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Gemini Surfactants Synthesis Interfacial And Solution Phase Behavior And Applications Pdf

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Synthesis and properties of novel gemini surfactant with short spacer

By Bogumil E. Brycki, Iwona H. 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. 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.

Application and Characterization of Surfactants. Everything in the world involves chemistry and chemicals. Chemistry is essential for our life and our existence in the material world. Without chemistry there would literally be nothing.

The diversity of life and material forms is based on versatility of chemical compounds and interactions between them. Therefore, the better we know chemistry, the better we know our world. From among of over millions of currently known organic and inorganic compounds [ 1 ], some of them have a very special meaning to facilitate our life. One of the very important and it seems to be irreplaceable groups of chemicals are surfactants. The surfactant molecules contain at least two moieties, hydrophobic and hydrophilic one.

Hydrophobic moiety is usually a straight or branched hydrocarbon or fluorocarbon chain with 8—18 carbon atoms, whereas hydrophilic moiety is a polar or ionic group. The balance between hydrophobic and hydrophilic parts, hydrophilic-lipophilic balance HLB , is responsible for special properties of these amphiphilic compounds in solutions such as adsorption on the surfaces and interfaces and formation of self-assembly aggregates.

This fundamental feature of amphiphiles is a base of their very wide practical applications. Surfactants are used in almost every field of our activities. They find application in detergents [ 2 ], in personal care products [ 3 ], as additives for paints and coatings [ 4 ], as dyestuffs [ 5 , 6 ], as biocides [ 7 — 10 ], in material science [ 2 ], in organic synthesis [ 11 , 12 ], in pharmacy [ 5 , 13 ], in textiles and leather [ 2 , 14 , 15 ], in agrochemicals [ 16 ], in fibres [ 17 — 19 ], in plastics [ 20 ], in food processing [ 21 , 22 ], in petroleum industry for enhanced and tertiary oil recovery [ 23 — 25 ], in environmental protection oil slick dispersant [ 26 , 27 ] and in explosives [ 28 ].

Surfactants are also used to replace traditional solvents, giving lower risk and reduced environmental impacts [ 29 ]. Surfactants can also play a key role in the development of technologies such as nano- and smart materials [ 30 ]. Currently, the global surfactant market has been segmented into anionic, cationic, non-ionic and amphoteric [ 31 ]. These surfactants are largely used in industrial and institutional cleaners and detergents.

Cationic surfactants, like quaternary alkylammonium salts, exhibit mainly softening, antistatic, soil-repellent, antibacterial and corrosion inhibitory effects, whereas non-ionic surfactants, that is, alcohol ethoxylates, are suitable for cleaning purposes, as they are not sensitive to water hardness. Amphoteric zwitterionic surfactants, mainly derivatives of trimethyl glycine, are pH sensitive and have excellent dermatological properties.

Besides, of these four main groups, there are also special surfactants, that is, fluorocarbon and silicone surfactants, sugar-based surfactants derived from mono- and polysaccharides, biosurfactants and polymeric surfactants. An increasing use of surfactants is mainly driven by higher demand for personal care products, detergents, cleaners and industrial—anticorrosion and biocidal—products. This, in turn, is expected to lead to the introduction of innovative, more effective, surfactant-based products in the near future.

The higher efficacy of surfactants is directly related to lower CMC and surface tension as well as the efficient emulgation and solubilization effects. Such profile of innovative surfactants is accomplished to a high extent by gemini surfactants [ 34 — 36 ]. These compounds contain two hydrophilic head groups and two hydrophobic tails linked by a spacer at the head groups or closed to them. The structure of linker and its affinity to solvents can vary in a wide range. The gemini alkylammonium salts show unique surface and interfacial properties in aqueous solution.

Critical micelle concentrations CMCs of gemini surfactants are usually much lower, up to hundred times, than CMCs of corresponding monomeric surfactants. The effectiveness of dimeric surfactants in lowering the surface tension is also much better than their monomeric analogues. Moreover, gemini surfactants can form in solution many morphological structures, like spherical, ellipsoidal, rod shape and worm-like micelles as well as vesicles and helical or tubular forms.

These unusual properties of gemini surfactants are ground of their applications as emulsifiers, dispersants, coating agents and corrosion inhibitors. Dimeric quaternary ammonium salts are also the excellent microbiocides. The antimicrobial activity minimal inhibitory concentration - MIC of quaternary ammonium salts strongly depends on their hydrophilic-lipophilic balance HLB and the length of the spacer.

The longer the spacer, the better the antimicrobial activity. It is because gemini surfactants with longer spacers are more flexible and easily connect with the negative-charged surface of bacteria or fungi. To better understand the fascinating physicochemical and biological properties of gemini surfactants and their wide potent applications, we present a review of synthesis, structure, properties and applications of these compounds.

Gemini surfactants contain two hydrophilic head groups and two hydrophobic tails linked by a spacer at the head groups or closed to them. The substituents in gemini surfactants are responsible to high extent for behaviour of these compounds in solution and their possible applications.

It is a very important part of gemini surfactant which regulates the adsorption on the surfaces and interfaces and formation of self-assembly aggregates. To get the anticipated properties of gemini surfactants, the structure has to be optimized by modification of HLB. It can be done by introduction of balanced polar or hydrophobic groups both to substituents and spacers.

Polarity can be increased by ester, ether, amide, sulphide and cyclodextrin group [ 39 — 41 ]. To increase hydrophobicity some fluorine groups [ 42 ] or a dehydroabietylamine derivative [ 43 ] can be introduced to substituent. To increase biodegradability some amide or ester groups, which facilitate the biodegradation should be also introduced [ 44 ].

The study of bisquaternary ammonium surfactants—gemini surfactants—has been commenced by Bunton and collaborators in [ 45 ]. They described the synthetic approach and kinetic of these nucleophilic reactions. Some years later Devinsky et al. A unique self-assembly behaviour of gemini surfactants in comparison to their monomeric analogues has been perceived by Zana [ 47 ] and Esumi et al.

The first anionic dimeric salts with two sulphate groups and two alkyl chains have been synthesized by Okahra in [ 49 ]. The yield of the synthesis of the symmetrical gemini surfactants mainly depends on reactivity of dihalogenoalkanes and polarity and protic character of solvent [ 50 — 52 ].

The best results are achieved in aprotic and polar solvents. Some of these reactions can also be carried out without solvent in mild conditions with very high yields [ 53 ]. In the first step, intermediates—alkyl 2-bromopropionates with 6, 8, 10, 12 and 14 carbon atoms in their alkyl chain—were obtained by acylation of the appropriate alkanols with 2-bromo-propanoyl bromide. Most of the amino acid-based gemini surfactants synthesized so far are N- alkylamides and ester derivatives of the amino acids N -alkanoyl derivatives, N- alkylamides and O-alkyl esters.

These compounds are prepared by condensation reactions at either the amino or the carboxyl group of the amino acid [ 57 ]. Cationic serine-based gemini surfactants were obtained by the reductive amination of glutaraldehyde with the O-protected amino acid. To avoid the cyclization reaction, the dialdehyde substrates must contain very short or very long alkyl substituent. Another possibility is to prepare N -alkyl derivatives before introduction of the linker [ 58 ].

Most studies on the synthesis and biological evaluation of the amino acid gemini surfactants address arginine derivatives [ 59 ]. A few reports on lysine-, glycine- and cystine-based gemini surfactants have also been published [ 60 — 63 ]. Quaternization of nitrogen atoms by aliphatic n -iodides was the last step of the reaction procedure [ 64 ].

Zwitterionic gemini surfactants contain positive and negative atoms inside one molecule [ 64 ]. The synthesis of zwitterionic geminis is quite complicated; therefore only a few reports appeared so far. Yoshimura et al. Xie et al. Quagliotto et al.

Limei Zhou et al. Dissymmetric gemini surfactants contain two nonidentical polar head groups and two different or identical lengths of alkyl tails according to Alami and Holmberg [ 73 ].

The first heterogemini surfactants containing quaternary ammonium and carboxylate head groups and two dodecyl or tetradecyl tails have been obtained by Jaeger et al. Some other dissymmetric gemini cationic surfactants with hydroxyl group in the spacer and different long carboxylic acid dimethylethylamine esters as cationic parts [ 75 ]. Surface activity of heterogeminis strongly depends on degree of the asymmetry.

Similarly, CMC values are much lower than those of their symmetrical counterparts. Gemini surfactants can be also prepared in microwave-assisted organic syntheses. The usefulness of 5. A large number of analytical methods can be applied to study gemini surfactants and their structure, surface behaviour and interaction with polymers and other materials.

To determine structures of gemini surfactants, the standard spectroscopic methods, nuclear magnetic resonance NMR spectroscopy 1 H, 13 C and 31 P , mass spectrometry fast atom bombardment and Fourier-transformed infrared spectroscopy FT-IR are mostly used.

In turn, protons of hydrocarbon chain at highly hydrophobic section of the surfactant residue in the core portion of micelle are highly shielded; hence 1 H NMR peaks are observed in lower ppm regions [ 78 ]. The variation of the chemical shifts due to the hydrophobicity can be used as a method to study of the aggregation process. Diffusion coefficients from pulsed gradient spin-echo PGSE NMR experiments reveal that the annulene gemini micelles are similar in size and shape to those of simple monomeric surfactants [ 71 ].

The very interesting results have also been observed for 1 H NMR study of two series of quaternary ammonium gemini surfactants s and s at concentrations below their CMC in aqueous solutions. The analysis of self-diffusion coefficients, changes in chemical shift, line width and line shapes indicates the premicellization of these two series of geminis below their CMC values [ 79 ].

NMR technique has been also applied to study of the binding isotherms of the surfactants to the polymers [ 79 — 82 ]. McLachlan and Marangoni have investigated the interactions between poly styrenesulfonate PSS , dodecyltrimethylammonium bromide DTAB and cationic gemini surfactants s [ 80 ]. For the gemini cationic surfactants, the NMR chemical shifts indicate that the manner in which the gemini surfactants self-assemble with the polymer is dependent on the spacer length of the surfactant.

The 1 H chemical differences indicate that the manner in which the DTAB and the long-spacer gemini surfactants interact with the PSS is fundamentally similar, whereas the short-spacer gemini surfactants have a different 1 H chemical shift difference pattern for the spacer and chain protons; this may indicate subtle differences in the nature of the binding of these cationic surfactants to the polyanions.

The unusual self-assembly behaviour of gemini surfactants possesses challenging puzzles to theoretical investigations [ 83 ]. In view of the above, the cationic gemini surfactant designated as E ethane-1,2-diyl bis N,N -dimethyl- N -hexadecylammoniumacetoxy -dichloride was obtained and investigated as a corrosion inhibitor for mild steel MS in 1 M HCl solution by refined analytical methods and weight loss measurements.

Moreover, the inhibition effect of the investigated compound was analysed by DFT method [ 84 ]. Cationic gemini surfactants of the mm type have been investigated with luminescence probing and neutron scattering [ 85 ].

Multifunctional Gemini Surfactants: Structure, Synthesis, Properties and Applications

By Bogumil E. Brycki, Iwona H. 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. 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.

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Either your web browser doesn't support Javascript or it is currently turned off. In the latter case, please turn on Javascript support in your web browser and reload this page. Read article at publisher's site DOI : J Am Chem Soc, 10 Langmuir, 20

Book Gemini Surfactants Synthesis Interfacial And Solution Phase Behavior And Applications 2003

Improvements in transfection efficiency are required in order to make the goal of cellular gene delivery by non-viral vectors realizable. Novel derivatives of gemini surfactants having dissymmetric tail groups have been designed specifically as a means to improve DNA transfection; the micelle and interfacial properties are reported herein. The effect of these substitutions on the aggregation properties of the gemini surfactants is discussed in the context of results for the m m gemini series, previously reported in the literature. Phytanyl substitution results in lower cmc and higher micelle ionization. In addition, the phytanyl substituted gemini surfactants form vesicles at room temperature.

2 Comments

Armina M. 23.03.2021 at 02:49

Synthesis, Interfacial and Solution-Phase Behavior, and Applications It surveys the state of special gemini surfactants, including nonionic, zwitterionic.

Aglaya M. 23.03.2021 at 03:29

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