Filip Walkiewicz

Synthesis, toxicity, biodegradability and physicochemical properties of 4-benzyl-4-methylmorpholinium-based ionic liquids

A series of 4-benzyl-4-methylmorpholinium salts have been synthesized producing morpholinium ionic liquids with inorganic (chloride, nitrate, tetrafluoroborate, hydrogen sulphate) and organic (formate, acetate, methoxyacetate, 2-(2-methoxyethoxy)acetate, hexanoate, octanoate, dodecyl sulphate, 2-ethylbutyrate, lactate, crotonate, maleate, salicylate, saccharinate) anions. Their physicochemical properties, cytotoxicity to the promyelocytic leukaemia rat cell line IPC-81, oral toxicity and biodegradability were determined. The anion significantly determined the state of aggregation and cytotoxicity. The results enabled 4-benzyl-4-methylmorpholinium ionic liquids to be classified as being of moderate or low toxicity (EC50 between 0.15 and 14.13 mM). The acute toxicity for 4-benzyl-4-ethylmorpholinium acetate is between 300–2000 mg kg−1b.w. in female rats. The activity of these morpholinium salts against bacteria and fungi was very low. It was found that new 4-benzyl-4-methylmorpholinium-based ionic liquids with anions commonly used for dissolving cellulose, such as formate or acetate, can also be used as new biomass solvents.

Bis(ammonium) ionic liquids with herbicidal anions

The method of synthesis of the novel bis(ammonium) herbicidal ionic liquids with the cation containing two quaternary nitrogen atoms was described. New compounds, containing three structurally different linkers, were prepared via acid–base reaction between the corresponding bis(ammonium) hydroxides and herbicides in the form of free acids. In addition, phase transitions, thermal stability and solubility in common solvents were determined. The herbicidal efficacy was tested in greenhouse experiments, wherein test plants were lambsquarters (Chenopodium album L.) cornflower (Centaurea cyanus L.), white mustard (Sinapis alba L.) and winter rape (Brassica napus L.). The biological activity of the anion (2,4-D, MCPA, Mecoprop, Dicamba) in all new HILs was preserved. Moreover, the efficacy of some salts was several times higher when compared to commercial formulations.

Synthesis and properties of ammonium ionic liquids with cyclohexyl substituent and dissolution of cellulose

We have synthesized alkyl(cyclohexyl)dimethylammonium bromides, formates and acetates, 2-methoxyacetates, 2-(2-methoxyethoxy)acetates, 2-[2-(2-methoxyethoxy)ethoxy]acetates, and 2-ethoxyacetates and assessed their ability to dissolve cellulose. Their physicochemical properties and microbiological activity were determined. Alkyl(cyclohexyl)dimethylammonium cation dimensions of alkyl groups are essential for cellulose solubility and are generally limited to butyl, hexyl, and octyl as effective substituents. In parallel, the alkyl group determines activity of the entire molecule against microbes. The molecules biological activity against microbes begins when a length of the alkyl substituent begins to block cellulose solubility. We present the computational model of the solubility mechanism, composed of an ensemble of two cellobiose units and (cyclohexyl)hexyldimethylammonium acetate.

Ammonium ionic liquids with anions of natural origin

This study was focused on presenting a new class of ionic liquids (ILs) with anions of natural origin. The salts were obtained by hydrolysis of defined triglycerides or edible vegetable oils (coconut oil and canola oil) by quaternary ammonium hydroxides. The basic physicochemical properties of the obtained products were studied and their microbial and deterrent activity was determined. Additionally, their susceptibility to biodegradation was evaluated. The described synthesis pathway utilizes vegetable oils and quaternary ammonium hydroxides as reactants in order to obtain ILs with anions of natural origin, which are characterized by specific biological activity. The majority of the prepared ILs exhibited excellent feeding deterrent properties and could be classified as readily biodegradable compounds. The employed method is characterized by low cost of substrates, high yields and high purity of the obtained products. It might potentially find application as a tool to synthesize environmentally friendly ILs with attractive properties for a wide range of applications.

Sweet ionic liquids-cyclamates: Synthesis, properties, and application as feeding deterrents

In this paper, we show that sweet quaternary ammonium, pyridinium, and imidazolium cyclamates are cheap, thermally stable, surface and biologically active ionic liquids, with potential application as feeding deterrents.

Multifunctional long-alkyl-chain quaternary ammonium azolate based ionic liquids

A new group of quaternary ammonium ionic liquids with azolate (benzotriazolate, 1,2,4-triazolate, 4-nitroimidazolate, 2-methyl-4-nitroimidazolate) anions was prepared and characterized. The synthetic method employed was easy and quick, and required a polar solvent. The obtained ionic liquids were tested as anti-microbial and anti-fungal plant protection agents. Additionally, the surface-active properties and the phytotoxicity of the quaternary ammonium azolates were also studied. These clearly defined ionic liquids were found to be very effective anti-bacterial and anti-fungal agents.

Known triazole fungicides – a new trick

Tebuconazole and propiconazole were converted into salts by reaction with inorganic and organic acids. Numerous novel salts were obtained as a result, many of which could be characterized as protic ionic liquids. Their thermal stability and biological activity against fungal species Fusarium culmorum, Microdochium nivale, Sclerotinia sclerotiorum and Botrytis cinerea (in concentration range from 10 up to 1000 ppm) were assessed in the framework of this study. The evaluation revealed that high antifungal activity of the synthesized tebuconazole- and propiconazole-based salts, which may be classified as new triazole fungicides, was preserved. Physical properties of the obtained salts have changed significantly, thus creating new application possibilities of known triazole fungicides.

Synthesis and antioxidant properties of dicationic ionic liquids

Hydroxyl functionalized ammonium dicationic ionic liquids containing naturally derived ions and ether linkage between cationic head groups were synthesized and described as a novel form of antioxidant. A simple neutralization reaction with protocatechuic and gentisic acids as the source of anions was used for the preparation of ionic liquids. All compounds were characterized in terms of phase transitions and thermal stability via differential scanning calorimetry and thermogravimetric analysis techniques. In addition, the structures of salts were confirmed by nuclear magnetic resonance spectroscopy. Antioxidant activity was evaluated using free radical quenching and reducing power assays as well as lipid peroxidation inhibition. The studies confirmed that the obtained dicationic ionic liquids with 3,4- or 2,5-dihydroxybenzoate anions exhibit significant radical scavenging activity or reducing power. The results were better than those obtained with commonly used antioxidants, such as Trolox. However, only the protocatechuate DILs exhibited linoleic acid peroxidation inhibition.

Electrochemical properties of positive electrode in lead-acid battery modified by ammonium-based ionic liquids

AbstractThe influence of selected types of ammonium ionic liquid (AIL) additives on corrosion and functional parameters of lead-acid battery positive electrode was examined. AILs with a bisulfate anion used in the experiments were classified as protic, aprotic, monomeric, and polymeric, based on the structure of their cation. Working electrodes consisted of a lead-calcium-tin alloy utilized in the industry for manufacturing current collectors of positive electrodes in lead-acid batteries (LABs). This alloy was used in the first part of the study for the evaluation of corrosion intensity and stability of electrolyte with AIL additives. In the second part, the grid made of the examined alloy was covered with positive active mass, the composition of which was modified by selected AIL. The selection of an appropriate substance was made based on parameters such as corrosion potential, corrosion current, polarization resistance, and hydrogen and oxygen evolution potentials. Techniques such as linear sweep voltammetry, corrosimetry, and electrochemical impedance spectroscopy were used. The conducted measurements revealed that polymeric AIL additive had an exceptionally positive influence on the inhibition of the corrosion process in LAB and electrochemical window of the electrolyte. The influence of this compound on the specific capacity and resistance of the active mass was also discussed. Graphical abstractᅟ