Evaluation of APTES-Functionalized Zinc Oxide Nanoparticles for Adsorption of CH and CO.

ZnO nanoparticles functionalized with APTES were obtained to evaluate their CH and CO adsorption at 298 K in a range between 0 and 10 bar. First, ZnO nanoparticles were obtained by a precipitation method and subsequently coated with (3-aminopropyl)triethoxysilane (APTES). As a preliminary study, the results were compared with previously reported naked nanoparticles in order to evaluate the influence of APTES coating on CO selectivity.

Preparation of a heterogeneous biocatalyst through Thermomyces lanuginosus lipase immobilization on pore-expanded SBA-15.

Heterogeneous biocatalysts were prepared by adsorbing T. lanuginosus lipase (TLL) onto uncalcined (SBAUC-TLL) and calcined (SBAC-TLL) SBA-15, using ammonium fluoride as a pore expander to facilitate TLL immobilization. At an enzyme load of 1 mg/g, high immobilization yields (>90 %) and recovered activities (>80 % for SBAUC-TLL and 70 % for SBAC-TLL) were achieved.

Zeolites synthesis from phyllosilicates and their performance for CO adsorption.

Five phyllosilicates (kaolinite, montmorillonite, saponite, sepiolite and palygorskite) have been selected as starting materials for the synthesis of zeolites. Among them, kaolinite and montmorillonite display the lowest Si/Al molar ratio leading to aluminosilicates with high crystallinity. Thus, the hydrothermal treatment under basic conditions forms 4A zeolite when kaolinite is used as starting material while 13X zeolite is obtained when montmorillonite is used as starting material.

Valorization of wipe wastes for the synthesis of microporous carbons and their application in CO capture, gas separation and H-storage.

Wipe wastes have been used as a cellulosic source to synthesize biochars. Prior to the synthesis of the adsorbents by the pyrolysis of wipes wastes, this waste was treated to remove the pathogenic agents. Then, the wipe wastes were pyrolyzed between 500 and 900 °C to obtain biochars, whose microporosity increased proportionally to the pyrolysis temperature, achieving a maximum CO-adsorption uptake of 2.

Modification of the Textural Properties of Chitosan to Obtain Biochars for CO-Capture Processes.

Three chitosans with different morphologies have been used (commercial chitosan powder, chitosan in film form and chitosan in globular form synthesized by the freeze-dried method) for the synthesis of biochars. The pyrolytic treatment has revealed that the biochar synthesized from the chitosan formed by the freeze-dried method reaches the highest CO-adsorption capacity (4.11 mmol/g at 0 °C and a pressure of 1 bar) due to this adsorbent is highly microporous.

How Reproducible are Surface Areas Calculated from the BET Equation?

Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials.

Protein Adsorption onto Modified Porous Silica by Single and Binary Human Serum Protein Solutions.

Typical porous silica (SBA-15) has been modified with pore expander agent (1,3,5-trimethylbenzene) and fluoride-species to diminish the length of the channels to obtain materials with different textural properties, varying the Si/Zr molar ratio between 20 and 5. These porous materials were characterized by X-ray Diffraction (XRD), N adsorption/desorption isotherms at -196 °C and X-ray Photoelectron Spectroscopy (XPS), obtaining adsorbent with a surface area between 420-337 m g and an average pore diameter with a maximum between 20-25 nm. These materials were studied in the adsorption of human blood serum proteins (human serum albumin-HSA and immunoglobulin G-IgG).

CO Valorization and Its Subsequent Valorization.

After the industrial revolution, the increase in the world population and the consumption of fossil fuels has led to an increase in anthropogenic CO emissions [...

Assessing CO Adsorption on Amino-Functionalized Mesocellular Foams Synthesized at Different Aging Temperatures.

A wide variety of solid sorbents has recently been synthesized for application in CO adsorption. Among them, mesoporous silicas deserve attention because of their ability to accommodate large concentrations of different chemicals as a consequence of their surface chemistry and tunable pore structure. Functionalized materials exhibit promising features for CO adsorption at high temperatures and low CO concentrations.

Ferric sludge derived from the process of water purification as an efficient catalyst and/or support for the removal of volatile organic compounds.

Ferric chloride solutions are used as coagulants or flocculants in water treatment operations for human consumption. This treatment produces large amounts of clay-type solids formed mainly of montmorillonite with iron oxides and humic substances. This ferric sludge can be used as an efficient catalyst for the removal of volatile organic compounds (VOCs) by total oxidation.

CO₂ Capture with Mesoporous Silicas Modified with Amines by Double Functionalization: Assessment of Adsorption/Desorption Cycles.

CO₂ adsorption on mesoporous silica modified with amine by double functionalization was studied. Adsorption microcalorimetry was used in order to investigate the influence of increasing the nitrogen surface density on double functionalized materials with respect to the only grafted materials. The distribution of sites and the rate-controlling mechanism of adsorption were evaluated.

Synthesis, Characterization, Uses and Applications of Porous Clays Heterostructures: A Review.

Porous clay heterostructures (PCH) are obtained by the insertion of an organic bulky cation in the interlayer spacing of a smectite, causing a swelling of the clay mineral. Right after, oxides species, mainly silicon oxide, are incorporated as pillars galleries between adjacent layers to form a porous structure after the removal of the template. The ordering of the clay mineral as well the organic cation incorporated in the synthetic step favors the modulation of the textural properties of the PCH.

Influence of buffer solutions in the adsorption of human serum proteins onto layered double hydroxide.

The adsorption of human immunoglobulin G (IgG) and human serum albumin (HSA) on a non-calcined Mg-Al layered double hydroxide (3:1 Mg-Al LDH) was studied in batch and fixed bed experiments, focusing on the effect of buffer solution and pH over sorbent uptake. Mg-Al LDH was synthesized and characterized by X-ray diffraction (XRD), N adsorption-desorption isotherms at -196°C, X-ray photoelectron spectroscopy (XPS), Zero point charge (pHzpc), particle size distribution and Fourier transform infra-red (FTIR). Batch adsorption experiments were performed in order to investigate the effects of pH on IgG and HSA adsorption with different buffers: sodium acetate (ACETATE), sodium phosphate (PHOSPHATE), 3-(N-morpholino) propanesulfonic acid (MOPS), 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES) and trizma-hydrochloric acid (TRIS-HCl).