scholarly journals Fast Method for Testing the Photocatalytic Performance of Modified Gypsum

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 693 ◽  
Author(s):  
Janus ◽  
Zając ◽  
Ehm ◽  
Stephan
Keyword(s):  
Photocatalytic Activity ◽  
Building Materials ◽  
Photocatalytic Performance ◽  
Air Purification ◽  
Fast Method ◽  
Angle Measurements ◽  
Activity Measurements ◽  
Contact Angle Measurements ◽  
Different Types

The measurement of the photocatalytic activity of building materials is quite time-consuming. Up until now, researchers have mainly used the equipment described in ISO 22197-1 to ISO 22197-4 for the determination of air purification activity, although other apparatus such as colorimeters, UV-Vis/DR spectroscopes and equipment for contact angle measurements have also been used. Usually, photocatalytic activity measurements take from one hour up to several hours. In this study, we present a very fast method for the measurement of the photocatalytic activity of gypsum. A specially designed printer with a modified bubblejet cartridge was used to apply a special ink on the surface of gypsum plates. Then the surface was irradiated by UV-A light and every 3 s a picture of the surface was taken. The results showed that the discoloration of the dye occurs after a few seconds of irradiation and the time depends on the amount of photocatalyst used as well as the number of printed ink layers. It was concluded that it is possible to use this method for a quick comparison of the photocatalytic activity of different types of modified gypsum materials.

Nanocomposite Photocatalyst Based on Layered Double Hydroxides (LDHs) Associated with TiO2

2014 ◽  
Vol 92 ◽  
pp. 100-109 ◽  
Author(s):  
Jonjaua Ranogajec ◽  
Andrijana Sever-Skapin ◽  
Ognjen Rudic ◽  
Snezana Vucetic
Keyword(s):  
Photocatalytic Activity ◽  
Layered Double Hydroxides ◽  
Direct Contact ◽  
Building Materials ◽  
Specific Problem ◽  
The Self ◽  
Different Types ◽  
Double Hydroxides ◽  
Positive Effect ◽  
Material Porosity

The surfaces of building materials are constantly exposed to the actions of environmental factors, pollutants of inorganic and organic origin as well as to microorganisms, which significantly contribute to corrosion phenomena.The application of coatings decreases the negative action of the pollutants minimizing their direct contact with the substrate. Different types of coatings with additional functions have been developed. A specific problem of these applications is the lack of compatibility of the photocatalysts with the surface of the building materials and the detachment of potentially toxic TiO2nanoparticles. In the present study, this problem was solved by the proper immobilization of TiO2nanoparticles onto the photocatalyst support, layered double hydroxides (LDHs). The newly formed coating possesses acceptable porosity for a porous building material (porosity within the range of 30-46 %) and satisfied photocatalytic activity, as well as mineralogical compatibility with the substrates (mortars, renders, bricks). Additionally, a positive effect considering the self-cleaning phenomenon was attained.

scholarly journals Determination of Hemicellulose, Cellulose, and Lignin Content in Different Types of Biomasses by Thermogravimetric Analysis and Pseudocomponent Kinetic Model (TGA-PKM Method)

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1048
Author(s):  
David Díez ◽  
Ana Urueña ◽  
Raúl Piñero ◽  
Aitor Barrio ◽  
Tarja Tamminen
Keyword(s):  
Thermogravimetric Analysis ◽  
Kinetic Model ◽  
Lignin Content ◽  
Low Cost ◽  
Biomass Composition ◽  
Fast Method ◽  
Additional Information ◽  
Extraction And Purification ◽  
Different Types

The standard method for determining the biomass composition, in terms of main lignocellulosic fraction (hemicellulose, cellulose and lignin) contents, is by chemical method; however, it is a slow and expensive methodology, which requires complex techniques and the use of multiple chemical reagents. The main objective of this article is to provide a new efficient, low-cost and fast method for the determination of the main lignocellulosic fraction contents of different types of biomasses from agricultural by-products to softwoods and hardwoods. The method is based on applying deconvolution techniques on the derivative thermogravimetric (DTG) pyrolysis curves obtained by thermogravimetric analysis (TGA) through a kinetic approach based on a pseudocomponent kinetic model (PKM). As a result, the new method (TGA-PKM) provides additional information regarding the ease of carrying out their degradation in comparison with other biomasses. The results obtained show a good agreement between experimental data from analytical procedures and the TGA-PKM method (±7%). This indicates that the TGA-PKM method can be used to have a good estimation of the content of the main lignocellulosic fractions without the need to carry out complex extraction and purification chemical treatments. In addition, the good quality of the fit obtained between the model and experimental DTG curves (R2Adj = 0.99) allows to obtain the characteristic kinetic parameters of each fraction.

scholarly journals Comments on “An Essay on Contact Angle Measurements”: Determination of Surface Roughness and Modeling of the Wetting Behavior

2011 ◽  
Vol 8 (11) ◽  
pp. 998-1002 ◽  
Author(s):  
Antonia Terriza ◽  
Rafael Alvarez ◽  
Francisco Yubero ◽  
Ana Borras ◽  
Agustin R. González-Elipe
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Wetting Behavior ◽  
Angle Measurements ◽  
Contact Angle Measurements

Determination of Components of Cassiterite Surface Free Energy from Contact Angle Measurements

1993 ◽  
Vol 161 (1) ◽  
pp. 209-222 ◽  
Author(s):  
B. Jańczuk ◽  
J.M. Bruque ◽  
M.L. González-Martı́n ◽  
J.Moreno del Pozo
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Angle Measurements ◽  
Contact Angle Measurements

scholarly journals Fundamental Investigations Regarding Barrier Properties of Grafted PVOH Layers

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Markus Schmid ◽  
Andreas Benz ◽  
Camelia Stinga ◽  
Daniel Samain ◽  
Klaus Peter Zeyer
Keyword(s):  
Water Vapour ◽  
Transmission Rate ◽  
Barrier Properties ◽  
Temperature Reaction ◽  
Angle Measurements ◽  
Water Vapour Transmission Rate ◽  
Contact Angle Measurements ◽  
Different Types ◽  
Transfer Method ◽  
Water Vapour Barrier

The current work focuses on fundamental investigations regarding the barrier properties of grafted PVOH layers produced by the Transfer Method. The layers (or papers) used for the different experiments were produced and grafted during the course of this work. Papers with different types of PVOH (different Mowiol types) were produced by coating. Experiments using different parameters (temperature, reaction duration, and concentration) were performed using the Transfer Method. Contact angle measurements and Cobb60measurements were carried out on the grafted and untreated PVOH layers. Furthermore, the water vapour transmission rate of the PVOH layers was determined. The results of this work showed that the method of chromatogeny or chromatogenic chemistry improves the water vapour barrier properties of grafted PVOH layers enormously.

scholarly journals A Comparison of Commercial and Experimental Ultrafiltration Membranes via Surface Property Analysis and Fouling Tests

2006 ◽  
Vol 41 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Huyen T. Dang ◽  
Roberto M. Narbaitz ◽  
Takeshi Matsuura ◽  
Kailash C. Khulbe
Keyword(s):  
Ultrafiltration Membranes ◽  
Force Microscopy ◽  
Ottawa River ◽  
Angle Measurements ◽  
Atomic Force ◽  
Molecular Weight Cutoff ◽  
Contact Angle Measurements ◽  
Different Types ◽  
Transport Analysis ◽  
Surface Modified

Abstract Surface modified polyethersulfone (PES) membranes via the addition of different hydrophiLic Surface Modifying Macromolecules (LSMMs) have been developed by Matsuura, Narbaitz and co-workers. This study compares the performance of the best PES-LSMM membrane with nine commercial ultrafiltration membranes manufactured using five different types of base polymers (polyethersulfone, polysulfone, celluloseacetate, polyacrylonitrile and cellulose) in the same range of molecular weight cutoff (MWCO) (from 40 to 120 kDal). All membranes were characterized by using atomic force microscopy, contact angle measurements, solute transport analysis and then evaluated through fouling tests with Ottawa River water (ORW). While PES-LSMM membranes had much lower initial flux than the commercial membranes, they had the highest total organic carbon (TOC) rejection (80%) and the lowest flux reduction (62%). For the commercial membranes, the range of TOC rejections and flux reductions were 62 to 80% and 68 to 80%, respectively. Given their high TOC rejection and relatively high foulant deposition, fouling of the PES-LSMM membranes appears to be controlled by a surface gel.

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