UV Bulb Research Articles

Photoluminescent Applications for Urban Pavements

Photoluminescent materials used on street and road pavements could absorb solar energy during the day and emit it at night, which will save energy and improve visibility with a consequent improvement in road safety. The aim of this study is to evaluate the luminance of different photoluminescent applications for pavements (bituminous mixes, mortars, and paints) in which strontium aluminate and glass beads were used. Sunlight was simulated with two bulbs, one LED and one UV bulb, inside a measuring apparatus specially developed for this work. The luminance of the different designed solutions was determined at different time periods after their excitation. The results obtained showed that luminescent paints can reach higher luminance than bituminous mixes and mortars. The colour of the base surface on which the paints are applied had a great influence on the obtained luminance, which increases with the aluminate and glass beads content. Among all the solutions evaluated, the paint made with 60% aluminate and 6% glass beads, spread on a white surface, allowed the highest luminance values to be obtained. This study leads to the conclusion that it is possible to achieve a good photoluminescent level while economising on the amount of materials necessary.

Photocatalytic Hydrolysis-A Sustainable Option for the Chemical Upcycling of Polylactic Acid.

Plastic waste is a critical global issue, yet current strategies to avoid committing plastic waste to landfills include incineration, gasification, or pyrolysis high carbon emitting and energy consuming approaches. However, plastic waste can become a resource instead of a problem if high value products, such as fine chemicals and liquid fuel molecules, can be liberated from controlled its decomposition. This letter presents proof of concept on a low-cost, low energy approach to controlled decomposition of plastic, photocatalytic hydrolysis. This approach integrates photolysis and hydrolysis, both slow natural decomposition processes, with a photocatalytic process. The photocatalyst, α-Fe2O3, is embedded into a polylactic acid (PLA) plastic matrix. The photocatalyst/plastic composite is then immersed in water and subjected to low-energy (25 W) UV light for 90 h. The monomer lactide is produced as the major product. α-Fe2O3 (6.9 wt %) was found to accelerate the PLA degradation pathway, achieving 32% solid transformation into liquid phase products, in comparison to PLA on its own, which was found to not decompose, using the same conditions. This highlights a low energy route toward plastic waste upgrade and valorization that is less carbon intensive than pyrolysis and faster than natural degradation. By directly comparing a 25 W (0.025 kWh) UV bulb with a 13 kWh furnace, the photocatalytic reaction would directly consume 520× less energy than a conventional thermochemical pathway. Furthermore, this technology can be extended and applied to other plastics, and other photocatalysts can be used.

Response surface methodology (RSM) and artificial neural network (ANN) approach to optimize the photocatalytic conversion of rice straw hydrolysis residue (RSHR) into vanillin and 4-hydroxybenzaldehyde

Abstract Effective use of waste lignin is always a challenging task, technologies have been applied in the past to get value-added compounds from waste lignin. However, the existing technologies are not economical and efficient to produce the value-added chemicals. Alkali soluble lignin from rice straw hydrolysis residue (RSHR) is subjected to photocatalytic conversion into value-added compounds. Photocatalysis is one of the multifarious advanced oxidation processes (AOPs), carried out with TiO2 nanoparticles under a 125 W UV bulb. Gas chromatography mass spectroscopy (GCMS) confirmed the formation of vanillin and 4-hydroxybenzaldehyde. RSM and ANN techniques are adopted to optimize the process conditions for the maximization of the products. The response one (Y 1) vanillin (24.61 mg) and second response (Y 2) 4-hydroxybenzaldehyde (19.51 mg) is obtained at the optimal conditions as 7.0 h irradiation time, 2.763 g/L catalyst dose, 15 g/L lignin concentration, and 14.26 g/L NaOH dose for alkali treatment, suggested by face-centered central composite design (CCD). RSM and ANN models are statistically analyzed in terms of RMSE, R 2 and AAD. For RSM the R 2 0.9864 and 0.9787 while for ANN 0.9875 and 0.9847, closer to one warrant the good fitting of the models. Therefore, in terms of higher precision and predictive ability of both models the ANN model showed excellence for both responses as compared to the RSM model.

Optimal production of vanillin and 4-hydroxybenzaldehyde from rice straw hydrolysis residue (RSHR) over TiO2/UV and ZnO/UV system

Numerous approaches and technologies have been used in the past few decades to produce value-added chemicals from waste lignin. However, the existing technologies were not efficient and economical to produce the value-added chemicals. Rice straw hydrolysis residue (RSHR) was subjected to alkali treatment followed by photocatalysis with a 125 W UV bulb. Producing vanillin and 4-hydroxybenzaldehyde was confirmed by GCMS. The process parameters, irradiation time (IT), and catalyst dose (CD) were optimized using RSM to obtain the maximum yields of responses. Experiments were designed as per matrix generated according to central composite design (CCD) over TiO2 and ZnO photocatalyst. The formation of compounds first increased attained their maxima, and thereafter decreased with increasing irradiation time. The higher dose of catalysts gradually increased the formation of compounds in all cases. To get maximum production of compounds, ZnO photocatalyst was found better than TiO2 photocatalyst. The statistical analysis was also carried out in terms of RMSE, R2, AAD, and % error band that showed a good agreement with the experimental results in all cases. However, the RSM model showed excellence for 4-hydroxybenzaldehyde production as compared to vanillin production over both catalysts.

SYNTHESIS, CHARACTERIZATION AND PHOTOCATALYTIC APPLICATIONS OF S-DOPED GRAPHITIC CARBON NITRIDE NANOCOMPOSITES WITH NICKEL DOPED ZINC OXIDE NANOPARTICLES

Coprecipitation method was adopted for the synthesis of undoped and Ni-doped zinc oxide nanoparticles. The photocatalytic activity of the synthesized particles was examined by degradation of methylene blue under UV bulb. The S-doped graphitic carbon nitride was obtained by calcination of thiourea and composites were formed with S-doped graphitic carbon nitride and nickel doped zinc oxide nanoparticles using liquid exfoliation method. The ethanol and water were used as solvents for the liquid exfoliation. The photocatalytic activity was performed under UV and visible light by using a UV-visible spectrophotometer with different concentrations of composites for the degradation of methylene blue. The doping of nickel on zinc oxide nanoparticles and formation of sulfur doped graphitic carbon nitride composites were confirmed by FTIR and XRD analyses. The FTIR analysis sowed a signal at 838cm-1 due to the presence of Ni-O bond. The peaks at 3649cm-1 and 3735cm-1 confirmed the presence of amide group. The shift in absorption maxima from 364nm to 376nm (red shift) in UV spectrum was a confirmation of increased Ni content. The different concentrations of composites showed great impact on the degradation of methylene blue.

A Study on the Photocatalytic Reduction of Some Metal Ions in Aqueous Solution Using UV- Titanium Dioxide System

The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution has been investigated. The photocatalyst utilized was nano titanium dioxide, composed of 80% anatase and 20% rutile; the UV light source was a 15 W UV bulb with a wavelength of 254 nm. The results obtained indicated a reduction efficiency order as follows; Cr6+ > Cu2+ > Pb2+ > Cd2+. It was observed that these results correlate with the respective reduction potentials of the metal ions. The effect of pH on the photocatalytic reduction of the metal ions was also carried out and results obtained indicated that with the exception of Cr (VI) ions, higher percentage removal of metal ions from their aqueous solution was recorded at alkaline pH than at acidic pH. This was attributed to an extensive formation of precipitate by the metal ions at alkaline pH. Kinetic studies revealed that the removal of metal ions from their solutions largely followed the pseudo- first-order kinetics. Therefore, the results of this study will be useful in metal ion removal from industrial waste water using photocatalytic process.

Fecal coliform concentrations in effluent from ultraviolet disinfection units installed in onsite wastewater treatment systems.

Ultraviolet disinfection (UVD) units enhance onsite sewage systems (OSSs) in areas where conventional treatment is limited by site characteristics. Although UVD units are efficacious under testing conditions, few studies have considered their effectiveness when installed. This study used a mixed-methods approach to examine UVD unit effluent quality and determine the association between UV bulb status and fecal coliform levels. Samples from UVD units and pump chambers were tested for bacterial and physiochemical parameters. Field data were supplemented with data from retrospective compliance samples. A multivariate Tobit regression model predicted that the geometric mean (GM) fecal coliform concentration was 122% higher when the UV bulb was deficient than when it was not deficient, adjusted for other OSS deficiencies (95% CI: 36-428, p-value <0.001). The predicted GM fecal coliform concentration in malfunctioning UVD unit effluent (745 CFU/100 mL) exceeded field compliance standards (400 CFU/100 mL), and the odds of exceedance were 7.48 times higher when the UV bulb was deficient, adjusted for other OSS deficiencies (95% CI: 4.03-13.9, p-value <0.001). Despite limitations in the characterization of UV dose, the results validate the importance of UVD units to reduce bacterial loads and the need for further research into their field effectiveness.

Assessment of mechanisms for enhanced performance of TiO2/YAG:Yb+3,Er+3 composite photocatalysts for organic degradation

Wastewater remediation is a key component to a sustainable water management program and the use of photo-activated catalysis has emerged as a promising advanced oxidative process for the decomposition of organic contaminants to innocuous products. Although the process is feasible using UV photons, only ∼5% of solar insolation is comprised of UV photons and few advances have been made to improve upon commercial TiO2 (i.e., P25). Here, composite catalysts containing both an upconversion phase (Yb+3/Er+3/Y-Al garnet or YAG host) and a photocatalyst (TiO2) are assessed for enhancing the photocatalytic activity of TiO2 for organic degradation using simulated insolation. Samples of the upconverting phosphor (YAG host) were prepared utilizing the Pechini method with varying molar concentration of Yb+3 ions [0%, 10%, 15%, or 20%] and a constant concentration of Er+3 ions [2%]. The composite materials were then obtained via calcination of the various YAG:Yb+3,Er+3 samples with titania at molar concentrations of [10%, 15%, or 20%]. Structures and properties of the upconverting phosphors and composite materials were verified with characterization analyses including X-ray diffraction, diffuse reflectance spectroscopy, transmission electron microscopy, and photoluminescence spectroscopy. For rose bengal degradation in a batch slurry reaction using a simulated ‘daylight’ spectrum as the irradiation source, results indicated that a mixed phased, Y-Al oxide doped with 2mol% Er+3 and 15mol% Yb+3 with 10mol% doped YAG/balance TiO2 composite yielded a 42% higher rate constant and apparent quantum yield than TiO2 alone. Additional kinetic studies with portions of the solar spectrum (i.e., UV bulbs or UV or IR LEDs) were conducted to further probe the effect of photon energies and suggested that rate and apparent quantum yield enhancements were largely attributed to increased amounts of organic adsorption and close proximity between phases, which coincided with the presence of the monoclinic phase (not cubic) of the Y-Al oxide structure. Upconversion and decreased charge carrier recombination rates were deemed to provide minimal contribution to these enhancements.

Detection of Plasmodium falciparum Infection in Anopheles squamosus (Diptera: Culicidae) in an Area Targeted for Malaria Elimination, Southern Zambia.

Southern Zambia is the focus of strategies to create malaria-free zones. Interventions being rolled out include test and treat strategies and distribution of insecticide-treated bed nets that target vectors that host-seek indoors and late at night. In Macha, Choma District, collections of mosquitoes were made outdoors using barrier screens within homesteads or UV bulb light traps set next to goats, cattle, or chickens during the rainy season of 2015. Anopheline mosquitoes were identified to species using molecular methods and Plasmodium falciparum infectivity was determined by ELISA and real-time qPCR methods. More than 40% of specimens caught were identified as Anopheles squamosus Theobald, 1901 of which six were found harboring malaria parasites. A single sample, morphologically identified as Anopheles coustani Laveran, 1900, was also found to be infectious. All seven specimens were caught outdoors next to goat pens. Parasite-positive specimens as well as a subset of An. squamosus specimens from either the same study or archive collections from the same area underwent sequencing of the mitochondrial cytochrome oxidase subunit I gene. Maximum parsimony trees constructed from the aligned sequences indicated presence of at least two clades of An. squamosus with infectious specimens falling in each clade. The single infectious specimen identified morphologically as An. coustani could not be matched to reference sequences. This is the first report from Zambia of infections in An. squamosus, a species which is described in literature to display exophagic traits. The bionomic characteristics of this species needs to be studied further to fully evaluate the implications for indoor-targeted vector control.

Comparisons of interdisciplinary ballast water treatment systems and operational experiences from ships.

There are high functioning and low functioning ballast water treatment systems on board ships. In this study, five systems were analysed so as to methodically examine the operational difficulties for ship crew members while giving important consideration to sustainable environment practices. Multi-criteria analysis, a questionnaire, survey and interviews were used as the research method so as to ascertain and corroborate existing problems on board ships, and the reliability of the systems was calculated. The co-insistency, maintenance and the efficiency of the systems, were shown as being the major problem as there are no systems for tracking ship ballast operations from land. The treatment system that used oxidants was, through multi criteria analysis, evaluated as being the best and was ranked first. However, the survey results showed that the ship’s crew had serious problems with this system which difficult to solve during the ship’s operations with cargo. The deoxygenation system was the most appropriate according to ballast water treatment criteria in the port or at sea. The treatment system which used electrolysis with oxidant was better in terms of efficacy and the treatment system electrolysis with ultra violet light was better in terms of the criterion environment pollution footprint. During further research, it was shown that 7 % of the surveyed crew members had major problems with operating ballast water treatment systems, including the system which was ranked first through multi criteria analysis. They by-passed these systems while continuing to ballast or de-ballast. It was calculated that of the total time needed for the ballast water treatment system operation, 9 % of this time was used for repairs or maintenance of the systems. Some examples are changing a used UV bulb, cleaning the filter or controlling the amount of oxidant which would be discharged into the sea. A conclusion was made and solution was suggested. The study results emphasised taking action in the interest of protecting the natural world, with particular attention being given to environmental protection to support human life.

A facile route to synthesis of S-doped TiO2 nanoparticles for photocatalytic activity

There is always a market for cost effective methods of pollution degradation and one of the best areas to keep costs down is through synthesis techniques. This paper provides a simple technique to synthesise porous TiO2 nanoparticles with increased surface area through a scaffold template technique. Their photocatalytic activity is enhanced by incorporating sulphur as a dopant and were validated by analysing the degradation of malachite green (MG). The materials were doped at a molar ratio of 100:1 (Ti:S) and calcined at different temperatures to adjust the anatase/rutile content. Detailed characterisation of the materials was undertaken using XRD, BET, XPS, TEM and FTIR. The nanoparticles displayed a microporous structure and had an increased surface area of 115m2g−1 which was reduced by doping and temperature induced phase transformation. Photocatalytic testing showed that the doped materials calcined at 700°C preformed the best in. It was observed that 20mgl−1 of MG was decomposed in 30min using a 40W UV bulb at pH 9 and the results surpassed those achieved by the commercial catalyst P25 which was also tested for comparison.

"IJIMAI Editor's Note - Vol. 3 Issue 2",

In order to have drinking water, some countries have to use chlorine. It is use cause is effective and it's cheap. An alternative to this process is the UV disinfection of drinking water. Most of the devices in the market use UV bulbs or mercury lamps. The UV LED, which is cheaper and smaller, allows creating new smaller devices. The main contribution of this paper is the use of Genetic Algorithms to help design a drinking water device with UV LEDs.

Photocatalytic properties of metal and non-metal doped novel sub 10 nm titanium dioxide nanoparticles on methyl orange

This study examines the addition of various dopants to TiO2 nanoparticles for the enhancement of photocatalytic activity. The materials were tested for efficiency on the degradation of methyl orange under UV light. The dopants were added at different molar ratios to find the ideal amount required for optimum results. BET analysis was used to determine surface areas while X-ray diffraction (XRD) analysis was used to study the effect of the dopant on the transformation of the TiO2 structure. The dopants used were Ag, S and Zr and displayed high levels of activity and show some ability to be reused. Decomposition of methyl orange was carried out using a 40W UV bulb at 365nm and results were measured by UV–vis spectrometry. It was determined that, overall, Ag doping displayed the best photocatalytic properties but was poor upon reuse.

Analysis of Chemical and Physical Effects of Ultraviolet Bulbs on Cooking Emissions

ABSTRACT There is a growing recognition of the risks to health, fire hazard, and air quality from cooking emissions. Recent research has identified what is emitted when foods are cooked. Some of the emitted mass is captured in the exhaust system. The balance is expelled into the atmosphere. The outlet of the exhaust system is a demarcation point—upstream the captured mass is the operator or building owner's concern, whereas downstream into the atmosphere, it affects air quality. Building codes have long required operators to deal with the upstream section. More recently, regulations are being placed on what kitchens can emit to the atmosphere. The industry is responding to this challenge with product innovations. Recently gained understanding of cooking emissions supports much of the innovation—but not all. This paper evaluates the purported benefit of adding better filtration and ultraviolet C (UVC) bulbs in kitchen hoods. A “UV hood” claims a two-step process to reduce emissions: better filters capture more emitted mass, and UVC photons and ozone drive photo-decomposition and oxidation reactions of some of the remaining greasy constituents. Adding UV to a hood at least doubles the cost compared to an equivalent non-UV hood. There is evidence that UV hoods do reduce some emissions. The essential question is whether improved performance is due to UV or relatively inexpensive, improved filters. Experimentation exposed an oleic acid aerosol, representative of cooking emissions, to UVC energy and ozone at higher concentrations and for longer exposure times than can occur in a UV hood. Particle-size and chemical changes were measured on samples collected with UV bulbs off and on. Results strongly indicate little change is happening and most emission reductions are caused by better filtration and not UV. The conclusion is that UV hoods fall short of claimed performance, and unreacted ozone may increase air pollution. IMPLICATIONS Commercial cooking emissions present problems in certain locations because of odors, fine particles, and volatile organic compounds (VOCs). Air quality regulations are increasingly requiring emission reductions. One attempted innovation is to place improved filters and ultraviolet bulbs in kitchen hoods. UV and the accompanying ozone are claimed to photo-decompose and oxidize much of the emitted organic constituents to smaller components. Testing with a representative emission constituent demonstrates that UV has little effect in reducing the mass or composition of the emissions, and that relatively inexpensive, better filters are responsible for most reduction. Additionally, air pollution, due to created ozone, may be increased.

Improved photocatalytic degradation rates of phenol achieved using novel porous ZrO 2-doped TiO 2 nanoparticulate powders

This paper studies the photocatalytic degradation of phenol using zirconia-doped TiO 2 nanoparticles. ZrO 2 was chosen due to its promising results during preliminary studies. Particles smaller than 10 nm were synthesised and doped with quantities of ZrO 2 ranging from 0.5 to 4% (molar metal content). Particles were calcined at different temperatures to alter the TiO 2 structure, from anatase to rutile, in order to provide an ideal ratio of the two phases. Powder X-ray diffraction (PXRD) analysis was used to examine the transformation between anatase and rutile. Degradation of phenol was carried out using a 40 W UV bulb at 365 nm and results were measured by UV–vis spectrometry. TEM images were obtained and show the particles exhibit a highly ordered structure. TiO 2 doped with 1% ZrO 2 (molar metal content) calcined at 700 °C proved to be the most efficient catalyst. This is due to an ideal anatase:rutlie ratio of 80:20, a large surface area and the existence of stable electron–hole pairs. ZrO 2 doping above the optimum loading acted as an electron–hole recombination centre for electron–hole pairs and reduced photocatalytic degradation. Synthesised photocatalysts compared favourably to the commercially available photocatalyst P25. The materials also demonstrated the ability to be recycled with similar results to those achieved on fresh material after 5 uses.

Oxford receives supply contract from PTT

Continuous surface treatment of PET and PTT fabrics was carried out to introduce nanoscale surface roughness using an electrodeless UV bulb for different periods of time. Reflectance of the irradiated fabrics decreased in the low wavelength regions of visible light, especially at 400 nm. The surface roughness of the irradiated fabrics was investigated to verify the scattering and destructive interference of visible light using SEM and AFM analyses. AFM images indicated that the treatment developed the nano-sized roughness on the polyester surfaces. The surface roughness increased by two-fold from 58 nm to 122 nm in terms of peak–valley roughness, which can interfere destructively the incident light of as high as 488 nm wavelength in the visible spectrum. The dyeability of the surface modified polyester fabrics to disperse dyes was similar to that of untreated fabrics. However, irradiation both after and before dyeing with black disperse dyes significantly decreased lightness of the dyed fabrics up to 8% with increasing treatment due to the enhanced surface roughness. Surprisingly color fastness of the dyed polyester fabrics was excellent because of surface-limited treatment of the polyester fabrics.

Comparison Between E-beam and Ultraviolet Curing to Perform Porous a-SiOC : H

Porous ultralow-k films are required by the microelectronics industry as interlayer dielectrics for technologies and below. These porous insulating films can be deposited by plasma-enhanced chemical vapor deposition using a porogen approach. It consists of the codeposition of a matrix precursor and a sacrificial organic porogen, and then on a post-treatment to remove the organic porogen phase and create porosity in the film. In this work, an e-beam assisted thermal curing was compared to an ultraviolet-assisted thermal curing. Basic film properties such as , film shrinkage, porosity, pore size, and pore size distribution were evaluated. NMR and Fourier transform infrared analyses were used to study the chemical modifications induced by the post-treatment. These analyses show that the post-treatment impact depends on the radiation used. Both treatments lead to a removal of terminal nonbridging bonds such as , , and and can contribute to a subsequent formation of crosslinks. Both treatments remove methyls from , but the e-beam induces a bond increase while the UV bulb used decreases the contribution. The cross-linking improvement induces an increase of Young’s modulus, the elastic properties being mainly correlated to the volumic bond concentration in the film.

Impact of Phlebotomine Sand Flies on U.S. Military Operations at Tallil Air Base, Iraq: 3. Evaluation of Surveillance Devices for the Collection of Adult Sand Flies

We evaluated the effectiveness of commercially available light traps and sticky traps baited with chemical light sticks for the collection of phlebotomine sand flies. Evaluations were conducted at Tallil Air Base, Iraq, in 2003. In an initial study, a Centers for Disease Control and Prevention (CDC)-style trap with UV bulb collected significantly more sand flies than did an up-draft CDC trap, a standard down-draft CDC trap (STD-CDC), or a sticky strap with a green chemical light stick. In a subsequent study, we found that the addition of chemical light sticks to sticky traps resulted in a significant increase in the number of sand flies collected compared with sticky traps without the light sticks. These data indicate that 1) the CDC light trap with an UV bulb is an effective alternative to the standard CDC light trap for collecting phlebotomine sand flies in Iraq, and 2) that the addition of a chemical light stick to a sticky trap can result in a field-expedient tool for the collection of sand flies.

Process Optimization of UV Curing for Ultra Low-k Dielectrics and High-Stress SiN Liners

ABSTRACTThis paper describes process optimization of UV curing for ultra Low-k SiOC (ULK-SiOC, k=2.65) and High stress silicon nitride (HS-SiN) liner. We have investigated the impact of UV curing using different UV bulbs (UV-X and UV-Y) on BEOL process damages to the ULK-SiOC. The k-value variations of ULK-SiOC modified with UV-X with higher photon energy than UV-Y are greater than those of the pristine ULK-SiOC and the ULK-SiOC modified with UV-Y. These results are consistent with the previously reported FT-IR and NMR analyses that the UV-X generates 3-fold Si-O ring defects and Si-H bonds in the ULK-SiOC. In order to discuss the pore structure in UV-modified ULK-SiOC, the solvent diffusion of toluene and ethanol in ULK-SiOC were measured. The solvent diffusion of the UV-modified ULK-SiOC with UV-X is faster than that of the UV-modified ULK-SiOC with UV-Y. This result indicates that the pore size of UV-modified ULK-SiOC with UV-X is larger than that of UV- modified ULK-SiOC with UV-Y. The dependence of the stress increase in HS-SiN liner on different UV bulbs (UV-X and UV-Y) has been investigated by using stress measurement and FT-IR. The UV-modified HS-SiN liner with UV-Y achieves higher tensile stress, compared to the UV-X. FT-IR results have revealed that UV-Y is more effective for the dehydrogenation and SiN crosslinking, resulting in the greater increase in the tensile stress. In conclusion, UV-Y bulb with medium photon energy yields the desired UV modifications for ULK-SiOC and HS-SiN applications.

Film Characterization of Ultra Low-k Dielectrics Modified by UV Curing with Different Wavelength Bands

AbstractThis paper describes film characterization of Ultra Low-k (ULK) dielectrics modified by UV curing with different wavelength bands. We have demonstrated UV hardening of ULK-SiOC (k=2.65) with two types of UV bulbs (UV-X and UV-Y) and the UV modifications of ULK-SiOC film properties are characterized by using FT-IR spectroscopy, 29Si Solid-state NMR spectroscopy and Raman spectroscopy. FT-IR and NMR analyses reveal that UV-Y curing is preferable for UV curing modification of ULK-SiOC. UV-Y curing increases Q mode peak in NMR, resulting in the enhanced Si-O crosslinking, while UV-X curing increases TH mode and TOR mode peaks. Spin lattice relaxation time T1 for 29Si is decreased with UV curing. This result indicates that UV curing enhances molecular motion in Si-O network. Raman analysis shows that UV curing increases amorphous carbon groups, which corresponds to the enhanced molecular motion in Si-O network.