Preliminary studies of photocatalytic activity of gypsum plasters containing TiO2 co-modified with nitrogen and carbon

Abstract The conducted studies were focused on the development of the gypsum material exhibiting self-cleaning properties. To this end, the raw gypsum was mixed with unique TiO2-based photocatalysts, previously modified by nitrogen and/ or carbon doping. The photocatalytic activity of the obtained gypsum plasters was evaluated trough the degradation of model organic compound (Reactive Red 198) under UV-vis irradiation. The impact of the photocatalysts presence on the physicochemical properties of the obtained gypsum plasters was evaluated. Furthermore, the role of non-metals presence on the photocatalytic properties of the TiO2 was determined. It was confirmed that the addition of N,C co-modified titanium dioxide into gypsum bestows this material with self-cleaning properties. The highest dye removal rate was displayed by the gypsum plaster containing optimal amount (10 wt%) of co-modified TiO2/N,C photocatalyst, after 20 hours of UV-vis irradiation.

Download Full-text

Superhydrophobic and photocatalytic self-cleaning on cotton fabric using fluorine-free flower-like-TiO2/PDMS coatings

10.21203/rs.3.rs-404885/v1 ◽

2021 ◽

Author(s):

Esfandiar Pakdel ◽

Hai Zhao ◽

Jinfeng Wang ◽

Bin Tang ◽

Russell Varley ◽

...

Keyword(s):

Photocatalytic Activity ◽

Cotton Fabric ◽

Nitrogen Doping ◽

Dip Coating ◽

Polydimethyl Siloxane ◽

Water Contact ◽

Highly Efficient ◽

Coating Method ◽

Self Cleaning ◽

The Impact

Abstract This research presents the development of novel self-cleaning cotton fabric with dual functionalities of superhydrophobicity and photocatalytic activity. Fluorine-free coating formulations composed of either flower-like TiO2 or nitrogen-doped TiO2 particles, with a hierarchical surface morphology, and polydimethyl siloxane (PDMS) polymer were applied to cotton fabrics using a facile dip-coating method. The self-cleaning performance of fabrics was assessed based on their superhydrophobicity and effective removal of oil-based food stains. Additionally, the impact of nitrogen doping on photocatalytic activity of flower-like TiO2 particles was investigated. The obtained results demonstrated that the presence of both PDMS and hierarchical particles generated excellent superhydrophobicity on the cotton fabric with a water contact angle of 156.7 ± 1.9⁰. In addition, the coated fabric exhibited highly efficient photocatalytic activity, decomposing stains under simulated sunlight. Nitrogen doping process significantly boosted the photocatalytic activity of TiO2 particles in degrading stains and dye solution. The developed superhydrophobic fabric showed high robustness against both chemical and physical durability tests. This research contributes significantly to the continued advancement of highly efficient self-cleaning textiles via the development of dual functions of superhydrophobicity and photocatalytic activity.

Download Full-text

Modelling the potential role of media campaigns on the control of Listeriosis

Mathematical Biosciences and Engineering ◽

10.3934/mbe.2021375 ◽

2021 ◽

Vol 18 (6) ◽

pp. 7580-7601

Author(s):

C. W. Chukwu ◽

◽

F. Nyabadza ◽

Fatmawati ◽

◽

...

Keyword(s):

Removal Rate ◽

Bacterial Pathogen ◽

Food Contamination ◽

Food Products ◽

Model Parameters ◽

Media Campaigns ◽

Awareness Campaigns ◽

Contaminated Food ◽

The Impact

<abstract><p>Human Listeria infection is a food-borne disease caused by the consumption of contaminated food products by the bacterial pathogen, Listeria. In this paper, we propose a mathematical model to analyze the impact of media campaigns on the spread and control of Listeriosis. The model exhibited three equilibria namely; disease-free, Listeria-free and endemic equilibria. The food contamination threshold is determined and the local stability analyses of the model is discussed. Sensitivity analysis is done to determine the model parameters that most affect the severity of the disease. Numerical simulations were carried out to assess the role of media campaigns on the Listeriosis spread. The results show that; an increase in the intensity of the media awareness campaigns, the removal rate of contaminated food products, a decrease in the contact rate of Listeria by humans results in fewer humans getting infected, thus leading to the disease eradication. An increase in the depletion of media awareness campaigns results in more humans being infected with Listeriosis. These findings may significantly impact policy and decision-making in the control of Listeriosis disease.</p></abstract>

Download Full-text

Contact Vs. Non-Contact Cleaning: Correlating Interfacial Reaction Mechanisms to Processing Methodologies for Enhanced FEOL/BEOL Post-CMP Cleaning

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.314.237 ◽

2021 ◽

Vol 314 ◽

pp. 237-246

Author(s):

Katherine M. Wortman-Otto ◽

Abigail N. Linhart ◽

Allie M. Mikos ◽

Kiana A. Cahue ◽

Jason J. Keleher

Keyword(s):

Supramolecular Structure ◽

Performance Metrics ◽

Defect Formation ◽

Molecular Level ◽

Removal Rate ◽

Clear Correlation ◽

Particle Removal ◽

Effective Particle ◽

The Impact

Due to the emergence of sub-7 nm technologies, next generation CMP slurry formulations have continued to increase in additive (nanoparticle and chemistry) complexity to meet stringent device specifications. Therefore, it is essential to probe the molecular level interactions at the nanoparticle/slurry chemistry/substrate interface and in turn correlate them to key performance metrics such as removal rate, post CMP defects, and planarization efficiency. This work will address key interactions through a series of case studies focusing on the role of supramolecular structure and cleaning method (i.e. contact vs. non-contact) during STI post-CMP cleaning, probing the impact of supramolecular structure and mode of cleaning relevant to Cu post-CMP, and development of a biomimetic matrix with chemical activity to act as a brush in STI post-CMP cleaning processes. Results show in both BEOL and FEOL post-CMP cleaning there is a strong correlation to the delivery and “soft” nature of the chemistry to allow for effective particle removal at low mechanical force and prevent further defect formation. Furthermore, this work shows a clear correlation between supramolecular structure and particle removal efficiency under both contact and non-contact post-CMP processes.

Download Full-text

Improved Self-Cleaning Properties of Photocatalytic Gypsum Plaster Enriched with Glass Fiber

Materials ◽

10.3390/ma12030357 ◽

2019 ◽

Vol 12 (3) ◽

pp. 357 ◽

Cited By ~ 1

Author(s):

Kamila Zając ◽

Magdalena Janus ◽

Antoni Morawski

Keyword(s):

Mechanical Properties ◽

Methylene Blue ◽

Titanium Dioxide ◽

Photocatalytic Activity ◽

Glass Fiber ◽

Glass Fibers ◽

The Self ◽

Gypsum Plaster ◽

Self Cleaning ◽

Reactive Orange

In the study the self-cleaning properties of photoactive gypsum plasters are presented. The modified gypsum plasters were obtained by addition of 1 and 3 wt.% of nitrogen-modified titanium dioxide (TiO2/N) and 0.1, 0.3, and 0.5 wt.% of glass fiber. The self-cleaning ability of the obtained materials was tested during two dyes decomposition: Methylene Blue (MB) and Reactive Orange (RO). It was found that presence of glass fiber increased photocatalytic activity of modified gypsum plasters, which may be due to the fact glass fiber may act as ducts for light and transport it to sites screened by TiO2 or glass fiber can retard charge recombination. Moreover, unexpectedly the addition of glass fiber did not increase the mechanical properties of modified gypsum plasters, which may be because gypsum does not strongly adhere to the surface of glass fibers.

Download Full-text

Intergroup Threat and Outgroup Attitudes

Social Psychology ◽

10.1027/1864-9335/a000127 ◽

2013 ◽

Vol 44 (5) ◽

pp. 311-319 ◽

Cited By ~ 12

Author(s):

Marco Brambilla ◽

David A. Butz

Keyword(s):

Gay Men ◽

Social Group ◽

Welfare Recipients ◽

Intergroup Attitudes ◽

Social Policies ◽

Intergroup Threat ◽

Economic Threat ◽

The Impact ◽

General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

Download Full-text