scholarly journals Synthesis and Characterization of High-Performing Sulfur-Free Tannin Foams

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 564 ◽  
Author(s):  
Jonas Eckardt ◽  
Jonas Neubauer ◽  
Thomas Sepperer ◽  
Sandro Donato ◽  
Michela Zanetti ◽  
...  

Tannin foams are green lightweight materials that have attracted industrial interest for the manufacturing of sandwich panels for insulation purposes. However, the dimensions of the cells and the presence of sulfur in the formulation developed until now have discouraged their upscaling. In this work, we present the synthesis and the characterization of the more promising small cell and sulfur-free materials. It was observed that, with respect to standard ones, foams catalyzed with nitric acid present similar physical properties and more phenolic character, which favors the absorption of ionic pollutants. Conversely, the foams blown with aliphatic solvents and surfactants present smaller pores, and higher mechanical and insulating properties, without affecting the chemical properties or the heating value. The combined foam produced with nitric acid as a catalyst and petroleum ether as a blowing agent result in sulfur-free and small cell material with overall improved features. These foams have been produced at 30 × 30 × 3 cm3, with high homogeneity and, to date, they represent the most suitable formulation for industrial upscaling.

2014 ◽  
Vol 70 (a1) ◽  
pp. C1223-C1223
Author(s):  
Jason Benedict ◽  
Ian Walton ◽  
Dan Patel ◽  
Jordan Cox

Metal-organic Frameworks (MOFs) remain an extremely active area of research given the wide variety of potential applications and the enormous diversity of structures that can be created from their constituent building blocks. While MOFs are typically employed as passive materials, next-generation materials will exhibit structural and/or electronic changes in response to applied external stimuli including light, charge, and pH. Herein we present recent results in which advanced photochromic diarylethenes are combined with MOFs through covalent and non-covalent methods to create photo-responsive permanently porous crystalline materials. This presentation will describe the design, synthesis, and characterization of next-generation photo-switchable diarylethene based ligands which are subsequently used to photo-responsive MOFs. These UBMOF crystals are, by design, isostructural with previously reported non-photoresponsive frameworks which enables a systematic comparison of their physical and chemical properties. While the photoswitching of the isolated ligand in solution is fully reversible, the cycloreversion reaction is suppressed in the UBMOF single crystalline phase. Spectroscopic evidence for thermally induced cycloreversion will be presented, as well as a detailed analysis addressing the limits of X-ray diffraction techniques applied to these systems.


2019 ◽  
Vol 803 ◽  
pp. 346-350
Author(s):  
Jessalyn C. Grumo ◽  
Lady Jaharah Y. Jabber ◽  
Arnold A. Lubguban ◽  
Rey Y. Capangpangan ◽  
Arnold C. Alguno

We report on the rigid polyurethane foam (RPUF) with varying amount of blowing agent. The effects of blowing agent in the formation of polyurethane will be characterized using scanning electron microscopy (SEM) and fourier transform infrared (FTIR) spectroscopy. SEM images revealed that varying the amount of blowing agent will significantly change the surface morphology of the resulting RPUF. The average cell size of the RPUF increases with increasing amount of blowing agent. Moreover, FTIR results revealed the presence of functional group related to formation of urethane bonds such as N-H, C=O, C=N and C-O-C stretching suggesting that polyurethane foam was successfully synthesized. This simple and straightforward process of RPUF using water as blowing agent will be economical.


2013 ◽  
Vol 203-204 ◽  
pp. 81-85 ◽  
Author(s):  
Małgorzata Zienkiewicz-Strzałka ◽  
Marek Rotko ◽  
Stanislaw Pikus

This paper reports, for the first time, synthesis and characterization of new bifunctional materials containing platinum and silver ions deposited on mesoporous ordered silica SBA-15. Both types of ions were incorporated on silica surface during adsorption from water solutions containing various amounts of dissolved tetraamineplatinum(II) dichloride and diamminesilver(I) hydroxide or tetraamineplatinum(II) dichloride and diamminesilver(I) chloride complexes. The silanol groups on silica surface play important role in adsorption mechanism and one of the most commonly used technique for their characterization is photoacoustic spectroscopy. This technique provides clear evidence of successfully incorporation two types of precious metal ions (Pt and Ag) on SBA-15 surface. The decomposition process of absorbed complexes was investigated according to high temperature in helium. The products of decomposition were analyzed by mass spectrometer. Obtained results show that decomposition temperature of platinum and silver complexes are quite vary. Similarly mechanisms of decomposition of ligands from silver and platinum complexes are also different. Moreover, the structural and chemical properties of Pt,Ag-SBA-15 samples were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS).


2008 ◽  
Vol 73 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Lei Wang ◽  
Yaqing Feng ◽  
Jinqiang Xue ◽  
Li Yukun

Novel porphyrin Schiff bases were synthesized by a simple Schiff base condensation in refluxing toluene between 5-(4-aminophenyl)-10,15,20-triphe?nylporphyrin (ATTP) 3 and styryl aldehydes 4-6 or p-halobenzaldehydes 7-9. The newly synthesized porphyrin Schiff bases were characterized on the basis of their chemical properties and spectral data. A good intramolecular energy transfer from the styryl unit to the porphyrin moiety was found.


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