Fourier Transform Infrared Results Research Articles

Effects of alkaline treatment on the properties of pineapple (Ananas Comosus) leaf fiber (Palf) reinforced with tapioca-based bio resin (Cassava Starch)

The poor compatibility of natural fibers with hydrophobic matrices due to their hydrophilic nature has led researchers to improve their properties to enable better compatibility. Pineapple leaf fiber is one of the abundantly available natural fibers obtained from pineapple leaf. It has good chemical properties and strong admirable mechanical properties and can be used as a replacement for synthetic fibers despite the same deficiencies as other natural fibers. In this study, Pineapple leaf fiber was treated with Alkali at varying concentrations, temperatures, and times. Treated pineapple leaf fiber was reinforced with tapioca-based bio resin (cassava starch). This fiber was subjected to tensile testing and Fourier transform infrared (FTIR) spectroscopy. The results of FTIR indicated the various peaks in the absorbance versus wave number relation. The FTIR analysis of untreated pineapple leaf fiber indicated the presence of O-H stretch, N-H stretch, C ≡ stretch, C=O stretch, and H-C-H bond. The modification of fibers achieved by disruption of hydrogen bonding in the network structure was possible due to its treatment with alkali. Mechanical testing (tensile test) and FTIR were also used to know the effects of chemical treatment on the fibers. Alkali treatment improved the fiber properties as the concentration, temperature, and treatment time increased.

Deterioration Effects of Oxidative Aging on Graphene-Asphalt Nanocomposite Interfaces: Multiscale Modeling.

The purpose of this study is to explore the mechanism of interfacial degradation of graphene-asphalt nanocomposites by oxidative aging and to explain the principle of reduced cracking resistance. In this study, density functional theory (DFT), molecular dynamics (MD) simulation, atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, and linear amplitude scanning test (LAS) were used to quantify the effect of oxidative aging on the interfacial degradation of graphene-asphalt nanocomposites with different scales, and the coupling mechanism between scales was systematically analyzed. The results show that interfacial degradation is a complex multiscale coupling behavior. Oxidative aging reduced the fatigue life (Nf) of graphene-asphalt nanocomposites by 8.6% due to a 63.9% reduction in shear barriers and a 14.2% reduction in energy barriers at the molecular interface. Furthermore, oxidative aging enhanced the intermolecular interactions and compatibility of the graphene-asphalt molecules. The interfacial interaction of aged graphene-asphalt nanocomposites is mainly van der Waals force. Graphene-aged aromatics and graphene-aged saturates were the most compatible interfaces, and there was typical benzene ring stacking between graphene and aged aromatic 2. Aged aromatics and aged saturates are the main promoters of interfacial strength and stress transfer, while aged asphaltenes and aged resins sometimes play a weakening role, as verified by the AFM. In addition, DFT calculations show that there is no chemical reaction between graphene and aged asphalt molecules, which is consistent with the FTIR results. This study provides a theoretical basis for the development of targeted antiaging and anticracking technologies for asphalt-based materials.

Environmental influence of high Na2O additions on microstructure and ligand field parameters of Cr3+ inside borosilicate glass

A glass system based on the Na2O/B2O3-doped CrO3 borosilicate has been prepared by the melt quenching technique. The structure, color, optical absorbance and ligand field parameters were investigated for a wide range of Na2O additives (20–60 mol%). All X-ray photoelectron spectroscopy (XPS) profiles were used to study the chemical shift states of the glass-constituting elements. Fourier transform infrared (FTIR) analyses explored the internal structure and subnetwork units. Furthermore, from the FTIR results, we concluded the transformation of trigonal borate units (BO3) to tetrahedral borate units (BO4) and the possibility of transformation from B3-O-Si linkages to B4-O-Si linkages. Despite the fixed CrO3 content, the doped glasses showed a color transition from green to yellow with additional Na2O content. The increased intensity of the band at 451–427 nm and the decreased intensity of the band at 619–627 nm are the main reasons for this color transformation. The optical absorption spectra confirmed the existence of Cr3+ and Cr6+ states. A decreasing behavior for the crystal field splitting (10Dq) and an increasing behavior for Racah parameter (B) were obtained with further Na2O additives. The decreasing behavior of 10Dq was attributed to reduced oxygen concentrations with more Na2O/B2O3 substitutions. The increasing behavior of B reflects the tendency of the bond between the Cr cations and their oxygen ligands towards an ionic nature. Moreover, the Dq/B values indicated that Cr3+ cations are in high-field positions for the glass sample containing 20 mol% Na2O, and Cr3+ cations are in intermediate field positions for the glass sample containing 30 mol% Na2O. However, for the glass samples doped with 40, 50 and 60 mol% Na2O glass samples, Cr3+-cations are in weak field positions. These results of (Dq/B) recommend the glass sample doped with 20 mol% Na2O for tunable laser applications.

Effect of addition of K2CO3 on the structure of coals with different ranks by FTIR and TG/MS

K2CO3 was considered as the effective catalyst on the pyrolysis performance of coal, however, its effect on coals with different ranks and coalification jumps is unknown until now. This study aims to explore the catalytic mechanism of K2CO3 on coals with different ranks. 8 coals with a vitrinite reflectance (Ro,max) ranging from 0.68% to 1.71% were catalyzed by K2CO3. Thermogravimetric-Mass spectrometry analyzer (TG/MS) and Fourier Transform Infrared (FTIR) spectroscopy were used to characterize the structural variation before and after the addition of K2CO3. FTIR results showed that the length of aliphatic chains (CH2/CH3) decrease and then increase with the turning point near Ro,max = 1.53%, the degree of condensation of aromatic ring (DOC),aromaticity (I) decreased and the concentration of aliphatic hydrogen (Hal/H) increased for all coal samples except for DQ coal (Ro,max = 1.53%) after the addition of K2CO3, indicating the abrupt changes occurred at Ro,max = 1.53%. TG/MS results showed that both the weight loss rate and the maximum weight loss rate temperature exhibit reflection changes near 0.68% and 1.2% of Ro,max. The evolution rate of hydrogen and ethane showed turning changes near Ro,max = 1.21%, while the evolution rate of methane and benzene present transitive changes near Ro,max = 1.53%. Ro,max = 1.21% and Ro,max = 1.53% are consistent with the second and the third coalification jump, respectively. Both TG/MS and FTIR results demonstrated that the effect of K2CO3 is related to coal rank, especially the coalification jump. K2CO3 may tend to act on CC structures furthermore promote the evolution of gaseous products during pyrolysis. The results provide deeply understanding for the coalification jumps and theoretical basis for the selection of suitable catalysts with different coal ranks.

Research on surface morphology characteristics and micro-damage mechanism of asphalt mastic based on charge transfer principle

Asphalt mastic damage is a major element influencing the mechanical qualities of the asphalt mixture. Based on electrochemistry theory, the idea of charge transfer of moisture between asphalt-asphalt and asphalt-mineral powder is proposed in this study to explore the damage mechanism of asphalt mastic under the operation of freeze–thaw cycles.On this basis, the damage mechanism of asphalt mastic was analyzed at multiple scales using relevant experimental means (Scanning electron microscopy-Energy dispersion spectrum(SEM-EDS) experiment, Fourier Transform Infrared(FT-IR) experiment and Atomic Force Microscope(AFM) experiment). FT-IR and AFM experiments results showed that: Water molecules in asphalt mastic might compete for asphaltene electrons in the asphalt mastic, causing the carboxyl dimer formed between asphaltenes to be disrupted. This causes asphaltene dispersion and a reduction in asphaltene concentration. Asphalt colloid structure changes from gel to sol, causing asphalt mastic degradation. Furthermore, freeze–thaw cycles accelerate the damage. On the other hand, the results of FT-IR and SEM-EDS experiments showed that: Freeze-thaw processes in asphalt mastics can also result in varying pore sizes and higher carbon concentration. Water molecules can create structural water on the subsurface of mineral powder crystals as well as physical water on the surface of mineral powder. This affects the adsorption of structural asphalt on the subsurface of the mineral powder crystals, resulting in the dissociation of the adsorbed asphalt from the mineral powder crystals' surface. The results of the study have some theoretical value to further explore the damage mechanism of asphalt mastic.

Development and characterization of a copolymeric micelle containing soluble and insoluble model drugs.

Micelles are nano-sized particles with a core-shell structure that are made by natural or synthetic polymers or copolymers. The aim of this study was to develop and characterize a copolymeric micelle using two polymers loaded with hydrophilic and lipophilic drugs. Poly(ethylene glycol) and poly(ε-caprolactone) (PEG-PCL) were used to form a copolymeric micelle which was further loaded with either moxifloxacin or clarithromycin as hydrophilic and lipophilic drug samples, respectively. Characterization tests were done including fourier transform-infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, encapsulation efficiency, particle size, zeta potential, polydispersity index, transmission electron microscopy, and in-vitro release test. The construction of the copolymer was confirmed by the results of FT-IR and 1H NMR spectroscopy tests. The encapsulation efficiency test exhibited that loading was about 50% for twelve formulations. Particle size, zeta potential, polydispersity index, and transmission electron microscopy confirmed the formation of monodispersed, uniform, and nano-sized micelles with a few negative charges. The kinetic model of release was fitted to the Higuchi model. Polymeric micelles consisting of PEG-PCL copolymer were loaded with adequate concentrations of hydrophilic (moxifloxacin) and lipophilic (clarithromycin) model drugs, with a mean particle size under 300 nm. Therefore, copolymeric micelles can be used as a suitable drug delivery system for mucous membranes and skin.

FTIR and multivariate analysis of total phenolic content, antioxidant and anti-amylase activities of extracts and milk of Glycine max L. and Phaseolus vulgaris L.

BackgroundAlpha-amylase is a digestive enzyme which hydrolyses the glycosidic bonds in polysaccharides into monosaccharides. Inhibition of α-amylase can help to retard carbohydrate digestion in the small intestine and decrease blood glucose level. The effect of solvent extraction and milk processing on total phenolic content (TPC), antioxidant and anti-amylase activities, and Fourier-transform infrared (FTIR) spectra of Glycine max L. and Phaseolus vulgaris L. were estimated by Principal Component Analysis (PCA) and Partial Least Squares Structural Equation Modelling (PLS-SEM). ResultsThe result showed that the aqueous extract of P. vulgaris L. had the greatest antioxidant activity and anti-amylase activity, while the ethanol extract of G. max L. showed the greatest TPC. Interestingly, the milk of P. vulgaris L. seed showed the greatest level of TPC, antioxidant activity and anti-amylase activity. Mixed milk of G. max L. and P. vulgaris L. (8:2 v/v) showed high anti-amylase activity, while the mixed milk (5:5 v/v) showed high TPC and antioxidant activity. The FTIR result showed five wavenumber ranges associated with functional groups of phenolic compounds. Moreover, the PLS-SEM result revealed a significant positive correlation between TCP and FTIR data (β = 0.335, t = 2.112, p-value < 0.05), and between TCP and antioxidant activity (β = 0.346, t = 2.150, p-value < 0.05). ConclusionsThe result indicated that the solvent types and cooked beans could affect the biological activities and chemical content. The application of chemical content, biological activities, and FTIR technique combined with PLS-SEM and PCA analysis could discriminate bean types, solvent types, and between raw and cooked beans.How to cite: Thummajitsakul S, Paensanit P, Saeieo T, et al. FTIR and multivariate analysis of total phenolic content, antioxidant and anti-amylase activities of extracts and milk of Glycine max L.and Phaseolus vulgaris L. Electron J Biotechnol 2023;64. https://doi.org/10.1016/j.ejbt.2023.04.001.

Hybrid rGO-AgNPs Conductive Ink for Inkjet Printed Flexible Humidity Sensor

Due to the challenging dispersion of graphene in aqueous media, organic solvents are commonly used in conductive graphene inks. This will result in safety issues and environmental pollution. In this study, we demonstrated a green approach of graphene ink preparation through one-pot synthesis reaction that produce a hybrid reduced graphene oxide (rGO)-silver nanoparticles (AgNPs), with deionized water as solvent. The synthesized rGO-AgNPs was monitored using ultraviolet–visible (UV-Vis) spectroscopy and fourier transform infrared (FTIR). A stable dispersion of rGO-AgNPs ink was confirmed through UV-Vis analysis. FTIR result showed the removal and the reduction in the intensities of absorption bands of oxygen-containing functional groups, which indicated that graphene oxide (GO) has been successfully reduced to rGO in the hybrid ink. The printed film of rGO-AgNPs exhibited a high conductivity of 1.50 × 104 S/cm, proven that the electrical performance of the hybrid ink has been improved as compared to previously reported GO-based ink. Printed into interdigitated electrode (IDE), the impressive characteristic of our hybrid ink performed well as a high-sensitivity flexible humidity sensor.

Synthesis and photocatalytic effects of TiO2-Ag on antibiotic-resistant bacteria

Titanium dioxide (TiO2) is a semiconductor metal oxide extensively studied due to its photocatalytic properties that can be applied in various areas. However, the catalytic performance of TiO2 is limited at the UV spectrum, and the silver doping to titanium dioxide (Ag-TiO2) can increase the catalytic performance for visible light. In this work, Ag-doped TiO2 nanoparticles were synthesized to evaluate photocatalytic activity against sensitive and methicillin-resistant Staphylococcus aureus frequently associated with skin infections. The sol-gel method followed by Ag doping was applied to NPs synthesis. NPs were characterized by UV-vis spectroscopy, scanning electron microscopy (SEM), UV-vis diffuse reflectance spectrophotometry (DRS), Semi-quantitative energy dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. FTIR and EDS results confirmed the doping of silver in TiO2. MEV analysis evidenced spherical nanoparticles between 8.5 - 25.6 nm. The TiO2 nanoparticles combined with silver improved the antimicrobial effect of TiO2 under visible light at 180 min, however, the greatest antimicrobial effect was observed under UV light at 120 min.

Changes in Structures and Properties of Collagen Fibers during Collagen Casing Film Manufacturing.

Collagen casing is an edible film, which is widely used in the industrial production of sausages. However, the detailed changes in the collagen fibers, from the raw material to the final collagen film, have rarely been reported. In this research, the changes in the collagen fibers during the manufacturing process, including the fiber arrangement, the triple-helix structure and the thermal stability, were investigated using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy. The relationship between the structure stability and the arrangement of the collagen fibers was also discussed. According to the SEM, XRD, TGA, DSC and FTIR results, the collagen fibers were depolymerized during the acid swelling and became uniformly aligned after the homogenization process. Degassing had no obvious effect on the triple-helix structure. Alkaline neutralization with ammonia destroyed the triple-helix structure, which could be partly reversed through the washing and soaking processes. During the final drying step, the depolymerized triple helix of the collagen fibers recombined to form new structures that showed decreased thermal stability. This study expands our knowledge about the behavior of collagen fibers during the industrial process of producing collagen biobased casings.

Analysis of Exopolysaccharides in Lactobacillus casei group Probiotics from Human Breast Milk

Exopolysaccharides get a lot of attention because they can improve the host immune system. Exopolysaccharide is a polysaccharide that is produced and secreted from microbes outside the cell, usually found on the outside of the bacterial structure. The Lactobacillus casei group from human breast milk is thought to have the ability to produce exopolysaccharides. The purpose of the study was to examine the exopolysaccharide of the L. casei group that was isolated from breast milk. The methods used include the gravimetric, the phenol-sulfuric acid and the Fourier Transform Infra-Red (FTIR). The results showed that the L. casei group could produce exopolysaccharides, and had high exopolysaccharide total sugar content. Lactobacillus paracasei had the highest exopolysaccharide and total sugar content of 3660 mg/L and 80.6%, respectively. The FTIR results of the L. casei group exopolysaccharides showed the presence of hydroxyl functional groups O-H (3425.76-3295.98 cm-1), methyl C-H (2930.86-2856.70 cm-1), carbonyl C=O (1660.11-1647.27 cm-1), C-H (1456.16-1373.44 cm-1) and C-O-C ether (1071.08-1056.82 cm-1) which are specific characters of exopolysaccharides. Since the FTIR profile demonstrates that the L. casei group can produce exopolysaccharides, it has greater potential as a a probiotic.

Mineralogy and geochemical characterization of geophagic clays consumed in parts of southern Nigeria

This study seeks to determine health risk associated with consumption of clay in different areas in southern Nigeria. Different clay samples sold for consumption were purchased from Mowe, Ikorodu and Onitsha Markets in southern Nigeria. The clays were subjected to mineralogical and geochemical characterization using X-Ray Diffractometry (XRD), Fourier Transform Infrared (FTIR) and Inductively Coupled Plasma-Atomic EmissionSpectrometry. Potential health risk assessment was calculated using a standardized Hazard Quotient (HQ) and Total Hazard Index (THI). XRD and FTIR results revealed the clay contains varying percentage of quartz, kaolinite, anatase, halite, pyrite, goethite, smectite and palygorskite while geochemical analysis result revealed wide range of elemental concentration (ppm). Mean concentration (ppm) of Cu, Pb, Zn, Cr, Ni and Co from the markets are 5.8 – 8; 17.4 – 29.6; 32.4 – 95.8;111.6 – 103.4; 18.6 – 39.4 and 4 – 16.6 respectively while As was below detection limit in most of the samples. HQ values were used to calculate the THI. THI values for children and adults for Mowe market samples range from 0.9 to 2.1 and 0.5–1.1 respectively, for Ikorodu market samples, THI for children and adult ranges from 1.0- 1.8 and 0.6–1.0 respectively, while THI for children and adults for Onitsha market samples ranges from 1.5 to 2.6 and 0.8–1.84 respectively. In conclusion, children that consume clay from the markets are more exposed to non-carcinogenic risks than adults. It is therefore advisable that the clays should not be consumed for a long period of time to avoid health problems.

Sources of n-Type Conductivity in Single Crystal β-Ga2O3 and Monoclinic WO3 Nanoparticles

The source of the commonly observed unintentional n-type conductivity in wide-band-gap oxides is controversial. For high-quality β-Ga2O3 single crystals, the physical characteristics of H-containing defects are studied by solid-state nuclear magnetic resonance (ssNMR) and Fourier transform infrared (FT-IR) spectroscopy. NMR observation demonstrated that the hydrogen atoms occur exclusively in the positive charge state, and three trapped protons are housed in two “half vacancies” left by the Ga vacancy to form a VGa–H2+1 complex. Protons trapped in the vacancies are hardly ever able to diffuse out due to the strong hydrogen bonds they establish, even at relatively high temperatures. The hydrogen atoms in one of the two “half vacancies” are the bridged protons in Ga–O(H2)–Ga bonds, the hydrogen atoms can readily donate electrons to the conduction band, and these hydrogen atoms become the shallow donors. The VGa–H2+1 complex provides high-quality β-Ga2O3 single crystals with the extra-stability and the n-type conductivity. For monoclinic WO3 nanoparticles, NMR, FT-IR, and EPR results show that the bridged proton in W–O(H2)–W groups was assumed to be responsible for the so-called “hidden” hydrogen, which can be converted into a shallow donor in the course of sample processing. Our results provide a guide to more refined experimental studies of point defects and impurities in wide-band-gap oxides and their influence on the control of n-type conductivity.

Yttrium aluminum garnet-based filler resin composites used as clear aligner attachments.

The objective of this study was to develop a novel resin composite containing yttrium aluminum garnet (Y3Al5O12, YAG) nanoparticles for clear aligner attachments. After the silanization of YAG, their Fourier-transform infrared (FT-IR) and thermogravimetric (TGA) analyses were performed. By conducting flexural and compressive strength measurements, the optimal YAG concentration was selected for the subsequent experiments. Next, Vickers microhardness values, fluidities, attachment volumes, conversion degrees, and volumetric shrinkages of the resin were determined. The obtained FT-IR and TG results revealed that γ-methacryloxypropy ltrimethoxysilane coupling agent was successfully grafted onto the surface of YAG, which enabled their use as inorganic fillers. Furthermore, adding 9 wt% YAG in the resin can increase Vickers hardness and fluidity, reduce polymerization shrinkage, and enhance the restoration of the clear aligner attachment shape on the premise of guarantee proper flexural and compressive strength of the resin, which can help control tooth movement and increase orthodontic efficiency.

Fatty acid profile and rheological behavior of annatto seed oil (Bixa orellana), cupuassu seed fat (Theobroma grandiflorum), and their blends

Annatto seed oil (ASO) and cupuassu seed fat (CSF) were combined at the ratios: 30:70, 50:50, and 70:30 (% w/w). Their fatty acid profile, nutritional quality, FTIR (Fourier Transform Infrared) spectra, and rheological behavior were evaluated. ASO increased the content of polyunsaturated fatty acids in the blends; whereas CSF conferred higher contents of monounsaturated fatty acids. The blends exhibited low atherogenicity and thrombogenicity indices, suggesting nutritional advantages. The Newtonian fluid behavior and FTIR results suggested that mixing ASO and CSF at different proportions did not affect the functional groups. ASO showed an activation energy value which indicated that this fat viscosity was more sensitive to temperature changes. The Newtonian model proved to be suitable to describe the behavior of samples, according to statistical fit parameters R2, χ2, and RSS. The resulting blends presented improved physicochemical properties and nutritional attributes, indicating their feasibility for the development of new products.

Gamma-ray induced effect on the structural and optical properties and durability of neodymium-doped zinc–bismuth–borotellurite glasses and glass ceramics

This study explores the effect of gamma rays on a new glass and glass–ceramic 10ZnO–34.5B2O3–34.5TeO2–20Bi2O3–1Nd2O3. The samples were exposed to different gamma-ray doses of 2.5, 10, and 50 kGy. The impact of gamma-ray irradiation was investigated using different physicochemical methods. The X-ray diffraction (XRD) results for glass samples show that the amorphous nature did not change before and after irradiation, and a shift in the main peak along with a change in the unit cell volume with increasing doses was observed in glass-ceramic matrix. The Fourier transform infrared (FTIR) and Raman spectra (IR) for the glass samples show change in intensity without variation in the band position. The 50 kGy dose hid a high wavenumber peak in the FTIR and Raman spectra for the glass–ceramic sample, indicating a significant change in the glass–ceramic matrix. The reduction in the band gap energy for the glass samples confirms the FTIR results. The durability of the glass samples was gradually enhanced by increasing the dose up to 10 kGy. The up-conversion photoluminescence in the glass samples exhibits an emission peak at 525 nm that decreases in intensity as the dose increases. The mean free path results confirm the shielding features of the glass when compared to other reference glass materials. The results show that the glass is excellently stable and can withstand high gamma-ray doses, making it suitable for radiation applications.

G-C3N4 Dots Decorated with Hetaerolite: Visible-Light Photocatalyst for Degradation of Organic Contaminants

In this paper, a facile hydrothermal approach was used to integrate graphitic carbon nitride dots (CNDs) with hetaerolite (ZnMn2O4) at different weight percentages. The morphology, microstructure, texture, electronic, phase composition, and electrochemical properties were identified by field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), ultraviolet-visible diffuse reflectance (UV-vis DR), photoluminescence (PL), electrochemical impedance spectroscopy (EIS), Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH), and photocurrent density. The results of XRD, FT-IR, EDX, and XPS analyses confirmed the synthesis of CNDs/ZnMn2O4 (20%) nanocomposite. As per PL, EIS, and photocurrent outcomes, the binary CNDs/ZnMn2O4 nanocomposite revealed superior features for interfacial transferring of charge carriers. The developed p–n heterojunction at the interface of CNDs and ZnMn2O4 nanoparticles partaken a significant role in the impressive charge segregation and migration. The binary nanocomposites were employed for the photodegradation of several dye pollutants, including rhodamine B (RhB), fuchsin, malachite green (MG), and methylene blue (MB) at visible wavelengths. Amongst the fabricated photocatalysts, the CNDs/ZnMn2O4 (20%) nanocomposite gave rise to about 98% RhB degradation efficiency within 45 min with the rate constant of 747 × 10−4 min−1, which was 66.5-, 3.44-, and 2.72-fold superior to the activities of CN, CNDs, and ZnMn2O4 photocatalysts, respectively. The impressive photodegradation performance of this nanocomposite was not only associated with the capacity for impressive visible-light absorption and boosted separation and transport of charge carriers, but also with its large surface area.

A Phosphonic Functionalized Biopolymer for the Sorption of Lanthanum (III) and Application in the Recovery of Rare Earth Elements

Phosphonic acid functionalization of gellan gum and chitosan biopolymers was successfully performed. In the first step, the sorption was investigated using La(III) ions before testing for the recovery of rare earth elements (REEs) from pretreated industrial acidic leachate. The sorbent was characterized by Fourier-transform infrared (FTIR), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and pH of zero charge (pHPZC) determination. FTIR and EDX results show efficient grafting of phosphoryl groups. The sorption was determined for the crude materials before functionalization (PGEG) and after phosphorylation (TBP-PGEG). More efficient sorption was seen for phosphorylated sorbent than for the crude composite. The sorption capacity is 0.226 mmol La g−1 for the PGEG while the value is 0.78 mmol La g−1 for the TBP-PGEG. We infer that phosphonate groups participate in the sorption. The most effective sorption is at pH = 4. The kinetic behavior was described using pseudo first-order equations (PFORE), pseudo second-order equations (PSORE), and resistance to intraparticle diffusion (RIDE). The sorption isotherms can be better represented by Langmuir and Sips equations than by the Freundlich equation. The sorbent shows high stability performance during reuse cycles with a limit on the decrease in the sorption performances and stability in the desorption performances. We have thus developed a good tool for the recovery of REEs with a selectivity higher than that of the non-functionalized components.

Using design of experiments (DoE) to optimize performance and stability of biomimetic cell membrane-coated nanostructures for cancer therapy.

Introduction: Cell membrane-covered biomimetic nanosystems have allowed the development of homologous nanostructures to bestow nanoparticles with enhanced biointerfacing capabilities. The stability of these structures, however, still represents a challenge for the scientific community. This study is aimed at developing and optimizing cell derived membrane-coated nanostructures upon applying design of experiments (DoE) to improve the therapeutic index by homotypic targeting in cancer cells. Methods: Important physicochemical features of the extracted cell membrane from tumoral cells were assessed by mass spectrometry-based proteomics. PLGA-based nanoparticles encapsulating temozolomide (TMZ NPs) were successfully developed. The coating technology applying the isolated U251 cell membrane (MB) was optimized using a fractional two-level three-factor factorial design. All the formulation runs were systematically characterized regarding their diameter, polydispersity index (PDI), and zeta potential (ZP). Experimental conditions generated by DoE were also subjected to morphological studies using negative-staining transmission electron microscopy (TEM). Its short-time stability was also assessed. MicroRaman and Fourier-Transform Infrared (FTIR) spectroscopies and Confocal microscopy were used as characterization techniques for evaluating the NP-MB nanostructures. Internalization studies were carried out to evaluate the homotypic targeting ability. Results and Discussion: The results have shown that nearly 80% of plasma membrane proteins were retained in the cell membrane vesicles after the isolation process, including key proteins to the homotypic binding. DoE analysis considering acquired TEM images reveals that condition run five should be the best-optimized procedure to produce the biomimetic cell-derived membrane-coated nanostructure (NP-MB). Storage stability for at least two weeks of the biomimetic system is expected once the original characteristics of diameter, PDI, and ZP, were maintained. Raman, FTIR, and confocal characterization results have shown the successful encapsulation of TMZ drug and provided evidence of the effective coating applying the MB. Cell internalization studies corroborate the proteomic data indicating that the optimized NP-MB achieved specific targeting of homotypic tumor cells. The structure should retain the complex biological functions of U251 natural cell membranes while exhibiting physicochemical properties suitable for effective homotypic recognition. Conclusion: Together, these findings provide coverage and a deeper understanding regarding the dynamics around extracted cell membrane and polymeric nanostructures interactions and an in-depth insight into the cell membrane coating technology and the development of optimized biomimetic and bioinspired nanostructured systems.

Evolution of pyrolysis characteristics and gas components of biochar prepared by either mixing or layering rice husk with inert aluminum oxide

A comparison of pyrolysis characteristics and gas product evolution of biochar with different packing arrangements was investigated. Pyrolysis properties and released gas products of rice husk char were obtained by particles in two different modes of packing. The results of the combustion characteristics of rice husk/char showed that the maximum pyrolysis rate of the rice husk decreased and the pyrolysis curve shifted to higher temperatures when the biomass was covered by Al2O3. The volatilization analysis of char from the covered biomass had a larger characteristic index and a lower activation energy. The 2D Fourier transform infrared (FTIR) results showed that layering hindered gaseous products from being released during rice husk pyrolysis, and there was no obvious release peak of C=O-containing organic matter. The 3D FTIR results showed that gaseous product absorption peak of solid product char pyrolysis gradually decreased while the rice husk conversion rate increased. The amount of H2O, CO2, CO, CH4, and C=O-containing organic components released during combustion of pyrolyzed char when blended with Al2O3 decreased gradually. However, the pyrolysis gaseous product release was increased by the layering procedure.