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This paper aims to investigate effects of acrylic functionalisation of multiwalled carbon nanotubes (MWCNTs) on properties of carbon nanotubes/epoxy nanocomposites.

A number of analytical techniques, including Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy, were used to assess the effects of acid treatment on MWCNTs. Ultraviolet-curable coatings were fabricated by sonication and cast moulding process. The mechanical properties of MWCNTs/epoxy composites at different weight fractions were evaluated by performing tensile tests and dynamic mechanical analysis tests. Also, gel contents were examined.

It was found that addition of nanotubes monomer to epoxy formulations had significant effect on the viscoelastic and mechanical properties.

Improving dispersion and alignment of MWCNTs in the composite matrix will contribute to the development of resin/MWCNTs nanocomposites and promote the applications.

The paper establishes a method to introduce MWCNTs into epoxy matrix as a monomer to enhance the photo curable and dispersion properties of the MWCNT/epoxy films.

Piperidine side chain-functionalized N, N′-bissalicylidene phenylene di amine di-anion (salphen) consisting of salphen-Zn and salphen-Cu are able to intercalate with nucleic base stacking of DNA and can be applied as an optical DNA hybridization detector. Attaching DNA and salphen to glass surfaces has been done via coating the surface with the silane coupling agents containing 3-aminopropyltriethoxysilane that was synthesized for acting as a high-affinity RNA carrier matrix. The Schiff base salphen-zinc (II) and salphen-Cu (II) complexes-labelled probe to target nucleic acid renders a colour change of the DNA biosensor to a green and red background colour for zinc and copper, respectively. This study aims to indicate that the DNA biosensor data with high efficiency is used for detection of dengue virus serotypes 2 (DENV-2) and Chikungunya virus (CHIKV) concentration via salphen-Zn (II) and salphen-Cu (II), respectively, in human samples.

¹H-NMR and ¹³C-NMR have been used via PerkinElmer LAMBDA 35 instrument. The authors also used a double beam spectrophotometer with (CH₃)4Si (TMS) as reference and dimethyl sulfoxide as solvent reference in pH = 7.0. Various DNA concentrations have been used for UV spectrophotometry at 300 nm and 400 nm for zinc and copper complexes, respectively. BRUKER mass spectra with DIONEX Ultimate 3000 LC model were used for all measurements. Mettler Teledo model (DSC882e) of differential scanning calorimeter (DSC) was used for measure the melting temperature of metal zinc and copper complexes. The morphology of the silica Nano spheres (SiNs) were scanned by FESEM with Model JSM-6700F from Japan.

The Cu (II) and Zn (II)-salphen-viruses DNA system for CHIKV and DENV-2, respectively, in different concentration have been investigated via various spectroscopies (Figure 3). CHIKV and DENV-2 DNA were selected from human saliva and urine samples as models for conformations of human G4-DNA. By increasing the amounts of DNAs, and G4, the UV–Vis bands of located above 300 nm, experienced a hypochromic effect. The Cu2+ complex exhibits selectivity towards the G4, and there is a similar affinity for Zn²⁺ complex binds to the G4. These results collectively suggest that the Cu²⁺ complex is stronger than the Zn2+ complex. The authors have found copper (II) and zinc (II) compounds and nucleic acid-complexes are strongly fluorescent molecules in the low energy range, from the visible to the near-infrared. Since the fluorescent emission of Zn (II) and Cu (II) complexes are enhanced by the binding to nucleic acids upon visible light exposure when bound to DNA. These complexes are important as selective fluorescent probes for nucleic acids and to highlight their potential application. UV–vis spectroscopy is an accurate for finding the extent of ligand interaction with DNA and metallic complexes–DNA binding. Generally, the binding of intercalative compounds to DNA can be characterized through absorption spectral titrations, where lowering in absorbance (hypochromism) and shift to longer wavelengths (red shift) were observed in this work.

The serum samples have been provided as citrate and collected in tubes after blood is allowed to clot. Then, it has been separated by centrifugation, and the authors have kept serum refrigerated at 4°C or frozen at –20°C. It is notable; specimens have been confirmed by Centres for Disease Control (CDC)-Dengue Branch previously. For the work, these samples have been frozen previously, and the diagnostic practiced tests at the CDC-Dengue Branch have been validated in serum and plasma. Therefore, plasma separated in lavender or heparins are suitable and acceptable for serology testing.

A common procedure for processing stereolithography epoxy injection molds includes a one hour post‐cure in a UV chamber. This research investigates the degree of cure achieved in the UV chamber and the degree of cure achieved by heating in a thermal oven. It is hypothesized that a more fully cured mold is harder and hence will produce more parts before failure. This research investigates various post‐cure processes and suggests a post‐cure strategy to achieve this end.

Rapid prototypes formed using stereolithography (SL) method have to undergo post‐curing to increase their strength and rigidity. This study attempts to reduce, if not eliminate, post‐cure distortion by characterising curing behaviours. Curing (both heat and UV initiated) characteristics of an acrylic‐based photopolymer under actual fabrication conditions were studied using Raman spectroscopy as well as differential scanning calorimetry (DSC) and differential scanning photo‐calorimetry (DSP). Specimens of single photopolymer lines were created using a SL machine. Raman spectroscopy was used to quantify the curing percentage at different areas on the cross‐section of these lines. Curing percentages before and after post‐curing were also obtained from the experiments. Difference in percentage of post‐curing gave an indication of the distortions faced. It was found that uncured and partially cured resins trapped within the photopolymer resulted in inhomogeneity of curing in the specimens causing shrinkage and distortion.

Water‐borne coatings Increasing use of water‐borne emulsion coatings for original equipment manufacturers (OEM) and product finishes is requiring greater efficiency in coalescing‐aid solvents, an Eastman Chemical Co. representative said at a recent Chicago Society for Coatings Technology meeting. Eastman's Ronald K. Litton said emulsions designed for OEM and industrial applications have higher glass transition temperatures than emulsions used in architectural paints. That requires higher levels of coalescing aid to achieve good film formation. As a result, coalescing‐aid efficiency with a given emulsion system is a key factor, both from environmental (lower‐volatile organic compound (VOC)) and economic standpoints. Several properties should be examined when a coalescing aid is selected for water‐borne emulsion industrial coatings. The formulator should consider the evaporation rate and solubility parameter of the coalescing aid, along with its distribution pattern in a specific emulsion system. Those properties are important in defining the efficiency of a coalescing aid in terms of its ability to lower the minimum film‐forming temperature (MFFT) of an emulsion system. The coalescing aids also must be hydrolytically stable to provide minimum loss of efficiency due to ageing, Litton said. He showed several charts designed to assist formulators in the selection of optimum coalescing aids for emulsion systems. At the same conference, James T.K. Woo of The Glidden Co. discussed the grafting of high‐molecular‐weight epoxy resins with styrene‐methacrylic acid monomers, producing a water‐reducible copolymer. Grafting takes place at the aliphatic carbons of the epoxy resin, according to carbon‐13 NMR spectroscopy. The study was a follow‐up to a paper presented 14 years ago. Woo said recent research indicates that five grafting “peaks” were identified on a 400 megacycle carbon‐13 nuclear magnetic resonance spectroscopy instrument. The paper provided several theoretical calculation on grafting. Three of the graft peaks resulted from grafting at the secondary methylene carbons ‐CH2‐ and two resulted from grafting at the tertiary carbon ‐CH‐. The ratio of grafting at ‐CH2‐ to ‐CH‐appears to be 2.7:1 — lower than the 4:1 ratio of protons present on the aliphatic carbons that are susceptible to hydrogen abstraction leading to grafting. That indicates that the tertiary hydrogen is somwhat more susceptible to grafting than the methylene hydrogens, he said.

The purpose of this paper is to explore the synthesis, preparation and investigation of micro structural, optical and mechanical studies of polyvinyl alcohol (PVA) doped with tungsten oxide (WO₃) nanocomposites films. These films were prepared by simple solvent casting method is further characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-visible spectroscopy, universal testing machine (UTM), scanning electron microscope (SEM), energy-dispersive analysis of X-rays (EDAX) and atomic force microscope (AFM) techniques to determine the enhancement in structural, optical and mechanical properties with increase in dopant concentration.

The present paper deals with the synthesis of WO₃ nanoparticles using precipitation method and doping into PVA matrix to prepare a polymer nanocomposite film using coagulation and solvent casting method. The FTIR explores the interaction of dopants with PVA matrix. The XRD spectra investigate the variation of crystallinity. The UV/Vis-spectra reveals the information of optical energy band gap and the Urbach Energy for different doping concentrations. The mechanical properties of the nanocomposites were exposed using UTM. The phase homogeneity, film topography, chemical composition of nanocomposites is analyzed using SEM, EDAX and AFM techniques supporting the above results.

The films characterized by FTIR spectroscopy explores the irregular shift in the bands of pure and doped PVA can be understood on the basis of intra/inter molecular hydrogen bonding with the adjacent OH group of PVA backbone. The XRD result reconnoiters that the particle size and crystallinity increases whereas microstructural strain and dislocation density decreases with increase in dopant concentration. Further the drastic decrease in optical energy band gap E _g =0.94 eV for doping concentration x=15 wt% and the increase in values of Urbach Energy (E _u ) with doping concentrations were investigated by UV/Vis spectra. Also the extinction coefficient was high in the wavelength range of 250-400 nm and low in the wavelength range of 400-1,200 nm. The mechanical studies indicates that the addition of the WO₃ with weight percentage concentration x=15 percent increases the tensile strength and Young’s modulus. The phase homogeneity, the particle size of the dopants and chemical composition of nanocomposites is analyzed using SEM and EDAX. The film topography of the nanocomposites is analyzed using AFM techniques supporting the above results.

The investigation of synthesis, preparation and investigation of micro structural, optical and mechanical studies of PVA doped with WO₃ nanocomposites films as been done. The results prove that these nanocomposites having good mechanical strength with crystalline nature and also very low optical energy gap value that could find possible applications in industries.

The purpose of this paper is to develop a new water based coating system composed of poly(acrylamide‐co‐acrylic acid) and anthocyanin colourant extracted from Hibiscus sabdariffa L. and characterise the system.

Anthocyanin from Hibiscus sabdariffa L. (roselle) calyxes was extracted using optimised water extraction method with ratio of calyxes to water being 1:2. UV‐Vis absorption spectroscopy was conducted on the anthocyanin extract to monitor its degradation. Poly(acrylamide‐co‐acrylic acid) was mixed with the extracted anthocyanin solution in two different weight ratios. The mixtures were coated on glass substrate and let to cure for approximately one day. FTIR spectroscopy was conducted on the samples to determine their functional groups and identify the compounds in the samples. Cross hatch test was performed on the samples to determine the adhesion properties. Thermal degradation of the samples was determined through thermogravimetric analysis. Surface roughness of the samples was studied by atomic force microscopy. Colour stability was determined before and after UV irradiation.

Anthocyanin pigment from roselle extracted with water was found to be stable with 6.0 per cent drop in absorbance value over the 15 day period. The reaction rate was found to be 0.000181 h⁻¹, and the half life was calculated to be 3,850 hours. Better adhesion of the samples to the glass substrate was due to the higher concentration of poly(acrylamide‐co‐acrylic acid). Thermogravimetric analysis revealed similar thermal stability of the samples. Surface roughness study revealed that sample with higher anthocyanin content has higher surface roughness. Colour stability of the 20PBR was found to be better than 10PBR.

Usage of poly(acrylamide‐co‐acrylic acid) as coating is limited by its weak water resistance property. Improvement could be made in this direction for future applications.

Mixture of water‐based polymer and anthocyanin colourant from roselle has been developed into coating for the first time. Commercialisation is possible if more research is conducted towards water resistance property of poly(acrylamide‐co‐acrylic acid), storage condition for the pigment and coating, and mass production of the pigment.

Incorporation of anthocyanin pigment into water based coating is the first of its kind.

This paper aims to describe the techniques used in industrial optical chemical sensors and to consider future prospects.

This paper discusses the techniques and technologies used in today's optical chemical sensors. It highlights their limitations and considers briefly certain new technological developments.

This paper shows that techniques such as wet reagent‐aided photometry, UV absorption, spectroscopy and UV fluorescence satisfy a range of industrial chemical sensing applications and that optode technology is making limited commercial inroads. It identifies the need for inexpensive, wet reagent‐free chemical sensors and suggests that both solid‐state electrodes and lab‐on‐a‐chip devices may ultimately resolve this issue.

This paper provides a technical insight into the state of optical chemical sensing and illustrates that generic families of inexpensive chemical sensors are yet to be developed.

The purpose of this paper is to synthesize Cr-ZSM-5 using hydrothermal synthesis in acidic fluoride medium and the investigation of its catalytic performance in heterogeneous oxidation of 2-mercaptobenzothiazole in the presence of H₂O₂.

The framework was characterized by chemical composition, FT-IR, UV-visible spectroscopy, N₂ adsorption (BET), and diffraction x-ray (DRX). FT-IR spectroscopy shows the characteristic band of Si-O-Cr linkage around 960-990 cm⁻¹ and bands around 688-690 and 627 cm⁻¹, indicating the presence of extraframework chromium oxide. UV spectra show a shoulder around 244-257 and bands around 360-380 nm, assigning the tetrahedral coordinated environment in (O²⁻=Cr⁶⁺) − (Cr⁵⁺-O⁻¹), charge transfer transition state (CT) of isolated Cr (VI) inside the structure of Cr-ZSM-5.

The catalytic degradation of 2-mercaptobenzothiazole by H₂O₂ heterogenous oxidation using catalyst Cr-ZSM-5 showed the formation of bis (benzothiazoyl) disulfide with 95 percent yield.

The application of this process in the environment (catalysis, adsorption, and degradation of organic compounds).