scholarly journals Innovative approaches to thermochromic materials for adaptive building envelopes

2021 ◽  
Vol 2069 (1) ◽  
pp. 012132
Author(s):  
G Pérez ◽  
V Serra ◽  
S Garshasbi ◽  
F Favoino ◽  
P Sirvent ◽  
...  
Keyword(s):  
Smart Materials ◽  
Urban Areas ◽  
Optical Response ◽  
Degradation Process ◽  
Laboratory Evaluation ◽  
Photoluminescence Intensity ◽  
Photo Degradation ◽  
Building Envelopes ◽  
Material Durability ◽  
Innovative Approaches

Abstract Thermochromic (TC) materials are characterized by a change of their optical response at a specific temperature. They can work based on both, the alteration of solar reflection by temperature, or the change of photoluminescence intensity. In building applications, this type of smart materials enhances the rejection of solar heat for high temperatures to favour cooling of the envelopes and reduces this rejection for low temperatures to improve surface heating. This adaptive optical response improves energy efficiency and reduces environmental impact of urban areas. Most of the current advances in this area are related to TC glazing based on Vanadium oxide, while opaque TC materials have been developed as based on Leuco dyes. The main drawback of these last materials is their significant aging in outdoor applications due to a photo-degradation process. The present work shows the recent results of a multidisciplinary and multinational consortium for research on innovative approaches to thermochromic materials for adaptive building envelopes. Next steps will be focused on building simulation to evaluate material choices across different performance aspects, while physical prototypes will be used for inter-laboratory evaluation of such performance and material durability.

scholarly journals Degradasi Tirosina Menggunakan Mangkinfoto Berasaskan TiO2

2012 ◽  
Author(s):  
Rusmidah Ali ◽  
Siti Salamah Maisoan @ Selamat
Keyword(s):  
Amino Acid ◽  
Metal Ions ◽  
Uv Light ◽  
Degradation Process ◽  
Aqueous System ◽  
Visible Spectroscopy ◽  
Photo Degradation ◽  
Efficient System ◽  
Catalyst Powder ◽  
Uv Visible

Asid amino merupakan bahan asas dalam tisu tumbuhan dan haiwan. Tirosina (Tr) salah satu jenis asid amino yang mengandungi gelang aromatik, telah dipilih sebagai sampel untuk proses degradasi dalam medium akueus. Ini bertujuan melihat kesan penggunaan mangkinfoto dalam sinaran ultralembayung (λ < 400 nm) atau cahaya matahari ke atas molekul tirosina. Kajian telah dijalankan menggunakan sistem cahaya, mangkin serbuk TiO2, hidrogen peroksida, H2O2 dan ion logam. Penambahan ion logam seperti Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ dan Cd2+ dan agen pengoksidaan, iaitu hidrogen peroksida adalah untuk mendapatkan kaedah yang paling cekap. Keputusan menunjukkan penambahan H2O2 dan ion Fe2+ dan Ni2+ berjaya meningkatkan kecekapan proses degradasifoto tirosina. Ion Ni2+ memberikan keputusan terbaik berbanding ion-ion lain. Ion Cu2+, Ag+, Mn2+ dan Cd2+ merencat proses degradasi. Keputusan juga menunjukkan cahaya matahari adalah setanding dengan cahaya ultralembayung. Kepekatan H2O2 terbaik adalah 5.0 x 10-2M dan semakin banyak TiO2 digunakan semakin baik peratus degradasi tirosina. Oleh itu kaedah optimum untuk proses degradasifoto ialah Tr 2.5 x 10-4 M + TiO2 + H2O25.0 x 10-3 M + Mn+ 1.0 x 10-2 M. Proses degradasifoto dikaji menggunakan spektroskopi ultralembayung-nampak pada julat panjang gelombang 400-200 nm. Kata kunci: Tirosina; degradasifoto; serbuk TiO; akueus Amino acid is a basic component in plant or animal tissue. Tyrosine (Tr), an amino acid which contains aromatic ring, was chosen as a sample for a photodegradation process in an aqueous system. The purpose of the experiment is to study the effect of photocatalysis under UV (λ < 400 nm) or sunlight on tyrosine. The experiment was carried out by using UV light, catalyst powder (TiO2), hidrogen peroxide H2O2 and metal ions system. The addition of oxidising agent H2O2 and metal ions such as Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ and Cd2+ were used in order to achieve the most efficient system. Results showed that the system with added H2O2 and metal ions such as Ni2+ and Fe2+ had successfully enhanced the process of the tyrosine photodegradation. Other metal ions system such as Cu2+, Ag+, Mn2+ and Cd2+ were found to inhibit the degradation process. The results also showed that sunlight was comparable to ultraviolet light. The best H2O2 concentration was 5.0 x 10-2 M and the percentage of tyrosine degradation increased with the addition of more TiO2) by mass. Therefore, the optimum condition for tyrosine photodegradation process was in Tr 2.5 x 10-4 M + TiO2 + H2O2 5.0 x 10-3 M + H2O2 1.0 x 10-2 M. The dissappearance of tyrosine in the photo degradation process was monitored by UV-visible spectroscopy between 400-200 nm. Key words: Tyrosine; photodegradation; TiO2 powder; akueus

Modeling and Optimization of Photocatalytic Degradation of Methylene Blue Using Lanthanum Vanadate

2020 ◽  
Vol 1008 ◽  
pp. 97-103
Author(s):  
Mahmoud Samy ◽  
Mona G. Ibrahim ◽  
Mohamed Gar Alalm ◽  
Manabu Fujii
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Textile Industry ◽  
Degradation Process ◽  
Optimum Conditions ◽  
Photo Degradation ◽  
Operational Conditions ◽  
Degradation Rates ◽  
Effects Of Ph

Methylene blue (MB) is one of the commonly used dyes in the textile industry and can be used as a model pollutant for the textile industry wastewater. In this work, the photocatalytic degradation of MB by synthesized nanoparticles of lanthanum vanadate (LaVO4) was assessed. The effects of pH, initial MB concentration and catalyst dose on the removal performance of MB were investigated and measuring the optimum values of these operational conditions was performed using response surface methodology (RSM). Catalyst dose of 0.43 g/L, initial MB concentration of 5.0 mg/L, and pH of 6.86 were found to be the optimum conditions in reaction time of 60 min. A mathematical model was formed to relate the removal efficiency of MB to the aforementioned operating parameters. The removal efficiency of MB was 91% without any scavengers at a catalyst dose of 0.3 g/L, pH of 7 and initial MB concentration of 10 mg/L. The trapping experiments confirmed the participation of different reactive species in the photo-degradation process. The degradation rates of MB were 91%, 86%, 81%, 77.70% and 72% in five successive runs using LaVO4.

Environmental Oxidative Degradation and Biodegradation of Eco-Benign Plastics

2013 ◽  
Vol 538 ◽  
pp. 146-149 ◽  
Author(s):  
Xin De Tang ◽  
Jing Lun Zhou ◽  
Hai Rong Lu ◽  
Nian Feng Han
Keyword(s):  
Structural Characteristics ◽  
Oxidative Degradation ◽  
Environmental Issues ◽  
Degradation Process ◽  
Linear Low Density Polyethylene ◽  
Soil Environment ◽  
Photo Degradation ◽  
Soil Burial ◽  
Ft Ir ◽  
Abiotic Oxidation

Polyethylene (PE) has found widespread use as a packaging material. Plastics waste disposal, as one of the serious environmental issues, has caused much criticism. The environmental oxidative- and bio- dual degradable linear low-density polyethylene (LLDPE) samples containing Eco-Benign Plastics (EBP) pro-oxidant additives were submitted to an investigation aimed at evaluating their preliminary oxidative degradation in natural environment or accelerated oven aging and their ultimate biodegradation in solid incubation substrate or soil composting conditions. Original and test samples submitted to abiotic oxidation including photo degradation and thermal degradation were characterized by means of FT-IR and GPC. Biodegradation test simulating soil burial and composting conditions reveals that the biodegradation degree exceeded 30%. The degradation process is accompanied by a dramatic change in the structural characteristics of the test samples. It is clear that LLDPE-EBP formulations are effective in promoting the oxidation and subsequent biodegradation of polyethylene in natural and soil environment.

Laboratory Simulation Study of Photo-Degradation Process of Fenvalerate in Aqueous Solution

2013 ◽  
Vol 312 ◽  
pp. 886-892
Author(s):  
Yan Ru Liang ◽  
Yu Yun Wen ◽  
Xiao Yan Hong ◽  
Zhen Bin Gong ◽  
Wen Quan Li
Keyword(s):  
Aqueous Solution ◽  
Reaction Rate ◽  
Organic Molecules ◽  
Spectral Characteristics ◽  
Degradation Process ◽  
Laboratory Simulation ◽  
Fluorescent Substance ◽  
Photo Degradation ◽  
Small Organic Molecules ◽  
Degradation Reaction

A laboratory-made the efficient photochemical degradation experimental device, combined with high performance liquid chromatography-tandem diode array detector device (DAD), fluorescence detector (FLD), mass spectrometer detector (MS), research fenvalerate its photo degradation. The structure of the spectral characteristics is the product, photo degradation reaction kinetics of degradation products, suggesting fenvalerate light chemical degradation process in an aqueous solution. The spectral characteristics of fenvalerate under ultraviolet light can be degraded into smaller organic molecules; maternal and main product have strong UV - visible absorption, fenvalerate are weakly fluorescent substance in the aqueous solution. The major products are strong fluorescent substance. Almost no effect The photo degradation kinetic data show fenvalerate photo degradation in an aqueous solution to approximate a reaction of the reaction; pesticide initial concentration, the pH value of the aqueous solution of pesticides photo degradation reaction rate; To accelerate the increase of salinity, light intensity fenvalerate in aqueous photo degradation reaction rate; significant influence of small organic molecules, with the type of small organic molecules.

scholarly journals Optical Properties of Composites Based on Graphene Oxide and Polystyrene

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2419 ◽  
Author(s):  
Malvina Stroe ◽  
Mirela Cristea ◽  
Elena Matei ◽  
Andrei Galatanu ◽  
Liviu C. Cotet ◽  
...  
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Degradation Process ◽  
Covalent Functionalization ◽  
Photo Degradation ◽  
Quenching Process ◽  
Uva Light ◽  
First Time ◽  
Pl Quenching ◽  
Properties Of Composites

In this work, new optical properties of composites based on polystyrene (PS) microspheres and graphene oxide (GO) are reported. The radical polymerization of styrene in the presence of benzoyl peroxide, pentane and GO induces the appearance of new ester groups in the PS macromolecular chains remarked through an increase in the absorbance of the infrared (IR) band at 1743 cm−1. The decrease in the GO concentration in the PS/GO composites mass from 5 wt.% to 0.5 wt.% induces a diminution in the intensities of the D and G Raman bands of GO simultaneous with a down-shift of the D band from 1351 to 1322 cm−1. These variations correlated with the covalent functionalization of the GO layers with PS. For the first time, the photoluminescent (PL) properties of PS/GO composites are reported. The PS microspheres are characterized by a PL band at 397 nm. Through increasing the GO sheets’ concentration in the PS/GO composite mass from 0.5 wt.% to 5 wt.%, a PS PL quenching process is reported. In addition, in the presence of ultraviolet A (UVA) light, a photo-degradation process of the PS/GO composite having the GO concentration equal to 5 wt.% is demonstrated by the PL studies.

scholarly journals Degradation of Polyfurfuryl Alcohol-based Biopolymer by Soil-burial and Photo-degradation Methods

2021 ◽  
Author(s):  
Priyaragini Singh ◽  
K. Dinesh Kumar ◽  
Rakesh Kumar
Keyword(s):  
Weight Loss ◽  
Ring Opening ◽  
Furan Ring ◽  
Degradation Process ◽  
Casting Method ◽  
Photo Degradation ◽  
Soil Burial Test ◽  
Soil Burial ◽  
Polyfurfuryl Alcohol ◽  
Degraded Samples

Abstract Recently, polyfurfuryl alcohol (PFA) based material has been gaining attention. Despite its use as an intermediate in various industries, the degradation process of PFA has rarely been reported. In this study, neat PFA (PF) and polylactic acid (PLA) incorporated PFA (PF-PL) based thermoset biopolymers were prepared by casting method. The degradation of the prepared biopolymer specimens was carried out under environmental conditions via soil-burial test and photo-degradation method for 21-months. The extent of degradation of PF and PF-PL was assessed by evaluating weight loss, structural and morphological change by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), respectively. Weight loss percentage in case of photo-degraded samples was found to be much higher compared to soil buried specimens. SEM micrographs showed a blistered surface with visible cracks on the surface of soil buried and photo-degraded samples. FTIR spectra of photo-degraded samples showed a new peak at 673 cm-1 indicating the furan ring opening during the degradation process. Significant variation in mechanical properties of PF and PF-PL specimens after soil-burial test also indicated biodegradable nature of the biopolymers. Approximately 45% and 63% of loss in tensile strength was obtained in PF and PF-PL soil buried specimens, respectively. All the obtained data revealed the fragmentation of biopolymers, hence supporting the biodegradable nature of PFA-based biopolymer.

Reverse Logistics for Sustainable Waste Management Processes

2012 ◽  
pp. 224-237 ◽  
Author(s):  
Fraser McLeod ◽  
Tom Cherrett
Keyword(s):  
Public Transport ◽  
Reverse Logistics ◽  
Urban Areas ◽  
Household Waste ◽  
Sustainable Waste Management ◽  
Management Processes ◽  
Take Back ◽  
Freight Consolidation ◽  
Delivery Vehicles ◽  
Innovative Approaches

This chapter highlights some of the innovative approaches that have been taken by businesses involved in reverse logistics for the removal of waste from urban areas. The chapter reviews some of these approaches and suggests which could be used more widely, recognising the specific limitations which may restrict their applicability. These innovative approaches include: the use of delivery vehicles to take-back waste/recyclate to out-of-town facilities such as a freight consolidation or recycling centre; combining commercial and household waste collections; deploying public transport vehicles to carry specialist recyclate; using multi-modal transport; ‘smart’ bin technology and pipelines for the removal of waste from buildings.

Photo-Degradation of Cypermethrin in Aqueous Solution Studied by HPLC-DAD

2013 ◽  
Vol 634-638 ◽  
pp. 1044-1048
Author(s):  
Yan Ru Liang ◽  
Zhen Bin Gong ◽  
Wen Quan Li
Keyword(s):  
Aqueous Solution ◽  
High Performance ◽  
Degradation Products ◽  
Degradation Process ◽  
Mass Spectrometric ◽  
Photochemical Degradation ◽  
Pseudo First Order Reaction ◽  
Photo Degradation ◽  
Mass Spectrometric Detector ◽  
Degradation Reaction

The photo-degradation process of cypermethrin in aqueous solution was studied using the laboratory-built photochemical degradation device and commercial high performance liquid chromatography (HPLC) with ultraviolet-visible absorbance detector and mass spectrometric detector. Spectrometric characteristics of cypermethrin and its main degradation products suggest that cypermethrin could be photo-degradated and converted into smaller molecular under ultraviolet irradiation. The photo-degradation reaction of cypermethrin in aqueous solution is approximately pseudo-first-order reaction. Light strength, pH and salinity have significant effects on the photo-degradaiton reaction of cypermethrin. Mass spectrometric results show that cypermethrin pesticide can be degraded into new and easily photochemical degrading products through the removal of chlorine.

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