Direct Synthesis of Hybrid Organic−Inorganic Nanoporous Silica Microspheres. 1. Effect of Temperature and Organosilane Loading on the Nano- and Micro-Structure of Mercaptopropyl-Functionalized MSU Silica

2003 ◽  
Vol 15 (1) ◽  
pp. 327-334 ◽  
Author(s):  
Luc Beaudet ◽  
Kazi-Zakir Hossain ◽  
Louis Mercier
Keyword(s):  
Direct Synthesis ◽  
Effect Of Temperature ◽  
Nanoporous Silica ◽  
Micro Structure ◽  
Silica Microspheres

Experimental Investigation of Friction Reduction in Transport of Fluids Using Surfactants

2012 ◽  
Author(s):  
Florencio Sanchez-Silva ◽  
Ignacio Carvajal-Mariscal ◽  
Pedro Quinto-Diez ◽  
Juan Gabriel Barbosa-Saldana
Keyword(s):  
Nonionic Surfactants ◽  
Sodium Salicylate ◽  
Friction Reduction ◽  
Effect Of Temperature ◽  
Experimental Facility ◽  
Micro Structure ◽  
Surfactant Mixtures ◽  
Pressure Losses ◽  
Mass Fluxes ◽  
Inner Diameter

This paper presents the results of the influence of surfactants in reducing friction while driving fluid in pipes. Experimental research was conducted with water-surfactant mixtures which were tested three types of these additives: anionic, cationic and nonionic surfactants. Was designed and built an experimental facility in which the test area was acrylic pipe with an inner diameter of D = 19 mm and a length of 300 D. The concentrations of surfactants in the mixtures were 150, 250, 500, 750 and 1000 ppm, added according to a pilot program that took into account the amount and type of additive added in different liquid mass fluxes. Pressure losses were compared against those obtained when flow is the same water flows through the installation. The results obtained show a reduction of up to 43.9% of the friction which is achieved with a Re = 11243 and surfactant concentrations of 250 ppm (cetyl trimethyl chloride ammonium), to which was added as a stabilizer for the micro structure of the surfactant, sodium salicylate, which applies only to the cationic type surfactants. The results are promising but left to study such issues as: the injection and recovery of surfactant, more efficient mixing, the mechanisms that lead to a reduction of friction and the effect of temperature among others.

Nanoporous silica microspheres–ploymethylpentene (TPX) hybrid films toward effective daytime radiative cooling

2020 ◽  
Vol 206 ◽  
pp. 110301 ◽  
Author(s):  
Jingnan Yang ◽  
Xiangdong Gao ◽  
Yongqing Wu ◽  
Tongtong Zhang ◽  
Huarong Zeng ◽  
...  
Keyword(s):  
Nanoporous Silica ◽  
Radiative Cooling ◽  
Hybrid Films ◽  
Silica Microspheres

Analysis the Effect of Temperature and Holding Time of Full - Annealing Heat Treatment to Micro Structure, Mechanical Properties, and Electrical Conductivity of Aluminium Copper (Al-Cu) Alloy

2019 ◽  
Vol 964 ◽  
pp. 280-285
Author(s):  
Dian Mughni Fellicia ◽  
Rochiem Rochman ◽  
Clarissa Changraini
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Holding Time ◽  
Effect Of Temperature ◽  
Pure Aluminium ◽  
Micro Structure ◽  
Aluminium Copper ◽  
Annealing Heat Treatment ◽  
Full Annealing ◽  
Annealing Heat

Good electrical conductivity properties of aluminium are the main reason this metal become an option as material of electrical devices. To improve the ductility and electrical conductivity properties, aluminium is combined with copper. The aim of this study is to analyze the effect of temperature and holding time of full-annealing heat treatment to the micro structure, hardness, and electrical conductivity of aluminium copper alloy (Al-Cu). In this research, pure aluminium with the addition of 4% copper (Cu) composition has been casted with gravity die casting mold made from ductile cast iron, and continued full-annealing heat treatment with 3 variations at temperature (2600C, 3500C, and 4400C), and 3 variations of holding time (2 hours, 3 hours, and 4 hours). It was found that the effect of higher temperature at the same holding time with the full-annealing heat treatment caused the grains of phase α become more regular and greater so that the hardness decreased and the electrical conductivity was increased.

scholarly journals Lipase B from Candida antarctica Immobilized on Epoxy-functionalized Hollow Silica Microspheres: Efficient Biocatalysts for Enantiomer Selective Acylation of Alcohols and Amines

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Márk Oláh ◽  
Szandra Suba ◽  
Zoltán Boros ◽  
Péter Kovács ◽  
Mathilde Gosselin ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Kinetic Resolution ◽  
Operation Time ◽  
Candida Antarctica ◽  
Effect Of Temperature ◽  
Flow Mode ◽  
Silica Microspheres ◽  
Lipase B ◽  
Hollow Silica ◽  
Racemic Amines

Hollow silica microspheres with promising physical properties (MAT540TM) as support for enzyme immobilization and biocatalyst were investigated in this study. The amine-functionalized MAT540TM was activated by six bisepoxides inclosing different spacers and used as epoxy-functionalized carrier for immobilization of lipase B from Candida antarctica (CaLB). The novel, covalently fixed CaLB biocatalysts were compared in kinetic resolution (KR) of racemic 1-phenyethanol rac-1 and five racemic amines rac-3a-e using shaken flasks and continuous-flow packed-bed microreactors. Mechanic stability, re-usability and the effect of temperature (0–90 °C) on productivity and enantiomer selectivity of the covalently immobilized CaLB were investigated. The best performing CaLB biocatalyst showed good mechanic stability after 24 h operation time in continuous-flow mode at 60 °C and provided in KRs of racemic 1-phenyethanol rac-1 with vinyl acetate and of five racemic amines with isopropyl 2-ethoxyacetate as acylating agent the non-reacted (S)-alcohol [(S)-1] or (S)-amines [(S)-3a-e] and the forming (R)-ester [(R)-2] or (R)-amide [(R)-4a-e] in good yields with high enantiomeric excess (ee > 99 %, for all).

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