Fourier Transform Infrared Spectroscopy Test Research Articles

Exploration of rice husk ash as a green corrosion inhibitor immersed in NH4Cl 7.5 % solution

The study reports the development of a liquid smoke solution of rice husk ash (RHA) as a green corrosion inhibitor in NH4Cl solution in approaching corrosion protection for refinery facilities. The recent utilization of RHA has a partial solution to address the possible chemical to form a filming layer to disconnect bare metal and their environment. This work prepared the RHA solution by condensing the RHA vapor before adding it to various concentrations. The corrosion test of potentiodynamic and electrochemicals intends to discover the inhibitor's corrosion resistance before examining the electronic transition corresponding to the contribution of several functional groups using Ultraviolet Visible (UV–Vis) and Fourier-Transform Infrared Spectroscopy (FTIR). Surface evaluation intends to unveil the nature of the corrosion by utilizing the Scanning Electronic and Atomic Force Microscope. The corrosion test result shows the depression of corrosion rate to 0.120 mmpy with high efficiency beyond 96 % in the addition of 7.5 ppm RHA inhibitor. The greater Nyquist semicircle diameter at high concentrations increases the adsorption of the RHA on the surface of C1018. The electronic transition of n–π* and π –π* shows an extensive contribution of CC, CO, and –OH based on the UV–Vis and FTIR test. The formation of a complex compound of Fe-(NH4Cl-RHA)n blocks the corrosion active sites to reduce the corrosion. This study paves the way for using RHA as an organic compound under NH4Cl conditions, such as in a refinery process facility.

Influences of sodium hydroxide and oxalic acid treatments on physical, mechanical, thermal properties, and morphology of ramie fibers

The environmentally friendly properties of natural fibers cause their use as reinforcement in polymer matrices to continue to grow. However, its hydrophilic properties can significantly reduce interfacial interactions. Chemical treatment is one method used to reduce the hydrophilic nature of ramie fibers. This study aimed to investigate the effects on ramie fiber of three chemical treatments: oxalic acid at a concentration of 5 (wt.%), sodium hydroxide at 3, 5, and 7 (wt.%), and a combination of both treatments. Physical properties, moisture content, tensile strength, X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), thermal properties, contact angle, and morphology of ramie fibers before and after treatment were observed in this investigation. FT-IR test results showed a partial loss of amorphous content and more intense cellulose peaks in treated ramie fibers. The combination treatment of alkali and oxalic acid gave the best results, which initiated the dissolution of some of the lignin, hemicellulose, and extractive content. XRD results indicated the surface treatment also led to a 20.35% rise in the crystalline index. In addition, there was a significant increase in tensile strength of 136.10 % in fibers soaked with chemicals. The morphology of the fibers with treatment showed defibrillation and loss of contaminants on the fiber surface, which was the cause of the smaller fiber diameter. Therefore, this optimum treatment is expected to improve the interfacial properties of natural fibers and polymer matrices so that they can enhance the properties of composites when applied in industries.

Experimental Investigation of Date seed and Neem Powder Reinforced Natural Fiber Composites

Natural fillers have received great attention among researchers due their its light weight, high strength, degradability, and eco-friendly behavior. This work is focused on developing a laminate of date palm seed powder and neem gum powder reinforced epoxy resin. Epoxy resin is an excellent thermoset polymer with anoutstanding cost to performance ratio. Date palm seeds have highly competitive properties in improving the mechanical and thermal properties of composites by their good adherence to polymer matrix. Neem gum powder is used as a binder in increasing ratios of 0 %, 10 %, 15 %, 20 %, 25 %, and 30 % to test their strength in different compositions. Date seed powder has been reinforced in decreasing weight percent as 30 %, 25 %, 20 %, 15 %, 10 %, 5 %, and 0 %. The specimens prepared through the compression moulding technique were subjected to various mechanical tests like a tensile test, flexural test, and impact test as per the ASTM standards. Fractography analysis using FESEM (Field Emission Scanning Electron Microscopy) and FT-IR(Fourier Transform Infrared spectroscopy) test have determined the surface characteristics and chemical composition of the samples. The result shows that, by adding neem gum powder in increasing quantities the mechanical properties like tensile and flexural decreases. However, it does not affect the impact strength of the material. A detailed study of their behavior is discussed in this work.

Evaluation of benzaldehyd and dioctyl phthalate modified direct coal liquefaction residue asphalt binder based on rheology and microscopic mechanisms

This study intends to investigate the influence of benzaldehyde and dioctyl phthalate (DOP) on the rheological properties and microstructure of direct coal liquefaction residue (DCLR) modified asphalt binder. The high and low temperature rheological properties and fatigue properties were obtained by dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. The scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR) tests were conducted to evaluate the mechanism of property improvement in the DCLR modified asphalt binder. The results showed that the addition of DCLR increased the complex shear modulus G*, rutting factor G*/sin δ and fatigue life Nf of base asphalt binder, significantly improving the high temperature deformation resistance and fatigue resistance of base asphalt binder. This was attributed to the hardening effect resulting from the addition of DCLR, which enhanced the elastic properties, weakened the viscous properties and fluidity of asphalt binder. Additionally, the use of benzaldehyde and DOP reduced the creep stiffness S and lower continuous grading temperature Tc of DCLR modified asphalt binder, which compensated for the shortcomings of low temperature rheological properties of asphalt binder. The SEM images indicated that benzaldehyde and DOP significantly increased the compatibility of DCLR with the base asphalt binder. The FTIR tests showed that the addition of benzaldehyde and DOP introduced the aldehyde and ester groups, which were interacted with more polar functional groups in the asphalt to reduce the resistance to movement between the heavy components in the DCLR modified asphalt binder, which promoted the flow of asphalt and the dispersion of DCLR, and as a result, the benzaldehyde and DOP modified DCLR asphalt binder exhibited satisfied rheological properties.

A data-driven analysis of HDPE post-consumer recyclate for sustainable bottle packaging

The packaging industry faces mounting demand to integrate post-consumer recyclate (PCR). However, the complex structure-property relationships of PCRs often obscure their performance compared to virgin equivalents, posing challenges in selecting suitable PCRs for applications. Focused on extrusion blow moulding grade high-density polyethylene (HDPE), this study presents the most extensive characterisation of HDPE PCR to date, encompassing 23 resins (3 virgin, 20 PCR). Employing Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), rheology, colour analysis, and mechanical testing, we established a feature-rich dataset with 56 distinctive characteristics. Utilising a data science approach based on principal component analysis, with the virgin samples as a benchmark, we identified that combining FTIR, TGA and mechanical testing provided effective identification of PCRs that closely match the properties of virgin HDPE. The pipeline created can be utilised for new PCRs to determine suitability as a replacement for virgin plastic in a desired application.

A molecular dynamics simulation study on the recovery performance of aged asphalt binder by waste vegetable oil rejuvenators

This study employed molecular dynamics to simulate the recovery performance of a waste vegetable oil rejuvenator on aged asphalt binder. The model's accuracy was verified through density and glass transition temperature (Tg) calculations. The Radial Distribution Function (RDF) was utilized to assess the aggregation state of different asphalt binder components. The impact of the waste vegetable oil rejuvenator on asphalt binder microstructure was evaluated using cohesive energy density (CED), relative concentration, mean square displacement (MSD), radius of gyration (Rg), and free volume amount. Changes in functional groups of the aged and recycled asphalt binder samples were analyzed using Fourier transform infrared spectroscopy (FT-IR). Results indicate that the rejuvenator significantly influences the dispersion of SARA components. Improved compatibility between aged and virgin asphalt binders is achieved through increased activity of asphaltenes and resins. The incorporation of rejuvenators into asphalt binder mildly counters the aggregation of asphalt binder molecular structure, mitigates the negative effects of aging, and restores asphalt binder structure. The rejuvenator, enriched with polar groups as per FT-IR tests, increases the proportion of polar groups in the recycled asphalt binder. The recycled asphalt binder exhibits a higher proportion of polar molecules, and the rejuvenator reacts with the polar molecules in the asphalt binder at high temperatures.

Fabrication and characterization of lignocellulosic coconut and energy reed straw-reinforced methylene diphenyl diisocyanate-bonded sustainable insulation panels

The use of renewable environmental resources and plastics that can be returned to the biological cycle shows a new direction in the application of composite building materials. This study investigated the potential and strengthening effects of developing composite panels from coconut materials (CM) and reed straw (RS) particles in the presence of methylene diphenyl diisocyanate (MDI). Five composite panels with 100:0, 60:40, 50:50, 40:60, and 0:100% proportions were produced. The nominal density was 600 kg/m3 and the dimensions were 400 × 400 × 8 mm3. The panels were produced by hot-pressing for a total of 10 min at a maximum pressure of 7.2 MPa and at 135 degrees, and then slowly cooled at room temperature. The following experiments were performed: mechanical, physical and morphological properties, thermal conductivity, FTIR (Fourier transform infrared spectroscopy), and EDX (Energy disruptive X-ray). The study gave the following results: the thermal conductivity of the coir and reed panels is competitive with the thermal insulation capacity of similar natural-based insulation materials, and is close to the values of other mineral and plastic-based insulation materials. The values of thermal conductivity coefficient ranged from 0.08 to 0.10 W/(mK). Only reeds (MDI_1) boards have better results than coconut materials. Among the mechanical properties, flexural strength and internal bonding strength increased proportionally with the increase in the amount of coconut. The Young's modulus reached its maximum in the case of a 50–50% coir-reed mixture. The best values of the panels are: 6.33 MPa for flexural strength, 1.83 GPa for Young's modulus and 0.36 MPa for internal bonding strength. The morphological recordings confirmed the proper mixing and binding of the lignocellulosic materials in the composite. FTIR tests proved the successful chemical interactions. The findings support the possibility of creating a promising, environmentally friendly building material.

A novel method for examining the influence of molecular and structural properties of the asphaltene fraction on the wettability change of the calcite surface

Asphaltene deposition in the porous media of the reservoir during the production life causes serious challenges with significant economic cost. From the point of view of proactive action to prevent the formation of such precipitates, today asphaltene inhibitors are widely used in the oil industry. The successful performance of inhibitors strongly depends on molecular structure of asphaltene. This study investigates the effect of molecular-structural properties of asphaltene in four crude oil samples on calcite surface wettability. The wettability of the calcite surface is evaluated with contact angle test and micromodel. The crude oil properties are determined using DHA (Detailed Hydrocarbon Analysis) and FTIR (Fourier Transform Infrared Spectroscopy) tests, while the molecular-structural properties of asphaltene are assessed using elemental analysis, FESEM (Field Emission Scanning Electron Microscopy), NMR (Nuclear Magnetic Resonance), and FTIR techniques. Based on FTIR analysis of oil samples, the higher polarity of samples B and G compared to samples F and A can be attributed to the presence of C = O carboxylic acid stretches. In addition, DHA analysis indicates that sample B, which contains heavier compounds comprising 27.4220 % of the C14+ compounds by weight, exhibits distinct characteristics. The FESEM images demonstrate a uniform and smooth spread surface morphology of the asphaltene samples. However, the elemental analysis does not establish a correlation between the heteroelement ratios of N/C, O/C, and S/C and asphaltene adsorption tendency. FTIR and NMR analyses suggest that the wetting properties observed on the surface are mainly attributed to the high aromatic and aliphatic compounds present in the asphaltene of sample B, while the polar compounds are less influential. The results reveal that crude oil sample B exhibits the highest percentage of damage to the porous medium caused by asphaltene deposition, with a rate of 36.18 % and a contact angle of 163.53 degrees. This indicates a wetter surface of the oil compared to other samples. Samples G and A follow with contact angles of 157.34° and 153.60°, respectively. On the other hand, sample F shows the lowest wettability change on the calcite surface with a contact angle of 144.77° and only 0.08 % damage to the porous medium.

Effect of polyaspartic acid as an environmental-friendly depressant on flotation separation of chalcopyrite from arsenopyrite

The selection of environmental-friendly and high-efficiency depressants is a major research priority for removing arsenic from copper concentrates. The polyaspartic acid (PASP, (C4H6O3N) n) was used for the selective separation of chalcopyrite from arsenopyrite to explore the depression mechanism of PASP using micro-flotation experiments, contact angle measurements, zeta potential measurements, fourier transform infrared spectroscopy (FT-IR), local electrochemical impedance (LEIS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The flotation results showed that recovery of chalcopyrite reached up 90.18 %, while the recovery of arsenopyrite was only 23.48 %, when the PASP was added. The contact angle measurements and zeta potential measurements showed that PASP selectively adsorbed on the surface of arsenopyrite, but was not adsorbed on the surface of chalcopyrite. The FT-IR tests further confirmed that the adsorption was chemical adsorption. The LEIS tests revealed that the conductivity of arsenopyrite surface increased with the addition of PASP, while chalcopyrite was almost unaffected. The ToF-SIMS analyses illustrated that the arsenopyrite with Fe and As sites was reacted with —NH– in the structure of PASP to form stable complexes. Finally, the mechanism diagram was designed to provide insight into the adsorption mechanism of PASP on the surface of arsenopyrite and its selective inhibition of arsenopyrite.

Selective depressing mechanism of H-acid monosodium salt on flotation separation of graphite and sphalerite

Micro-flotation experiments, Fourier transform infrared spectroscopy (FT-IR) tests, Zeta potential tests, X-ray photoelectron spectroscopy (XPS) analysis and molecular dynamics simulation were used to study the flotation behavior, separation and depressing mechanisms of graphite and sphalerite in the presence of H-acid monosodium salt (HAMS). Under the optimum flotation conditions, the recovery of sphalerite and graphite in the concentrate of mixed mineral flotation was 93.37% and 4.98%, respectively. Zeta potential tests and XPS analysis indicated that HAMS was considerably adsorbed on graphite surfaces but virtually absent on sphalerite surfaces. The FT-IR tests revealed that HAMS had no significant chemisorption on graphite surfaces. Molecular dynamics simulation inferred that the hydrophobic interaction between the naphthalene ring in HAMS and graphite was responsible for the adsorption of HAMS on the graphite surface.

Green synthesis of silver nanomaterials and evaluation of their antibacterial and antioxidant effectiveness in chicken meat

Nanomaterials, chiefly silver nanoparticles (AgNP), are widely used in many commercial products, including medical commodities, food packaging and cosmetics. The goal of this research was to establish a cost-effective and environmentally safe approach to synthesize AgNP using turmeric powder. The reduction of silver ions resulted in an alteration of the turmeric extract color from yellow to brown after 24 h of reaction. The characterization of AgNP was accomplished by UV–vis spectroscopy, energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The prominent peak of AgNP colloid in a UV–vis spectrum appears at 444 nm. EDS mapping showed a potent signal of the silver element. According to TEM, most of the synthesized AgNP was spherical with an average size of 23 ± 0.49 nm. Moreover, FTIR test proved the presence of organic constituents in the AgNP colloid. The green AgNP exhibited significant (P ≤ 0.05) antibacterial activities with a 2-log CFU reduction of a Salmonella Typhimurium and Salmonella Enteritidis cocktail in chicken meat after a 1-day direct exposure to 6, 12, and 18 μg/mL of AgNP. The phytoconstituents on the surface of the AgNP exhibited good antioxidant activities by scavenging DPPH and ABTS radicals. Moreover, the nanoparticles had a higher antioxidant capacity compared to standard ascorbic acid solution, especially at 12 and 18 μg/mL of AgNP concentrations. These outcomes indicate that AgNP coated with phyto-constituents possess powerful bioactivities by inhibiting the growth of food pathogenic bacteria and, simultaneously, conferring antioxidant capability.

Sustainable production of eco-friendly rubberized asphalt binders through chemically crosslinking with polymer modifier

The incorporation of waste tire rubber into asphalt pavement can facilitate the development of sustainable transportation infrastructure. Recently, terminal blend (TB) rubberized asphalt incorporating polymers has gained popularity due to its improved performance and eco-friendliness. However, the crosslinking mechanism between terminal blend (TB) rubberized asphalt and supplemented polymer modifier is not well understood. The present paper aims to investigate the crosslinking mechanism between degraded rubber, styrene-butadiene-styrene (SBS) polymer and crosslinking agent, and to clarify the effect of crosslinking reaction on the properties and production of eco-friendly rubberized asphalt. In this paper, Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), dynamic shear rheological (DSR), multiple stress creep recovery (MSCR) and bending beam rheometer (BBR) tests were employed to investigate the chemical and physical properties of TB rubberized asphalt after incorporating various contents of SBS and crosslinking agent. FTIR test indicates that the conjugated olefins released from crumb rubber have the possibility to react with sulfur. However, sulfur alone fails to greatly improve the rheological performance of TB rubberized asphalt, for the level of crosslinking reaction between sulfur and TB rubberized asphalt is weak. Therefore, it is necessary to further add SBS polymer to enhance the crosslinking reaction. Further study showed that there are two types of crosslinking reactions when involving conjugated olefins. Type I is the reaction of sulfur with conjugated olefins provided by the degraded rubber, which helps the conjugated olefins to crosslink themselves, resulting in increase of the amount of trans olefins. Type II is that sulfur bridges the SBS polymer and degraded rubber through the chemical link between the opened trans olefins double bonds located in SBS and opened conjugated olefins from degraded rubber, which leads to reduction of the amount of trans olefins. Type II crosslinking reaction can effectively improve the high temperature performance of TB rubberized asphalt. The findings of this study not only provides valuable insights into the interaction mechanism of eco-friendly rubberized asphalt, but also promote the recycling of waste tire rubber.

Fabrication of superhydrophobic surface by a dimensional change in surface topography of microchannel on polymer substrate through induction-aided hot embossing: parametric investigation and optimization

Hot embossing (HE) is a micro-fabrication technique employed to create micron-scale patterns on the polymer substrate. An in-house induction-assisted hot embossing (IHE) setup was fabricated to complete the embossing in a short duration as compared to traditional hot embossing process. This work alters the polymer surface topography to make it superhydrophobic for self-cleaning. Fiber laser machining was used to produce four-microchannel designs on an Aluminum-6061 plate in which the microchannel width was varied from 600 μm to 150 μm while maintaining a constant adjacent distance of 300 μm. This textured plate is employed as a mold in the IHE setup. IHE process parameters, embossing temperature, pressure, time, and deembossing temperature were varied to emboss the mold designs on a polyethylene terephthalate substrate. Thereafter, the embossed microchannel height, surface roughness, and water contact angle perpendicular to the embossed microchannels (WCA⟂) were calculated. The parametric analysis examined how operational factors affected the output. The experiment was done as per the central composite design (experimental design) part of the design-of-experiments useful in the response surface model. Parametric research demonstrates that embossed microchannel height and width had a maximum effect on WCA⟂. Type-IV microchannels with 150 μm width demonstrated the highest WCA⟂. The WCA⟂ was mostly impacted by embossed microchannel height; hence a regression model was created using type-IV channel height data. Analysis of variance showed that embossing temperature mainly impacts microchannel height. The recently invented Jaya-algorithm optimized this model to increase embossed microchannel height and WCA⟂. Setting the parameters at the best level predicted by Jaya-algorithm yielded an embossed microchannel height inaccuracy of 2.18%. The WCA⟂ measured on the surface of a sample prepared at the best parameters was found to be 154.71° 2°. Lastly, FTIR (Fourier-transform-infrared-spectroscopy) test showed no chemical composition change between the embossed and bare samples.

Theranostic RGD@Fe3O4-Au/Gd NPs for the targeted radiotherapy and MR imaging of breast cancer

BackgroundAs a radiosensitizing agent in magnetic resonance imaging (MRI), gadolinium is disadvantageous in that it confers a rather high toxicity and low longitudinal comfort time (r1). We hypothesized that gadolinium when combined with gold-coated iron oxide nanoparticles (NPs), might deliver better radiosensitization in MRI-based cancer theranostics. After being synthesized ligand/receptor RGD@Fe3O4-Au/Gd nanoparticles, they were characterized via some methods, such as visible–ultraviolet spectroscopy (UV–VIS), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and transmission electron microscope (TEM). Using relaxometry, the parameters of contrast change in T1-weighted MRI and the rate of radiation sensitivity on cancerous (MCF-7, SK-BR-3 and MDA-MB-231 (and reference (MCF-10a) breast cell lines were investigated.ResultsThe presence of ultra-small iron oxide, gold, gadolinium, and RGD peptide as components of the RGD@Fe3O4-Au/Gd nanocomplex was confirmed by UV–visible, FTIR, EDX and XRD tests. With a size ranging from 4.124 nm (DLS) to 15 nm (TEM), these NPs exhibited a surface charge of –45.7 mV and a magnetic saturation of 3 emu/g. The concentrations of iron, gadolinium and gold samples in the nanocomplex were 1000, 1171 and 400 parts per million (ppm), respectively. In the relaxometry test, the rates of r2/r1 and r1 NPs were 1.56 and 23.5 mM−1 s−1. The dose increase factor for targeted (RGD@Fe3O4-Au/Gd) and non-targeted (Fe3O4-Au/Gd) NPs at 6 MV and 2 Gy was 89.1 and 59.1, respectively.ConclusionOwing to an enhanced signal-to-noise ratio (SNR), as confirmed by the MRI of RGD receptor-expressing MDA-MB-231 cells, RGD@Fe3O4-Au/Gd NPs were found to confer higher radiosensitization and an overall better performance as a novel radiosensitizer for MRI-based breast cancer theranostics than Fe3O4-Au/Gd nanocomplex.Graphical

Ca–Zn Phosphate Conversion Coatings Deposited on Ti6Al4V for Medical Applications

This paper aims to study the possibility of improving the chemical and surface characteristics of the Ti6Al4V alloy by depositing phosphate layers on its surface. Accordingly, an innovative phosphating solution was developed and used in a chemical conversion process to obtain Ca–Zn phosphate layers on the base material surface. Moreover, the chemical composition of the phosphate solution was chosen considering the biocompatibility of the chemical elements and their possibility of contributing to the formation of phosphate compounds. The obtained layer was characterized by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and potentiodynamic polarization tests. The wetting of the Ca–Zn sample surface was also investigated using water and two liquids similar to body fluids, namely, Ringer and Dulbecco solutions. According to the surface energy study, the polar component is almost two times larger compared with the dispersive one. The SEM and EDS tests revealed a uniformly coated surface with intercalated crystals leading to a rough surface. Furthermore, the XRD results showed not only the presence of hopeite and scholzite but also of phosphophyllite. By the vibrations of the PO4−3 groups, the FTIR test confirmed the presence of these phases. The potentiodynamic tests revealed that the samples coated with the Ca–Zn phosphate layer present better corrosion resistance and a lower corrosion rate compared with the uncoated ones.

The Effectiveness of Salvadora persica Extracted Miswak and ZnO NPs on Pathogenic Bacteria

Salvadora persica, (Miswak) deem oral hygiene essential biological and chemical activities. The current study aimed to study the biological activity of S. persica of extract using Fourier transform infrared spectroscopy (FTIR) show that contains analysis of the FTIR test results of miswak extract. While the analysis using UV-vis displays that the extract contains analysis of UV-vis test for miswak extract. The extract shows higher activity against bacteria than fungi. The inhibition zone of Escherichia coli, Staphylococus aureus, and the ZnO nanoparticles show high biological activity against (bacteria and fungi). The chewing stick which is commonly known as the Miswak tree and its scientifi c name is S. persica L, occurs in most of the countries of Asia and Africa. The plant has long been prized in the Middle East for its vital biological and chemical properties and its usage in mouth hygiene, as mentioned in ethnobotanical records. This research aims to summarize this species’ biological eff ects (antibacterial and antifungal) by testing the eff ect of diff erent concentrations of extracted Miswak (aqueous extracts) in E. coli as gram-negative In addition to use diff erent measurement devices, FTIR, UV-vis spectroscopy, and gas chromatography (GC) to analyze the extracted Miswak. We found that S. persica has benefi cial therapeutic eff ects and has the potential to be used as a useful adapt genic herbal treatment based on its chemical and pharmacological characteristics.

Multi-scale analysis of mechanical properties of KH-560 coupling agent modified PVA fiber-rubber concrete

ABSTRACT Amphiphilic Silane coupling agent (SCA) improves the weak bond between the two phases of rubber and hydration products, fills the interfacial gaps and effectively repairs the interfacial defects between rubber and hydration products. The addition of PVA fibers mainly improves the cracking performance and durability of concrete. However, most of the studies addressing this issue have been limited to phenomenology, ignoring the mechanism of action at the atomic structure level. Therefore, this study investigates the strengthening mechanism of the interfacial properties of KH-560 coupling agent-reinforced PVA fiber-rubber concrete from the multi-scale analysis of macro-mechanical properties, micro and fine structure, chemical composition and nano-optical level. Based on the results of macro-mechanical tests, it was found that the KH-560 coupling agent could improve the compressive, flexural and shear strength of PVA-rubber concrete, so that the damage morphology also changed from brittle damage to plastic damage, and the compressive strength of concrete was slightly reduced due to the addition of PVA, but the durability and cracking resistance were enhanced. XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy) and SEM (scanning electron microscopy) tests observed the presence of some gels and polymers that filled the interfacial slits and effectively repaired the interfacial defects. The two-phase interface was simulated by molecular dynamics at the nano level, and it was found that KH560 molecules could be closely connected with C-S-H gel collectively through Si-O-Si chemical bonding, and KH560 molecular bonds were unevenly distributed between the C-S-H and rubber interfaces, while the addition of modifier KH560 and PVA fibers caused more hydrogen and ionic bonds at the interface, which enhanced the interfacial interaction energy. Systematic experiments were conducted on PVA fiber-rubber soil materials before and after SCA modification under macroscopic, microscopic, fine and nano-level multi-scale analyses, which ultimately lead to the design and performance improvement of SCA modification of PVA-rubber cement-based materials in a multi-scale framework. The graphic summary is shown in Figure 1.

Development of rejuvenator using waste vegetable oil and its influence on pavement performance of asphalt binder under ultraviolet aging

With the development of road engineering, the shortage of resources and road damage are becoming increasingly serious. In this research, The regeneration effect of a rejuvenator on the ultraviolet (UV)-aged asphalt is tested. The rejuvenator is composed of base oil, plasticizer, toughener and petroleum resin. The recovery performance of aged asphalt inareas with strong UV light is compared using indoor asphalt aging tests. A representative UV aged asphalt is selected for experiments. The basic performance of regenerated asphalt with the mixed ratio of different materials is measured using penetration, softening point, and ductility tests. The orthogonal test design (OTD) and analytic hierarchy process (AHP) model are established, and the optimal match design of a rejuvenator is obtained. The performance of UV aged asphalt before and after regeneration is tested by dynamic shear rheology (DSR) and the Fourier Transform Infrared Spectroscopy (FTIR) test. The results show a strong link between the asphalt from the areas with intense UV light and the asphalt after indoor 50 h UV aging. Waste vegetable oil (WVO) is selected as the base oil for the rejuvenator. The proportion of plasticizer in the WVO was determined to 30% based on OTD-AHP model optimization, the toughening agent is 4%, and petroleum resin is 9%. The high-temperature performance of asphalt can be improved with a reasonable regenerative agent dosage. The FTIR test shows that the rejuvenator can dilute carbonyl and sulfoxide groups in aged asphalt, soften asphalt and restore asphalt pavement performance. The results of this study can be applied to the asphalt regeneration to provide road remediation measures for asphalt deterioration in high UV areas.

Research on rheological properties of CNT-SBR modified asphalt

For the sake of improving the high-temperature rutting resistance, storage stability, and fatigue endurance of SBR-modified asphalt. In this study, powdered carbon nanotubes (CNT) with a fineness of 1000 mesh were used to modify 4 % further SBR-modified asphalt. The physical properties and modification mechanism of CNT-SBR modified asphalt were studied by segregation test, temperature sweep, multiple stress creep test (MSCR), bending beam rheological test (BBR), linear scanning (LAS), and Fourier transform infrared spectroscopy (FTIR). Based on the test results, CNT incorporation can significantly enhance the rheological properties of SBR-modified asphalt, making it suitable for supporting higher traffic loads. Compared with SBR-modified asphalt, 1.5 %CNT-SBR modified asphalt significantly enhanced its high-temperature characteristics and anti-aging performance. −12 °C low-temperature stress relief rate raised by 12.6 %. Meanwhile, the 1.5 %CNT-SBR modified asphalt has excellent storage stability at high temperatures, the 70℃ dissociation rate is only 0.03, and fatigue life could be increased by 80.4 %. FTIR test showed that the reaction process of CNT, SBR, and neat asphalt belongs to physical blending. Moreover, FTIR test results showed that CNT and SBR could improve the anti-aging performance of neat asphalt. Careful consideration of CNT-SBR modified asphalt mechanical properties, when the SBR content is 4 %, the recommended CNT content is 1.5 % (1.5 %CNT-SBR).

Identification of Active Compounds of Tantrum Leaves (Indigofera tinctoria) as Natural Textile Dyes

The use of natural dyes as textile dyes is increasing due to environmentally friendly standards and does not require the use of synthetic dyes. By banning the use of synthetic dyes containing azo groups, this is the right moment to reintroduce natural dyes that have been abandoned for a long time. This study aims to identify the active compound of tantrum leaves (Indigofera tinctoria) as a natural textile dye by maceration extraction method with variations in maceration time and material treatment on wet and dry tantrum leaves. This experimental research method was carried out using several stages of analysis, namely the phytochemical test, FTIR (Fourier Transform Infrared Spectroscopy), and UV-Vis (Ultraviolet-Visible Light) spectrophotometer. The results of the phytochemical tests showed that the compounds contained in the Indigofera tinctoria plant were indigo, flavonoids, steroids, and alkaloids. The FTIR test indicated that the dye content in the extract was from the indigo group. The results of the UV-Vis spectrum showed that there was maximum absorption in wet tantrum leaf extract, dry tantrum leaf extract, and alkaline extract at wavelengths of 406.50 nm, 365.50 nm, and 664.50 nm, respectively. Natural dyes in textiles have a positive impact on the environment, the color waste products are biodegradable and can be decomposed.