Ultraviolet Irradiation Technique Research Articles

Treatment and nutrient recovery from landfill leachate by sequential persulfate oxidation and struvite precipitation: An evaluation of technical feasibility.

The technical feasibility of advanced oxidation process, in particular persulfate (PS) oxidation followed by struvite precipitation for landfill leachate treatment and nutrient recovery has been depicted in the current study. Furthermore, the impact of activation of PS with thermal and ultraviolet (UV) irradiation techniques on COD removal efficiency is also investigated. A maximum COD removal efficiency of 96% is accomplished at 65°C together with supply of UV irradiation. The impact of persulfate dose, pH, and PS/65°C/UV system on COD and biodegradability is also illustrated in the current study. Additionally, decomposition rate constant values are also ascertained in the present study. Afterwards, nutrient recovery using struvite precipitation is carried out for sustainable utilization of resources. Preliminary treatment of leachate with PS/65°C/UV system is greatly conducive to recovering high quality struvite crystals. Besides, 94.9%, 83.5%, and 91.3% of PO43- -P, NH4+ -N, and Mg2+ recovery efficiency attained respectively at pH 9.5 and 1.2:1:1 molar ratio of Mg2+: NH4+-N: PO43--P. Additionally, all the nutrient recovery studies are validated using chemical equilibrium model Visual MINTEQ. Later, bioavailable fraction of PO43--P in the recovered struvite is also investigated for utilization as fertilizer. The presence of Cu and Zn in the recovered struvite precipitate enhanced its economic value as a fertilizer. Since Cu and Zn are vital micronutrients for growth of plants. The low soluble values of recovered struvite precipitate confirmed its utilization as slow releasing fertilizer.

An efficient and durable bifunctional electrocatalyst based on PdO and Co2FeO4 for HER and OER

The adoption of effective, minimal, and versatile electrocatalysts for water splitting to generate hydrogen fuels is of critical importance. The bulk of newly described materials have considerable onset potential, but their electrocatalytic activity is limited by weak electrical conductivity and a limited range of catalytic sites. The combination of a few precious metals added with transition metal-based compounds is a novel and captivating approach. Herein, cobalt ferrite oxide (Co2FeO4) @ palladium oxide (PdO) nanostructures have been prepared through the combined use of hydrothermal and ultraviolet (UV) irradiation techniques. For hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) kinetics, the modified composition offers a high concentration of active sites, improved electrical conductivity, and stability. The Co, Fe, and Pd ions at the composite system's interface may affect the adsorption energy of reaction intermediates synergistically, enabling the process to continue with less potential. The electrocatalyst Co2FeO4@PdO demonstrates an excellent bifunctional approach to electrochemical water splitting (EWS) for HER and OER in alkaline medium. As-prepared electrocatalyst shows an overpotential value of 269 and 259 mV for HER and OER at 10 and 20 mA/cm2 current densities respectively. The low charge transfer resistance values such as 72.2 and 62.4 Ω and durability for 48 h has been observed toward HER and OER, support this material as an efficient and durable electrocatalyst for energy conversion systems.

Surface Modification of Polymethylmethacrylate (PMMA) by Ultraviolet (UV) Irradiation and IPA Rinsing.

Polymethylmethacrylate (PMMA) is commonly applied to microfluidic devices due to its excellent biocompatibility, high optical transparency, and suitability for mass production. Recently, various surface treatment methods have been reported to improve the wettability of polymers, which is directly related to adhesion. In this research, the effect of a UV irradiation technique and an IPA rinsing technique as surface treatments for PMMA is investigated regarding the water contact angle of the PMMA surface. PMMA sheets that were 1.62 mm thick and commercially available were exposed to UV light with four different exposure times. Significant decreases in the water contact angle were observed after exposure to UV light, and the lowered contact angles due to the UV irradiation increased over time. According to the measurement, the water contact angle is a function of UV exposure dose as well as storage time after UV exposure. We examined the effect of a IPA rinsing process after UV irradiation and observed an increase in the water contact angle.

Influence of graphite particles in UV-curable corrosion protection coating from palm oil based urethane acrylate (POBUA)

Replacing petroleum oil with renewable sources from natural oil in producing polymer coating is being widely attracting many researchers and inventors. In this study, palm oil-based urethane acrylate (POBUA) coating was developed as a protective coating for mild steel by using the ultraviolet irradiation technique. The POBUA was synthesized by reacting acrylated palm oil and isocyanate via in situ intercalative polymerizations with the presence of hydroxyethyl acrylate and 4 methoxy phenol (4mph). Different loadings of graphite particles (0.1 wt%, 0.5 wt% and 0.8 wt%) were introduced into the POBUA with the presence of Irgacure 184 as the photoinitiator. The formulated coating resin was applied on the mild steel substrates and the overall performances were investigated using Fourier transform infrared spectroscopy , contact angle measurements, X-Ray Diffraction, thermogravimetric analysis, electrochemical impedance spectroscopy , and Field Emission Scanning Electron Microscopy . Meanwhile, Gel content extraction and Pendulum Hardness were done on the cured film to investigate the performance of the polymerized coating polymer. The obtained results exposed good distribution of graphite particles in the POBUA polymeric matrix will influence the overall performance of the POBUA coatings at POBUA + 0.5 wt% graphite. Infrared spectrum demonstrated the formation of the crosslinked network was not disrupted with the addition of graphite particles, while increment of crystallinity index and hardness observed. Meanwhile TAFEL polarization elucidate the present of graphite particles reduced the curable POBUA coating corrosion current density from 102.6 × 10 −6 to 27.3 × 10 −12 Acm −2 with decreasing of mild steel corrosion rate per year from 31.24mpy to 125.1 × 10 −6 mpy. However, morphology showed that the addition of high graphite content (0.8 wt%) increased the tendency to particles agglomeration. Nevertheless, the results obtained showed that the presence of graphite particles in POBUA is beneficial in improving the strength of the coating against surface degradation and corrosion. This research demonstrates that POBUA/Graphite curable coating has a good potential application in mild steel protection. • Anticorrosion study for palm oil-based urethane acrylate enhanced by graphite was carried out. • Graphite particles influences the corrosion behavior as shown in Tafel plot. • The strength of the coating against corrosion was enhanced with the presence of graphite. • Graphite particles enhanced charge transfer resistance R ct of POBUA. • The POBUA R ct increased from 0.92 × 10 6 Ω up to 9.253 × 10 6 Ω.

A New Drug-Free Cancer Therapy Using Ultraviolet Pulsed Irradiation. PDT (PhotoDynamic Therapy) to PPT (Pulsed Photon Therapy)

Pulsed ultraviolet (UV) irradiation can be used to generate a broad UV-C spectrum. The pulsing nature of such a spectrum helps increase the damage to cancer cells, leading to their injury and death. In contrast, non-tumor cells repair the damage and survive the same pulsed UV irradiation energy. Herein, we describe the development of a pulsed UV irradiation method for cancer cell dysfunction that irradiates cells with pulsed light by generating tremendous instantaneous UV energy-tens of thousands of times greater than that generated by UV lamps-to cause specific cell injury and dysfunction of cancer cells. A newly developed pulsed ultraviolet irradiation device was used. Features of the device used in this study. This device employs a quartz discharge xenon lamp. Cultured tumor cells and non-tumor cells were irradiated with pulsed light at different irradiation doses, and their reactions were observed using optical, electron, and laser microscopes. Cancer cells have more FAS (CD95) receptor domains than non-cancer cells, and pulsed UV irradiation stimulates the production of reactive oxygen species (ROS) and OH, which exceeds the oxidative stress removal function, resulting in cell injury and death. That is, at low UV doses, only cancer cells underwent cell death, whereas non-cancer cells did not. The pulsed UV irradiation technique directly destroys cancer cells and minimizes the number of residual cancer cells while allowing minimum invasion into non-tumor cells, thereby improving their survival. This suggests the possibility of activating the host's local immune response to eliminate residual cancer cells. A newly developed pulsed UV radiation system shows potential for use in the development of a drug-free cancer treatment system that selectively kills tumor cells by irradiating them with high-intensity pulsed UV rays over a broad UV-C range of 230-280 nm.

Reusability of P3 Facial Filter in a Pandemic Emergency: A 3D Analysis of Filter Microstructure with X-ray Microtomography Images after Dry Heat and UV Sterilization Procedures.

Objective: Our goal is to evaluate the effects of heat and ultraviolet (UV) irradiation on P3 facial respirator microstructure. Intervention: P3 facial filters were exposed to dry heat and UV sterilization procedures. Methods: P3 facial filter samples underwent a standardized sterilization process based on dry heat and UV irradiation techniques. We analyzed critical parameters of internal microstructure, such as fiber thickness and porosity, before and after sterilization, using 3D data obtained with synchrotron radiation-based X-ray computed microtomography (micro-CT). The analyzed filter has two inner layers called the “finer” and “coarser” layers. The “finer” layer consists of a dense fiber network, while the “coarser” layer has a less compact fiber network. Results: Analysis of 3D images showed no statistically significant differences between the P3 filter of the controls and the dry heat/UV sterilized samples. In particular, averages fiber thickness in the finer layer of the control and the 60° dry heated and UV-irradiated sample groups was almost identical. Average fiber thickness for the coarser layer of the control and the 60° dry heated and UV-irradiated sample groups was very similar, measuring 19.33 µm (±0.47), 18.33 µm (±0.47), and 18.66 µm (±0.47), respectively. There was no substantial difference in maximum fiber thickness in the finer layers and coarser layers. For the control group samples, maximum thickness was on average 11.43 µm (±1.24) in the finer layer and 59.33 µm (±6.79) in the coarser layer. Similarly, the 60° dry heated group samples were thickened 12.2 µm (±0.21) in the finer layer and 57.33 µm (±1.24) in the coarser layer, while for the UV-irradiated group, the mean max thickness was 12.23 µm (±0.90) in the finer layer and 58.00 µm (±6.68) in the coarser layer. Theoretical porosity analysis resulted in 74% and 88% for the finer and coarser layers. The finer layers’ theoretical porosity tended to decrease in dry heat and UV-irradiated samples compared with the respective control samples. Conclusions: Dry heat and UV sterilization processes do not substantially alter the morphometry of the P3 filter samples’ internal microstructure, as studied with micro-CT. The current study suggests that safe P3 filter facepiece reusability is theoretically feasible and should be further investigated.

The functionalization of selected chemical agents on a polypropylene fiber and the study on the physical and anti‐bio‐fouling properties of the functionalized fibers

AbstractThe functionalizing of a fiber surface by a chemical may alter the physical and biological properties of the fiber. The functionalization of a polypropylene fiber (PP) by selected monomers (1) acrylic acid (AA), (2) 2‐hydroxyethyl methacrylate (HEMA), (3) 2‐dimethyl amino ethyl methacrylate (DMAEMA), and (4) methyl acrylate (MA) studied using two different ultraviolet (UV) irradiation techniques, simultaneous UV irradiation and functionalization (SUVF) and pre‐UV irradiation (PUV). Based on the measured grafting parameters, it found, the tendency of monomers for functionalizing on the PP surface was the highest for the AA and HEMA, and the lowest for the MA and DMAEMA for used SUVF and PUV techniques, respectively. The SEM micrographs showed the smooth surface of the PP fiber changed to a rough surface after functionalization. The functionalization also increased the crystallinity with little effect on melting point of the fiber. Except for the MA, functionalization increased the hydrophilic properties of the fiber. The PUV technique was more effective on the grafting degree % of the monomer than the SUVF technique for functionalized fibers with HEMA and MA. The biological experiments demonstrated the eligibility of AA as a favorable functionalizing agent for increasing the anti‐bio‐fouling properties of the studied PP fiber.

Pd functionalization on ZnO nanowires for enhanced sensitivity and selectivity to hydrogen gas

The detection of hydrogen (H2) gas is of importance owing to its increasing use in the modern society to achieve a cleaner life environment. In this study, bare and palladium (Pd)-functionalized ZnO nanowires (NWs) were synthesized for H2 gas sensing. The ZnO NWs were fabricated by a vapor–liquid–solid technique and Pd functionalization was performed using an ultraviolet irradiation technique. Enhanced H2 gas response of the ZnO NWs was observed after Pd functionalization. Additionally, the Pd-functionalized ZnO NW gas sensor exhibited high selectivity to H2 gas. The superior hydrogen gas sensing of the Pd-functionalized ZnO NW sensor was related mainly to the sensitization of the Pd nanoparticles, metallization effect of ZnO at the sensing temperature (350 °C), and partial PdHx formation. This study demonstrates the effectiveness of the Pd functionalization on the ZnO NWs for the realization of practical hydrogen gas sensors.

Dynamic Thermomechanical Analysis on Water Tree Resistance of Crosslinked Polyethylene

The water tree resistance of crosslinked polyethylene (XLPE) initiated by ultraviolet (UV) irradiation technique is investigated through a water blade electrode method, and the effects of the mechanism of UV irradiation crosslinking on inhibiting water tree growth are revealed with dynamic thermomechanical analysis (DMA). The accelerated water tree aging experiment shows that UV irradiation crosslinking inhibits the growth rate of water trees, and the water tree length and width is reduced with the increase of the crosslinking degree of XLPE. The DMA result demonstrates that the molecular activity of the amorphous phase in XLPE as represented by polyethylene β-relaxation is gradually intensified with the increase of the crosslinking reaction. Combined with the fatigue mechanism of water tree growth in semi-crystalline polymers, it is suggested that the UV irradiation crosslinking reaction can significantly improve the anti-water-tree performance of linear low-density polyethylene (LLDPE). The crosslinking bond in the amorphous phase of UV-photoinitiated crosslinking polyethylene can produce a large number of cross-connected polymer chains, by which the length of fiber is obviously increased, leading to an reduced force from the micro-water beads onto the crack tip and thus decreasing the rate of the material being destroyed by micro-water beads.

Disinfection of municipal secondary effluents with microwave-induced electrodeless ultraviolet irradiation for water reuse

BACKGROUND Disinfection is an essential way to ensure the safety of recycled water. Ultraviolet (UV) is an effective and environmentally friendly technique suitable for the disinfection of recycled water. However, UV disinfection also leads to photoreactivation. This work proposes a combined use of UV irradiation and microwave technique to compensate for the limitations of UV disinfection. RESULTS The process of microwave-induced electrodeless ultraviolet (MW-EUV) irradiation was utilized to disinfect municipal secondary effluents. A homemade columnar electrodeless UV lamp was used as the source of UV irradiation. Good disinfection results the under optimal microwave power at 600 W were obtained. There was no photoreactivation after sufficient irradiation. Cell damage of Escherichia coli by MW-EUV irradiation was investigated by measuring the leakage of K+ and protein from cells and was observed by an atomic force microscope (AFM). CONCLUSION The MW-EUV irradiation is demonstrated to be a faster and more effective disinfection method in this study. The irradiated samples could meet the hygienic standards for the reuse of urban recycling water (Standard Number GB/T 18920–2002) in China. The disinfection mainly depends on UV irradiation. The microwave was the main causes of bacterial breakup and deformation. This irreversible damage offsets the biological self-healing phenomenon in UV disinfection.

A Convenient Ultraviolet Irradiation Technique for Synthesis of Antibacterial Ag-Pal Nanocomposite.

In the present work, palygorskite (Pal) was initially subjected to an ion-exchange reaction with silver ions (Pal-Ag+). Subsequently, Ag-Pal nanocomposites were assembled by a convenient ultraviolet irradiation technique, using carbon dots (CDs) derived from wool fiber as the reducing agent. The obtained nanocomposites were characterized by powder X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy. The XRD patterns and UV-vis absorption spectra confirmed the formation of the Ag nanoparticles (NPs). Meanwhile, the TEM images showed that the Ag NPs, which exhibited sizes in the range of 3–7 nm, were located on the surface of the Pal nanofiber structures. Furthermore, the antibacterial activity of the nanocomposites was evaluated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria by applying the disc diffusion method and minimum inhibitory concentration test. Owing to their good antibacterial properties, the Ag-Pal nanocomposites are considered to be a promising bactericide with great potential applications.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1643-y) contains supplementary material, which is available to authorized users.

Extrinsic and intrinsic performance effects on the electrical property in few-layer graphene

The effects of extrinsic and intrinsic performances on the electrical property of few-layer graphene (FLG) are investigated. This study uses the ultraviolet irradiation technique to tune the electrical parameters of FLG for analyzing the extrinsic/intrinsic contribution to the electrical conductivity. A correlation between the temperature-dependent electrical properties, phonon and impurity scatterings, and thermal activation of charge carriers is identified. The observed temperature evolution of resistivity is understood from the competition among the effects of phonon and impurity scatterings and thermal activation of charge carriers. It is important to identify the carrier transport behavior for enhancing the FLG-based device performance.

Rapid formation of hydroxyapatite layer on polyetheretherketone by vacuum ultraviolet irradiation and microwave heating techniques

Rapid formation of hydroxyapatite [Ca10(PO4)6(OH)2; HAp] layer on the polyetheretherketone (PEEK) substrate was examined by the combined techniques of vacuum ultraviolet (VUV) irradiation and microwave heating. The surface properties of PEEK substrate were modified by the formation of carboxyl group due to the VUV irradiation at room temperature in air, whereas the formation of HAp layer was encouraged by the microwave heating of surface-modified PEEK substrate in the HAp-dissolved solution. The optimization of the fabrication conditions was conducted by checking (i) the distance of VUV lamp to PEEK substrate (1–12 mm) and VUV irradiation time (0–120 min) for the surface modification of PEEK substrate, and (ii) the microwave heating temperatures (100 and 140°C) for the rapid formation of HAp layer on the PEEK substrate. When the PEEK substrate was surface-modified by the VUV irradiation for 120 min with the distance of VUV lamp to PEEK substrate kept being 1 mm, and then was microwave-heated in the HAp-dissolved solution at 140°C for 10 min, the thickness of the HAp layer on the PEEK substrate attained approximately 10 µm.

An Integrated Simulation-based Process Control and Operation Planning (IS-PCOP) System for Marine Oily Wastewater Management

The chronic discharge of oily wastewater, mainly including bilge water, offshore produced water and ballast water, has been referred to as a major contributor to marine oil pollution. Although gravity-based treatment techniques have been widely used to separate oil from wastewater, many dissolved toxic organics, particularly Polycyclic Aromatic Hydrocarbons (PAHs), are not likely to be effectively removed and may cause severe environmental problems. Further treatment has therefore become necessary for the shipping and offshore oil and gas industries, particularly in the harsh environments (e.g., the Arctic Ocean) where ecosystems are extremely vulnerable. Among many chemical and biological treatment techniques, ultraviolet (UV) irradiation and advanced oxidation techniques have been recently regarded as promising solutions to the removal of PAHs. Such advanced treatment systems, as compared to the traditional ones, are usually lack of in-depth understanding of reaction mechanisms and kinetics, process control requirements, and long-term planning strategies. More particularly, the integration of process control and operation planning has been proven in the literature to greatly reduce process cost and improve system performance. However, such integration is usually complicated by many factors such as the multi-scale nature of decisions, the lack of knowledge of process dynamics and control, and uncertainty. These deficiencies can drastically hinder the widespread application of these advanced treatment systems in the shipping and offshore industries. In response to these knowledge and technique gaps, this research proposes an integrated process control and operation planning system to aid marine oily wastewater management based on experimental study, process modeling, process control, operation planning and their coupling.

Softening of seawater and desalination brines using grafted polysaccharide hydrogels

This paper investigates the potential of using polysaccharide hydrogels as softeners for saline solutions of seawater and reverse osmosis desalination brine. Grafting of acrylamide onto alginate and chitosan was conducted using microwave (MW) and ultraviolet (UV) irradiation techniques. The produced hydrogels: alginate (Alg-UV and Alg-MW) and chitosan (Ch-UV and Ch-MW) were characterized using X-ray diffraction and scanning electron microscopy. Hydrogel products were tested for their swelling behavior in distilled water and saline solutions, and their calcium and magnesium adsorption capacities in the pre-swollen and dry forms were measured in saline solutions. Swelling in distilled water was found to exceed that in saline solutions by 16.7–21-fold. Maximum attained swelling ratios in distilled water were 168 and 173 g/g for Alg-UV and Ch-MW grafted acrylamide hydrogels, respectively. Dry hydrogels had relative selectivity toward calcium adsorption in seawater and magnesium adsorption in brine. Furthermore, pre-swollen hydrogel manifested favorable adsorption for calcium and magnesium when compared to dry hydrogel at the same adsorbate volume. For both dry and pre-swollen hydrogels, maximum calcium adsorption capacities were 54 and 34 mg/g from seawater using Alg-MW and UV-prepared alginate and chitosan hydrogels, respectively. Maximum magnesium adsorption capacities from brine were 280 and 316 mg/g using dry alginate and chitosan hydrogels, respectively, prepared by MW technique. Magnesium adsorption capacities of the prepared hydrogels in brine were higher than those of tested commercial resins. It is concluded that alginate- and chitosan-grafted acrylamide hydrogels are promising softeners for saline solutions.

Green synthesis of silver nanowires via ultraviolet irradiation catalyzed by phosphomolybdic acid and their antibacterial properties

In this study, we have fabricated well-defined silver nanowires by an ultraviolet (UV) irradiation technique in the presence of phosphomolybdic acid (PMo), which acted as a catalyst and stabilizing agent. The effect of fabrication parameters on the morphology of silver nanowires, such as initial concentrations of reactants, AgNO3 : PMo ratio, UV irradiation time, and temperature, are presented in detail. This suggests that the appropriate amount of PMo plays a relevant role in the formation of the silver nanowires, and temperature is another important factor determining the morphology of the silver nanowires. Furthermore, the antibacterial properties of silver nanowires was investigated against Escherichia coli, Staphylococcus aureus and Bacillus subtilis, and the mean diameters of the inhibition zones are 15.4 mm, 20.9 mm and 26.7 mm, respectively. This work provides a simple and green method for the synthesis of silver nanowires in aqueous solution with promising antibacterial properties.

Characterization of hydrogel synthesized from natural polysaccharides blend grafted acrylamide using microwave (MW) and ultraviolet (UV) techniques

AbstractGrafting is a powerful method for producing substantial modification in the polysaccharide polymer properties thereby enlarging the range of its utilization. The aim of this work is to identify the appropriate conditions for grafting a candidate synthetic monomer (acrylamide) onto a blend of polysaccharides (PsB) comprising of starch, chitosan, and alginate. Grafting process was carried out in the presence of a low concentration of potassium persulfate initiator and methylenebisacrylamide crosslinker using microwave (MW) or ultraviolet (UV) irradiation techniques. Different Am/PsB weight ratios (0.6–0.96) has been performed. The produced hydrogel was characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM) as well as nitrogen percent (%N). This study is focusing on comparing hydrogel samples in terms of grafting percentage (%G), grafting efficiency (%GE) and %add‐on. UV graft PsB (PsB‐g‐Am) gave the highest %G (157.8%), %GE (84%), %add‐on (61.95%) and %N (8.79%). Swelling water ratio (SWR) for the grafted samples in distilled water (DW) and different pH solutions (3–13) has been studied. UV grafted hydrogel gave a maximum SWR of 39 g/g. Am/PsB weight ratio and irradiation source had a direct effect on SWR of the produced hydrogel.

Synthesis of PVP capped gold nanoparticles by the UV-irradiation technique

Multi twinned gold nanoparticles have been synthesized by an ultraviolet irradiation technique involving the reduction of a gold salt in the presence of polyvinyl pyrrolidone (PVP).

Synthesis and properties of polyimide/silver nanocomposite containing dibenzalacetone moiety in the main chain

A new thermally stable polyimide–silver nanocomposite containing dibenzalacetone moiety in the main chain was synthesized by a convenient ultraviolet irradiation technique. A precursor such as AgNO3 was used as the source of the silver nanoparticles. Polyimide 6 as a source of polymer was prepared by polycondensation reaction of 2,5-bis(4-aminobenzylidene) cyclopentanone 4 with pyromellitic anhydride 5 in m-cresol solution and in the presence of iso-quinoline as a base. The resulting nanocomposite film was characterized by FTIR spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), Thermal gravimetric analyses (TGA), differential gravimetric analyses (DTG) and differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) confirmed the formation and dispersion of silver nanoparticles in polymer matrix having average size of ∼20 nm. Incorporation of inorganic metal silver nanoparticles has improved the thermal behavior of the nanocomposite film as compared to pure polyimide film. Also 2,5-bis(4-aminobenzylidene) cyclopentanone 4 was synthesized by using a two-step reaction.

Synthesis and Characterization of Polyimide–Silver Nanocomposite Containing Chalcone Moieties in the Main Chain by UV radiation

The soluble polyimide (PI)–silver nanocomposite (PISN) 6a containing chalcone moieties as a photosensitive group was synthesized successfully by a convenient ultraviolet irradiation technique. A precursor such as AgNO3 was used as the source of the silver particles. PI 6 was synthesized by the one-step synthesis of PI from polycondensation reaction of 4,4′-diamino chalcone 4 with pyromellitic anhydride 5 in the presence of iso-quinoline solution. The resulting composite film was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetry analysis, and differential scanning calorimetry.