Papers by Keyword: Fourier Transform Infrared Spectroscopy

Abstract: The durability and functionality of medical rubber products made from natural rubber or poly (cis-1,4-isoprene) are essential in medical and healthcare applications. However, natural rubber products are prone to degradation over time, which can compromise their performance. This study investigates the impact of limonene on the degradation of natural rubber, focusing on the material’s physical and chemical properties. To achieve this, natural rubber samples were prepared and exposed to different concentrations of limonene oil (20%, 40% 60%). The effect of limonene on the natural rubber was assessed by measuring the changes in tensile strength, physical size of samples, stability and chemical composition over immersion times of 30, 60 and 90 minutes. The findings of this study revealed that the immersion of natural rubber in d-limonene led to a significant reduction of tensile properties due to chain scission and bond breaking as well as cross-linking within the rubber. These mechanical alterations were more distinct with the longer immersion times and the higher limoneone concentrations. Additionally, the samples exhibited noticeable dimensional changes with greater concentrations of d-limonene leading to more substantial swelling and ultimately causing a reduction in tensile strength. FTIR-ATR spectroscopy analysis had also revealed chemical modifications in the rubber's structure, particularly related to carbonyl groups. This study provides valuable insights into the vulnerability of natural rubber to limonene-induced degradation. It highlights the need for further research and formulation to enhance medical-grade rubber products' performance for SDG-3.

Abstract: On place research was conducted on a farm where cows were fed by a mixture of traditional pasturing and feed supply. Pyrolysis was carried out directly on the farm to produce a ready-to-use biochar product. The product of biochar after pyrolysis was mixed with an organic adhesive dopant into 100 gram processed products for commercial use. This processed product was analyzed by elemental analysis, proximate analysis, TGA, FTIR and electron paramagnetic resonance spectroscopy. Data from these analyses was compared to those of brown coal Aduunchuluun, which is originally from the same place as the bio waste. Heavy elements content in biochar such as silicon, aluminium, sulphur, etc. is significantly less than compared to the brown coal. TGA and DTG analysis on the biochar product showed a total weight loss of 0.87%, where nearly 0.26% of the moisture was released in the temperature interval of 30 - 300°C, 0.46% of devolatilization occurred in 300 - 600°C, and 0.15% of mass loss in combustion reaction in 600 - 700°C. The residue after the thermal processing was minimal and consisted of hemicellulose and cellulose after volatilization. From the FTIR analysis, we see a disappearance of hydroxyl group vibration around 3400 cm^-1 and carbonyl C=O stretching 1733 cm^-1 from the biochar product compared to brown coal. The aromatic absorption near 1600 cm^-1 is shifted to 1392 cm^-1 in biochar. EPR spectrum of bio product consists of two lines, broad and narrow in the resonance field of ≈ 3500 Gs. Corresponding g-factor of narrow line and broad line 2.0022. It is calculated the spin numbers in biochar sample, that is compared to brown coal related data.

Abstract: The objective of the presented research is to improve the ballistic performance of para-aramid woven fabric by deposition of graphene coatings directly on woven textile substrates. The improvement of mechanical properties of the ballistic fabric is attributed to the formation of a highly ordered layered structure and the efficient load transfer between the fabric fibers and the graphene nanosheets. The results of deposition of layered graphene coatings on woven textiles are discussed here. The pristine graphite directly subjected to a solvent treatment in this work, which resulted in the production of exfoliated graphene sheets in the form of a dispersion that allow immediate utilization obtained dispersion for deposition on the para-aramid samples. In order to prepare the dispersion, graphite flakes were first dispersed into liquid media followed by graphite intercalation (division into microlayers) and nano-layers exfoliation. Dipolar aprotic organic solvent DMAc (N,N-Dimethylacetamide) and Cyrene (Dihydrolevoglucosenone) as a bio-based alternative for dipolar aprotic solvents were used as main components of liquid media. At the final stage, a stable dispersion of isolated flakes by using two types of liquid medium was obtained. To study the effects of dip coating and rolling parameters, six kinds of samples with different pull-out speeds and compression ratios were prepared, and their functional properties were measured and compared.

Abstract: Corrosion is an inevitable process of deterioration of metal but it can be slowed down using inhibitors, enhancing the durability of the metal. In the present study, the aqueous extract of Aegle Marmelos Leaves from surrounding area were tested as green corrosion inhibitor for aluminium metal in 1M H₂SO₄ acidic medium. The leaves extract characterization was analyzed using Fourier Transform Infrared Spectroscopy (FT-IR), the surfaces of Aluminium Sheets were examined using scanning electron microscopy (SEM) and atomic forced microscopy (AFM). Different techniques like weight-loss analysis, UV-VIS studies, pH are done to study for inhibition efficiency. At different temperatures the inhibition efficiency is tested and results showed a good restrain approximately to 81% at 90% (v/v) of inhibitor solution in H₂SO₄ acidic medium.

Abstract: Silver nanoparticles were synthesized using locally purchased honey and silver nitrate solution. This method provides a simplistic and straightforward approach to the formation of silver nanoparticles. The silver nanoparticles with varying amounts of silver nitrate solution were characterized using ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy. In addition, dynamic light scattering characterization was used to determine the average size and size distribution of silver nanoparticles. Experimental results revealed that varying the amount of silver nitrate solution can control the size and absorption spectra of silver nanoparticles. A large amount of silver nitrate solution will exhibit a peak in the higher wavelength. The shifting of the absorption peaks at 401, 406, 407, 408, and 409 nm are believed to be related to the wavelength of the surface plasmon resonance. Moreover, a larger amount of silver nitrate solution also results in an increasing size with 27.2, 57.9, and 63.4 nm as revealed in the size distribution via dynamic light scattering. This green synthesis method of silver nanoparticles will provide a cost-effective production as an alternative to commercial antibacterial agents.

Abstract: This research study focused on the fabrication and characterization of sodium alginate incorporated with iron (III) oxide in the form of beads and biofilm for biomedical application. The fabrication of the samples was carried out by using solution casting method and syringe pump extrusion technique. Beads and biofilm of sodium alginate incorporated with iron oxide were characterized by several characterization testing such as XRD, FTIR and contact angle measurement. From the XRD testing shows the diffraction peak that confirmed the cubic structure of Maghemite. Then, FTIR analysis shows the presence of several intermolecular and intramolecular bond stretching of sodium alginate. Lastly, contact angle measurement exhibits that alginate incorporated with iron oxide has hydrophilic behavior due to the contact angle less than 90Also, it was found that as the contact angle reduced as the weight of iron oxide increased.

Abstract: Asphalt aging is a pivotal factor affecting the service performance of asphalt pavement. Previous studies often ignored the influence of ultraviolet radiation on asphalt aging. Coincidentally, there is no standard test method of photooxidation aging that can be applied to guide engineering practice. In this paper, the influence of ultraviolet aging on the composition, structure and properties of asphalt was studied by adopting Bert four-component method, Fourier transform infrared spectroscopy aned dynamic shear rheometer. Bert four-component method elaborates that the content of asphaltene increases and the content of aromatic component decreases after UV aging. Fourier transform infrared spectroscopy indicates that there are obvious peaks of carbonyl and sulfoxide groups after aging, the penetration of asphalt decreases while the softening point and viscosity increase. Moreover, the composite modulus of asphalt increases obviously at low temperature, but has little effect on the composite modulus at high temperature.

Abstract: In this study, the Pb(II) ions adsorption unto nanoscale zerovalent iron particles (nZVI) supported on rice husk has been carried out. The challenge of nanoparticles agglomeration makes immobilising them on rice husk desirable. Optimization of process parameters, pH (4 – 10), adsorbent dose (0.5 – 2.0 g) and contact time (60 – 300 min), was carried out using response surface methodology (RSM) based on Box-Behnken design. Optimum condition for maximum Pb(II) ions of 98.74% was predicted at contact time of 60.12 min, pH of 4.01 and adsorbent dose of 0.5 g. At these optimized conditions, 97.23% removal was achieved experimentally. Analysis of variance carried out on the experimental data showed that the model was significant with a R² of 0.9883. The synthesised adsorbent was characterized with Fourier transform-infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The SEM showed that RH-nZVI has a very porous surface structure. Amine, carboxyl and hydroxyl groups were some of the identified functional groups present in the adsorbent for adsorption. This study suggests that nZVI supported on rice husk is a viable low-cost adsorbent for removing Pb(II) ions from wastewater.

Abstract: We measured Fourier transform infrared (FT-IR) and cathodoluminescence (CL) spectra of SiO₂ films with a various thickness, grown on 4H-SiC substrates. The peak frequency of the transverse optical (TO) phonon mode was blue-shifted by about 5 cm⁻¹ as the oxide-layer thickness decreased from 50-60 nm to 10 nm. The blue shift of the TO mode is considerd to be caused by interfacial compressive stresses in the oxide-layer. On the other hand, the TO phonon mode was found to dramatically decrease as the oxide-layer thickness decreased from 10 nm to 1.7 nm. The CL measurement indicates that the intensity of the CL peaks at about 460 and 490 nm attributed to oxygen vacancy centers (OVCs) for No.2 become stronger than that for No.1. From a comparison between FT-IR and CL measurements, we concluded that the red-shift of the TO phonon with decreasing the oxide-layer thickness can mainly be attributed to an increase in inhomogeneity at the SiO₂/SiC interface with decreasing oxide-layer thickness.

Abstract: The amount and alignment of hydroxyl ions influence the bioactivity of hydroxyapatite. Hydroxyl ions in hydroxyapatite are the most mobile and upon heating are the first to leave the lattice to form oxyhydroxyapatite. This work describes a method for producing hydroxyapatite with different amounts of hydroxyl ions, and reports on the changes in Fourier transform infrared absorption at increasing level of dehydroxylation. Detailed analysis of spectra in the 500 – 700 cm^-1 range showed a peak shift for the hydroxyl ion absorption line at 632 cm^-1 to 637 cm^-1 and an increase in the wavenumber for the phosphate line at 575 cm^-1.