In plants, the epidermis cells may show some morphological variations, but the model presented in Fig. Adsorption isotherms for three isomerically pure alkylbenzene sulfonates were measured on alumina and kaolinite from aqueous solutions. including new information on gemini surfactants (a new type of powerful This is always attributed to the formation of cationic surfactant complexes through the electrostatic attraction of hydrophilic groups. nanostructured superhydrophobic surfaces was developed that is very effective in removing Surfactant research. the contaminated areas and that can be easily removed after cleaning by rinsing without damaging The presence of the amphiphilic molecules is effective in lowering the contact angle in a hydrophobic or still superhydrophobic range. ist inzwischen möglich, superhydrophobe Oberflächen nach dem Vorbild der Natur zu konstruieren. However, C12DAO was observed to interact more favorably with SDS and with C12TAB than was predicted by the MT theory. * Clearly explains the Excimers are molecular associates that exist only in excited electronic states. glass and plastic surfaces and their wetting properties. While in the low-affinity region the amount adsorbed and the integral enthalpies of displacement are only slightly smaller for C8G1 than for C8E4, the deviation increases to 1 order of magnitude in the aggregative adsorption region. TEGOTENS® AM VSF proved to be unsuitable for cleaning micro-und nanostructured Lotus- Effect® This paper compares the theoretical prediction with matching experiments. the surface. sample, the super- hydrophobic plastic surface showed smaller roughness and higher waviness We first compared the predicted micellar titration data to experimental micellar titration data that we obtained for varying compositions of mixed micelles containing the pH-sensitive surfactant dodecyldimethylamine oxide (C12DAO) mixed with either a cationic surfactant (dodecyltrimethylammonium bromide, C12TAB), a nonionic surfactant (dodecyl octa(ethylene oxide), C12E8), or an anionic surfactant (sodium dodecyl sulfate, SDS) surfactant. Superhydrophobe Oberflächen stehen in der Industrie kurz vor dem Durchbruch. Molecules of biological importance and especially proteins, nucleic acids and glycopolymers, are the targets, where the principles of biomolecular recognition are of great utility. Studies on silicon surfaces patterned with pillars of varying diameter, height and pitch values and deposited with a hydrophobic coating were performed to demonstrate how the contact angles vary with the pitch. into the nanotextures, lead to an irreversible loss of the self- cleaning properties and an However, for branch-tailed surfactants such as sodium-bisethylhexylsulfosuccinate and didodecyldimethylammonium bromide, superhydrophobic surfaces can turn superhydrophilic by increasing cs owing to continuous reduction of solid-liquid interfacial tension. Es gibt zwei Herausforderungen. The adsorption isotherms of the two mixed systems exhibit different characteristics which can be attributed to the magnitude of the difference in critical micelle concentrations (cmc's) of the individual components in each pair. Four different surfactants were examined and the cationic surfactant TEGOTENS® DO of The effect of surface heterogeneity on the wettability of an idealized heterogeneous surface has been studied with the aid of a digital computer. surfactants at the alumina-water interface, Hemimicelle Formation of Cationic Surfactants at the Silica Gel–Water Interface, Some thoughts on superhydrophobic wetting, Solvent Effect on the Vibrational Structures of the Fluorescence and Absorption Spectra of Pyrene, Adsorption and Aggregation of C 8 E 4 and C 8 G 1 Nonionic Surfactants on Hydrophilic Silica Studied by Calorimetry, Ueber das Verhalten der fettsauren Alkalien und der Seifen in Gegenwart von Wasser. The other phase contains only small amount of surfactants and contaminants as the treated water. The MT theory presented here represents the first molecular-based quantitative description of the micellization behavior of mixtures of pH-sensitive surfactants and conventional surfactants, and allows qualitative and quantitative predictions of the micellization behavior of a variety of surfactant systems. In this Chapter the reader may not find exhaustive coverage of data on the sensing of all possible targets. Interactions between surfactant solutions and solid surfaces play a key role in technologically important processes such as The main point of departure from previous theories lies in the recognition and elucidation of the role of geometric constraints in self-assembly. Privatsphäre-Einstellungen TRUMPF nutzt Cookies, um eine Vielzahl von Services anzubieten, diese stetig zu verbessern sowie Werbung entsprechend den Interessen unserer Besucher anzuzeigen. the decamine oxide type and the nonionic surfactant TEGOTENS® EC Furthermore, dynamic contact Die Seifen als Colloïde, TiO2 Photocatalysis: A Historical Overview and Future Prospects, Roughness optimization for biomimetic superhydrophobic surfaces, Adsorption of Surfactants on Mineral Oxide Surfaces from Aqueous Solutions. CORE is a not-for-profit service delivered by We also compared predictions to data from the literature for mixtures of C12DAO and SDS. Increasing the complexity of the target molecules requires adequate improvement of the binding and reporting properties of the sensors. disappears as the concentration of propylene glycol increases. Their use as water-repellent coatings is established, but their potential for use in microfluidics and sensor applications remains largely unfulfilled. [S. Chander, D. W. Fuerstenau and D. Stigter, in Adsorption From Solution, ed. The values of the amplitude parameters Ra, Rq and Rz for the plastic surface are 0.920 Starting with the outside of the epidermis cell, ones finds the outermost layer of a thin extracellular membrane, called cuticle. The anionic surfactants proved to be Non-contact, optical profilometry The following general evolution of the adsorbed layer morphology with increasing surface hydrophobicity was observed:  diffuse micellar coverage; dense micellar coverage; bilayer; and finally a monolayer structure at the most hydrophobic surface. cleaning process and the resulting adsorption of surfactants at the surfaces. More significantly, it has been used as a white pigment from ancient times, and thus, its safety to humans and the environment is guaranteed by history. A transition can occur between the different states by an external disturbance. The results indicate that at a certain critical concentration or critical pH, adsorption increases markedly through association of the hydrocarbon chains of the adsorbed sulfonate ions to form hemimicelles at the solid-liquid interface. Compared to the glass ionic to nonionic components were analyzed by two independent theories. The adsorption of the mixtures C14E6−C10E6 and C12E5−C12E8 onto a silica surface has been studied by in situ null ellipsometry. The surface active properties of the used surfactant mixtures were calculated using the surface tension measurements and the critical micelle concentration (CMC) values. [citation needed] In contrast, hydrophiles are attracted to water. Patent, DE 10 2006 009 761: 1–13. Access scientific knowledge from anywhere. Google Scholar excellent. The main result is that from θ = 0.07 to θ = 0.8, the adsorbed layer has a fragmented (or micellar) structure whereas, beyond θ = 0.8, it is better described as an "infinite", or continuous, medium in which large diffusion paths exist for the probe molecules. In addition, when a large amount of potassium ion was added to a solution including Triton X-100, Triton X-100 could be determined by the same technique as described above because of formation of the K+-Triton X-100 cation. Branching decreases the contribution of hydrophobic interactions to two-dimensional condensation (hemi-micelle formation) at the solid-liquid interface. benzylhexadecyldimethylammonium chloride (C16BzCl), hexadecyltrimethylammonium bromide (C16Br), and polyoxyethylene(20)mono-n-hexadecyl ether (Brij-58) with a 16-carbon (C16) hydrophobic chain; the second series consisted of dodecyltrimethylammonium bromide (C12Br), dodecylethyldimethylammonium bromide (C12EBr), and polyoxyethylene(4)mono-n-dodecyl ether (Brij-30) with a 12-carbon (C12) chain. superhydrophobic surfaces by generating several surface parameters. hydrophobic oily/greasy soils at low concentrations without damaging the surface. Using this approach, we were able to describe the experimental surface tension isotherms for mixtures of surface-active sugar derivatives and ionic surfactants. 11 of the end-capped fatty alcohol ethoxylate type proved to be most efficient on the nile-red Four different surfactants were examined and the cationic surfactant TEGOTENS® DO of When tetrakis(4-fluorophenyl)borate was added dropwise to the solution, the color of the organic phase turned to yellow at the. nat. Dies ermöglicht der Herstellung von anisometrischen „patchy particles“ durch Verwendung von zusätzlichen magnetischen Fe3O4-Nanopartikeln. To read the full-text of this research, you can request a copy directly from the author. accumulation of soil in this area. applications), and dynamic surface tension (an important interfacial µm, It was found that phase separation only occurs over a narrow range of molar ratios of DTAB:DPDS from 1.6:1 to 2.4:1. following the total wetting Wenzel regime whereas the plastic surface could be described by the We also review a few special case studies aimed at adopting these biomimetlc schemes to design and fabricate functional self-cleaning surfaces. Especially Genapol® LRO (90%) 172° were measured. concentration on the cleaning efficiency were investigated. This leads to the establishment of a design criterion for a robust hydrophobic rough surface on which the apparent contact angle will not change as a result of an external disturbance. Therefore, it is important to study the adhesion and friction properties of these surfaces that mimic nature. Responding to intermolecular interactions, fluorescent dyes can recognize the medium and determine its physical parameters, such as temperature and pressure. various wetting regimes, contact angle and contact angle hysteresis. into the nanotextures, lead to an irreversible loss of the self- cleaning properties and an solution for superhydrophobic surfaces that already function at low concentrations specifically in The correlation of the intensities of the fluorescence and absorption bands to solvent polarities is discussed. These data suggest that the selective adsorption of a group on alumina is due to a polarization of its p or π electrons in a strong positive surface field. sulfate sodium salt, 78%) and REWOPOL® SB DO 75 (di-isooctyl sulfosuccinate, 87%). 1.304 µm and 8.526 µm. At the same time the maximum micellar interaction parameter was obtained by the mixtures VIII and IV (−1.85 and −1.80, respectively). Water penetration into the pattern cavities is accompanied by a change in the apparent contact angle. biomimetic superhydrophobic surfaces have been fabricated by mimicking the structure of the Superhydrophobe Oberflächen mit Kontaktwinkeln zwischen 173 und 180° lassen sich einfach durch spontane Abscheidung einer strukturierten Gold‐ oder Silberschicht und darauf einer selbstorganisierten Monoschicht aus Polyfluoralkylthiol herstellen. Superhydrophobic surfaces have considerable technological potential for various applications due to their extreme water-repellent properties. The study of the kinetic behavior of the mixtures reveals that the adsorption characteristics are similar for the two systems, while during desorption they behave very differently. Durch diese extrem feinen Strukturen (ein Nanometer ist ein milliardstel Meter) sind die Oberflächen grundsätz-lich äußerst empfindlich gegenüber Abrieb und damit nicht robust ge-nug für alltägliche Anwendungen. To achieve low contact angle hysteresis along with a high contact angle, superhydrophobic surfaces should form composite interface (0) with air pockets in the valleys between asperities. hexadecyltrimethylammonium bromide (CTAB), dodecylpyridinium bromide (DPyB), and hexadecylpyridinium bromide (CPyB), the anionic surfactant sodium dodecyl sulphate (SDS), and the nonionic surfactant Triton X‐100 were used. Comparisons with adsorption on silica, Contact Angle Hysteresis. The observed difference in the adsorption behavior is interpreted in terms of the different hydrophilic head groups of the two amphiphiles. In addition, use of RSA has been extended, with fair success, to predict partition coefficients of ternary surfactant systems using data of binary surfactants systems. As in the case of benzene, the Ham bands of pyrene were assigned to the 0–0 and ag-vibration bands. and Hostapur® OS (83%) have been demonstrated to be very effective in removing the standard soil In conclusion, in cooperation with the industrial project partners a cleaning agent for micro- and glass and plastic surfaces and their wetting properties. The molar enthalpies of aggregate formation at the silica/water interface were found to be close to those in the bulk solution, indicating that surface aggregation and bulk micellization are very similar phenomena. The critical micelle concentrations and the enthalpies of micelle formation of n-octyl tetraethylene glycol monoether (C8E4) and n-octyl β-d-monoglucoside (C8G1) in water have been determined at 298.15 K by titration microcalorimetry. superhydrophobic glass surface. Mixtures of anionic and cationic surfactants can also exhibit aqueous-aqueous phase separation and can be used in the ASTP extraction process. In conclusion, in cooperation with the industrial project partners a cleaning agent for micro- and 1.304 µm and 8.526 µm. This finding is in contrast to that obtained for the interactions between cationic and nonionic surfactants under the same conditions. The unique surface structure of the lotus leaf in combination with hydrophobic epicuticular wax In der Orthopädie und Unfallchirurgie leisten sie hierdurch einen wichtigen Beitrag zur Lösung der aktuellen und zukünftigen Herausforderungen. Additionally, the QSPR models can be used to predict the cleaning efficiency of aqueous solution. The MT theory was validated by examining mixtures containing both a pH-sensitive surfactant and a, Benzene, toluene, ethylbenzene, and xylene are frequently observed contaminants in industrial wastewaters causing concerns about environmental and health effects. cleaning process and the resulting adsorption of surfactants at the surfaces. Finally, we have to identify bacteria and viruses, achieving ultimate speed and ultimate sensitivity of their detection. sample, the super- hydrophobic plastic surface showed smaller roughness and higher waviness In contrast to the structural dimensions, the process parameters had only a minor impact on the contact angle. accumulation of soil in this area. The combination of these two functions has opened up various novel applications of TiO2, particularly in the field of building materials. We show, on the basis of experimental evidence, that there can be two contact angles on the same rough surface, depending on how a drop is formed. Silicone surfaces, which aim to imitate the surface of the lotus plant, were prepared using a microstructured injection mold. The biggest problem of the fine surface roughness is the sensitivity to oily solutions of highly hydrophobic surfaces (important in agricultural Barthlott W& Ehler N Rasterelektronenmikroskopie der Epidermis-Oberflächen von Spermatophyten. Im Rahmen dieser Arbeit wurden nano-TiO2-Partikel unter Rückfluss und durch Autoklavbehandlung hergestellt. The results show that all the adsorption isotherms exhibit two plateaux either with or without various additives. For the Lotus-Effect® plastic surface we obtained Contact angle is controlled by surface tension for common linear surfactants and becomes independent of cs as cs>critical micelle concentration. The adsorption increases rapidly beyond a certain concentration. Our results reveal that it is possible to produce robust superhydrophobic surfaces in a single-step liquid silicone injection molding process. Superhydrophobic surfaces were fabricated by the complex coating of silica nanoparticles with functional groups onto cotton textiles to generate a dual-size surface roughness, followed by hydrophobization with stearic acid, 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane or their combination. III. grayscale evaluations. Therefore, each of the eleven surfactants were combined with a Especially Genapol® LRO (90%) of the superhydrophobic surfaces at low concentrations. Bei „Fluoropor“ hingegen ist die The detailed adsorption isotherms of five isomers of sodium dodecylbenzene sulfonate at the alumina-water interface have been determined as a function of concentration and pH. 11 of the end-capped fatty alcohol ethoxylate type proved to be most efficient on the nile-red Practical When a liquid drop impinges a hydrophobic rough surface it can either bounce off the surface (fakir droplets) or be impaled and strongly stuck on it (Wenzel droplets). a contact angle of 167.7° ± 1.5°. We show how static contact angles vary with micro- and nanopatterns on the polymer surfaces. Nach IUPAC-Definition ist die Hydrophobie der Zusammenschluss unpolarer Gruppen oder Moleküle in einer wässrigen Umgebung, aufgrund der Tendenz von Wasser, unpolare Gruppen oder Moleküle auszuschließen. fundamental physical mechanisms of wetting, including the transition between The anionic surfactants proved to be cleanability. silica. Contact angle and advancing and receding contact angles on the Lotus-Effect® glass surface were The simultaneous analysis of the time laws for the pyrene monomer and excimer decays has been performed along the TX 100 adsorption isotherm from θ = 0.07 to θ = 1 (θ being the apparent surface coverage, i.e., the ratio "amount adsorbed/amount adsorbed at the plateau of the isotherm"). The enthalpy/entropy balance of the formation of the adsorption layer has been described in terms of thermodynamic potential functions.

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