Environmental behaviour and ecotoxicity of cationic surfactants towards marine organisms

Cationic surfactants are surface-active compounds that can be found in many products, including household and cleaning agents. As a consequence, they tend to be discarded into water streams, ultimately ending up in the aquatic environment. In spite of this environmental issue, studies describing their effects towards marine species are lacking. The aim of this study was therefore to evaluate the short-term exposure effects of two commercial cationic surfactants and three novel gemini surfactants on four marine species, the green microalgae Nannochloropsis gaditana and Tetraselmis chuii, the diatom Phaeodactylum tricornutum, and the crustacean Artemia salina. Furthermore, biodegradation and size distribution of the cationic surfactants in artificial seawater were also studied by UV–vis spectrophotometry and dynamic light scattering, respectively. Ecotoxicity tests revealed that the commercial cationic surfactant N-cetyl-N,N,N-trimethylammonium bromide is toxic to all tested marine species while N-dodecyl-N,N,N-trimethylammonium chloride and 1,4-bis-[N-(1-dodecyl)-N,N-dimethylammoniummethyl]benzene dibromide showed the lowest toxicity among the tested cationic surfactants. Besides the novel insights regarding the effects caused by these five cationic surfactants, this work opens prospects for the replacement of commercially available surfactants by more environmentally friendly alternatives.publishe

Organic Corrosion Inhibitors

Organic corrosion inhibitors are one of the five ways, besides material selection, design, cathodic protection and coatings, to protect materials against corrosion. Corrosion is an ubiquitous phenomena that deteriorates all materials, metals, plastics, glass and concrete. The costs of corrosion are tremendous and amounts to 4.0% of gross domestic product (GDP) in USA. The similar losses of GDP are noted in all countries around the world. At this point of time, there is no way to completely stop the corrosion processes. Some new solutions can only slow this process. Organic corrosion inhibitors are widely used in industry because of their effectiveness at wide range of temperatures, compatibility with protected materials, good solubility in water, low costs and relatively low toxicity. Organic corrosion inhibitors adsorb on the surface to form protective film which displace water and protect it against deteriorating. Effective organic corrosion inhibitors contain nitrogen, oxygen, sulfur and phosphorus with lone electron pairs as well can contain structural moieties with π-electrons that interact with metal favoring the adsorption process. This review presents mechanisms and monitoring of corrosion, laboratory methods for corrosion study, relationship between structure and efficacy of corrosion inhibitions, theoretical approach to design new inhibitors and some aspects of biocorrosion

Multifunctional Gemini Surfactants: Structure, Synthesis, Properties and Applications

Gemini cationic surfactants are compounds which are composed of two hydrophilic head groups and two hydrophobic tails linked by a spacer at the head groups or closed to them. The spacer can be either hydrophobic or hydrophilic. It can be rigid or flexible. The neutral charge of the molecule is retained by the presence of organic or inorganic counterions. Critical micelle concentrations (CMCs), surface tension (γ) and minimal inhibitory concentration (MIC) are dozen times lower than corresponding parameters of monomeric surfactants. The unique properties of gemini surfactants with a wide range of hydrophilic-lipophilic balance (HLB) make them a very useful, innovative material in detergents, cosmetics, personal care products, additives for paints and coatings, biocides, material science, organic synthesis, pharmacy, textiles, enhanced oil recovery, nanotechnology, petroleum and many other branches of life. A large number of papers concerning gemini surfactants have been published so far. This review presents a synthetic look at current work devoted to structure, synthesis and applications of gemini surfactants

Anti‑algal activity of the 12‑5‑12 gemini surfactant results from its impact on the photosynthetic apparatus

A rapid amplification of algal population has a negative impact on the environment and the global economy. Thus, control of algal proliferation is an important issue and effective procedures which reduce algal blooms and control algal fouling are highly desired. Gemini surfactants are considered to have a low environmental impact, therefore they seem to be a promising group of detergents which could reduce algal blooms in water systems. Furthermore, due to their emulsifying properties they could replace algaecides added to antifouling paints and decrease algae adhesion to various surfaces. In this study the toxic effect of the 12-5-12 gemini surfactant was investigated on Chlorella cells and close attention was paid to a potential mechanism of its action. At the high cell density (10.05 × 107 cells/mL) a dose-dependent cell death was found and the IC50 value was reached at the concentration of 19.6 µmol/L after 72-h exposure to the surfactant. The decrease in chlorophyll autofluorescence shows that the photosynthetic apparatus seems to be the target of the tested compound. The presented studies indicate that gemini surfactants could effectively reduce algal blooms in water systems, and if added to paints, they could decrease algal growth on external building walls or other water immersed surfaces

Corrosion inhibition efficiency of functionalized dimeric tetraalkylammonium salts

Wydział Chemii: Pracownia Chemii MikrobiocydówW prezentowanej rozprawie doktorskiej przedstawiono syntezę dimerycznych czwartorzędowych soli amoniowych z różnym łącznikiem i łańcuchami alifatycznymi zawierającymi dwanaście lub osiemnaście atomów węgla. Struktura zsyntezowanych związków została potwierdzona spektroskopowo. Krytyczne stężenia micelizacji wyznaczono wykorzystując metodę konduktometryczną oraz spektrofluorymetryczną. Określono wpływ struktury gemini surfaktantów na wartości CMC. W celu scharakteryzowania właściwości ekologicznych badanych związków z dwunastowęglowymi łańcuchami w części hydrofobowej zbadano ich biodegradację oraz toksyczność dla środowiska wodnego wobec Daphnia magna. Efektywność hamowania oraz szybkość korozji stali nierdzewnej w kwasie solnym o stężeniu 3M przez zsyntezowane gemini surfaktanty została określona w testach 24-godzinnych na drodze pomiarów potencjometrycznych oraz z wykorzystaniem elektrochemicznej spektroskopii impedancyjnej. Morfologia powierzchni stali nierdzewnej przed i po zanurzeniu w agresywnym czynniku została zbadana przy użyciu laserowego skaningowego mikroskopu konfokalnego oraz skaningowego mikroskopu elektronowego. Na podstawie wyników testów 24-godzinnych wybrano trzy najbardziej efektywne gemini surfaktanty i przeprowadzono dla nich testy tygodniowe. Obliczenia kwantowo-chemiczne wykorzystano do teoretycznej oceny zdolności hamowania korozji a uzyskane wyniki porównano z danymi eksperymentalnymi.This dissertation presents the synthesis of dimeric quaternary ammonium salts with a different spacer and chains containing twelve or eighteen carbon atoms. A structure of the compounds were confirmed by spectroscopic methods. Values of the critical micelle concentration was determined by conductometry and spectrofluorimetry. The effect of the structure of the gemini surfactants on the CMC was determined. In order to characterize ecological properties of the gemini surfactants with twelve carbon atoms in the alkyl chains, biodegradation and aquatic toxicity to Daphnia magna were determined. Corrosion inhibition efficiency of the dimeric salts and corrosion rate of stainless steel in 3M HCl were determined based on 24-hours tests by potentiometric and electrochemical impedance spectroscopy measurements. Surface morphology of the steel before and after immersion in the aggressive solution, without and with the tested compounds, was examined by laser scanning confocal microscope and scanning electron microscope. Three the most effective surfactants were selected, based on 24-hours test, and took part in a weekly test. Quantum-chemical calculations were used to theoretically assess the corrosion inhibiting ability and compared to the experimental data

Corrosion inhibition efficiency of functionalized dimeric tetraalkylammonium salts

Wydział Chemii: Pracownia Chemii MikrobiocydówW prezentowanej rozprawie doktorskiej przedstawiono syntezę dimerycznych czwartorzędowych soli amoniowych z różnym łącznikiem i łańcuchami alifatycznymi zawierającymi dwanaście lub osiemnaście atomów węgla. Struktura zsyntezowanych związków została potwierdzona spektroskopowo. Krytyczne stężenia micelizacji wyznaczono wykorzystując metodę konduktometryczną oraz spektrofluorymetryczną. Określono wpływ struktury gemini surfaktantów na wartości CMC. W celu scharakteryzowania właściwości ekologicznych badanych związków z dwunastowęglowymi łańcuchami w części hydrofobowej zbadano ich biodegradację oraz toksyczność dla środowiska wodnego wobec Daphnia magna. Efektywność hamowania oraz szybkość korozji stali nierdzewnej w kwasie solnym o stężeniu 3M przez zsyntezowane gemini surfaktanty została określona w testach 24-godzinnych na drodze pomiarów potencjometrycznych oraz z wykorzystaniem elektrochemicznej spektroskopii impedancyjnej. Morfologia powierzchni stali nierdzewnej przed i po zanurzeniu w agresywnym czynniku została zbadana przy użyciu laserowego skaningowego mikroskopu konfokalnego oraz skaningowego mikroskopu elektronowego. Na podstawie wyników testów 24-godzinnych wybrano trzy najbardziej efektywne gemini surfaktanty i przeprowadzono dla nich testy tygodniowe. Obliczenia kwantowo-chemiczne wykorzystano do teoretycznej oceny zdolności hamowania korozji a uzyskane wyniki porównano z danymi eksperymentalnymi.This dissertation presents the synthesis of dimeric quaternary ammonium salts with a different spacer and chains containing twelve or eighteen carbon atoms. A structure of the compounds were confirmed by spectroscopic methods. Values of the critical micelle concentration was determined by conductometry and spectrofluorimetry. The effect of the structure of the gemini surfactants on the CMC was determined. In order to characterize ecological properties of the gemini surfactants with twelve carbon atoms in the alkyl chains, biodegradation and aquatic toxicity to Daphnia magna were determined. Corrosion inhibition efficiency of the dimeric salts and corrosion rate of stainless steel in 3M HCl were determined based on 24-hours tests by potentiometric and electrochemical impedance spectroscopy measurements. Surface morphology of the steel before and after immersion in the aggressive solution, without and with the tested compounds, was examined by laser scanning confocal microscope and scanning electron microscope. Three the most effective surfactants were selected, based on 24-hours test, and took part in a weekly test. Quantum-chemical calculations were used to theoretically assess the corrosion inhibiting ability and compared to the experimental data

Green Nanotechnology: The Latest Innovations, Knowledge Gaps, and Future Perspectives

Nanotechnology is a key enabling technology bringing together chemists, biologists, physicists, and materials science engineers, among others [...

Cationic gemini surfactants containing an O-substituted spacer and hydroxyethyl moiety in the polar heads: self-assembly, biodegradability and aquatic toxicity

Micellization and some ecological properties of new cationic gemini surfactants with oxygen-substituted spacer and hydroxyethyl groups connected to the polar heads have been studied. The incorporation of a hydroxyethyl group in the polar head favors self-aggregation whereas the presence of the oxygen in the spacer increases critical micelle concentration. Surfactants investigated are not biodegradable due to their toxic effect on microorganisms responsible for biodegradation. Aquatic toxicity increases with the hydrophobic chain and decreases by increasing the hydrophilicity of spacer and polar heads. New gemini surfactants are less toxic to the aquatic environment than monomeric surfactants and non-oxygen-containing gemini surfactants.The authors thanks to Renata Kulesza and Karolina Kozupa from the Institute of Heavy Organic Synthesis, Kedzierzyn-Koźle, Poland, for making the equipment for preliminary study of cmc available. This work was supported by the Spanish Ministry of Economia y Competitividad (CTQ2013-41514-P) and the National Center for Research and Development (Poland; TANGO1/266340/NCBR/2015).Peer reviewe