mesoporous amino-silica thin film,(b)as for(a)after the surface-initiated polymerization of poly(styrene sulfonate)br

8、ushesFig.3 Cyclic voltammograms corresponding to:(a)mesoporous amino-silica thin film,(b)PSS brush-modified mesoporous silica film obtained by SI-ATRP in the presence of 1 mM Ru(NH3)6 3+(red trace)and 1 mM Fe(CN)63-(blue trace),respectively.Scan rate:100 mV s-1.Supporting electrolyte:0.1 M KCl(pH 3.

9、5).Recent work by White and co-workers,(Langmuir,Vol.22,No.9,2006)using nanoporous opal films(tortuous cavities 35 nm)modified with monolayer assemblies,revealed that the presence of high ionic strength environments could significantly affect the permselective properties of the film.Estimation of th

10、e degree of polymerization of the PSS brushes from XPS measurements 1 In this work,the authors showed for the first time the use of polyelectrolyte brushes as building blocks enabling the facile manipulation of the permselective properties of mesoporous thin films.This result introduces an interesti

11、ng example of molecular design of a functional interface using tools from two well-established research areas,i.e.:mesoporous films and polymer brushes.3 They envisioned that this approach combining elements from macromolecular and solgel chemistry will pave the way to the rational design and facile creation of highly functional interfacial architectures.SummaryThank you!