Transmission Fourier Transform Infrared Spectroscopy Research Articles

Development of maintenance-free coatings using composite titania and silica

Atmospheric conditions and the effect of pollutants on the frequently exposed glass furnishings like windows in constructions and windshield in automotive industries often require maintenance due to their extensive usage and heavy exposure. This demanded an additional coating on the conventional glass furnishings to free from the pollutants without additional cleaning cost. Hydrophilicity and hydrophobicity are properties of titania (TiO2) and silica (SiO2) dielectric materials, although when coated as a composite material, they exhibit a larger affinity for water than carbon contamination. Hence, the contamination adsorbed on the surface of the glass can be easily cleaned by water without help of any detergent or cleaning agents. In this work, we report the fabrication and analysis of three TiO2-SiO2 composite coatings (single coated 1C, double coated 2C and triple coated 3C) on glass substrates using the sol-gel spin coating technique. The coatings were subjected to X-ray diffraction (XRD) analysis, which revealed a broad peak at Bragg angle 25 °, confirming the existence of mixed anatase TiO2 and amorphous SiO2. Fourier transform infrared transmission spectroscopy (FT-IR) studies on the coatings demonstrated peaks at 906 cm−1 and 768 cm-1 that corresponds to the characteristic bond of Si-O-Ti, and stretching bond of Ti-O-Ti respectively. The ultraviolet visible and near-infrared spectroscopy (UV-Vis-NIR) studies on the coatings endorsed 40% reflection in the ultraviolet and near-infrared spectral regions and found increasing the composite coating can increase the reflectance further. Finally, water contact angle (WCA) analysis indicated the hydrophilic character of the coatings, with contact angles of 74.8 ° (1C), 83.3 ° (2C), and 112.7 ° (3C) and suggested as a maintenance free coating on the glass furnishings.

Collagen stabilization by natural cross-linkers: A qualitative and quantitative FTIR study on ultra-thin dentin collagen model.

Due to its low tolerance to external factors such as enzymes, dentin collagen often requires stabilization, which can be achieved through cross-linking. In this study, qualitative and quantitative Fourier transform infrared (FTIR) analyses were used to assess dentin collagen stabilization effects of three structurally-different flavonoids -A-type linkage proanthocyanidins (A-PA), B-type linkage proanthocyanidins (B-PA), and epigallocatechin gallate (EGCG), all from natural extracts. Particularly, transmission FTIR spectroscopy was used for the first time to quantitatively assess the biodegradation of fresh ultra-thin (10 µm) dentin collagen films caused by collagenase digestion. Two traditional analytical methods, namely the hydroxyproline assay and weight loss analysis, were also used for comparison purposes. The results from all three methods showed consistently that A-PA and B-PA provide better collagen stabilization than EGCG at concentrations of 0.65% and 1.3% (p<0.01). FTIR is demonstrated to be a valuable and reliable analytical tool for qualitative and quantitative evaluation of ultra-thin collagen films.

Fourier Transform Infrared (FTIR) Spectroscopic Analyses of Microbiological Samples and Biogenic Selenium Nanoparticles of Microbial Origin: Sample Preparation Effects.

To demonstrate the importance of sample preparation used in Fourier transform infrared (FTIR) spectroscopy of microbiological materials, bacterial biomass samples with and without grinding and after different drying periods (1.5–23 h at 45 °C), as well as biogenic selenium nanoparticles (SeNPs; without washing and after one to three washing steps) were comparatively studied by transmission FTIR spectroscopy. For preparing bacterial biomass samples, Azospirillum brasilense Sp7 and A. baldaniorum Sp245 (earlier known as A. brasilense Sp245) were used. The SeNPs were obtained using A. brasilense Sp7 incubated with selenite. Grinding of the biomass samples was shown to result in slight downshifting of the bands related to cellular poly-3-hydroxybutyrate (PHB) present in the samples in small amounts (under ~10%), reflecting its partial crystallisation. Drying for 23 h was shown to give more reproducible FTIR spectra of bacterial samples. SeNPs were shown to contain capping layers of proteins, polysaccharides and lipids. The as-prepared SeNPs contained significant amounts of carboxylated components in their bioorganic capping, which appeared to be weakly bound and were largely removed after washing. Spectroscopic characteristics and changes induced by various sample preparation steps are discussed with regard to optimising sample treatment procedures for FTIR spectroscopic analyses of microbiological specimens.

Ga speciation in Ga/H-ZSM-5 by in-situ transmission FTIR spectroscopy

H-ZSM-5 supported Ga (Ga/H-ZSM-5) has long been recognized as a promising catalyst for nonoxidative dehydrogenation and dehydroaromatization of alkanes. However, Ga speciation under reaction conditions remains controversial. In this work, in-situ transmission Fourier Transform infrared (FTIR) spectroscopy is employed to systematically investigate Ga speciation in Ga/H-ZSM-5 with three Si/Al ratios (15, 28 and 39) and a wide range of Ga/Al ratios (0–1.7). Quantitative FTIR spectroscopy with pyridine reveals that one Ga atom roughly replaces one Brønsted acid site (BAS) at Ga/BAS ratio up to 0.7, however, only up to ~80% of the BAS on the H-ZSM-5 can be exchanged even with excess amounts of Ga. At a low Si/Al ratio of 15, the intensity of GaHx bands on reduced Ga/H-ZSM-5 at 550 °C increases almost linearly at low Ga loadings (Ga/Al < 0.13), and then levels off. In contrast, no detectable GaHx bands are observed on Ga/H-ZSM-5 with a high Si/Al ratio of 39, with Ga/Al ratios up to 1.3. The dependence of GaHx bands on both the Si/Al ratios and the Ga/Al ratios shows that Ga speciation varies with BAS density in the zeolite. We hypothesize that paired BAS sites are preferentially exchanged with Ga+, leading to the formation of Ga+−H+ pair sites, while the exchange of isolated BAS form isolated Ga+ species. Using water as a probe molecule, we show that isolated Ga+ and Ga+−H+ pair sites have distinct properties, i.e., the former can be easily oxidized by water at 150 °C to form GaOOH species, while the latter is inactive under the same conditions. These results provide direct experimental evidence for the existence of two types of Ga species on reduced Ga/H-ZSM-5, highlighting the possibility that they have different catalytic activities in alkane dehydrogenation reactions.

Insights into the methanol synthesis mechanism via CO2 hydrogenation over Cu-ZnO-ZrO2 catalysts: Effects of surfactant/Cu-Zn-Zr molar ratio

In this study, we evaluated aspects of the CO2 hydrogenation mechanism, correlating structure-activity relationships of Cu-ZnO-ZrO2 catalysts prepared by one-pot surfactant-assisted co-precipitation with different surfactant ratios. Identifying the CO2 hydrogenation pathway intermediates is key to controlling the reaction selectivity. Experimental evidence shows that the CO2 is dissociating into CO* and O* onto the surface of the Cu-ZnO-ZrO2 catalyst. The adsorption and dissociation of CO2 were evidenced by a combination of in situ ambient-pressure X-ray Photoelectron Spectroscopy (AP-XPS) and Fourier Transform Infrared Spectroscopy (FTIR) with a transmission cell. AP-XPS showed that the catalysts are composed of a Cu2+, Zr3+, and Zr4+ mixture and two kinds of Zn2+ species. After the H2 reduction process, only Cu2+ was reduced to Cu0. The Zn and Zr species were oxidized by the dissociated O* species. In situ transmission FTIR showed that CO was adsorbed onto the Cu+/0 sites. The catalyst with the higher surfactant molar ratio exhibited the highest CO2 conversion close to the equilibrium conversion, as well as a good methanol formation rate.

Assessment of Molecular Mechanism of Gallate-Polyvinylpyrrolidone-Capped Hybrid Silver Nanoparticles against Carbapenem-Resistant Acinetobacter baumannii.

Acinetobacter baumannii is an opportunistic nosocomial pathogen and causes bacteremia, urinary tract infections, meningitis, and pneumonia. The emergence of drug-resistant strain makes most of the current antibiotics ineffective. It is high time to screen some therapeutics against drug-resistant strains. Plant-based medicines have recently emerged as one of the important therapeutic choices. Therefore, in the present study, we have screened the metabolites of Phyllanthus emblica, Ocimum tenuiflorum, and Murraya koenigii for their antibacterial effect against carabapenem-resistant strain (RS-307) of A. baumannii. The result showed that the methanolic extract of P. emblica inhibits the growth of RS-307. The composition of this extract was determined using phytochemical screening and nuclear magnetic resonance (1D and 2D-NMR). The mechanism of action of the plant extract was validated by estimating reactive oxygen species (ROS), lipid peroxidation, protein carbonylation, and membrane damage. The result showed that treatment with this extract showed a significant elevation in the production of ROS generations, lipid peroxidation, and protein carbonylation. This confirms that plant extract treatment confirmed ROS-dependent membrane damage mechanism. The NMR result showed the presence of ethyl gallate, ellagic acid, chebulagic acid, quercetin, flavonoid, and alkaloid. To validate the antimicrobial activity of the secondary metabolite (i.e., gallic acid), we synthesized gallate-polyvinylpyrrolidone-capped hybrid silver nanoparticles (G-PVP–AgNPs) and characterized using Fourier transform infrared spectroscopy (FTIR). G-PVP–AgNPs showed good antimicrobial activity against RS-307, and its mechanism of action was investigated using fluorescence and transmission electron microscopy and FTIR that confirmed ROS-dependent killing mechanism. Therefore, the present study highlighted and recommended the use of G-PVP–AgNPs as suitable therapeutics against carbapenem-resistant A. baumannii.

Application of a Microreactor to Pharmaceutical Manufacturing: Preparation of Amorphous Curcumin Nanoparticles and Controlling the Crystallinity of Curcumin Nanoparticles by Ultrasonic Treatment

Amorphous nanoparticles of curcumin (ANC) with primary particle sizes of 50 to 100nm were prepared using a forced thin film reactor (FTFR). An ethanolic solution of curcumin and polyvinylpyrrolidone was mixed with purified water in an FTFR to precipitate the curcumin nanoparticles. In order to obtain amorphous particles, the solvent used and the operation conditions of FTFR such as the rotation speed of the disk and the flow rate of solutions were adjusted. According to powder X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FT-IR), amorphous curcumin nanoparticles were obtained. To control the crystallinity, ultrasonic treatment was carried out on ANC suspended in water or hexane to which a polymer or a surfactant was added to prevent the growth of the particles. Transmission electron microscopy, XRD, and FT-IR analyses indicated that the treatment enabled the transformation of ANC to crystalline form 1 (a fundamental curcumin structure) and then to crystalline form 2 or crystalline form 3 without any change in the size of the primary particles. These findings suggest the possibility of preparing solid particles with a desired particle size and crystallinity.

Photocatalytic degradation of navy blue textile dye by nanoscale cobalt aluminate prepared by polymeric precursor method

The photocatalytic degradation of Novacrom of navy blue textile dye was investigated using nanocrystalline cobalt aluminate spinel (CoAl2O4) as a photocatalyst. This compound was prepared by thermal decomposition of a polymeric precursor obtained by the sol-gel method. The crystallization process of the precursor was evaluated by thermogravimetry-differential thermal analysis (TG/DTA). The structural characterization was carried out by X-ray diffraction (XRD) and Fourier Transform Infrared Transmission Spectrometry (FTIR). The morphological properties were investigated by transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET). The optical properties of CoAl2O4 nanoparticles were evaluated by UV–vis diffuse reflectance measurements. The crystallization of CoAl2O4 spinel phase was entirely completed at 900 °C. This obtained powder was formed of relatively spherical grains with size about 25 nm and exhibits a specific surface area close to 34 m2/g. The optical band gap energy was estimated to be about 2.4 eV. The photodegradation process of the dye was followed by UV–vis absorption spectroscopy analyzes. The photocatalytic activity tests under UV light irradiation show a 42% of discoloration efficiency after 150 min. The addition of H2O2 increases this rate to 67%.

Synthesis and characterizations of Ag-decorated graphene oxide nanosheets and their cytotoxicity studies

In this paper, reduced graphene oxide nanosheets decorated with silver nanoparticles (AgNPs/rGO) were prepared by a wet chemical method. In this method, graphene oxide (GO), silver nitrate, and ammonia were used as a precursor. AgNPs/rGO composite was characterized by UV–Vis spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared transmission spectroscopy (FTIR), and transmission electron microscopy (TEM). The results show that the spherical silver nanoparticles with average size of about 6–10 nm were distributed on GO sheets. In vitro cytotoxicity of the prepared AgNPs/rGO samples was studied on neuro2A cells and found that the sample eliminates the growth of neuro2A cells up to 50% and Ag nanoparticles reduce the cytotoxicity of the GO sheets.

Assessing magmatic volatile equilibria through FTIR spectroscopy of unexposed melt inclusions and their host quartz: a new technique and application to the Mesa Falls Tuff, Yellowstone

Fourier transform infrared spectroscopy (FTIR) is a precise, non-destructive, and highly sensitive means of measuring volatile species in melt inclusions. Existing methods of applying FTIR to quartz-hosted melt inclusions, however, require challenging physical manipulation of the host quartz crystals, which can present a significant limitation. Here, we describe a technique for measuring the H2O and CO2 concentrations of melt inclusions fully enclosed in quartz crystals using transmission FTIR, where melt inclusion thickness is calculated using the host quartz silicate overtones. The greater thickness of quartz crystals permitted by this technique allows an additional assessment of volatile equilibrium by measuring structural OH− within the quartz host itself. To demonstrate the advantages of this technique, we applied it to quartz crystals from the Mesa Falls Tuff, Yellowstone. The majority of melt inclusions consist of transparent or brown glassy melt inclusions and record concentrations of 2.9–3.3 wt% H2O and 181–561 ppm CO2, with precision similar to that obtained by standard double-exposed FTIR. Based on volatile saturation models, such concentrations reflect a largely un-degassed magma body equilibrated at pre-eruptive pressures of 100–150 MPa. These H2O concentrations and equilibrium conditions are supported by independent assessments using mineral–mineral and mineral-melt thermohygrometry and thermodynamic modelling using rhyolite-MELTS. The preservation of pre-eruptive volatile concentrations is further corroborated by measurements of OH− in the quartz hosts. A clear decrease in hydroxyl concentrations from core to rim matches closely the zoning in Al, which, combined with the position of quartz infrared bands, most likely reflects variations in Al-moderated OH− solubility rather than diffusive loss. The outermost 200 µm rims, however, show a sharper decline in OH− and corresponding increase in Li+ which is interpreted to record minor diffusive H+ loss and incorporation of Li+ to maintain charge balance. Our FTIR-based technique is simple, effective, and widely applicable to other quartz-bearing magmatic systems, opening up new possibilities to trace pre- syn- and post-eruptive volatile behaviour.

Magnetic Fe3O4-chitosan micro- and nanoparticles for wastewater treatment

ABSTRACTIn this study, first, magnetic nanoparticles (MNP) were synthesized using a coprecipitation method and the synthesized particles were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and vibrating sample magnetometry (VSM). According to DLS and VSM analyses results, it was seen that the size of the MNP was smaller than 10 nm and they exhibited superparamagnetic properties, respectively. Then, magnetic Fe3O4-chitosan micro/nanoparticles were synthesized using a suspension cross-linking method in the presence of the MNP. Fe3O4-chitosan microparticles (Fe3O4-CMs) and Fe3O4-chitosan nanoparticles (Fe3O4-CNs), which have different structural, morphological, and magnetic properties, were obtained. All of the particles were characterized using transmission electron microscopy (TEM), FTIR, TGA, DLS, and VSM. In the second part of the study, the dye adsorption properties of the two different adsorbents from aqueous solution were investigated. For these purposes, Bromothymol Blue (BB) was used as a dye and the parameters affecting adsorption of BB (contact time, initial dye concentration, temperature and pH) were investigated. When the optimum adsorption conditions were provided for each adsorbent, the adsorption capacities of Fe3O4-CNs and Fe3O4-CMs were 82.2 and 193.3 mg/g, respectively.

A green approach for quantification of Naproxen in bulk and oral dosage form by FT-IR method

A very simple, non-destructive, inexpensive and green strategy applied for the quantification of Naproxen using transmission Fourier Transform Infrared (FTIR) spectroscopy in bulk &amp; tablet dosage form and the Beer’s concentration range found to be 5-25μg. For the present investigation of Naproxen, O-H, 3000 - 3500cm-1 was selected for the analysis. The correlation coefficient for the method found to be 0.9965 and the developed method analyzed for specificity, limit of detection (LOD), limit of quantification (LOQ), linearity of response, precision and accuracy. This work clearly shows the capability of transmission FTIR spectroscopy for assessment of exact quantity of API to control the quality of finished products as well as during processing in pharmaceutical industries. Therefore, as compared to other spectroscopic or chromatographic method, costly chemicals and toxic solvents totally avoided in this direct, inexpensive and green approach. Such types of FTIR applications have a strong potential to replace classical methods in quality assurance /quality control (QA/QC) for the analysis of active contents in pharmaceutical preparations.&#x0D; Keywords: Accuracy; Beer’s law; Infrared spectroscopy; Limit of detection (LOD); Limit of Quantification; Naproxen

Infrared spectroscopic studies on crystalline phase transition of PVDF and PVDF/hyperbranched polyester blend ultrathin films

In this study, as cast (AC, at 30 °C) and annealed (AN, at 130 °C, 3 h) samples of polyvinylidene fluoride (PVDF) and PVDF/hyperbranched polyester (HBP) (90/10) blend ultrathin films were subjected to heating-cooling (30 → 210 → 30 °C) cycle, and studied for their changes in crystalline phase transition behavior using in-situ Fourier transform infrared-transmission spectroscopy (FTIR-TS) and grazing incident reflection absorption spectroscopy (FTIR-GIRAS) techniques. Factor analysis was employed to extract the pure crystalline and amorphous spectra as well as the percentage content of ferroelectric crystallinity for both the samples. Irrespective of the thermal treatment (AC or AN) and spectral measurement (FTIR-TS or GIRAS) techniques, neat PVDF sample exhibited irreversible phase transitions during heating-cooling cycle associated with the transformation from ordered β-crystalline (1276 cm−1) into disordered amorphous (1234 cm−1) form. Interestingly, annealed PVDF/HBP blend sample measured using FTIR-GIRAS exhibited reversible crystalline phase transition behavior similar to a ‘dipole memory effect’ even after heating to 210 °C (>Tm) and then cooled to 30 °C. Compared to neat PVDF, higher ferroelectric crystallinity and reversible phase transition in PVDF/HBP blend may be attributed to (i) the existence of H-bonding between HBP (CO and OH groups) and PVDF (CH2 and CF2) and/or (ii) HBP acting as a nanoparticle in PVDF matrix.

Facile preparation of reduced graphene by optimizing oxidation condition and further reducing the exfoliated products

Abstract

Incomplete elimination of precursor ligands during atomic layer deposition of zinc-oxide, tin-oxide, and zinc-tin-oxide.

For atomic layer deposition (ALD) of doped, ternary, and quaternary materials achieved by combining multiple binary ALD processes, it is often difficult to correlate the material properties and growth characteristics with the process parameters due to a limited understanding of the underlying surface chemistry. In this work, in situ Fourier transform infrared (FTIR) spectroscopy was employed during ALD of zinc-oxide, tin-oxide, and zinc-tin-oxide (ZTO) with the precursors diethylzinc (DEZ), tetrakis(dimethylamino)tin (TDMASn), and H2O. The main aim was to investigate the molecular basis for the nucleation delay during ALD of ZTO, observed when ZnO ALD is carried out after SnO2 ALD. Gas-phase FTIR spectroscopy showed that dimethylamine, the main reaction product of the SnO2 ALD process, is released not only during SnO2 ALD but also when depositing ZnO after SnO2, indicating incomplete removal of the ligands of the TDMASn precursor from the surface. Transmission FTIR spectroscopy performed during ALD on SiO2 powder revealed that a significant fraction of the ligands persist during both SnO2 and ZnO ALD. These observations provide experimental evidence for a recently proposed mechanism, based on theoretical calculations, suggesting that the elimination of precursor ligands is often not complete. In addition, it was found that the removal of precursor ligands by H2O exposure is even less effective when ZnO ALD is carried out after SnO2 ALD, which likely causes the nucleation delay in ZnO ALD during the deposition of ZTO. The underlying mechanisms and the consequences of the incomplete elimination of precursor ligands are discussed.

Preparation of highly exfoliated epoxy/clay nanocomposites by clay grafted with liquid crystalline epoxy

ABSTRACTEpoxy/clay nanocomposites with a high degree of exfoliation were achieved by intercalating liquid crystalline epoxy into clay intragallery as well as using a so-called ‘solution compounding’ process. In this process, clay modified was first treated with trichloromethane to form organoclay-trichloromethane suspension followed by liquid crystalline epoxy modification. The liquid crystalline epoxy grafted clay was then mixed extensively with epoxy to form epoxy/nanoclay composites. The mechanism of exfoliation was explored by monitoring the change of morphology of organoclay during each stage of processing with X-ray diffraction (XRD). The liquid crystalline epoxy grafted clay synthesised was characterised by fourier transform infrared spectroscopy (FT-IR) and polarising optical microscopy (POM). The clay platelets uniformly dispersed and highly exfoliated in the whole epoxy matrix were observed using transmission electron microscopy (TEM) and FT-IR imaging system. The epoxy nanocomposites were fabricated by incorporating different liquid crystalline epoxy grafted clay loading. The results revealed that the incorporation of liquid crystalline epoxy grafted clay resulted in a significant improvement in glass transition temperature (Tg) derived from dynamic mechanical analysis (DMA) and thermal stability measured by thermogravimetric analysis (TGA).

Rapid detection of talcum powder in tea using FT-IR spectroscopy coupled with chemometrics.

This paper investigated the feasibility of Fourier transform infrared transmission (FT-IR) spectroscopy to detect talcum powder illegally added in tea based on chemometric methods. Firstly, 210 samples of tea powder with 13 dose levels of talcum powder were prepared for FT-IR spectra acquirement. In order to highlight the slight variations in FT-IR spectra, smoothing, normalize and standard normal variate (SNV) were employed to preprocess the raw spectra. Among them, SNV preprocessing had the best performance with high correlation of prediction (RP = 0.948) and low root mean square error of prediction (RMSEP = 0.108) of partial least squares (PLS) model. Then 18 characteristic wavenumbers were selected based on a hybrid of backward interval partial least squares (biPLS) regression, competitive adaptive reweighted sampling (CARS) algorithm and successive projections algorithm (SPA). These characteristic wavenumbers only accounted for 0.64% of the full wavenumbers. Following that, 18 characteristic wavenumbers were used to build linear and nonlinear determination models by PLS regression and extreme learning machine (ELM), respectively. The optimal model with RP = 0.963 and RMSEP = 0.137 was achieved by ELM algorithm. These results demonstrated that FT-IR spectroscopy with chemometrics could be used successfully to detect talcum powder in tea.

Effect of calcined parameters on microstructure and electrical conductivity of 10Sc1CeSZ

10Sc1CeSZ (10 mol% Sc2O3–1 mol% CeO2–89 mol% ZrO2) nanopowders were prepared by hydrothermal and calcinations. The calcined powders were uniaxially compacted into pellets and sintered at 1400 °C for 2 h. The calcined powders and sintered pellets were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared transmission spectroscopy (FTIR) and impedance spectroscopy. The powders calcined at 800 °C for 2 h (and below 800 °C) was beneficial to pellets densification. After the powders were calcined at 800 °C for 2 h, the sintered pellets showed relative density of 97.5%, and its conductivity was 0.108 S cm−1 at 800 °C. The powders calcined at 800 °C for 24 h showed the better conductivity of 0.131 S cm−1 at 800 °C. The microstructure, bulk density and electrical properties of the sintered pellets can be tuned using different calcined parameters.

In situ photoacoustic FTIR studies on photocatalytic oxidation of 2-propanol over titanium(IV) oxide

Adsorption and photocatalytic reaction of 2-propanol over titanium(IV) oxide (TiO2) were studied by Fourier transform infrared spectroscopy (FTIR) using a photoacoustic (PA) technique. At first, the validity of the FTIR system using a home-made PA cell was confirmed by comparison with conventional transmission FTIR. The spectrum of TiO2 with 2-propanol showed different propoxy peaks from those of gaseous 2-propanol as a result of chemisorption on TiO2. Finally, in situ FTIR observation of the photocatalytic oxidation of 2-propanol was carried out. Under ultraviolet irradiation, PA spectra changed due to complete oxidation of 2-propanol through acetone as an intermediate.

Preparation of Polyurethane Flexible Foam Nanocomposites by Incorporation of Fe3O4Nanoparticles Modified by Reaction Product of GPTS and APTS

Synthesis and characterization of magnetic flexible polyurethane foam (PUF) nanocomposites is reported. In order to improving dispersion and preventing aggregation of Fe3O4nanoparticles in the polymer matrix, this material was modified by synthesized dipodal silane (ECA), the reaction product of 3-aminopropyltriethoxysilane (APTS) and γ-glycidoxypropyltrimethoxysilane (GPTS). The chemical structure of synthesized ECA was identified by nuclear magnetic resonance spectroscopy (1HNMR) and Fourier transform infrared spectroscopy (FT-IR), respectively. Magnetic flexible polyurethane foam nanocomposites prepared by the incorporation of ECA-modified Fe3O4nanoparticles and characterized by their apparent density, thermogravimetric analysis (TGA), magnetic properties analysis (VSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and FT-IR spectra, respectively. The TEM and SEM images indicated that the nanoparticles were dispersed homogeneously in PUF matrix. Finally, it was confirmed that the thermal and magnetic properties of magnetic PUF nanocomposite depend on the amount of magnetic nanoparticles.