scholarly journals Janus amphiphilic nanoplatelets as smart colloid surfactants with complementary face-to-face interactions

2020 ◽  
Vol 56 (45) ◽  
pp. 6031-6034
Author(s):  
Jin Yong Lee ◽  
Kyu Hwan Choi ◽  
Jaemin Hwang ◽  
Minchul Sung ◽  
Ji Eun Kim ◽  
...  

A new type of colloidal surfactant that not only has a nanoscale platelet geometry, but can also induce complementary face-to-face interactions among Pickering emulsion droplets is introduced.

Author(s):  
Timo Harrikari ◽  
Marjo Romakkaniemi ◽  
Laura Tiitinen ◽  
Sanna Ovaskainen

Abstract This article addresses the experiences of Finnish frontline social workers during the first wave of the COVID-19 pandemic in the spring of 2020. Two questions are addressed. First, ‘what types of challenges social work professionals faced’ in their everyday, ‘glocal’ pandemic setting and, second, what types of solutions they developed to meet these challenges. The data consist of 33 personal diaries that social work professionals created from mid-March to the end of May 2020. The diaries are analysed by a thematic content analysis and placed within the framework of a strengths, weaknesses, opportunities and threats analysis. The results suggest that the pandemic challenged social work at all levels, from face-to-face interactions to its global relations. The pandemic revealed not only the number of existing problems of social work, but also created new types of challenges. It demanded ultimate resilience from social workers and a new type of adaptive governance from social welfare institutions.


1968 ◽  
Vol 9 (1) ◽  
pp. 119-146 ◽  
Author(s):  
J. M. Lonsdale

This paper attempts to provide a frame of reference for evaluating the role of ordinary rural Africans in national movements, in the belief that scholarly preoccupation with élites will only partially illumine the mainsprings of nationalism. Kenya has been taken as the main field of enquiry, with contrasts and comparisons drawn from Uganda and Tanganyika. The processes of social change are discussed with a view to establishing that by the end of the colonial period one can talk of peasants rather than tribesmen in some of the more progressive areas. This change entailed a decline in the leadership functions of tribal chiefs who were also the official agents of colonial rule, but did not necessarily mean the firm establishment of a new type of rural leadership. The central part of the paper is taken up with an account of the competition between these older and newer leaderships, for official recognition rather than a mass following. A popular following was one of the conditions for such recognition, but neither really achieved this prior to 1945 except in Kikuyuland, and there the newer leaders did not want official recognition. After 1945 the newer leadership, comprising especially traders and officials of marketing co-operatives, seems everywhere to have won a properly representative position, due mainly to the enforced agrarian changes which brought the peasant face to face with the central government, perhaps for the first time. This confrontation, together with the experience of failure in earlier and more local political activity, resulted in a national revolution coalescing from below, co-ordinated rather than instigated by the educated élite.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1071 ◽  
Author(s):  
Yu-Jin Cho ◽  
Dong-Min Kim ◽  
In-Ho Song ◽  
Ju-Young Choi ◽  
Seung-Won Jin ◽  
...  

A pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA)-based oligoimide (PMDA-ODA) was synthesized by a one-step procedure using water as a solvent. The PMDA-ODA particles showed excellent partial wetting properties and were stably dispersed in both water and oil phases. A stable dispersion was not obtained with comparison PMDA-ODA particles that were synthesized by a conventional two-step method using an organic solvent. Both oil-in-water and water-in-oil Pickering emulsions were prepared using the oligoimide particles synthesized in water, and the size of the emulsion droplet was controlled based on the oligoimide particle concentration. The oligoimide particles were tested to prepare Pickering emulsions using various kinds of oils. The oil-in-water Pickering emulsions were successfully applied to prepare microcapsules of the emulsion droplets. Our new Pickering emulsion stabilizer has the advantages of easy synthesis, no need for surface modification, and the capability of stabilizing both oil-in-water and water-in-oil emulsions.


2021 ◽  
pp. 1-27
Author(s):  
Yichen Bao ◽  
Kai Liu ◽  
Quan Zheng ◽  
Lulu Yao ◽  
Yufu Xu

Abstract Pickering emulsion is a new type of stable emulsion made by ultra-fine solid particles instead of traditional surfactants as stabilizers, which has received widespread attention in recent years. The preparation methods of stator-rotor homogenization, high-pressure homogenization, and ultrasonic emulsification were compared with others in this work. The main factors affecting the stability of Pickering emulsion are the surface humidity of the solid particles, the polarity of the oil phase, and the oil-water ratio. These factors could affect the nature of the solid particles, the preparation process of Pickering emulsion and the external environment. Consequently, the long-term stability of Pickering emulsion is still a challenge. The tribological investigations of Pickering emulsion were summarized, and the multifunctional Pickering emulsion shows superior prospects for tribological applications. Moreover, the latest development of Pickering emulsion offers a new strategy for smart lubrication in the near future.


Author(s):  
Alison G. Vredenburgh ◽  
Gail L. Sunderman ◽  
Rodrigo J. Daly Guris ◽  
Sreekanth R. Cheruku

In this follow-up panel, we discuss what we have learned over the last year about responding to an epidemic or pandemic that has demonstrated a level of transmission unprecedented in the modern era. Two medical doctors that have worked on the front of this pandemic share their experiences transitioning from the “sharp end” of the response. Decisions about how to mitigate hazards have occurred at the personal, institutional, and health policy levels, in real-time, with frequent adaptation, and often in advance of concrete evidence. Over the course of the pandemic, hospital systems revised existing protocols to manage perceived risks in real time using emerging information from other centers. With the introduction of vaccines, there is a new type of risk perception. Is the vaccine perceived to be safe? Is there a disparity in perception among different population groups? That said, analyses are also complicated by emerging viral mutations with unclear implications. What factors increase or decrease public compliance with precautions? How are US education policymakers deciding about face-to-face classroom instruction? This panel includes a warnings expert, an expert on education policy, and two practicing physicians.


Soft Matter ◽  
2019 ◽  
Vol 15 (46) ◽  
pp. 9587-9596 ◽  
Author(s):  
Zhaoyu Xie ◽  
Christopher J. Burke ◽  
Badel Mbanga ◽  
Patrick T. Spicer ◽  
Timothy J. Atherton

We disentangle the influence of shape and kinetics in the structure of arrested Pickering emulsion droplets after coalescence.


2013 ◽  
Vol 110 (6) ◽  
Author(s):  
Guo Chen ◽  
Peng Tan ◽  
Shuyu Chen ◽  
Jiping Huang ◽  
Weijia Wen ◽  
...  

2015 ◽  
Vol 137 (3) ◽  
pp. 1362-1371 ◽  
Author(s):  
Hengquan Yang ◽  
Luman Fu ◽  
Lijuan Wei ◽  
Jifen Liang ◽  
Bernard P. Binks

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