Foaming behavior of fluorocarbon surfactant used in fire-fighting: The importance of viscosity and self-assembly structure

2020 ◽  
pp. 114811
Author(s):  
Xiaoyang Yu ◽  
Fan Li ◽  
Huasong Fang ◽  
Xuyang Miao ◽  
Jiyun Wang ◽  
...  
2019 ◽  
Vol 85 ◽  
pp. 56-64
Author(s):  
O. I. Stepanov ◽  
◽  
A. N. Denisov ◽  
M. V. Stakheev ◽  
◽  
...  
Keyword(s):  

Author(s):  
María Alonso-García ◽  
Aída Solís-Mellado ◽  
Cristina Gómez-Vázquez ◽  
Manuel Fernández-Rubio ◽  
Óscar D. de-Cózar-Macías ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
C.F. Castro-Guerrero ◽  
A.B. Morales-Cepeda ◽  
M.R. Díaz-Guillén ◽  
F. Delgado-Arroyo ◽  
F.A. López-González

Abstract Cellulose nanocrystals were extracted from cotton. The cellulose nanocrystals made a self-assembly structure when dried under slow conditions, as it was revealed by the characterization made to the material. The AFM images of the nanocrystals showed that they had a changing local orientation, pointing in a preferred direction that underwent a periodic change. This periodic change resembles the orientation of a chiral nematic phase. The TEM images showed that the nanocrystals had a rod-like appearance with average length size of 98.5 nm and a diameter of 4.7 nm. The TEM characterization showed the nanocrystals with more details than AFM. In this paper, the self-assembling of CNC was observed by AFM, and further investigations were done by TEM, deconvoluting the process of CNC nanorods aggregation.


2018 ◽  
Vol 5 (5) ◽  
pp. 180247 ◽  
Author(s):  
Yuanming Zhang ◽  
Tingting Sun ◽  
Wei Jiang ◽  
Guangting Han

In this paper, the crystalline modification of a rare earth nucleating agent (WBG) for isotactic polypropylene (PP) based on its supramolecular self-assembly was investigated by differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscopy. In addition, the relationship between the self-assembly structure of the nucleating agent and the crystalline structure, as well as the possible reason for the self-assembly behaviour, was further studied. The structure evolution of WBG showed that the self-assembly structure changed from a needle-like structure to a dendritic structure with increase in the content of WBG. When the content of WBG exceeded a critical value (0.4 wt%), it self-assembled into a strip structure. This revealed that the structure evolution of WBG contributed to the K β and the crystallization morphology of PP with different content of WBG. In addition, further studies implied that the behaviour of self-assembly was a liquid–solid transformation of WBG, followed by a liquid–liquid phase separation of molten isotactic PP and WBG. The formation of the self-assembly structure was based on the free molecules by hydrogen bond dissociation while being heated, followed by aggregation into another structure by hydrogen bond association while being cooled. Furthermore, self-assembly behaviour depends largely on the interaction between WBG themselves.


1961 ◽  
Vol 65 (611) ◽  
pp. 749-755 ◽  
Author(s):  
R. P. Fraser

The process of atomisation is of primary importance in several branches of engineering, such as in the combustion of liquid fuels, in the chemical industry, in operations involving drying, evaporation, absorption, and so on, in fire-fighting and the production and dissipation of fogs and in agriculture.In agriculture, the spraying of small drops is employed in the dissemination of insecticides, herbicides, etc., for the purpose of crop protection, and the spraying of large drops is used for overhead irrigation.Since the advent of the atomiser, a hundred years ago, the engineer has been in advance of theory in his practice of atomisation. For lack of fundamental data he has had to rely upon laborious hit and miss experiments to obtain a design suitable to a particular requirement. Thus the atomiser has been a fruitful avenue for the inventor. Its small size and apparent simplicity has, however, deceived many into the belief that the problem is simple. Research over the last thirty years has proved this to be anything but true, and even now our knowledge is still extremely limited.


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