Fourier Transform Infrared Results Research Articles

Flotation separation of smithsonite from calcite with guar gum as depressant

Naturally, smithsonite and calcite have similar surface physico-chemical properties so as similar floatability, hence their separation via flotation has always been one of the difficult problems in mineral processing industry. To solve this dilemma, efficient flotation reagents which could expand the difference in surface properties could be a good bailout. In this study, guar gum was successfully employed as depressant for calcite during the smithsonite flotation, and its function mechanism were studied by micro flotation, and X-ray photoelectron spectroscopy (XPS) analysis, Fourier transform infrared (FT-IR) analysis, and Zeta potential measurement. The result of micro flotation showed that using guar gum as a depressant can effectively separate smithsonite from calcite by flotation; the analysis results of XPS, FT-IR, and Zeta potential measurements showed that the adsorption behavior of Guar gum on calcite and smithsonite was significantly different. Guar gum selectively adsorbed on the calcite surface and formed strong Ca-O chemical bond via phosphate group and hydroxide radical, which reduced the number of Ca adsorption sites on the calcite surface and thus hindered the interaction between sodium oleate and calcite surface, realizing the effective flotation separation of smithsonite from calcite.

Synthesis of sodium alginate-polycarboxylate superplasticizer and its tolerance mechanism on montmorillonite

Sodium montmorillonite (MMT) is a major mineral component of clay in manufactured sand which is an economical aggregate in concrete. Its lamellar structure has a negative effect on an important concrete admixtures polycarboxylate superplasticizer (PCE). In this study, sodium alginate (SA), a polysaccharide, was grafted with an unsaturated amide, having a double bond structure, to synthesize the acrylamide modified sodium alginate (Ugi-SA) through the Ugi reaction. Then, Ugi-SA, acrylic acid (AA), and isopentenol polyoxyethylene ether (TPEG) were used to synthesize sodium alginate-polycarboxylate superplasticizer (SPCE) by free radical copolymerization. The structures of Ugi-SA and SPCE were determined by gel permeation chromatography (GPC) and Fourier transform infrared (FT-IR). The fluidity of the montmorillonite (MMT) cement paste with SPCE and the traditional polycarboxylate superplasticizer (TPCE) was investigated. Furthermore, the adsorption behavior of SPCE on MMT was measured by X-ray diffraction (XRD), thermogravimetric analysis (TGA), total organic carbon analyzer (TOC) and the tolerance mechanism of SPCE on MMT was discussed. The FT-IR and GPC results showed that Ugi-SA and SPCE were synthesized successfully. The initial fluidity test results indicated that SPCE had a better dispersion effect and MMT tolerance than TPCE. TGA, TOC and XRD tests showed that the adsorption of SPCE on MMT was much lower than that of TPCE. This study demonstrated that the SA structure of SPCE appears to exhibit a large steric hindrance, which prevents the intercalation of SPCE into MMT.

Mechanistic insights into ion-beam induced reduction of graphene oxide: An experimental and theoretical study

Interest in graphene oxide (GO) due to its controllable and adjustable properties has been increasing, especially in the field of electronic and electrochemical charge storage devices. Hence, the modification of surface chemistry and structure of GO can be outlined as crucial for achieving the preferable properties. In this study, we have investigated the influence of 15 keV proton-beam irradiation on GO structure and surface chemistry. The results obtained by Raman spectroscopy, Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) were complemented with theoretical ones, obtained by using density functional theory (DFT), semi-empirical (SE) calculations and inelastic thermal spike (iTS) model. The FTIR and XPS results showed that proton irradiation partially reduces the GO with the preferential removal of the alkoxy and epoxy groups. Also, we identified a clear linear relation between the decresase of oxygen content and the decrease of ID/IG ratio i.e. increasing disorder of GO structure. The SE and DFT calculations highlighted a reduction of GO as a single- or multi-step process depending on the type of basal-plane or edge oxygen group. Dynamic SE calculations revealed that for kinetic energy of hydrogen below 1.5 eV the reduction is chemically driven, while at energies higher than 20 eV, the reduction of GO is a result of physical processes. iTS results showed that increase of temperature might contribute to reduction of GO via desorption of epoxy and alcoxy groups, as the least thermally stable groups (T ∼200 °C). The results of this work emphasize the capabilities ion beam irradiation for gradual modification of surface chemistry and structural properties of GO by providing more information about the mechanisms of hydrogen interaction with individual groups, interplay between defect creation, oxygen content and accompaning effects of ion energy loss processes.

Supercapacitor and magnetic properties of Fe doped SnS nanoparticles synthesized through solvothermal method

We report the synthesis of pure and Fe doped SnS nanoparticles through the solvothermal method. Fe with different contents (0, 2, 4, and 6 %) were doped in SnS and designated as N1, N2, N3 and N4, respectively. The samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Cyclic voltammetry (CV), Charging/discharging (GCD) and Vibrating sample magnetometer (VSM) analysis. XRD patterns confirm that N 1, N2, N3, and N4 samples form an orthorhombic crystal structure. Based on the FT-IR and Raman results, a minor stretching vibration in Sn-S modes was observed in pure SnS and Fe doped SnS samples. SEM study shows samples exhibit ball-like spherical shapes, while the average particle size calculated from TEM images shows sizes between 25 and 30 nm. XPS confirm the chemical composition and binding energy of pure and Fe-doped SnS. Specific capacitance values for pure N1 electrode 419 F/g increases to 1242 F/g with Fe (%) doping which shows that doping has enhanced the electrochemical performance of SnS nanoparticles. The optimized assembled supercapacitor shows a high energy density of 34 Wh kg−1 at a power density of 3214 W kg−1 and owed 98.5 % columbic efficiency with 94.2 % capacitance retention after 5000 cycles. Room temperature Hysteresis measurement show samples exhibit weak ferromagnetism and the saturation magnetization increases with Fe doping. Magnetic studies suggest samples have the potential for data storage applications.

Physico-Chemical Properties of TiO2 Coatings Derived From Acid Catalyst-Free Precursor via Spin Coating

The present method of producing titania (TiO2) coatings involves the addition of an acid catalyst to prolong the shelf life of the initial precursor. However, this method has complex chemical routes that favor rutile TiO2 and result in higher bandgap energy. In this current work, unheated and heated TiO2 coatings were successfully prepared via spin-coating using an acid catalyst-free titania precursor. The TiO2 coatings were thoroughly investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman, Fourier transformed infrared (FTIR), and UV-Visible spectroscopic techniques. From XRD and Raman data, the unheated coating is amorphous, while the heated sample consists of anatase polymorph of TiO2. The FTIR results revealed traces of organic residues for the heated sample due to the organic nature of the precursor used. SEM showed that both samples were not uniform, porous, and consisted of spherical micro/nanostructured particles with some aggregation ascribed to the nature of the precursor. Diffuse reflectance indicated an absorption band edge at the UV region and showed similar absorption spectra to commercial TiO2 powder. However, a redshift of the UV-Vis reflectance spectra of the heated sample was observed. Using the baseline approach, the indirect optical bandgap of the unheated TiO2 coating decreased from 3.31 to 3.26 eV (± 0.2 eV) after the heat treatment, which is due to the crystallization of the sample into anatase TiO2.

Assessment of Physico-mechanical Properties of Natural Rubber and Modified Natural Rubber Vulcanizates with Watermelon Rind as Fillers

Natural Rubber (NR) has a relatively low tensile modulus and strength, hence the need for reinforcing fillers to increase its tensile strength, hardness and abrasion resistance. In this study, NR was deproteinized, epoxidized and depolymerized. The functional groups of the NR and the modified NR were determined using Fourier Transform Infrared (FT-IR) spectroscopy. Watermelon Rind (WR) was used as fillers to replace Carbon Black (CB) in the compounding process. The shells were collected, dried, milled and sieved to 75 µm mesh size. Powdered WR was carbonized at 250oC for 1.5 hrs to obtain Carbonized Watermelon Rind (CWR). The Uncarbonized Watermelon Rind (UWR) and CWR powder were characterized based on particle size, loss on ignition, volatile matter, moisture and ash content. The UWR and CWR were used to replace CB at 0, 50 and 100% for the NR and modified NR compounding. The physico-mechanical properties of the different vulcanizates were determined for the effect of modification on the NR. The FT-IR result of the NR samples showed the presence of O-H, C-H, C=C stretching with C=H wagging bands used as the fingerprint region of NR. The results of the physico-mechanical properties revealed that an increase in shell content in the NR decreased its tensile strength and elongation but improved the physico-mechanical properties of the modified NR. This study showed that watermelon rind can be a viable alternative source of carbon filler for improved physico-mechanical properties of modified natural rubber.

Paracoccidioidomycosis screening diagnosis by FTIR spectroscopy and multivariate analysis

Paracoccidioidomycosis (PCM) is a systemic mycosis with high incidence in Latin America, caused by species of the genus Paracoccidioides spp. Brazil is considered to be the endemic center of this disease, which is identified as the eighth cause of mortality from chronic infectious disease in the country. There are several specific diagnostic methods in PCM, such as microbiological, immunological, histopathological, and molecular. However, the standard laboratory diagnosis depends mostly on fungus direct observation - the gold standard of PCM diagnosis. The implementation of new technologies, such as Fourier Transform Infrared (FTIR), can contribute to the clinical diagnosis trial of this disease. Here, we evaluated a new strategy for the diagnosis of PCM by using blood serum FTIR spectra from 20 patients with PCM and 20 healthy individuals. Machine learning algorithms were able to provide an overall accuracy of 91.67% by using Cubic SVM in the PCA data from FTIR results.

The experimental and theoretical investigation of Sm/Mg co-doped hydroxyapatites

This study presents an extensive experimental and theoretical analysis of Mg-doped hydroxyapatite (HAp) samples with additional Sm doping at varying amounts. A wet chemical method was used to synthesize Mg-containing HAps at a constant amount of 0.133at.%, and in addition the second dopant of Sm was utilized at varying amounts of 0.133,0.266,0.399,0.532, and 0.665at.%. All of these samples were investigated experimentally and theoretically by using the X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Raman spectroscopy, differential thermal analysis (DTA), thermogravimetric analysis (TGA), in-vitro cell viability tests, and density functional theory (DFT) calculations. The bandgap energy was found to have reduced from 4.6115 eV to 4.3870 eV. The linear attenuation (or absorption) coefficient increased as the amount of Sm in the sample increased, and this parameter decreased as the photon energy increased for all samples. Both the lattice parameter and the theoretical density increased, whereas the unit cell volume and the lattice parameters declined. The XRD and FTIR results revealed that the HAp phase (over 98 percent for all samples) was a major phase formed, while the β-TCP phase (beta-tricalcium phosphate) was a minor phase. The β-TCP phase increased from 0.91to1.57 percent with an increasing amount of Sm. The volume of the unit cell trended in the same direction as predicted by the obtained results theoretically. Increased anisotropic energy density and a decrease in crystallinity have been observed. All samples were found to be thermally stable. Due to the presence of Sm content, cell viability was observed to be affected.

Nano-Sized Antioxidative Trimetallic Complex Based on Maillard Reaction Improves the Mineral Nutrients of Apple (Malus domestica Borkh.).

The metallic complex is widely used in agricultural applications. Due to the oxidation of the metal and environmental unfriendliness of ligand, maintaining an efficient mineral supply for plants without causing environmental damage is difficult. Herein, an antioxidative trimetallic complex with high stability was synthesized by interacting Ca2+, Fe2+, and Zn2+ with the biocompatible ligands from the Maillard reaction. The composite structure elucidation was carried out by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR). Thermal stability was measured by thermogravimetric (TG). Antioxidative activities were evaluated by ferric reducing antioxidant power and radical scavenging activity assays. The three metals were successfully fabricated on the Maillard reaction products (MRPs) with contents of Ca (9.01%), Fe (8.25%), and Zn (9.67%). Microscopy images revealed that the three metals were uniformly distributed on the MRPs with partial aggregation of <30 nm. FTIR and XPS results revealed that the metals were interacted with MRPs by metal–O and metal–N bonds. TG and antioxidative activity assays showed that the trimetallic complex meets the requirements of thermodynamics and oxidation resistance of horticultural applications. Additionally, the results of the exogenous spraying experiment showed that the trimetallic complex significantly increased the mineral contents of the “Fuji” apple. By treatment with the complex, the concentrations of Ca, Fe, and Zn were increased by 85.4, 532.5, and 931.1% in the leaf; 16.0, 225.2, and 468.6% in the peel; and 117.6, 217.9, and 19.5% in the flesh, respectively. The MRP-based complexes offered a higher growth rate of the mineral content in apples than ones based on sugars or amino acids. The results of the spraying experiment carried out in 2 years show that the method has high reproducibility. This study thus promotes the development of green metallic complexes and expands the scope of agrochemical strategy.

Pollution from Transport: Detection of Tyre Particles in Environmental Samples

Transport is one of the most important sources of environmental pollution. More and more information has shown that one of the greatest sources of emissions from transport are emissions related to the release of microplastics from tyres. This is one of the most underestimated sources of emissions into the environment. In this study, environmental samples are analysed for the presence of these particles. For this purpose, optical methods and spectroscopic methods are used. Fourier transform infrared (FTIR) spectroscopy is used to identify synthetic rubber, most likely derived from car tyres. A complementary confocal microscopy method is used to confirm the FTIR results. The soil samples and road dust from the areas with heavy traffic are tested. An average of 372 ± 50 fragments per kilogram dry weight are detected in the soil samples. In the case of samples from the road, this number is 515 ± 20 fragments per kilogram of dry matter. In the samples, most of the microplastics come from tyres, which confirms the scientists’ assumptions about the amount of emissions in the environment. More than 90% of the black fragments later identified as tyre-derived synthetic rubber are found in the samples. A greater number of microplastics are found in road dust samples than in the soil. This may be due to the direct influence of braking, which causes greater accumulation of samples at the emission source than at a short distance into the soil. There is also a noticeable difference in the size of the fraction. In the case of soils, a fraction below 50 µm accounts for the majority of cases. When one analyses road dust samples, one may observe that most of the fractions are between 50 and 200 µm. This may be due to the possibility of smaller emission particles over longer distances and the greater degradation process that occurs in soils. The microplastics from the road dust are less degraded than the microplastics from the soil.

Aromaticity effect on supramolecular aggregation. Aromatic vs. cyclic monohydroxy alcohols

In this paper, the steric hindrance effect related to the presence of either a cyclic or aromatic ring on the self-association process in the series of monohydroxy alcohols (MAs), from cyclohexanemethanol to 4-cyclohexyl-1-butanol and from benzyl alcohol to 4-phenyl-1-butanol, was studied using X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) spectroscopy, Broadband Dielectric Spectroscopy (BDS) and the Pendant Drop (PD) methods. Based on FTIR results, it was shown that phenyl alcohol (PhA) and cyclohexyl alcohol (CA) derivatives reveal substantial differences in the association degree, the activation energy of dissociation, and the homogeneity of supramolecular nanoassociates suggesting that the phenyl ring exerts a stronger steric impact on the self-assembling of molecules than cyclohexyl one. Additionally, XRD data revealed that phenyl moiety introduces more heterogeneity in the organization of molecules compared to the cyclic one. The changes in the self-association process of alcohols were also reflected in differences in the molecular dynamics of the H-bonded aggregates, as well as in the Kirkwood factor, defining the long-range correlation between dipoles, which were slightly higher for CAs with respect to those determined for PhAs. Unexpectedly it was also found that the surface layers of PhAs were more organized than those formed by CAs. Thus, these findings provided insight into the impact of aromaticity on the self–assembly process, H-bonding pattern, supramolecular structure, and intermolecular dynamics of the studied alcohols.

Microencapsulation of Lysiphyllum strychnifolium extract using pectin as a carrier matrix and its characterization

Lysiphyllum strychnifolium (Craib) A. Schmitz (LS, Fabaceae) is one of the folklore medicines in Thailand. The previous studies have demonstrated several pharmacological activities and high polyphenolic substances possessed by this plant. However, the suitable encapsulation of LS extract has not been discovered. This study aimed to develop LS microcapsules using spray-drying technique with pectin as a carrier. Moreover, the powder analysis and characterization were also conducted. The effects of inlet temperatures (80, 100, and 120°C) and carrier concentrations (1, 5, and 10 %w/v) on the encapsulation yield (EY), encapsulation efficiency (EE), total phenolic content (TPC), and main markers (trilobatin and yanangdaengin) of LS microcapsules were studied. Finally, the characterization was investigated by Fourier transform infrared (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The obtained results indicated that S2 microcapsule formulation, pectin to extract ratio 10:1 (w/w) at inlet temperature of 100°C, was chosen as the optimal condition because of the positive tendency to acquire higher EE as pectin level was increased. On the contrary, the level of TPC and markers was reduced due to the more addition of pectin. The FTIR, XRD, and DSC results suggested that the well-encapsulated microcapsules were obtained for S2 formulation and SEM represented the semi-spherical structure of its microstructures. The development of LS microcapsules with the proximity to gain the advantageous powder analysis and characteristic has been achieved. Therefore, this approach could be used for the subsequent manufacturing of LS extract.

Flotation Performance and Adsorption Mechanism of a Novel Chelating Collector for Azurite

Thiophosphate compounds have attracted much attention in coordination chemistry, but their deep adsorption mechanism remains underexplored as flotation collectors. The flotation performance and adsorption mechanism of a novel (dibutoxy-thiophosphorylsulfanyl)-acetic acid (CDDP) chelating collector on azurite surfaces were studied by micro-flotation tests, zeta potential measurements, and Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FE-SEM) analysis. The micro-flotation results indicated that CDDP exhibited superior collecting performances to direct flotation recovery of azurite and floated over 91.44% of azurite at pH 7. For sodium isopentyl xanthate (NaIX) and Benzohydroxamic acid (BHA) collectors, the addition of Na2S still did not show good collection performance. The results of zeta potential, FTIR, XPS and FE-SEM measurements, all confirmed that CDDP showed a better affinity to azurite surfaces than NaIX and BHA. Furthermore, XPS and FE-SEM provided obvious evidence that CDDP could easily react with Cu2+ sites on azurite surfaces. Using the density functional theory (DFT) method, the collection capacity of azurite was CDDP &gt; BHA &gt; NaIX, which exactly matched the micro-flotation results. In addition, this study provided an atomic-scale understanding of the structure–property relationship of CDDP as chelating agents for copper mineral flotation.

Preparation of the Heterogeneous Saponified Poly(Vinyl Alcohol)/Poly(Methyl Methacrylate-Methallyl Alcohol) Blend Film.

For the first time, poly(vinyl alcohol) (PVA)/poly(methyl methacrylate–methallyl alcohol) (P(MMA-MAA)) (9:1, 7:3, 5:5) blend films were made simultaneously using the saponification method in a heterogeneous medium from poly(vinyl acetate) (PVAc)/poly(methyl methacrylate) (PMMA) (9:1, 7:3, 5:5) blend films, respectively. The surface morphology and characteristics of the films were investigated using optical microscopy (OM), atomic force microscopy (AFM), X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Moreover, the effect of the PVAc content on the degree of saponification (DS) of the PVAc/PMMA films were evaluated and revealed that the obtained DS value increased with the increase in PVAc content in the PVAc/PMMA blend films. According to the OM results, the saponified films demonstrated increased surface roughness compared with the unsaponified films. The AFM images revealed morphological variation among the saponified PVAc/PMMA blend films with different mass ratios of 9:1, 7:3, and 5:5. According to the DSC and TGA results, all blend film types exhibited higher thermal property after the saponification treatment. The XRD and FTIR results confirmed the conversion of the PVAc/PMMA into PVA/P(MMA-MAA) films. Thus, our present work may give a new idea for making blend film as promising medical material with significant surface properties based on hydrophilic/hydrophobic strategy.

Analysis of Pyrolysis Performance and Molecular Structure of Five Kinds of Low-Rank Coals in Xinjiang Based on the TG-DTG Method.

Taking five coal samples (FCSs) in Xinjiang as the research object, characterizations such as proximate analysis, ultimate analysis, Fourier transform infrared (FTIR), and thermogravimetry-differential thermal analysis (TG-DTG) were carried out. The Coats–Redfern model was used to simulate pyrolysis kinetics of FCSs under different reaction orders (ROs). The results showed that except for HSBC, the R2 of the other four coal samples are all higher than 0.9, which showed a good correlation effect. FCSs present similar reaction activation energy in the same RO and temperature range. Results of FTIR showed that the hydroxyl groups of FCSs, in the range of 3100–3600 cm–1, were mainly self-associated hydroxyl hydrogen bonds and hydroxyl π bonds, and they occupied over 63%. Among them, the pyrolysis characteristic index (D) of XBC was 4.139 × 10–6, higher than those of other samples, and it showed good pyrolysis performance. Moreover, by reducing the temperature range appropriately, the fitting results showed a better correlation effect.

Effect of potassium oleate on chemical structure-compression relationship of natural rubber foam

Rubber foam-based products, such as mattresses, pillows, and cushions, are becoming increasingly popular. Rubber foam's formulation is still being developed to improve the properties, because of its wide range of applications. Potassium oleate is a surfactant for producing the rubber foam, although it can be used in different concentrations to prepare the different properties of rubber foam. The Dunlop method was used in this work, due to its simplicity and easy-to-use in the foam preparation. The effect of potassium oleate, which was used as a foaming agent, was investigated in this study by reducing the amount of potassium oleate. The density, compression, and Fourier transform infrared (FTIR) spectroscopy results showed that both density and compression of foam samples with half amounts of potassium oleate are higher than those of control sample with normal amounts of potassium oleate. Moreover, the FTIR result revealed a significant change in spectra with the reductions of potassium oleate contents. Therefore, rubber foam formulations are still developed to provide the optimum properties for suitable applications.

One-step extraction of cellulose nanocrystals from high lignin biomass through ammonium persulfate oxidation method

Cellulose nanocrystals (CNCs) are one of the emerging nanomaterials that have several interesting and unique properties such as high mechanical strength (Young modulus of 100–140 GPa), low density (1.6 g cm−3), and large surface area (150–250 m2 g−1) that are advantageous in a myriad of applications. In this study, CNCs were successfully prepared from empty fruit bunch (EFB), an agricultural waste from palm oil, using a one-step extraction method using ammonium persulfate oxidation. EFB was directly reacted with ammonium persulfate (APS) at different concentrations (1.0; 1.5 and 2.0 M) at 60 °C for 15 h to undergo the oxidation. The oxidised EFB samples were characterised by dynamic light scattering (DLS), x-ray diffraction (XRD), transmission electron microscope (TEM), Fourier-transform infrared (FTIR), and thermogravimetric analysis (TGA). The FTIR result shows that lignin and hemicellulose in the EFB were successfully removed using one-step extraction method with minimum APS concentration of 1.5 M. The CNCs product has a crystallinity index of 64.1%, a crystallite size of 3.86 nm, and (0 0 2) plane lattice spacing of 3.95 Å. Based on the lattice spacing calculation of all samples, the crystalline structure of cellulose does not change during the oxidation process. The proposed one-step extraction method has been proven to produce the CNCs from EFB with a crystallinity index of 64.1%, a length of 275.9 ± 82.8 nm, and a diameter of 25 ± 5.3 nm.

Investigating the Effect of Smoke Treatment on Hygroscopic Characteristics of Bamboo by FTIR and Raman Spectroscopy.

Treatment modification to improve the durability of bamboo against biotic and abiotic factors often results in adverse effects to its mechanical properties due to changes in hygroscopic characteristics. This study aims at exploring in more detail, the effect of treatment modification, in particular smoke treatment, on the hygroscopic nature of bamboo. In the first part of this study, changes to its chemical structure were investigated by Raman and Fourier-transform infrared (FTIR) spectroscopic techniques. From Raman analysis, specific bands attributed to lignin component in bamboo, namely at 1600 cm−1 and 1632 cm−1, which varied in intensities among treated and untreated specimens, could be considered to assess the extent of treatment modification. Besides, FTIR results showed that the chemical constituents of bamboo inner and outermost surfaces vary extensively with distinctive changes during treatment modification. The steam component in smoke treatment is assumed to cause a slight increase in the moisture content in the outermost surface of smoked bamboo as evidenced by FTIR results. In addition, the hydrophobic surface of smoked bamboo, which was affected during smoke treatment modification due to superior mean roughness parameter in its outermost surface, impacted its water-repelling ability. From FTIR results, an increase in lignin in bamboo was confirmed at peak 1114 cm−1, which occurred as a result of thermal effect above a temperature of 100 °C leading to poly-condensation reactions. The increase in lignin is assumed to cause an overall increase in hardness of smoked bamboo which was found to be two-fold higher when compared with the untreated ones. The approach of this research investigation, which has shown the benefit of using spectroscopic techniques to monitor and understand the changes in the hygroscopic nature of bamboo surfaces, can likewise be considered to predict the corresponding effects of treatment modification or degradation on the mechanical properties of natural materials.

UV Radiation Crosslinking of Acrylated Palm Olein (APO) Copolymer Resins for 3D Printing

Generally, only a few especially acrylic monomers have photoabsorption characteristics to allow for effective stereolithography (STL) to take place. Biomaterial product from palm oil, Acrylated Palm Olein (APO), is seen as an ideal alternative to petroleum-based polymers due the diminishing petrochemical supply and abundant of the natural polymer in the market. In this study, APO as a biopolymer is introduced to synthetic polymers Polyethylene Glycol Dimethylacrylate (PEGDMA) and Polyethylene Glycol Diacrylate (PEGDA), separately. All three polymers offer photoabsorption characteristics that enable them to be the resins for ultraviolet (UV) 3D printing. The crosslinking of both copolymers is optimized by comparing two different UV radiation techniques; UV cured machine and UV STL 3D printer. The degree of crosslinking for both APO-co-PEGDMA and APO-co-PEGDA through gel fraction analysis are studied and compared with their prepolymer resins. As predicted, the maximum degree of crosslinking of APO-co-PEGDMA and APO-co-PEGDA samples are achieved from the fabrication of samples by 3D printing and recorded at 67.50% and 59.50% respectively, comparing to the samples cured by UV cure machine, which recorded maximum crosslinking percentage at only 21.31%. Further analysis is done using swelling test to study water absorption capacities of copolymers and results shows that APO-co-PEGDMA able to retain water at maximum of 42.47% and APO-co-PEGDA at 52.02% from the 3D printed samples, and recorded lowest readings at 22.82% and 25.56% respectively. UV cured samples are recorded to have lowest readings at 3.89% for APO-co-PEGDMA, and 4.23% for APO-co-PEGDA. Fourier Transform Infrared (FTIR) Spectroscopy confirmed the successful crosslinked of the copolymers. Analysis of FTIR shows that there are presence of new peaks and shifting of peaks, indicating that APO is crosslinked with PEGDMA backbone as well as PEGDA backbone. These also suggest that both polymers are suitable to be incorporated with APO as new photopolymer resins, fabricated using UV radiation crosslinking, with PEGDMA shown a slightly better result. All results are agreeable with FTIR results.

Characterizations of Calcium Oxide from Calcined Eggshell Waste

The eggs are not only a good source of nutrients but their shells are rich in various minerals of which CaCO3 is the most prominent. Egg shell contains about 90% CaCO3 of the total weight. The interest in clean technology has attracted the use of eggshell waste as a focus of research. The objective of this work is to extract calcium oxide (CaO) from calcium carbonate (CaCO3) available in chicken eggshells. CaO is white in colour possessing high porosity with narrow particle size distribution. CaO have very high percentage of ceramic yield. This CaO can be used as precursor for synthesis of calcium phosphate that can be further used in biomaterial synthesis. The uncalcined eggshell waste (ESW) and calcined ESW powders were characterized by using X-ray diffraction (XRD), Scanning electron microscope (SEM) and Fourier transform infra-red (FTIR) analyses. The calcination temperatures were varied from 700 oC to 1100 °C. XRD and FTIR results suggested that CaCO3 is converted into calcium oxide at 900 °C and SEM micrographs also compliment these results. The calcination method can be used to extract calcium oxide from ESW being eco-friendly as well as low cost.