Thèses : « Single surfactant »

1

Bardhan, Soumik. « Physicochemical studies on some self organized assemblies of single and mixed surfactant systems ». Thesis, University of North Bengal, 2015. http://hdl.handle.net/123456789/1855.

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Ayewah, Daniel Osagie Oyinkuro. « Characterization of surfactant dispersed single wall nanotube - polystyrene matrix nanocomposite ». Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1397.

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3

Barnett, Catherine Margaret Eleanor. « Association of Single Nucleotide Polymorphisms in Surfactant Protein A and D with Otitis Media ». The University of Waikato, 2007. http://hdl.handle.net/10289/2338.

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Otitis Media is one of the most common childhood diseases. Recurrent acute otitis media RAOM is characterized by repeated episodes of inflammation of the middle ear in conjunction with middle ear fluid, and often with an inflamed or bulging eardrum. Defective clearance by the Eustachian tube results in mucus build-up and is characteristic of otitis media with effusion (OME). Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, respiratory syncytial virus, and rhinovirus are the most common contributors to otitis media pathogenesis. In New Zealand, OME has been implicated with conductive hearing loss in childhood and has been shown to significantly impact on speech and language development. New Zealand Māori and Polynesian children have displayed significantly higher hearing test failure rates than European-Caucasian children. The collectins, Surfactant Protein (SP)-A and -D are encoded by three genes (SP-A1, SP-A2, and SP-D) and are host defense proteins present in the middle ear and Eustachian tube. Single nucleotide polymorphisms (SNPs) in SP-A1 and SP-A2 have been associated with increased or decreased susceptibility to otitis media, meningococcal disease, and range of respiratory diseases. Using allele-specific primers and real-time PCR with SYBR Green I melting curve analysis, four groups of individuals were genotyped for eleven SP-A1, SP-A2, and SP-D SNPs: European-Caucasian individuals with RAOM/OME; New Zealand Māori/Polynesian individuals with RAOM/OME; individuals with meningococcal disease; and a control group. The computer program, Haploview, was employed to perform χ2 analyses and identify statistically significant associations of alleles/haplotypes with RAOM/OME or meningococcal disease. In the European-Caucasian population, two SP-A1 alleles, one SP-A2 allele, and four haplotypes (CGAGC, 1A3, 1A9, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). Conversely, haplotypes 6A2 and 1A2 were found to be protective against susceptibility to RAOM/OME (P lt; 0.05). In New Zealand Māori and Polynesian individuals, two SP-A1 alleles, three SP-A2 alleles, one SP-D allele, and four haplotypes (6A8, 6A10, 1A3, and 1A10) were found to be associated with increased risk of RAOM/OME (P lt; 0.05). An additional four haplotypes (6A2, 1A0, 1A2, and TA) were determined to be protective against susceptibility to RAOM/OME (P lt; 0.05). However, protective SPA1/SPA2/SPD haplotype 6A2-1A0-TA was significantly under-represented in the New Zealand Māori and Polynesian population (P lt; 0.05). A single allele and haplotype were associated with increased risk of meningococcal disease (P lt; 0.05). The findings of this study confirm that specific genetic variants of SP-A and SP-D are associated with either increased or decreased risk of developing RAOM and/or OME. Furthermore, it was demonstrated that New Zealand Māori and Polynesian individuals appear to exhibit more haplotypes susceptible to RAOM/OME. This may provide a partial explanation for the higher RAOM/OME-related failure rates of hearing tests in New Zealand Māori and Polynesian children. However, there are numerous socio-economic and environmental factors that also contribute to otitis media pathogenesis which were not considered in this study. The effects of the SP-A1, SP-A2, and SP-D alleles and haplotypes on the bacterial/viral binding efficiencies of SP-A and SP-D need to be investigated by further research, using a large population, to confirm the association with susceptibility or resistance with RAOM/OME.

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SAMPATHKUMAR, SETHURAGHAVAN. « INTERFACIAL CHARACTERISTICS AND EBULLIENCE IN AQUEOUS SURFACTANT SOLUTIONS : DYNAMIC SURFACE TENSION AND SINGLE BUBBLE BEHAVIOR ». University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1109001316.

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Sampathkumar, Sethuraghavan. « Interfacial characteristics and ebulience in aqueous surfactant solutions dynamic surface tension and single bubble behavior / ». Cincinnati, Ohio : University of Cincinnati, 2005. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1109001316.

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Wang, Zhiyong, Gang Wang, Haoyuan Qi, Mao Wang, Mingchao Wang, SangWook Park, Huaping Wang et al. « Ultrathin Two-Dimensional Conjugated Metal-Organic Framework Single-Crystalline Nanosheets Enabled by Surfactant-Assisted Synthesis ». Royal Society of Chemistry, 2020. https://tud.qucosa.de/id/qucosa%3A72508.

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Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have recently emerged for potential applications in (opto-)electronics, chemiresistive sensing, and energy storage and conversion, due to their excellent electrical conductivity, abundant active sites, and intrinsic porous structures. However, developing ultrathin 2D c-MOF nanosheets (NSs) for facile solution-processing and integration into devices remains a great challenge, mostly due to unscalable synthesis, low yield, limited lateral size and low crystallinity. Here, we report a surfactant-assisted solution synthesis toward ultrathin 2D c-MOF NSs, including HHB-Cu (HHB=hexahydroxybenzene), HHB-Ni and HHTP-Cu (HHTP=2,3,6,7,10,11-hexahydroxytriphenylene). For the first time, we achieve single-crystalline HHB-Cu(Ni) NSs featured with a thickness of 4-5 nm (~8-10 layers) and a lateral size of 0.25-0.65 μm², as well as single-crystalline HHTP-Cu NSs with a thickness of ~5.1±2.6 nm (~10 layers) and a lateral size of 0.002-0.02 μm². Benefiting from the ultrathin feature, the synthetic NSs allow fast ion diffusion and high utilization of active sites. As a proof of concept, when serving as a cathode material for Li-ion storage, HHB-Cu NSs deliver a remarkable rate capability (charge within 3 min) and long-term cycling stability (90% capacity retention after 1000 cycles), superior to the corresponding bulk materials and other reported MOF cathodes.

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7

Pal, Prem, Kazuo Sato, Miguel A. Gosalvez, Yasuo Kimura, Ken-Ichi Ishibashi, Michio Niwano, Hirotaka Hida, Bin Tang et Shintaro Itoh. « Surfactant Adsorption on Single-Crystal Silicon Surfaces in TMAH Solution : Orientation-Dependent Adsorption Detected by In Situ Infrared Spectroscopy ». IEEE, 2009. http://hdl.handle.net/2237/13883.

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8

Spohr, Reimar. « Ion Tracks for Micro- and Nanofabrication : From Single Channels to Superhydrophobic Surfaces ». Doctoral thesis, Uppsala universitet, Materialfysik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-111247.

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A method is described for preset-count irradiations between 1 and 100 ions singling-out individual ions from an ion beam with more than a billion ions arriving per second. The ion tracks are etched in a conductometric system with real-time evaluation of the acquired data. The etch process can be interrupted when reaching a preset channel diameter. Cylindrical channels are obtained by adding surfactants to the etch solution forming a self-assembled barrier between etching medium and polymer. Asymmetric etching of single ion tracks leads to pH sensitive conical pores with diode-like properties. Using etched channels as template, homogeneous and multilayer magnetic single-wires are electrodeposited. The magnetoresistivity of the wires is studied. Single-track applications comprise critical apertures (cylindric, conic, necked), asymmetric pores (pH sensitive, biospecific), Giant Magneto Resistance sensors, and spintronic devices. On the basis of studies with individual ion tracks we tackled tilted multiporous systems such as ion beam lithography with a masked ion beam leading to micro-structures with inclined walls and anisotropic superhydrophobic ion track textures, analogous to biological shingle structures on butterfly wings. We demonstrated qualitatively, that the asymmetry of the texture translates into motion under ultrasonic agitation. This could lead to the development of rotary drives.

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9

Fennell, John. « The electrochemistry of surfactants on gold single-crystals and of platinum-gold nanorods ». Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4168/.

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A series of Pt-coated gold nanorod (Au NR) electrocatalysts were prepared. STEM images showed that Pt nanodots grew epitaxially on the Au NR surface. A CO blocking technique was used in order to coat Pt in a more controlled, uniform manner. The nanorods were characterised using UV-visible spectroscopy and, after being immobilised onto a supported glassy carbon electrode, with cyclic voltammetry. The CO blocking technique was crucial in enhancing CO electrooxidation and oxygen reduction reaction activity of the nanorods, not only because of the higher coverage of Pt nanodots but also because of their electrocatalytically more active nature.

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10

Daful, Asfaw Gezae. « Microscopic modeling of the self assembly of surfactants : shape transitions and critical micelle concentrations ». Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/33596.

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El CMC, tamaño y forma de micelas son características importantes en la determinación de sus principales propiedades y campos de aplicación. Esta tesis tiene dos partes, las transiciones de forma de las micelas que se trata con "Single chain Field Theory, /SCMFT)" y simulaciones de Monte Carlo. El SCMFT reveló todas las características esenciales de las transiciones de forma esférica a cilíndrica y esférica a disco de las micelas. MC muestra que las transiciones esfera a cilindro se produce a través de una región en que esferas y cilindros coexisten junto con otras formas intermedias.

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11

Puvvada, Sudhakar. « Theoretical and experimental studies of micellization and phase behavior of aqueous solutions of single and mixed surfactants ». Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13105.

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Odame-Ankrah, Charles Anim. « Studies of Titanium Dioxide Nanoparticles and Surfactants Effects, Singly and in Combinations, on Luminescence Intensity of Some Aromatic Compounds ». Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1799.

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Luminescence techniques are sensitive, selective, and widely used in analysis. Luminescence intensity is attenuated by quenchers. This research has focused on the use of surfactants such as CTAB, SDS, and TX-100 singly or together with TiO2 nanoparticles to evaluate their individual and combined effects on some fluorescent aromatic compounds such as pyrene, fluoranthene, anthracene, phenanthrene, and carbazole. Rutile phase TiO2 was synthesized using the low temperature sol-gel method. Carbazole and phenanthrene were severely quenched by all surfactants singly or in combination with TiO2. Anthracene and fluoranthene showed some enhancement in their luminescence intensity. The most dramatic effect was observed on the fluorescence intensity of pyrene. Pyrene showed enhanced fluorescence after degassing the solution alone or with the addition of the surfactants alone or in combination with TiO2 after degassing. These results showed that surfactants and TiO2 nanoparticles either singly or in combination should be useful for analysis employing luminescence techniques.

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Hsu, Shu-Hao, et 許書豪. « Dynamic Surface Effect on Single-Orifice Bubble Formation in Surfactant Solutions ». Thesis, 1996. http://ndltd.ncl.edu.tw/handle/81583140579219045541.

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碩士
國立成功大學
化學工程學系
84
In this paper, bubble formation experiments are studied under the constantflow and the intermediate conditions using 99% pure SDS, 95% pure SDS, andTriton X-100 aqueous solutions. Equilibrium surface tensions and dynamic surfacetensions are also measured by the Wilheimy plate method and the maximum bubblepressure method, respectively, for these aqueous solutions. In addition,mixtures of 99% SDS and Triton X-100 are also studied to compare with previousresults from aqueous solutions using single surfactant. From the results of equilibrium surface tension and dynamic surface tension,we learn that Triton X-100 is the strongest, 99% SDS is the weakest, and 95% SDSis in the middle in the ability of decreasing surface tension. Nevertheless, 99%SDS is the fastest in the rate of decreasing surface tension, Triton X-100 isthe slowest, and 95% SDS is in the middle. Besides, from the experiments ofmixtures of 99% SDS and Triton X-100, we learn that the influence of synergisticeffect is not evident in this case. Under constant flow rate condition, we modified Ruff model (1972) to includedynamic surface tension effect, the predicted results show good agreement withthe experimental observations; however, the predicted results using modifiedTsuge and Hibino model (1978) (also considered the dynamic surface tension)deviates from experimental data under intermediate condition. Nevertheless, theexperimental data of surfactant solutions agree well with the predicted resultsusing the original Tsuge and Hibino model which considered the equilibriumsurface tension only.

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Xu, Shu-Hao, et 許書豪. « Dynamic Surface Effect on Single-Orifice Bubble Formation in Surfactant Solutions ». Thesis, 1996. http://ndltd.ncl.edu.tw/handle/97734415121454658558.

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15

Stanislaus, John Bosco [Verfasser]. « Single molecule study of polymer-surfactant interactions / vorgelegt von John Bosco Stanislaus ». 2007. http://d-nb.info/985566914/34.

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Huffman, Chad B. « Magnetic purification and spectral dependence onpH of surfactant suspended single wall carbon nanotubes ». Thesis, 2004. http://hdl.handle.net/1911/18644.

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Many properties of single wall carbon nanotubes (SWNTs) are unique and advantageous. The electrical, thermal, and strength properties of SWNT are highly desirable for many applications. To take advantage of these properties it is necessary to remove the impurities that are inevitability produced during the growth of the nanotubes. High gradient magnetic separation techniques have been used to separate the magnetic catalyst particles from the nanotubes. Even if all the impurities were removed there would still be many different types of SWNTs in a sample. For the first time, different types of SWNTs have been observed acting as individual chemical species by changing the pH of surfactant stabilized suspensions of SWNTs. In the future, one can expect this scheme to play an important role in the separation of SWNTs by type.

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Moore, Valerie C. « Single walled carbon nanotubes : Suspension in aqueous/surfactant media and chirality controlled synthesis on surfaces ». Thesis, 2005. http://hdl.handle.net/1911/18785.

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Single walled carbon nanotube (SWNT) researchers have many obstacles to overcome before SWNTs become commercially applicable including two equally important but separate issues: suspending pristine, individual SWNTs in water and chirality controlled synthesis. The first part of this thesis describes how to suspend, analyze, and manipulate individually suspended SWNTs in twenty four different surfactants and polymers. The second part of this thesis explains how to attach a metal nanoparticle to the open end of a short SWNT and seamlessly grow the same chirality SWNT. Suspending pristine, individual SWNTs in water is critical for some composite material applications and any biological application. This research characterizes the spectral properties and the ability to suspend individual SWNTs for over twenty surfactants and polymers. In addition, methods for concentrating and purifying the SWNT suspensions are detailed. Finally, three examples applications of these SWNT suspensions in material and biomedical application are described. Being able to synthesize chirality-specific SWNTs in bulk quantities is critical for chirality specific SWNT applications. Currently, the problem lies with the initial SWNT nucleation; there is no control. The method for controlling SWNT chirality proposed in this thesis is a templated growth model using an existing SWNT as the template. A new catalyst particle is attached to the end of a SWNT creating a SWNTcat. During growth the carbon addition is directed through the catalyst to the existing SWNT resulting in seamless, chirality consistent growth. To test the models validity, a proof of concept was carried out on surfaces where the growth could be monitored by atomic force microscopy (AFM). The SWNTcats were prepared with a variety of catalysts in several solvents. Straight, seamless growth of the SWNTcat was seen with a variety of growth conditions proving this is a viable route to large scale synthesis of chirality-specific SWNT production.

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18

Rickard, Deborah. « Multiphase, Multicomponent Systems : Divalent Ionic Surfactant Phases and Single-Particle Engineering of Protein and Polymer Glasses ». Diss., 2011. http://hdl.handle.net/10161/3934.

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This thesis presents an analysis of the material properties and phase behavior of divalent ionic surfactant salts, and protein and polymer glasses. There has been extensive interest in understanding the phase behavior of divalent ionic surfactants due to the many applications of ionic surfactants in which they come into contact with divalent ions, such as detergency, oil recovery, and surfactant separation processes. One goal of determining the phase boundaries was to explore the option of incorporating a hydrophobic molecule into the solid phase through the micelle-to-crystal bilayer transition, either for drug delivery applications (with a biologically compatible surfactant) or for the purpose of studying the hydrophobic molecule itself. The liquid micellar and solid crystal phases of the alkaline earth metal dodecyl sulfates were investigated using calorimetry, visual inspection, solubilization of a fluorescent probe, and x-ray diffraction. The Krafft temperature and dissolution enthalpy were determined for each surfactant, and partial composition-temperature phase diagrams of magnesium dodecyl sulfate-water, calcium dodecyl sulfate-water, as well as sodium dodecyl sulfate with MgCl₂ and CaCl₂ are presented. As a proof of concept, fluorescence microscopy images showed that it is, in fact, possible to incorporate a small hydrophobic molecule, diphenylhexatriene, into the solid phase.

The second, and main, part of this thesis expands on work done previously in the lab by using the micropipette technique to study two-phase microsystems. These microsystems consist of a liquid droplet suspended in a second, immiscible liquid medium, and can serve as direct single-particle studies of drug delivery systems that are formed using solvent extraction (e.g., protein encapsulated in a biodegradable polymer), and as model systems with which to study the materials and principles that govern particle formation. The assumptions of the Epstein-Plesset model, which predicts the rate of droplet dissolution, are examined in the context of the micropipette technique. A modification to the model is presented that accounts for the effect a solute has on the dissolution rate. The modification is based on the assumption that the droplet interface is in local thermodynamic equilibrium, and that the water activity in a solution droplet can be used to determine its dissolution (or dehydration) rate. The model successfully predicts the dissolution rates of NaCl solutions into octanol and butyl acetate up to the point of NaCl crystallization. The dehydration of protein solutions (lysozyme or bovine serum albumin) results in glassified microbeads with less than a monolayer of water coverage per protein molecule, which can be controlled by the water activity of the surrounding organic medium. The kinetics of dehydration match the prediction of the activity-based model, and it is shown how the micropipette technique can be used to study the effect of dissolution rate on final particle morphology. By using a stable protein with a simple geometry (lyosyzme), this technique was be used to determine the distance dependence of protein-protein interactions in the range of 2-25 Å, providing the first calculation of the hydration pressure decay length for globular proteins. The distance-dependence of the interaction potential at distances less than 9 Å was found to have a decay length of 1.7 Å, which is consistent with the known decay length of hydration pressure between other biological materials. Biodegradable polyesters, such as poly(lactide-co-glycolide) (PLGA), are some of the most common materials used for the encapsulation of therapeutics in microspheres for long-term drug release. Since they degrade by hydrolysis, release rates depend on water uptake, which can be affected by processing parameters and the material properties of the encapsulated drug. The micropipette technique allows observations not possible on any bulk preparation method. Single-particle observations of microsphere formation (organic solvent extraction into a surrounding aqueous phase) show that as solvent leaves the microsphere and the water concentration in the polymer matrix becomes supersaturated, water phase separates and inclusions initially grow quickly. Once the concentration in the polymer matrix equilibrates with the surrounding aqueous medium, the water inclusions continue to grow due to dissolved impurities, solvent, and/or water-soluble polymer fragments resulting from hydrolysis, all of which locally lower the water activity in the inclusion. Experiments are also presented in which glassified protein microbeads were suspended in PLGA solution prior to forming the single microspheres. This technique allowed the concentration of protein in a single microbead/inclusion to be determined as a function of time.

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19

Steinhausen, Matthias. « Numerical simulation of single rising bubbles influenced by soluble surfactant in the spherical and ellipsoidal regime ». Master's thesis, 2018. https://tuprints.ulb.tu-darmstadt.de/8296/1/Matthias_Steinhausen_MT.pdf.

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Surfactants are surface active agents that accumulate at fluid interfaces and influence interfacial properties, e.g. the surface tension. For single rising bubbles, even a small amount of surfactant causes Marangoni forces that influence the bubble rise significantly. In this work, Direct Numerical Simulations (DNS) with an Arbitrary Lagrangian-Eulerian (ALE) Interface-Tracking method are performed. The use of a subgrid-scale model enables the simulation of realistic time and length scales and the comparison with experiments. The resolution requirements close to the interface are examined using 2D simulations to reduce the computational costs further. Then, 3D simulations of single rising bubbles under the influence of Triton-X100 are carried out, investigating different bubble diameters and initial surfactant bulk concentrations. The 3D simulations provide new insights into the transition from a helical motion into a zig-zag motion, which can only be observed in the presence of a surfactant. Additionally, the reciprocal influence of the local surfactant distribution on the interface and the vortex structures for path-unstable bubbles are analysed. Finally, the local surfactant distribution on the interface is modelled using a data-driven approach. The model is based on the DNS data obtained from the 3D simulations and is in good agreement with the validation data. In future work, the derived model can be used to improve existing simplified models for the simulation of bubbly flows under the influence of surfactant.

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Chen, Yong-YI, et 陳勇毅. « Study on the Effet of Surfactant Adding and Ion Implantation Process in the Anisotropic Etching of Single-Crystal Silicon ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/38425154770072719215.

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碩士
國立高雄應用科技大學
光電與通訊研究所
98
The purpose of this dissertation is to study the etching effect of single-crystal silicon in the surfactant-added tetramethyl ammonium hydroxide (TMAH) solutions and the etch stop effect of doped silicon in TMAH solutions. In this study, the V-shaped three-dimensional suspended structures were fabricated in the surfactant-added TMAH. Furthermore, the single-crystal silicon membranes and <111>-oriented single-crystal silicon infrared micro-emitters were completed by using BF2 implantation and anisotropic etching processes. In our work, 0.1% volume ratio Triton X-100 was used as the surfactant in 25wt% TMAH solution, which was employed to restrain the etch rate of <110>-oriented silicon. The etch-stop <110>-oriented surface was observed obviously in this experiment results. The impurities, such as boron, phosphorus, nitrogen, arsenic, argon and boron fluoride, were implanted into single-crystal silicon wafers in order to improve the etching selectivity. The etch experiment shows the etch selectivity of the undoped <100>-oriented silicon to BF2 doped <111>-oriented silicon is 12899:1 in 5wt% dual doped TMAH. Single-crystal silicon membranes with a thickness of 200 nm and <111>-oriented single-crystal silicon infrared micro-emitters were fabricated by using BF2 implantation and anisotropic etching. The sheet resistance and the temperature coefficient of resistance （TCR）of infrared micro-emitter are 69Ω/sq and 0.0639 %/℃ respectively.

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Huang, Hsiang-Yun, et 黃湘雲. « The Modeling of Single-Walled Carbon Nanotubes in Ionic Surfactant Aqueous Solutions based on DLVO Theory and Coarse-grained Molecular Dynamic Simulation ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/02128067608634297076.

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碩士
國立交通大學
材料科學與工程學系所
104
The dispersion of the single-walled carbon nanotubes (SWCNTs) in aqueous solutions has been an important issue. However, it is a challenging task since it requires the understanding to both macroscopic properties of the solution and the colloidal mechanism in the molecular level. In this work, a simulation framework which combines the coarse-grained molecular dynamics (MD) simulations and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, is developed to predict the stability of the SWCNTs in aqueous solutions. The surfactant used here is sodium dodecyl sulfate (SDS). The adsorption of the solutions with different concentration of SDS is simulated. Next, the Langmuir isotherm model is used to find the relationship between the amount of the adsorbed SDS and the bulk SDS concentration. With the increasing number of the SDS covered on SWCNTs, the surface charge density is also enhanced, and thus, greater electrical double layer repulsion is achieved to prevent the aggregation of the SWCNTs. The potential energy barrier as a function of SDS concentration and radius of the SWCNT then can be obtained by using DLVO theory. It can predict the dispersion of the SWCNTs in the solution. The results suggest an optimal surfactant concentration which can stabilize the SWCNTs in the solution. The finding have good agreement with those in experiments. Many features of the solution, such as the relationship between radius of the SWCNTs and surfactant adsorption, are accurately predicted. We not only investigate the structural configuration of SDS ions absorbed on the SWCNT surface, but also discuss the configuration and interface characteristics of SDS self-assembled micelles. In addition, the distribution of SDS ions can affect the distribution of the sodium counterions in the solution. The current framework is expected to provide the guidance for the design of the concentration of SDS surfactants and the radius of SWCNTs in dispersed experiments.

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« Solubility, length characterization, and cryo-TEM of pristine and functionalized single-walled carbon nanotubes in surfactant and superacid systems, with application to spinning SWNT fibers ». Thesis, 2010. http://hdl.handle.net/1911/62052.

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Single wall carbon nanotubes (SWNTs) have remarkable properties: the thermal conductivity of diamond, the electrical conductivity of copper, and mechanical properties greater than steel at a sixth of the weight. If these properties can be retained at the macroscale, SWNT fibers could be used in many high performance applications. The difficulty lies with dispersing SWNTs at high concentrations. Strong van der Waals attractive forces cause bundle formation, which limits SWNT self-assembly into highly aligned macro-structures. Using additives, SWNTs can be dispersed as individuals at low concentrations. Although spinning fibers is difficult to do with these dispersions, I have exploited their ability to disperse individual SWNT to develop an easy technique to measure the SWNT length distribution through the bulk measurements of viscosity or polarized absorbance in an external magnetic field. Determining length is important for fiber spinning, since longer nanotubes offer promise of stronger, more conductive fibers at the cost of higher viscosities and difficulty in dispersing. To produce neat SWNT fibers, we use superacids, which can disperse SWNTs at high concentrations, forming liquid crystalline phases that are valuable in forming highly-aligned SWNT fibers. I found that functionalization improves SWNT stabilization and solubility at lower concentrations, but at high concentrations, most of functional groups studied prevents the formation of highly aligned phases, which translated into poorly-aligned fibers. I found that chlorosulfonic acid is the most effective solvent, yielding high isotropic solubility and liquid crystallinity at high concentrations. Moreover, cryo-TEM shows that chlorosulfonic acid dissolves as individuals 500mum-long SWNTs and MWNTs.

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Savva, Kleopatra. « A prospective randomized, double blind, placebo-controlled trial of a single dose of surfactant as rescue therapy for infants less than 1000grams who are not ventilated ». Thesis, 2014.

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To test if a single dose of artificial surfactant given as rescue therapy to extremely low birth weight ( ELBW) infants (i.e. those with birth weight <1000g) with hyaline membrane disease who are not ventilated, will improve their survival.

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Baker, Michael C. « The effects of surfactants on single droplet vapor explosions ». 1991. http://catalog.hathitrust.org/api/volumes/oclc/23960635.html.

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Thesis (M.S.)--University of Wisconsin--Madison, 1991.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 39-40).

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Krüger, Carsten. « Liquid Crystal Microswimmers - from single entities to collective dynamics ». Doctoral thesis, 2016. http://hdl.handle.net/11858/00-1735-0000-002B-7CA4-2.

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« Studies of Surfactants and Titanium Dioxide Nanoparticles Effects, Singly And in Combinations, on Luminescence Intensity of Some Aromatic Compounds ». East Tennessee State University, 2009. http://etd-submit.etsu.edu/etd/theses/available/etd-0708109-131456/.

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Liao, Chun-Yen, et 廖俊彥. « Synthesis and Study of Hydrogen-Bonded Bent Core Liquid Crystalline Mixtures Containing C60 Surface-Modified with Single and Double Benzoic Acid Surfactants ». Thesis, 2013. http://ndltd.ncl.edu.tw/handle/09027417812510703974.

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碩士
國立交通大學
材料科學與工程學系所
102
In this study we prepared novel composites materials from the hydrogen-bonded bent-core liquid crystal (LC) host and different mole ratios (0–90 mol%) of the surface-modified fullerenes(C60). The chemical structures of these compounds were characterized by 1H-NMR, 13C-NMR, IR spectra, MS as well as elemental analysis, and the liquid crystalline phases and mesomorphic behavior of all the compounds were identified from the results of DSC, POM, electro-optical measurement and XRD. The mesomorphic properties of the composites, including their mesophasic types and ranges, values of Ps, and saturated electric field were adjustable by varying the doping concentrations of fullerenes. By increasing the concentration of fullerenes, the polarity of the SmCP phase in the composite varied sequentially from anti-ferroelectricity to ferroelectricity. Futhermore, adding a little amount of surface-modified fullerenes make the mixtures possesses the best Ps value and saturated electric field.

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Chiocchini, Claudia [Verfasser]. « The surfactin biosynthetic complex of Bacillus subtilis : COM domain-mediated biocombinatorial synthesis, and single step purification of native multi-modular NRPSs and multi-enzyme complexes / vorgelegt von Claudia Chiocchini ». 2006. http://d-nb.info/982586426/34.

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Thèses sur le sujet « Single surfactant »

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