Curing Kinetic Analysis of Acrylate Photopolymer for Additive Manufacturing by Photo-DSC

In this research, the curing degree of an acrylate-based monomer using direct UV-assisted writing technology was characterized by differential photo calorimetry (Photo-DSC) to investigate the curing behavior. Triggered by the UV light, the duo function group monomer 1,6-Hexamethylene diacrylate (HDDA), photoinitiator 1173 and photoinhibitor exhibit a fast curing process. The exothermal photopolymerization reaction was performed in the isothermal mode in order to evaluate the different thermal effects that occurred during the photopolymerization process. The influences of both UV light intensity and exposure time were studied with single-factor analysis. The results obtained by photo-DSC also allow us to perform the kinetic study of the polymerization process: The results show that, for the reaction, the higher the UV intensity, the higher the curing degree together with faster curing speed. At the same time, the effect of the heat released during the exothermic reaction is negligible for the polymerization process. When increasing the exposure time, limited improvement of curing degree was shown, and the distribution is between 65–75%. The reaction enthalpy and related curing degree work as a function of time. The Avrami theory of phase change was introduced to describe the experimental data. The functions of a curing degree with light intensity and exposure time were achieved, respectively.

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QUINACRINE FLUORESCENCE AND Q-BANDING PATTERNS OF HUMAN CHROMOSOMES.: I. Effects of Varying Factors

Canadian Journal of Genetics and Cytology ◽

10.1139/g75-009 ◽

1975 ◽

Vol 17 (1) ◽

pp. 81-92 ◽

Cited By ~ 21

Author(s):

C. C. Lin ◽

H. van de Sande ◽

W. K. Smink ◽

D. R. Newton

Keyword(s):

Exposure Time ◽

Uv Light ◽

Human Chromosomes ◽

Concave Mirror ◽

Banding Patterns ◽

Fluorescent Microscope ◽

Sperm Dna ◽

Quinacrine Fluorescence ◽

Well Differentiated ◽

Salmon Sperm Dna

Various factors involved in the production of "Q-bands" have been studied. It was found that a Zeiss standard WL fluorescent microscope required a shorter exposure time for photography as compared to a Zeiss photomicroscope. The minimal exposure time was obtained when the standard WL microscope was equipped with a UV light source containing a DC powered mercury burner and a concave mirror. Further, the pH and type of water used in the staining, washing and mounting of the slide were also important factors in producing clear and well differentiated "Q-bands". It also appears that the factors involved in the production of "Q-bands" effect the enhancement or quenching of fluorescence by poly d(A-T).poly d(A-T) and salmon sperm DNA or poly dG∙poly dC respectively. This preliminary report also suggests that DNA or polynucleotides with a specific base sequence may play an important role in Q-banding patterns on chromosomes.

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Effect of light intensity and irradiation time on the polymerization process of a dental composite resin

Materials Research ◽

10.1590/s1516-14392004000200015 ◽

2004 ◽

Vol 7 (2) ◽

pp. 313-318 ◽

Cited By ~ 12

Author(s):

José Augusto César Discacciati ◽

Alisson Discacciati Neves ◽

Rodrigo Lambert Oréfice ◽

Flávio Juliano Garcia Santos Pimenta ◽

Herbert Haueisen Sander

Keyword(s):

Light Intensity ◽

Composite Resin ◽

Irradiation Time ◽

Dental Composite ◽

Polymerization Process ◽

Dental Composite Resin ◽

Effect Of Light

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Photodegradation of Trace Trichloronitromethane in Water under UV Irradiation

Journal of Chemistry ◽

10.1155/2014/283496 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Lin Deng ◽

Zhiren Wu ◽

Caiqian Yang ◽

Yung-Li Wang

Keyword(s):

Humic Acid ◽

Light Intensity ◽

Uv Light ◽

Control Strategies ◽

Chloride Ions ◽

Source Control ◽

Photochemical Degradation ◽

Nitrate Ions ◽

Photodegradation Rate ◽

Water And Wastewater

This study’s objective was to study the photodegradation of TCNM (trichloronitromethane) in water under UV light. The effects of light intensity, nitrate ions, chloride ions, humic acid, and pH on the photochemical degradation of TCNM were investigated under the irradiation of low pressure mercury lamp (λ= 254 nm, 12 W). The photodegradation rate of TCNM was found to increase with increasing the concentration of nitrate ions, chloride ions, humic acid, pH, and light intensity. The photodegradation of TCNM was examined at pH 6.0 with initial concentrations (C0) of TCNM at 10.0–200.0 µg/L. The overall rate of degradation of TCNM was modeled using a pseudofirst-order rate law. Finally, the proposed mechanism involved in the photodegradation of TCNM was also discussed by analysis. Results of this study can contribute to the development of new source control strategies for minimization of TCNM risk at drinking water and wastewater utilities.

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Kinetics of bulk photo-initiated copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) polymerizations

Polymer Chemistry ◽

10.1039/c5py01655j ◽

2016 ◽

Vol 7 (3) ◽

pp. 603-612 ◽

Cited By ~ 40

Author(s):

Han Byul Song ◽

Austin Baranek ◽

Christopher N. Bowman

Keyword(s):

Light Intensity ◽

Exposure Time ◽

Copper Salt ◽

Solvent Content ◽

Kinetics Of

Kinetics of bulk photo-initiated copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) polymerizations is governed by several factors including the physicochemical nature of the monomers; the copper salt and photoinitiator types and concentrations; light intensity; exposure time and solvent content.

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Optimasi UV-Photolithography Aligner dan Photomask Menggunakan Produk Komersial untuk Microfabrication

JTT (Jurnal Teknologi Terapan) ◽

10.31884/jtt.v2i1.22 ◽

2016 ◽

Vol 2 (1) ◽

Author(s):

Delffika Canra ◽

Dedi Suwandi

Keyword(s):

Light Intensity ◽

Exposure Time ◽

Low Cost ◽

Commercial Product ◽

High Price ◽

Percentage Error ◽

Original Design ◽

Main Component ◽

Uv Lamps ◽

Photolithography Process

The high price of a UV-photolithography aligner on the market is the reason for designing and characterize low cost UV-photolithography aligner. Photolithography process is simple but it needs patience, enable to modify photolithography aligner by using commercial components and certainly low price. The objective of this study is analyzing the ability of a commercial product in UV-photolithography process, search optimum exposure time and resolution. The method of photolithography process to be used is the method of contact alignment. Commercial UV lamps and cheap photomask are main component in this study. With a light intensity of 0.2 mW/cm2 require the exposure time at least 50 seconds. The smallest achievable resolution depends on the resolution photomask. The Results of smallest resolution is 165 m with a percentage error 10% of the original design.

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Treatment of High-Strength Animal Industrial Wastewater Using Photo-Assisted Fenton Oxidation Coupled to Photocatalytic Technology

Water ◽

10.3390/w11081553 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1553 ◽

Cited By ~ 1

Author(s):

Jae Hong Park ◽

Dong Seok Shin ◽

Jae Kwan Lee

Keyword(s):

Light Intensity ◽

Removal Efficiency ◽

Industrial Wastewater ◽

Uv Light ◽

High Strength ◽

Cod Removal ◽

Fenton Oxidation ◽

Optimal Conditions ◽

Experimental Conditions ◽

Animal Wastewater

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.

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Dual-Wavelength (UV and Blue) Controlled Photopolymerization Confinement for 3D-Printing: Modeling and Analysis of Measurements

Polymers ◽

10.3390/polym11111819 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1819 ◽

Cited By ~ 9

Author(s):

Jui-Teng Lin ◽

Da-Chuan Cheng ◽

Kuo-Ti Chen ◽

Hsia-Wei Liu

Keyword(s):

Light Intensity ◽

Blue Light ◽

Uv Light ◽

Numerical Data ◽

Coupling Factor ◽

Dual Wavelength ◽

Continuous Exposure ◽

Initiator Concentration ◽

Modeling And Analysis ◽

Inhibition Effect

The kinetics and modeling of dual-wavelength (UV and blue) controlled photopolymerization confinement (PC) are presented and measured data are analyzed by analytic formulas and numerical data. The UV-light initiated inhibition effect is strongly monomer-dependent due to different C=C bond rate constants and conversion efficacies. Without the UV-light, for a given blue-light intensity, higher initiator concentration (C10) and rate constant (k’) lead to higher conversion, as also predicted by analytic formulas, in which the total conversion rate (RT) is an increasing function of C1 and k’R, which is proportional to k’[gB1C1]0.5. However, the coupling factor B1 plays a different role that higher B1 leads to higher conversion only in the transient regime; whereas higher B1 leads to lower steady-state conversion. For a fixed initiator concentration C10, higher inhibitor concentration (C20) leads to lower conversion due to a stronger inhibition effect. However, same conversion reduction was found for the same H-factor defined by H0 = [b1C10 − b2C20]. Conversion of blue-only are much higher than that of UV-only and UV-blue combined, in which high C20 results a strong reduction of blue-only-conversion, such that the UV-light serves as the turn-off (trigger) mechanism for the purpose of spatial confirmation within the overlap area of UV and blue light. For example, UV-light controlled methacrylate conversion of a glycidyl dimethacrylate resin is formulated with a tertiary amine co-initiator, and butyl nitrite. The system is subject to a continuous exposure of a blue light, but an on-off exposure of a UV-light. Finally, we developed a theoretical new finding for the criterion of a good material/candidate governed by a double ratio of light-intensity and concentration, [I20C20]/[I10C10].

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