scholarly journals Hydrophobic coatings prepared using various dipodal silane-functionalized polymer precursors

2022 ◽  
Vol 7 ◽  
pp. 100207
Author(s):  
Gabriel Sikukuu Nambafu ◽  
Nahae Kim ◽  
Juyoung Kim
Author(s):  
X. Qiu ◽  
A. K. Datye ◽  
T. T. Borek ◽  
R. T. Paine

Boron nitride derived from polymer precursors is of great interest for applications such as fibers, coatings and novel forms such as aerogels. The BN is prepared by the polymerization of functionalized borazine and thermal treatment in nitrogen at 1200°C. The BN powders obtained by this route are invariably trubostratic wherein the sheets of hexagonal BN are randomly oriented to yield the so-called turbostratic modification. Fib 1a and 1b show images of BN powder with the corresponding diffraction pattern in fig. 1c. The (0002) reflection from BN is seen as a diffuse ring with occational spots that come from crystals of BN such as those shown in fig. 1b. The (0002) lattice fringes of BN seen in these powders are the most characteristic indication of the crystallinity of the BN.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 151
Author(s):  
Yuyang Liu ◽  
Chang-Hwan Choi

Sand, a cheap and naturally abundant particulate material, was modified with photocatalytic and hydrophobic coatings to reduce evaporation loss and facilitate the purification of water. The first-level photocatalytic coatings (TiO2 or ZnO nanocrystals) rendered nanoscale roughness on the surface of the sand. The additional second-level hydrophobic coating of a self-assembled monolayer of octyltrimethoxysilane (OTS) made the sand particles superhydrophobic because of the nanoscale roughness imposed by the nanocrystals. The superhydrophobic sand particles, floating on the free surface of water due to their superhydrophobicity, significantly reduced the evaporation loss of water by 60%–90% in comparison to an uncovered water surface. When the outer hydrophobic coatings are weathered or disengaged, the inner photocatalytic coatings become exposed to water. Then, the sand particles act as photocatalysts to degrade the contaminants in water under solar radiation.


2021 ◽  
Vol 9 (2) ◽  
pp. 249
Author(s):  
Thomas Schalck ◽  
Bram Van den Bergh ◽  
Jan Michiels

Fuels and polymer precursors are widely used in daily life and in many industrial processes. Although these compounds are mainly derived from petrol, bacteria and yeast can produce them in an environment-friendly way. However, these molecules exhibit toxic solvent properties and reduce cell viability of the microbial producer which inevitably impedes high product titers. Hence, studying how product accumulation affects microbes and understanding how microbial adaptive responses counteract these harmful defects helps to maximize yields. Here, we specifically focus on the mode of toxicity of industry-relevant alcohols, terpenoids and aromatics and the associated stress-response mechanisms, encountered in several relevant bacterial and yeast producers. In practice, integrating heterologous defense mechanisms, overexpressing native stress responses or triggering multiple protection pathways by modifying the transcription machinery or small RNAs (sRNAs) are suitable strategies to improve solvent tolerance. Therefore, tolerance engineering, in combination with metabolic pathway optimization, shows high potential in developing superior microbial producers.


Author(s):  
Petr Shkinev ◽  
Alina Evdokimova ◽  
Fedor V Drozdov ◽  
Lev L Gervits ◽  
Aziz M Muzafarov
Keyword(s):  

1993 ◽  
Vol 308 ◽  
Author(s):  
Sandrine Bec ◽  
André Tonck ◽  
Jean-Luc Loubet

ABSTRACTPyrolysis of polymer precursors (polysilazane) is a technologically and economically interesting way to produce thin ceramic coatings. However, many cracks appear and decohesion occurs during pyrolysis when the ceramic coatings (SiOCN) are thicker than 0.5 micrometers. In order to understand these cracking phenomena, the coatings are mechanically characterized by nanoindentation at different stages of the pyrolysis heat treatment.During pyrolysis, the cracking temperature is detected by in-situ optical observation. The thickness of the coatings varies during pyrolysis from 3 micrometers at the polymeric state to 1 micrometer at the ceramic state. The coatings' properties, hardness and Young's modulus are evaluated after heat treatment, taking into account the substrate's influence. A large variation of these properties occurs at the cracking temperature. Both the hardness and the Young's modulus are multiplied by a factor of 10. By analysing these results, we show that cracking is correlated with the evolution of the coatings' mechanical properties during the transformation.


2015 ◽  
Vol 27 (21) ◽  
pp. 7388-7394 ◽  
Author(s):  
Jing Huang ◽  
Xu Zhou ◽  
Alexandros Lamprou ◽  
Fernando Maya ◽  
Frantisek Svec ◽  
...  

2011 ◽  
Vol 115 (21) ◽  
pp. 10727-10735 ◽  
Author(s):  
V. M. Gun’ko ◽  
S. T. Meikle ◽  
O. P. Kozynchenko ◽  
S. R. Tennison ◽  
F. Ehrburger-Dolle ◽  
...  

2015 ◽  
Vol 12 (11) ◽  
pp. 1271-1283 ◽  
Author(s):  
Dimitrios A. Dragatogiannis ◽  
Elias Koumoulos ◽  
Kosmas Ellinas ◽  
Angeliki Tserepi ◽  
Evangelos Gogolides ◽  
...  

Langmuir ◽  
2007 ◽  
Vol 23 (10) ◽  
pp. 5505-5514 ◽  
Author(s):  
Mojca Fir ◽  
Boris Orel ◽  
Angela Šurca Vuk ◽  
Aljaž Vilčnik ◽  
Robi Ješe ◽  
...  

2016 ◽  
Vol 23 (2) ◽  
pp. 1038-1047 ◽  
Author(s):  
Jianlin Hu ◽  
Binhuan Lan ◽  
Ke Xu ◽  
Xingliang Jiang ◽  
Zhijin Zhang ◽  
...  

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