Time filter

Source Type

Choma J.,Military University of Technology | Osuchowski L.,Wojskowy Instytut Chemii i Radiometrii | Jaroniec M.,Kent State University
Ochrona Srodowiska | Year: 2014

Results of studies on the synthesis, characterization and applications of activated carbons from polymeric materials, including polymer wastes, were presented. The major methods of polymer carbonization were described as well as of their activation by different activators such as KOH, CO2 and H2O. Carbons of very good porous structure parameters could be obtained from sulfonated styrene- divinylbenzene resins and polyvinylidene chloride but also from polyethylene terephthalate that represents polymer wastes. Methods for physicochemical characterization of activated carbons obtained from polymers were briefly presented, mainly in relation to their adsorption properties. One of the best activated carbons obtained from sulfonated styrene-divinylbenzene resin had the specific surface area close to 4000 m2/g, total pore volume of about 2.1 cm3/g and could adsorb 40 wt % CO2 per 1 gram of carbon at 0 °C and under the pressure of 1 bar, and also 4 wt % H2 per 1 gram of carbon at -196 °C, under the pressure of 1 bar. Potential applications of these activated carbons for adsorption of CO2 and H2 as well as CH 4, C6H6, NO, CO, O2, SO2 and NH3 were also presented. Activated carbons obtained from polymer wastes could also be used for adsorption of dyes, herbicides, trace metal ions from water as well as adsorption of volatile organic compounds from the air. Attempts at the use of activated carbons for battery electrode and supercapacitor construction are also interesting. Activated carbons from polymeric materials attract a lot of attention due to their high specific surface area and large pore volume combined with large-scale and low-cost production.

Choma J.,Military University of Technology | Osuchowski L.,Wojskowy Instytut Chemii i Radiometrii | Dziura A.,Military University of Technology | Kwiatkowska-Wojcik W.,MASKPOL SA | Jaroniec M.,Kent State University
Ochrona Srodowiska | Year: 2014

A series of four microporous carbons was obtained from Kcvlar® fibers by carbonization followed by KOH activation. The resulting powdered activated carbons possessed a well-developed porous structure. Their maximum specific surface area was 2660 m2/g while the total pore volume was of 1.54cm3/g. The controlled process of carbonization and activation led to a significant ultramicropore and micropore development, the volume of which reached 0.54cm3/g and 1.35cm3/g, respectively. Measurements of physical adsorption of different substances demonstrated the following adsorption efficacy: CO2 - 4.47mmol/g (0°C, 800mmHg) and 2.68mmo]/g (25 °C. 850 mrnHg), H2 - 21.4mg/g (-196°C, 850mmHg), CH4 - 1.21mmol/g (20°C, 750mmHg) and C6,H6 - 17.3mmol/g (20°C, p/po≈1.0). Very good adsorption properties of microporous carbons obtained from Kcvlar® fibers indicated that they might be successfully used in enviromnental engineering for adsorption and storage of carbon dioxide as well as volatile organic compounds. Other applications are associated with storage and usage of the energy of adsorbed hydrogen.

Popiel S.,Military University of Technology | Clidzilo S.,Military University of Technology | Darlewski W.,Military University of Technology | Swiatkowski A.,Military University of Technology | Laszczak J.,Wojskowy Instytut Chemii i Radiometrii
Przemysl Chemiczny | Year: 2012

Com. activated C was oxidized with O 310 2 mixt. at 20°C for 15-180 min. The oxidized C samples were studied for functional (acidic) groups on the C surface by alkalimetric tiration, thermal stability (mass loss) at 150-550°C, and oxidn. degree by polarography and voltammetry (carbon paste electrodes). Nature of the chem. oxidn. of the C surface was disclosed.

Choma J.,Military University of Technology | Stachurska K.,Military University of Technology | Osuchowski L.,Wojskowy Instytut Chemii i Radiometrii | Dziura A.,Military University of Technology | Jaroniec M.,Kent State University
Ochrona Srodowiska | Year: 2015

A series of activated carbons obtained from different polymers such as polypyrrole, sulfonated styrene divinylobenzene resin, polycarbonate, Kevlar® fibers, and poly(vinylidine fluoride) were included in the study. The polymeric precursors were carbonized in flowing nitrogen at a temperature from 350 to 700°C and activated with KOH at the carbon: KOH ratio of 1:4 and 1:5 at 700°C. Specific surface area of carbons obtained ranged from 1810 to 2920 m2/g, their total pore volume - from 0.87 to 1.64 cm3/g, volume of micropores and small mesopores - from 1.07 to 1.47 cm3/g, and finally the ultramicropore volume varied between 0.44 and 0.72 cm3/g. Additionally, the commercial activated carbon Filtrasorb 400 was studied for the comparison purposes. The porous structure parameters for the carbons studied were on average about twice as large as those of the commercial carbon Filtrasorb 400. The polymer-derived carbons showed high adsorption capacities toward carbon dioxide at 0°C and under the pressure from about 2 to 900 mmHg. The maximum capacity for carbon dioxide adsorption under the aforementioned conditions varied from 4.31 to 7.58 mmol/g. The CO2 adsorption isotherms were fitted by the Dubinin-Radushkevich (DR) equation to evaluate the maximum CO2 uptake (ao) by the micropores as well as the B constant. It was demonstrated that the maximum CO2 uptake calculated by the DR equation correlated well with the volume of ultramicropores determined on the basis of pore size distribution by the DFT (density functional theory) analysis. Very good adsorption properties of the carbons obtained from polymeric precursors, including polymeric wastes, render them potentially useful materials for capture and storage of carbon dioxide.

Mirski T.,Osrodek Diagnostyki i Zwalczania Zagrozen Biologicznych Wojskowego | Gryko R.,Osrodek Diagnostyki i Zwalczania Zagrozen Biologicznych Wojskowego | Bartoszcze M.,Osrodek Diagnostyki i Zwalczania Zagrozen Biologicznych Wojskowego | Bielawska-Drozd A.,Osrodek Diagnostyki i Zwalczania Zagrozen Biologicznych Wojskowego | Tyszkiewicz W.,Wojskowy Instytut Chemii i Radiometrii
Medycyna Weterynaryjna | Year: 2011

Antimicrobial peptides (AMPs), also called peptide antibiotics, have been discovered in the early 1980s in frogs They were antimicrobial substances called magainins. AMPs are among the oldest defense mechanisms in plants, humans and animals. The major peptides include i.a. defensins, cathelicidins and protegrins. The mechanisms of action of antimicrobial peptides rely on the permeabilization of the microbial membrane, destabilization of the lipid bilayer structure, creation of micelles or channels within the membrane, binding lipopolysaccharide (LPS), preventing DNA replication, inhibiting protein expression, releasing ATP, as well as binding free iron and removing it from the microbial growth environment. At present, intensive research is being conducted on the use of AMPs in human and veterinary medicine, including treatment of infections such as acne, skin infections, sepsis, and bacterial infections of the diabetic foot. Among others, the following preparations are being tested: Ambicin, for the treatment of infections caused by Mycobacterium, and Iseganan, protegrin for the treatment of mouth inflammation, CF and chronic lung infections. P. aeruginosa-infected animals treated with the D2A21 preparation showed 100% survival. Some of the AMPs show biocidal activity against Bacillus anthracis. Defensins isolated from the mucus and tissues of many fish species have the ability to protect fish from infections by Aeromonas hydrophila, Pseudomonas fluorescens, and Vibrio anguillarum. Beneficial effects of using defensins in the treatment of Borrelia burgdorferi infections in dogs have been described. Synthetic peptides are used for the production of a vaccine against parvovirosis. Peptides obtained from lactic acid bacteria (LAB) reduce the contamination and increase the stability of food products. AMPs are also useful for decontaminating the environment and medical equipment, as well as for sterilizing catheters. They have also been used to develop biocidal self-disinfecting surfaces (BSOs). Moreover, AMPs can be used in hospital hygiene and veterinary medicine, e.g., for the treatment of protective clothing, wipes, filters, ventilation, etc.

Discover hidden collaborations