Diffusiophoresis in ionic surfactants: effect of micelle formation

Soft Matter ◽  
2019 ◽  
Vol 15 (2) ◽  
pp. 278-288 ◽  
Author(s):  
Patrick B. Warren ◽  
Sangwoo Shin ◽  
Howard A. Stone

We explore the consequences of micelle formation for diffusiophoresis of charged colloidal particles in ionic surfactant concentration gradients, using a quasi-chemical association model for surfactant self assembly.

Author(s):  
Regina A. Smith ◽  
Elena Yu. Demyantseva ◽  
Ol’ga S. Andranovich

Biotechnology is one of the fastest growing sector of scientific and applied activities of the humans, which needs to be successfully integrated into existing technologies. Such upcoming trend is the combination of conventional pulp treatment by surfactants and enzymatic processing in order to prevent pitch troubles in the pulp and paper mills. This article presents the research results of the abilities of non-ionic surfactants (sintamid-5, sintanol DS-10), enzyme (lipase) and their syner-gistic combinations to the micelle formation and solubilization. We chose the optimal synergistic compositions and investigated their colloid-chemical characteristics. There is no effect to the micelle formation ability of surfactants when addition of lipase is up to 30%. The largest deviation from the additive values of surface activity was observed for the mixture of individual non-ionic surfactant and lipase at the ratio of 70:30. However, in the all mixtures of both surfactants and lipase the ratio of experimental surface activity to the theoretically calculated is less than one. It looks, that hydrophilic areas of mixed aggregates block hydrophobic areas of lipase thereby preventing adsorption of lipase at the interface. A predominance of the surfactant in the composition will reduce its cost. The maximum of solubilizing capacity has sintanol DS-10 due to its highest HLB and the lowest CMC that leads to more micelles amount in solution and higher total hydrocarbon volume. The pitch solubilization in lipase solutions does not depend on enzyme concentration. The high pitch dissolving in synergistic mixture of sintanol DS-10 and lipase is observed. It is predetermines the usage of such systems for cellulose deresination.For citation:Smith R.A., Demyantseva E.Yu. Andranovich, O.S. Impact of lipase on micelle formation and solubilization abilities of non-ionic surfactants. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 6. P. 54-60


2021 ◽  
Vol 44 (4) ◽  
Author(s):  
Pooja Arya ◽  
Maren Umlandt ◽  
Joachim Jelken ◽  
David Feldmann ◽  
Nino Lomadze ◽  
...  

Abstract We consider sedimented at a solid wall particles that are immersed in water containing small additives of photosensitive ionic surfactants. It is shown that illumination with an appropriate wavelength, a beam intensity profile, shape and size could lead to a variety of dynamic, both unsteady and steady state, configurations of particles. These dynamic, well-controlled and switchable particle patterns at the wall are due to an emerging diffusio-osmotic flow that takes its origin in the adjacent to the wall electrostatic diffuse layer, where the concentration gradients of surfactant are induced by light. The conventional nonporous particles are passive and can move only with already generated flow. However, porous colloids actively participate themselves in the flow generation mechanism at the wall, which also sets their interactions that can be very long ranged. This light-induced diffusio-osmosis opens novel avenues to manipulate colloidal particles and assemble them to various patterns. We show in particular how to create and split optically the confined regions of particles of tunable size and shape, where well-controlled flow-induced forces on the colloids could result in their crystalline packing, formation of dilute lattices of well-separated particles, and other states. Graphic Abstract


Soft Matter ◽  
2021 ◽  
Author(s):  
Jiawei Lu ◽  
Xiangyu Bu ◽  
Xinghua Zhang ◽  
Bing Liu

The shapes of colloidal particles are crucial to the self-assembled superstructures. Understanding the relationship between the shapes of building blocks and the resulting crystal structures is an important fundamental question....


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2846
Author(s):  
Seung Hyuk Im ◽  
Dam Hyeok Im ◽  
Su Jeong Park ◽  
Justin Jihong Chung ◽  
Youngmee Jung ◽  
...  

Polylactide (PLA) is among the most common biodegradable polymers, with applications in various fields, such as renewable and biomedical industries. PLA features poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) enantiomers, which form stereocomplex crystals through racemic blending. PLA emerged as a promising material owing to its sustainable, eco-friendly, and fully biodegradable properties. Nevertheless, PLA still has a low applicability for drug delivery as a carrier and scaffold. Stereocomplex PLA (sc-PLA) exhibits substantially improved mechanical and physical strength compared to the homopolymer, overcoming these limitations. Recently, numerous studies have reported the use of sc-PLA as a drug carrier through encapsulation of various drugs, proteins, and secondary molecules by various processes including micelle formation, self-assembly, emulsion, and inkjet printing. However, concerns such as low loading capacity, weak stability of hydrophilic contents, and non-sustainable release behavior remain. This review focuses on various strategies to overcome the current challenges of sc-PLA in drug delivery systems and biomedical applications in three critical fields, namely anti-cancer therapy, tissue engineering, and anti-microbial activity. Furthermore, the excellent potential of sc-PLA as a next-generation polymeric material is discussed.


2021 ◽  
Vol 155 (8) ◽  
pp. 084902
Author(s):  
Iva Manasi ◽  
Mohammad R. Andalibi ◽  
Ria S. Atri ◽  
Jake Hooton ◽  
Stephen M. King ◽  
...  

2021 ◽  
Vol 1874 (1) ◽  
pp. 012059
Author(s):  
B BadrulHaswan ◽  
A R Hassan ◽  
K Ali ◽  
A A M Redhwan ◽  
A Nasir

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