scholarly journals A role of free silanol groups of nanosilica surface in interaction with poly(vinyl pyrrolidone)

2018 ◽  
Vol 72 (2) ◽  
pp. 51 ◽  
Author(s):  
Olga Voronina ◽  
Maria Malysheva ◽  
Liudmyla Nosach ◽  
Eugeny Voronin ◽  
Vladimir Gun’ko ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Crucial Role ◽  
Vinyl Pyrrolidone ◽  
Initial Amount ◽  
Silanol Groups ◽  
Adsorption Monolayer ◽  
Poly Vinyl Pyrrolidone

In this work, a role of the number of free silanol groups at a nanosilica surface (specific surface area S<sub>BET</sub> = 250 m<sup>2</sup>/g, initial amount of silanols α<sub>ОН</sub> = 0.60-0.62 mmol/g) was analyzed in interaction with poly(vinyl pyrrolidone) (PVP) vs. the degree (Q<sub>TMS</sub>) of silica hydrophobization by hexamethyldisilazane at 100 <sup>o</sup>C. The value of Q<sub>TMS</sub> was 0.07, 0.42, 0.67, 0.81, 0.82, and 1.0. Adsorption of PVP onto a nanosilica surface was carried out from a water and water-ethanol (1:1) solutions of the polymer. It was shown that free silanol groups play a crucial role in the adsorption of poly(vinyl pyrrolidone). The value of the maximal adsorption (monolayer capacity) on completely hydrophobic nanosilica surface is approximately by 6.5 times lower than that for unmodified nanosilica

Elucidating the Origin of the Toxicity of Nano-CeO2 to Chlorella pyrenoidosa：the Role of Specific Surface Area and Chemical Composition

2021 ◽  
Author(s):  
Changjian Xie ◽  
Yuhui Ma ◽  
Peng Zhang ◽  
Junzhe Zhang ◽  
Xiaowei Li ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Aquatic Environment ◽  
Cerium Dioxide ◽  
Environmental Application ◽  
Ecotoxicological Effects

With the increasing environmental application and discharge of nano cerium dioxide (nano-CeO2), it is urgent to fully understand its ecotoxicological effects on the aquatic environment. This study for the first...

Gaseous flow through coarse granular beds: The role of specific surface area

2020 ◽  
Vol 366 ◽  
pp. 821-831
Author(s):  
Thomas Buchwald ◽  
Gregor Schmandra ◽  
Lieven Schützenmeister ◽  
Tony Fraszczak ◽  
Thomas Mütze ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Gaseous Flow ◽  
Flow Through

Role of Acetaldehyde on Synthesizing Large Surface Area Porous g-C3N4 Nanosheets with Enhanced Photocatalytic Performance by Using Acetaldehyde–Melamine

NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050066
Author(s):  
Xiangxiang Cheng ◽  
Xiaojuan Xu ◽  
Hongliang Wang ◽  
He Cai ◽  
Lan Jia ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Photocatalytic Performance ◽  
Low Cost ◽  
High Concentration ◽  
Air Atmosphere ◽  
Oxidative Etching

Large specific surface area porous g-C3N4 nanosheets were prepared by utilizing acetaldehyde-mediated melamine. The synthetic processes adopted two-step thermal treatments which are in N2 and then in an air atmosphere. The introduced acetaldehyde made melamine condensation incompletely and generated body defects in g-C3N4 when heated in N2. Further heating in air realized pores formation at sites of body defects, thus increase the specific surface area of g-C3N4. Notably, the introduction of acetaldehyde is beneficial to generate high concentration defects, which are active sites for thermal oxidative etching, and increase the yield of g-C3N4 by inhibiting the sublimation of melamine. The photocatalytic performance of obtained g-C3N4 was evaluated by the degradation of 2-propanol under visible light irradiation ([Formula: see text][Formula: see text]nm). The porous g-C3N4 exhibits excellent photocatalytic performance than bulk g-C3N4. The addition of trace acetaldehyde significantly increased the specific surface area and enhanced photocatalytic activity, providing a new idea for the development of simple, low-cost and high active g-C3N4 photocatalyst.

Role of electrospun fibre diameter and corresponding specific surface area (SSA) on cell attachment

2009 ◽  
Vol 3 (4) ◽  
pp. 269-279 ◽  
Author(s):  
Ming Chen ◽  
Prabir K. Patra ◽  
Michael L. Lovett ◽  
David L. Kaplan ◽  
Sankha Bhowmick
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cell Attachment ◽  
Fibre Diameter ◽  
Electrospun Fibre
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