scholarly journals Effect of ultraviolet light on the degradation of Low-Density and High-Density Polyethylene characterized by the weight loss and FTIR

2019 ◽  
Vol 1 (2) ◽  
pp. 26-31
Author(s):  
Prakash Bhuyar ◽  
Nurul Aqilah Binti Mohd Tamizi ◽  
Mohd Hasbi Ab. Rahim ◽  
Gaanty Pragas Maniam ◽  
Natanamurugaraj Govindan
Keyword(s):  
Weight Loss ◽  
High Density Polyethylene ◽  
Uv Light ◽  
Incident Light ◽  
Degradation Process ◽  
Sem Analysis ◽  
Ftir Spectrum ◽  
Physical Treatment ◽  
Photo Degradation ◽  
Vibrational Energies

In this study, the research was made to understand the knowledge widely related to the degradation process of polyethylene polymer. The mode of treatment that involves in the degradation process of polyethylene is physical treatment while the method of degradation used is photo-degradation of UV light. By using the physical treatment of UV irradiation light, it helps by affecting the bonding that holds the polymer together to break and weakens the plastic. From the result obtained in FTIR and SEM analysis, in FTIR spectrum of LDPE shows higher transmittance compared to FTIR spectrum of HDPE both UV-treated for 30 days. This indicates the high transmittance have few bonds to absorb light in the LDPE sample, low transmittance in HDPE sample means has high population of bonds which have vibrational energies corresponding to the incident light. For SEM result, the polyethylene for LDPE plastic sheet shows the best results for degradation and managed to reduce the weight loss at 87.5% compared to HDPE plastic which at 21.6%.

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

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.

scholarly journals Wet Synthesis of Elongated Hexagonal ZnO Microstructures for Applications as Photo-Piezoelectric Catalysts

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2938 ◽  
Author(s):  
Rosanna Pagano ◽  
Chiara Ingrosso ◽  
Gabriele Giancane ◽  
Ludovico Valli ◽  
Simona Bettini
Keyword(s):  
Uv Light ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Degradation Process ◽  
Blue Dye ◽  
Present Contribution ◽  
Wurtzite Phase ◽  
Photo Degradation ◽  
Uv Photons ◽  
Wet Synthesis

It is well known that energetic demand and environmental pollution are strictly connected; the side products of vehicle and industrial exhausts are considered extremely dangerous for both human and environmental health. In the last years, the possibility to simultaneously photo-degrade water dissolved pollutants by means of ZnO nanostructures and to use their piezoelectric features to enhance the photo-degradation process has been investigated. In the present contribution, an easy and low-cost wet approach to synthetize hexagonal elongated ZnO microstructures in the wurtzite phase was developed. ZnO performances as photo-catalysts, under UV-light irradiation, were confirmed on water dissolved methylene blue dye. Piezoelectric responses of the synthetized ZnO microstructures were evaluated, as well, by depositing them into films onto flexible substrates, and a home-made layout was developed, in order to stimulate the ZnO microstructures deposited on solid supports by means of mechanical stress and UV photons, simultaneously. A relevant increment of the photo-degradation efficiency was observed when the piezopotential was applied, proposing the present approach as a completely eco-friendly tool, able to use renewable energy sources to degrade water solved pollutants.

scholarly journals Biofilm integrity and cytomorphology of Candida albicans after exposure to UV-light on ZnO thin films: SEM Analysis

2021 ◽  
Vol 27 (S1) ◽  
pp. 1896-1898
Author(s):  
Carlos Arzate-Quintana ◽  
César Leyva-Porras ◽  
María Alejandra Favila-Pérez ◽  
Alva Rocío Castillo-González ◽  
Celia María Quiñonez-Flores ◽  
...  
Keyword(s):  
Thin Films ◽  
Candida Albicans ◽  
Uv Light ◽  
Sem Analysis ◽  
Zno Thin Films

The Effect of Modifier on Properties of Bamboo Powder/High-Density Polyethylene Composites

2019 ◽  
Vol 69 (4) ◽  
pp. 313-321
Author(s):  
Xiaoxia Hu ◽  
Zhenghao Chen ◽  
Yang Cao ◽  
Zhangjing Chen ◽  
Shuangbao Zhang ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Dry Weight ◽  
Weight Percent ◽  
Sem Analysis ◽  
High Density ◽  
Hydroxyl Groups ◽  
Plastic Composites ◽  
Bamboo Powder ◽  
Plastic Matrix ◽  
Polyethylene Composites

Abstract The focus of this study was to observe the properties of bamboo plastic composites modified with a self-made modifier, 18 acyl-dopamine (0, 0.25, 0.50, 0.75, 1.00, and 1.25 weight percent [wt%] based on the dry weight of bamboo powder). The effects of the modifier were demonstrated by measures of mechanical properties, water absorption, thermal stability, and scanning electron microscopy (SEM). The results revealed that 18 acyl-dopamine could be used as an effective modifier of bamboo powder/high-density polyethylene composites. When the modifier was increased, the toughness of the composite deteriorated, and the strength and rigidity improved. This indicated that when the dosage became higher, the compatibilization became stronger, and the toughening effect became worse. Based on the experimental data, a small dosage modifier acted as a toughening agent; as the dosage increased to 1.0 wt%, the compatibility began to appear. The modifier reacted with the hydroxyl groups on the surface of the bamboo powder, which caused the bamboo powder to absorb less water, so the thickness expansion rate was lowest at 1.25 wt%. The pyrolysis peak of bamboo powder and plastic showed a tendency to be close to each other, indicating that the interface was improving. Based on the equation of Flynn-Wall-Ozawa, as the dosage of the modifier increased from 0.50 to 1.25 wt%, the apparent activation energy also increased. The SEM analysis showed the binding between bamboo powder and the plastic matrix was strongest when the modifier dosage was 1.25 wt%.

scholarly journals Effect of Gum Arabic and Starch-Based Coating and Different Polyliners on Postharvest Quality Attributes of Whole Pomegranate Fruit

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 164
Author(s):  
Tatenda Gift Kawhena ◽  
Umezuruike Linus Opara ◽  
Olaniyi Amos Fawole
Keyword(s):  
Weight Loss ◽  
Effective Treatment ◽  
Cold Storage ◽  
High Density Polyethylene ◽  
Gum Arabic ◽  
Soluble Solids ◽  
Postharvest Quality ◽  
Respiration Rates ◽  
Pomegranate Fruit

This study investigated the effect of gum Arabic and starch-based coating and two polyliners (Liner 1-micro-perforated Xtend® and Liner 2-macro-perforated high-density polyethylene) on whole ‘Wonderful’ pomegranate fruit during cold storage (5 ± 1 °C and 95 ± 2% RH). Uncoated (UC) and coated (GAMS) fruit were packaged into standard open top ventilated cartons (dimensions: 0.40 m long, 0.30 m wide and 0.12 m high) with (GAMS + Liner 1, GAMS + Liner 2, UC + Liner 1 and UC + Liner 2) or without (UC and GAMS) polyliners. After 42 d, treatment GAMS + Liner 1 recorded the least weight loss (4.82%), whilst GAMS recorded lower (8.77%) weight loss than UC + Liner 2 (10.07%). The highest (24.74 mLCO2 kg−1h−1) and lowest (13.14 mLCO2 kg−1h−1) respiration rates were detected in UC and GAMS + Liner 1, respectively. The highest and lowest total soluble solids were recorded for GAMS (16.87 °Brix), and GAMS + Liner 1 (15.60 °Brix) and UC + Liner 1 (15.60 °Brix), respectively. Overall, no decay was detected for coated fruit packaged with either Liner 1 or Liner 2. Therefore, the combination of GAMS with Xtend® polyliners proved to be an effective treatment to maintain the quality of ‘Wonderful’ pomegranates during storage.

scholarly journals Removal of 17β-Estradiol by Activated Charcoal Supported Titanate Nanotubes (TNTs@AC) through Initial Adsorption and Subsequent Photo-Degradation: Intermediates, DFT calculation, and Mechanisms

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2121
Author(s):  
Taobo Huang ◽  
Baozhu Pan ◽  
Haodong Ji ◽  
Wen Liu
Keyword(s):  
Activated Charcoal ◽  
Density Functional ◽  
Capillary Condensation ◽  
Uv Light ◽  
Density Functional Theory Calculation ◽  
Titanate Nanotubes ◽  
Photo Degradation ◽  
Photocatalytic Ability ◽  
17Β Estradiol ◽  
Initial Adsorption

A low-cost composite of activated charcoal supported titanate nanotubes (TNTs@AC) was developed via the facile hydrothermal method to remove the 17β-estradiol (E2, a model of pharmaceutical and personal care products) in water matrix by initial adsorption and subsequent photo-degradation. Characterizations indicated that the modification occurred, i.e., the titanate nanotubes would be grafted onto the activated charcoal (AC) surface, and the micro-carbon could modify the tubular structure of TNTs. E2 was rapidly adsorbed onto TNTs@AC, and the uptake reached 1.87 mg/g from the dual-mode model fitting. Subsequently, the adsorbed E2 could be degraded 99.8% within 2 h under ultraviolet (UV) light irradiation. TNTs@AC was attributed with a unique hybrid structure, providing the hydrophobic effect, π−π interaction, and capillary condensation for E2 adsorption, and facilitating the electron transfer and then enhancing photocatalytic ability for E2-degradation. In addition, the removal mechanism of E2 was elucidated through the density functional theory calculation. Our study is expected to provide a promising material for environmental application.

Studies on Effect Factors of Porous Titanium Dioxide Film Degrading Azo Dyes

2012 ◽  
Vol 531 ◽  
pp. 403-406 ◽  
Author(s):  
Sheng Min Sun
Keyword(s):  
Titanium Dioxide ◽  
Ph Value ◽  
Uv Light ◽  
Pure Titanium ◽  
Degradation Process ◽  
Porous Titanium ◽  
Titanium Dioxide Film ◽  
Effect Factors ◽  
Micro Arc Oxidation ◽  
Dioxide Film

In pure titanium body, through the method of micro-arc oxidation (MAO) on the surface of porous titanium dioxide film and study on factors of methyl orange in the light influence of catalytic degradation process, the results show that: with uv light for the source, pH value of 5, micro-arc oxidation voltage is 400 V, the catalytic activity of porous titanium dioxide film was the highest.

scholarly journals Photooxidation of Cyclohexane by Visible and Near-UV Light Catalyzed by Tetraethylammonium Tetrachloroferrate

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 403
Author(s):  
Kira Fahy ◽  
Adam Liu ◽  
Kelsie Barnard ◽  
Valerie Bright ◽  
Robert Enright ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Reaction Rate ◽  
Uv Light ◽  
Incident Light ◽  
Reaction Conditions ◽  
Primary Products ◽  
Photonic Efficiency ◽  
Quenching By Oxygen

Tetraethylammonium tetrachloroferrate catalyzes the photooxidation of cyclohexane heterogeneously, exhibiting significant photocatalysis even in the visible portion of the spectrum. The photoproducts, cyclohexanol and cyclohexanone, initially develop at constant rates, implying that the ketone and the alcohol are both primary products. The yield is improved by the inclusion of 1% acetic acid in the cyclohexane. With small amounts of catalyst, the reaction rate increases with the amount of catalyst employed, but then passes through a maximum and decreases, due to increased reflection of the incident light. The reaction rate also passes through a maximum as the percentage of dioxygen above the sample is increased. This behavior is due to quenching by oxygen, which at the same time is a reactant. Under one set of reaction conditions, the photonic efficiency at 365 nm was 0.018 mol/Einstein. Compared to TiO2 as a catalyst, Et4N[FeCl4] generates lower yields at wavelengths below about 380 nm, but higher yields at longer wavelengths. Selectivity for cyclohexanol is considerably greater with Et4N[FeCl4], and oxidation does not proceed past cyclohexanone.

Uniform and Gaussian UV Light Intensity Distribution on Droplet for Selective Area Deposition of Particles

2020 ◽  
Author(s):  
Tianyi Li ◽  
Aravinda Kar ◽  
Ranganathan Kumar
Keyword(s):  
Sessile Drop ◽  
Uv Light ◽  
Incident Light ◽  
Droplet Surface ◽  
Light Distribution ◽  
Surface Tension Gradient ◽  
Sharp Change ◽  
Sessile Droplet ◽  
Selective Area ◽  
Light Profiles

Abstract Particle transport through Marangoni convection inside a sessile droplet can be controlled by the UV light distribution on the surface. The photosensitive solution changes the surface tension gradient on the droplet surface and can induce clockwise and counter-clockwise circulations depending on the incident light distribution. In this paper, the stream function in the sessile drop has been evaluated in toroidal coordinates by solving the biharmonic equation. Multiple primary clockwise and counter-clockwise circulations are observed in the droplet under various concentric UV light profiles. The downward dividing streamlines are expected to deposit the particles on the substrate, thus matching the number of deposited rings on the substrate with the number of UV light rings. Moffatt eddies appear near the contact line or centerline of the droplet either due to a sharp change in the UV light profile or because the illuminated region is away from them.

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