S. I. Tsyganova

Formation of the Pore Structure of Modifi ed Wood by Treatment with Heat and Water

The effect of the heat treatment and subsequent treatment with water on the pore structure formation in a solid product made of birch sawdust with the addition of phosphoric acid was studied. The relationships characterizing the effect of the modifier, temperature, and treatment with water on the properties of the porous carbon material prepared from wood were revealed.

Deposition of Gold from Chloride Solutions on Microporous Iron-Carbon Sorbents

The process of deposition of gold from an aqueous solution of hydrogen tetrachloroaurate(III) on microporous composites synthesized from a blend of sawdust, iron and zinc chlorides was examined. Their high sorption capacity for gold was shown, one reason of which is the interaction chloroaurate ions with iron oxide.

Synthesis of a Highly Porous Carbon Material with Magnetic Properties

Double modification of birch wood sawdust was performed with the aim to prepare porous carbon materials with magnetic properties.

Synthesis of porous carbon materials from birch sawdust modified with ZnCl2

Carbonization of birch sawdust modified with zinc chloride and selected properties of the resulting porous carbon materials were studied.

Porous carbon materials produced by the chemical activation of birch wood

It was established that the main factors responsible for the yield and specific surface area of porous carbon materials obtained by the chemical activation of the wood of birch are the nature of a modifying agent and the temperature of pyrolysis. The additional opening of the porous structure of the product of the chemical activation of wood occurs at the stage of its water treatment as a result of the removal of water-soluble compounds. The conditions of the carbonization of birch wood modified with H3PO4, KOH, and ZnCl2 were chosen in order to provide the significant development of the porous structure of carbon materials. The porous carbon material with the highest specific surface area (more than 2560 m2/g) was obtained by the water washing of the product of the carbonization of birch wood modified H3PO4 at 400°C.

Production and properties of porous carbon materials from chemically modified microcrystalline cellulose

Certain fundamental aspects of how the porous structure is formed in carbon materials produced by pyrolysis of microcrystalline cellulose modified with phosphoric acid, potassium hydroxide, and zinc chloride were determined. The above chemical promoters shift the onset of the process of intense thermal transformation of cellulose to lower temperatures and promote formation of porous carbon materials. Water treatment of porous carbon materials produced by pyrolysis of microcrystalline cellulose with high content of a promoter leads to additional pore opening due to the removal of the excess amount of the promoter and soluble products formed in its interaction with cellulose, which makes it possible to obtain porous carbon materials with specific surface area of up to 1500 m2 g−1.

Synthesis of porous carbon materials from wood waste pre-treated with water

The possibility of producing porous carbon materials from birch sawdust exposed to natural decomposition in water was demonstrated. It was established that the carbon material carbonized at 800°C was of a specific surface area nearly by one order of magnitude higher than that of a product produced using ordinary sawdust under the same conditions. It was suggested that developing porous structure of the carbon product was due to structural changes in wood mainly by reducing an amount of α-cellulose and its interaction with water.

Formation of the porous structure of carbon materials during carbonization of microcrystalline cellulose modified by phosphoric acid and potassium hydroxide

Formation of the porous structure of carbon material obtained by carbonization of microcrystalline cellulose (MCC) in the presence of modifying additives KOH and H3PO4 has been investigated. The optimal conditions for the synthesis of porous carbon materials (PCMs) from chemically activated MCC have been revealed. The highest specific surface area (about 1500 m2/g) is observed for water-washed carbon products obtained by carbonization at 800°C of MCC containing 50 wt % KOH and by carbonization at 400°C of MCC with the addition of 50 wt % H3PO4.

Synthesis of a Carbon-Containing Composite Based on Aspen Wood and Its Structural and Electrochemical Properties

Highly porous ZnO/carbon composite with a specific surface area of up to 2050 m2 g–1 was prepared from aspen sawdust modified with zinc chloride. The effect of temperature, modifier, and long preliminary keeping in water on the structural characteristics of the final product was examined. The possibility of using porous materials synthesized from aspen wood waste as electrode materials was demonstrated. As shown by cyclic voltammetry, the apparent specific electrical capacitance reaches 104 F g–1.

Synthesis of highly porous zinc–carbon composites based on modified pine wood

Highly porous materials containing zinc oxide were prepared form modified pine wood. The growth dynamics of zinc oxide microcrystallites in the course of carbonization of pine sawdust mixed with ZnCl2 was studied. The hexagonal wurtzite-type ZnO phase is formed at 400°С and is broken down at approximately 800°С. The synthesized composite material has a high specific surface area, up to 1900 m2 g–1. The relationships of the porous structure formation in the composite in relation to the temperature and subsequent treatment with water were revealed. Opening of the porous structure of the composite in the course of carbonization of modified pine sawdust is associated with the formation of crystal-like phases of carbon and ZnO.