نتایج جستجو برای: mesoporosity

تعداد نتایج: 294  

2018
Maria Cristina Mascolo Terry Arthur Ring

Recyclable aggregates of mesoporous titania with different anatase-rutile ratios have been prepared by thermal treatments of either amorphous or peptized precursors. These last two have been obtained by hydrolysis of either Ti(OC₂H₅)₄ or of Ti(OC₂H₅)₄ in mixture with 5 mol % Zr(OC₃H₇)₄ at room temperature in the presence of NH₄OH as a catalyzing agent. The anatase-rutile ratio, the recyclable a...

2016
Xian-fa Li Xue-gang Luo Lin-qin Dou Ke Chen

A series of activated carbons (ACs) were prepared by K2CO3 activation from kraft lignin (KL) that was recovered from papermaking black liquor. The effects of process parameters such as the activation temperature (AT), activated period, K2CO3 to KL mass ratio, and N2 flow rate on the characteristics of the final product were determined. The ACs were characterized using nitrogen adsorption, morph...

2004
Andrew R. Zimmerman Keith W. Goyne Jon Chorover Sridhar Komarneni Susan L. Brantley

The ‘‘mesopore protection hypothesis’’ [Chem. Geol. 114 (1994) 347; Geochim. Cosmochim. Acta 58 (1994) 1271] proposes that organic matter (OM) may be protected from enzymatic degradation by sequestration within mineral mesopores (2–50 nm diameter). This hypothesis is a leading, though controversial, theory in explaining both the preservation of some extremely labile OM compounds and observed co...

2018
Rolf Beerthuis Liang Huang N Raveendran Shiju Gadi Rothenberg Wei Shen Hualong Xu

Catalytic biomass conversion is often hindered by coking. Carbon compounds cover active surface and plug pores, causing catalyst deactivation. Material design at the nanoscale allows tailoring of the catalytic activity and stability. Here, we report a simple synthesis of nanosized ZSM-5 materials by using a silicalite-1 seeding suspension. ZSM-5 crystals were grown from a deionized silica sourc...

Journal: :Dalton transactions 2016
Najam U Qadir Syed A M Said Rached B Mansour Khalid Mezghani Anwar Ul-Hamid

Conventional small-scale adsorption chillers generally employ silica-gel/water or zeolite/water working pairs given the relatively high level of mesoporosity and water affinity in these adsorbent materials. However, the coefficient of performance (COP) and specific cooling power (SCP) evaluated for the adsorption chiller using these adsorbent/adsorbate pairs cannot be still considered practical...

2001
Bernd Smarsly Sebastian Polarz Markus Antonietti

Sol-gel nanocasting is used to imprint the soft-matter structures of lyotropic phases of nonionic n-alkylpoly(ethylene oxide) amphiphiles (“CxEy”) into solid porous silica. Small angle X-ray scattering (SAXS), nitrogen sorption, and transmission electron microscopy (TEM) are used to investigate the dependence of the porosity on the block lengths or the block volumes, respectively. It is found t...

2014
Chengli Huo Jing Ouyang Huaming Yang

Highly ordered aluminum-containing mesoporous silica (Al-MCM-41) was prepared using attapulgite clay mineral as a Si and Al source. Mesoporous complexes embedded with CuO nanoparticles were subsequently prepared using various copper sources and different copper loadings in a direct synthetic route. The resulting CuO/Al-MCM-41 composite possessed p6mm hexagonally symmetry, well-developed mesopor...

Journal: :Water research 2009
K M Smith G D Fowler S Pullket N J D Graham

The imposition of more stringent legislation governing the disposal and utilisation of sewage sludge, coupled with the growth in its generation and the loss of traditionally accepted disposal routes, has prompted a drive for alternative uses for sewage sludge. One option that exhibits special promise, due to its potential to valorise the sludge, is the conversion of the sludge into adsorbents. ...

2009
Morgan Stefik Hiroaki Sai Kenneth Sauer Sol M. Gruner Francis J. DiSalvo Ulrich Wiesner

We report the first use of a block terpolymer for the synthesis of three-component nanocomposites. Here, the use of three chemically distinct polymer blocks enabled control over each of the three final components: partially graphitic carbon, crystalline transition metal oxide, and porosity. Tuning of the individual block lengths and block fractions resulted in control over the three components....

2017
Ewa Skwarek Olena Goncharuk Dariusz Sternik Wladyslaw Janusz Karolina Gdula Vladimir M Gun'ko

A series of composites based on nanohydroxyapatite (nHAp) and natural polysaccharides (PS) (nHAp/agar, nHAp/chitosan, nHAp/pectin FB300, nHAp/pectin APA103, nHAp/sodium alginate) was synthesized by liquid-phase two-step method and characterized using nitrogen adsorption-desorption, DSC, TG, FTIR spectroscopy, and SEM. The analysis of nitrogen adsorption-desorption data shows that composites wit...

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