KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Tamon, HajimeSubject: search.filters.subject.Adsorption

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Control of mesoporous properties of carbon cryogels prepared from wattle tannin and furfural
    (2008-12-01)
    Kraiwattanawong, Kriangsak
    ;
    Mukai, Shin R.
    ;
    Tamon, Hajime
    ;
    Lothongkum, Anchaleeporn W.
    Wattle tannin-furfural (TFu) carbon cryogels are synthesized by sol-gel polycondensation of wattle tannin with furfural by using sodium hydroxide (NaOH) as a catalyst, dried by freeze-drying technique and then pyrolyzed under inert atmosphere, respectively. The amounts of wattle tannin (T), furfural (Fu), NaOH (C) and distilled water (W) are changed for preparing the mesoporous TFu carbon cryogels. The mole ratio of tannin to catalyst T/C plays a crucial role for the synthesis of TFu organic and carbon cryogels. The results suggest that the T/C ratio should be above 0.25 but <1.0 to prepare the mesoporous and homogeneous cryogels. Although TFu carbon cryogels have the broad mesopore size distribution, the mesoporous structure is controllable by the synthesis conditions. The carbon cryogels possess the mesopore volume less than 0.56 cm<sup>3</sup>/g and the BET surface area less than 600 m<sup>2</sup>/g. Moreover, the ratio of catalyst to water C/W can be used to prepare the homogeneous and mesoporous carbon cryogels, and to control the mesopore radius of carbon cryogels in the range of 1.6-9.6 nm. © 2007 Springer Science+Business Media, LLC.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Improvement of mesoporosity of carbon cryogels by acid treatment of hydrogels
    (2008-11-01)
    Kraiwattanawong, Kriangsak
    ;
    Mukai, Shin R.
    ;
    Tamon, Hajime
    ;
    Lothongkum, Anchaleeporn W.
    Wattle tannin-furfural (TFu) gels are synthesized by the sol-gel polycondensation of wattle tannin with furfural by using sodium hydroxide as a catalyst and cured at 363 K. After cured, the TFu hydrogels are treated in hydrochloric acid (HCl) solutions with various variables as follows: aging temperature, HCl concentration and pH. TFu cryogels aged are then freeze-dried and pyrolyzed under an inert atmosphere to obtain TFu carbon cryogels. The TFu and carbon cryogels were characterized by N<inf>2</inf> adsorption and scanning electron microscope. The high HCl concentration yields the increase of mesopore volume almost twice especially at high temperature and the mesopore size distribution can be greatly developed sharper and narrower when the high concentration of HCl or/and the high temperature are used. Moreover, this method is the versatile approach for developing the mesopore structure of the low and high porous TFu hydrogels and has no serious problem of weight loss after treatment. © 2008 Elsevier Inc. All rights reserved.