Size-dependent dissociation of surface hydroxyl groups of silica in aqueous solution

Author(s):  
Ying Li ◽  
Na Du ◽  
Shue Song ◽  
Wanguo Hou
1986 ◽  
Vol 51 (7) ◽  
pp. 1430-1438 ◽  
Author(s):  
Alena Reissová ◽  
Zdeněk Bastl ◽  
Martin Čapka

The title complexes have been obtained by functionalization of silica with cyclopentadienylsilanes of the type Rx(CH3)3 - xSi(CH2)nC5H5 (x = 1-3, n = 0, 1, 3), trimethylsilylation of free surface hydroxyl groups, transformation of the bonded cyclopentadienyl group to the cyclopentadienyl anion, followed by coordination of (h5-cyclopentadienyl)trichlorotitanium. The effects of single steps of the above immobilization on texture of the support, the number of free hydroxyl groups, the coverage of the surface by cyclopentadienyl groups and the degree of their utilization in anchoring the titanium complex have been investigated. ESCA study has shown that the above anchoring leads to formation of the silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complex.


RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99712-99721 ◽  
Author(s):  
Yan Li ◽  
Yawen Wang ◽  
Yu Huang ◽  
Junji Cao ◽  
Wingkei Ho ◽  
...  

Surface modification by phosphate efficiently improves the photocatalytic performance of BiPO4 for the degradation of methylene orange (MO), by enhancing the concentration of surface hydroxyl groups and improving its hydrophilicity.


NANO ◽  
2020 ◽  
Vol 15 (01) ◽  
pp. 2050009 ◽  
Author(s):  
Zhikun Zhang ◽  
Qingqing Liu ◽  
Yumin Liu ◽  
Ran Qi ◽  
Lilong Zhou ◽  
...  

In view of the importance of convenient and rapid H2O2 detection for biological analysis, we herein propose Ag nanoparticle (NP)-decorated silica microspheres as a probe for instant and non-enzymatic on-site colorimetric detection of H2O2. The surface hydroxyl groups of silica microspheres were reacted with (3-mercaptopropyl)trimethoxysilane to afford thiolated microspheres that subsequently bind Ag NPs. The oxidation of residual –SH groups on the silica surface to –S–S– moieties in the presence of H2O2 induces the aggregation of decorated microspheres and is accompanied by a color change. Sensor response is found to be proportional to H2O2 concentration in the range from 100[Formula: see text]nM to 1[Formula: see text]mM, with UV–Vis and colorimetric detection limits determined as 10[Formula: see text][Formula: see text]M and 10[Formula: see text][Formula: see text]M, respectively. The developed platform is successfully used to detect H2O2 in simulated human urine and is, therefore, concluded to be sufficiently stable and selective for practical applications.


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