scholarly journals Strong synergistic effect of cationic hydrocarbon surfactant and novel nonionic tri-block short-chain fluorocarbon surfactant mixtures on surface activity, wettability and solubilization

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Yutang Zhou ◽  
Yong Jin ◽  
Yichao Shen ◽  
Liangjie Shi ◽  
Shuangquan Lai ◽  
...  

Abstract Mixing hydrocarbon surfactants with fluorocarbon surfactants is still an important strategy to improve the economic benefits and performances of fluorocarbon surfactants and expand their range of application. Herein, we prepared a novel kind of hydrocarbon-fluorocarbon surfactant mixtures via mixing a cationic surfactant, cetyltrimethylammonium bromide (CTAB), with a tri-block nonionic short-chain fluorocarbon surfactant (F9EG13F9) in aqueous solution. The results showed that adding a small CTAB amount to F9EG13F9 (the molar fraction of CTAB in the mixture (x1) was 0.2) could greatly reduce its critical micelle concentrations (cmc) from 0.408 mmol/L to 0.191 mmol/L. At this x1, the contact angle of the mixture was the minimum (57.7 °) at 100 s on polytetrafluoroethylene film, which was even lower than that of F9EG13F9. Besides, CTAB/F9EG13F9 mixtures possessed better colloidal stability and solubilization ability toward hydrophobic dye (Sudan І) than F9EG13F9. The outstanding performances of binary surfactant mixtures benefited from the non-ideal mixing and strong synergistic effect evidence that CTAB/F9EG13F9 surfactant mixtures could be used in practical applications instead of individual F9EG13F9, thereby reducing the used cost of F9EG13F9. Graphical abstract

2021 ◽  
Author(s):  
Guofeng Su ◽  
Ximing Zhong ◽  
Songfa Qiu ◽  
Jiajin Fan ◽  
hongjun zhou ◽  
...  

Abstract In this work, a novel antibacterial nanocomposite system was developed using mesoporous silica (MSN) as an effective nanocarrier, and the resultant nanocomposites demonstrated remarkable antibacterial performance due to the synergistic effect among nano zinc oxides, silver nanoparticles, and polydopamine (PDA). The successful synthesis of MSN/ZnO@PDA/Ag nanocomposites was confirmed. The physicochemical properties and the morphologies of these nanocomposites were investigated. It was found that the particle size increased along with the evolution of these nanocomposites. Besides, nano zinc oxides were formed in the nanoconfinement channel of mesoporous silica with a particle size about 2 nm, and that of silver nanoparticle was less than 50 nm. In addition, the results revealed that the presence of mesoporous silica could effectively prevent the formation of large-size silver nanoparticles and facilitate their well dispersion. Due to the synergistic effect among nano zinc oxides, silver nanoparticles, and polydopamine, these nanocomposites exhibited remarkable antibacterial performance even at a low concentration of 313 ppm, and the antibacterial mechanism was also elucidated. Therefore, this work provides a facile and controllable approach to preparing synergistically antibacterial nanocomposites, and the remarkable antibacterial performance make them suitable for practical applications.


Author(s):  
Amilton Arruda ◽  
Celso Hartkopf ◽  
Rodrigo Balestra

Over the past decade, one can observe a steady growth in the use of terms such as Place Branding, Nation Branding, Destination Branding and City Branding. Both in academic research and in the practical applications in large cities management and urban spaces, this new paradigm takes shape and, along with it, the need for definitions and concepts, methods and methodologies and the establishment of technical and theoretical standards. This approach was born in the Marketing field, specifically in what was called Place Marketing. In this context the Branding stood out as a development tool solutions to the need for differentiation, generation of solid images and the establishment of symbols and identity signs, in order to leverage economic benefits for countries, cities and regions. In a way, fulfilling, in the first instance, a similar role to the branding of products and services. But it was specifically in Branding corporations that were found the biggest matches to adapt this knowledge to management positions. Ashworth & Kavaratzis (2010) highlight the fact that both present multidisciplinary roots, a multiple number of strategic actors (stakeholders), high degree of intangibility and complexity of social responsibility, the multiplicity of identities and the long-term development needs are strong examples their similarities. The development and management of corporate identities, here expanded to the Branding corporations, it is a prolific field of Design. It great names of the area said their careers and built great legacy. The time of greater proficiency in the area were the 50s and 60s, dominated by modernist thought, and, coincidentally or not, exactly the time that focused efforts to assert the identity of the designer as a professional (STOLARSKI, 2006) . Nationally stand out names like Alexandre Wollner, Ruben Martins, the duo Carlos Cauduro and Ludovico Martino and Aloisio Magalhaes. In contrast, in the literature produced in the marketing field, often the role of design in this context is reduced to merely promotional measures, such as creating logos or advertising campaigns. In other words, defined as a work of low complexity and low social prägnanz. This approach comes at odds with contemporary theories of design, such as MetaDesign, Design Thinking and Design Collaborative, in which are presented motodológicos models of high relevance for the identification, analysis and solution of complex problems involving multiple elements and agents. The proposed article aims to survey the state of the art City Branding / Place Branding focused on publications produced in the disciplinary field of design. The literature review will grant that, before the above presented context, is analyzed as designers and researchers design face the contributions that the field can offer to the practice and theory of Branding places. Finally, Article yearns assess whether the pre-established hypothesis that there are possible and fruitful connections between contemporary theories of design and the City Branding, is being addressed in articles and publications area.DOI: http://dx.doi.org/10.4995/IFDP.2016.3288


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Jianhui Huang ◽  
Wenting Lin ◽  
Liyan Xie ◽  
Wingkei Ho

Nanocrystal ZnxCd1-xS solid solutions were successfully prepared using a facile and reproducible method of ultrasonic spray pyrolysis with Cd(Ac)2·2H2O, ZnCl2, and thiourea as precursors. Scanning electron microscopy and transmission electron microscopy images show that the prepared particles possess microspherical morphology. The band gaps of the solid solutions can be tuned by changing the constituent stoichiometries of Cd and Zn. The X-ray diffraction peaks gradually shift to small angle, and the absorption edge shifts to long wavelength with increasing Cd molar fraction in the solid solution. The sample prepared at the Cd/Zn ratio of 1 : 1 displays the optimal activity by using the photocatalytic degradation of methyl orange in the aqueous solution as model reactions under visible light irradiation. This study provides an effective route to prepare spherical ternary photocatalysts with mesoporous structure for further investigations and practical applications.


1992 ◽  
Vol 45 (4) ◽  
pp. 769 ◽  
Author(s):  
TJ Connolly ◽  
VC Reinsborough ◽  
XY Xiang

Solubilities of pyridine-2-azo-p-dimethylaniline ( pada ) were determined at 25�C in four mixed fluorocarbon/hydrocarbon short-chained surfactant systems: ( i ) sodium decyl sulfate/sodium perfluoroheptanoate; (ii) sodium octanesulfonate /sodium perfluorooctanoate ; (iii) sodium octanesulfonate /sodium perfluoroheptanoate ; (iv) sodium nonanesulfonate /sodium perfluoroheptanoate. Systems ( i ), (iii) and (iv) showed micellar miscibility (one mixed micelle) and synergistic solubilization effects. System (ii) had two critical micelle concentrations pointing to two micellar forms in solution, and no synergism could be detected. From these four examples, it is deduced that single mixed micelles are formed when the critical micelle concentrations of the pure surfactants are within a factor of 3 of each other.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Yingying Li ◽  
Wei Xiong ◽  
Cheng Zhang ◽  
Xing Yang

Glucose biofuel cell (GBFC) is a power supply device which has attracted considerable attention because of its green environmental protection and high economic benefits. Fuels like glucose and oxygen are ubiquitous in physiological fluids, allowing the direct harvest of energy from human bodies. Compared with conventional batteries such as Li-Po, GBFC is a more promising alternative to power medical devices without the need to be replaced or refueled. However, the energy conversion efficiency of the existing GBFCs still needs to be further improved for practical applications. In this paper, the performance of the GBFC was studied based on single-walled carbon nanotubes (SWCNTs), which have relatively high conductivity and large specific surface area that could improve the activity of enzymes immobilized on the electrode surface and thus realize the direct electron transfer (DET). After optimization of the catalysts’ amount, the GBFC based on SWCNTs performed well with two Pt layers sprayed on one side of the proton exchange membrane (PEM) and 1.5 mL glucose oxidase (GOx) dropped on the other side, which attained the highest open-circuit potential (OCP) of 0.4 V. After being encapsulated with a flexible porous enclosure made by polydimethylsiloxane (PDMS), the biological compatibility of the completed GBFC has been successfully improved, which provides great potential for powering wearable or implantable devices.


2006 ◽  
Vol 110 (23) ◽  
pp. 11369-11376 ◽  
Author(s):  
Elena Blanco ◽  
Paula Messina ◽  
Juan M. Ruso ◽  
Gerardo Prieto ◽  
Félix Sarmiento

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