Presence Of Carbonyl Groups Research Articles

Electronegativity Effects on Conformational Stability Using Bent's Rule: From Simple Molecules to Acetylcholine

Hybridization and electronegativity are fundamental concepts in chemistry connected by Bent's rule. This rule explains many aspects of the structural chemistry and reactivity of organic and inorganic compounds. Over decades, the application of Bent's rule has expanded, demonstrating its wide-ranging utility in elucidating molecular stability due to the substitution of highly electronegative atoms. This study successfully leverages Bent's rule to explain conformational energy difference in acetylcholine case using density-functional calculations. We used butane (Group 2) and butanone (Group 3) families to model the head of ACh+ and substituted one of the carbons with highly electronegative atoms: B, C, N, and O. This enabled us to evaluate the effects of electronegativity, as well as the presence of carbonyl groups, on their conformational stability and s character. There were three highlighted results. First, our calculations result in the s character are consistent with Bent's rule. Second, the high conformational energy differences can be attributed to the changes of s character in C2–Z bond: linear in Group 2 and exponential in Group 3, indicating the strong contribution of the carbonyl group. Third, the key determining factor in ACh+ conformational stability is the carbonyl group, which also strongly contributes to the solute-solvent interactions. Therefore, our study can be further applied to other similar molecules, potentially leading to broader applications in chemistry, especially for understanding ACh+ stability for Alzheimer’s Disease treatment.

Isolation, screening, and characterization of polyhydroxyalkanoate (PHA)‐producing Cellulosimicrobium cellulans: A promising approach for eco‐friendly biopolymer production

AbstractThe replacement of synthetic plastics with eco‐friendly biopolymers is a notable approach in the modern world. Polyhydroxyalkanoates (PHAs) have gained a lot of attention among researchers in recent decades. This study aimed to isolate and screen microorganisms capable of producing PHA from composite samples. Several composting unit samples were collected and used to isolate 15 distinct colonies which were then screened for PHA synthesis. Three isolates‐SS2, SSNA 1a, and SF2‐showed promising PHA production. Among these isolates, SS2 had the highest PHA content of 70.1%. The isolate SS2 was determined as Cellulosimicrobium cellulans DSM 43879 by gene sequencing. The polymer produced by SS2 was further characterized. The presence of carbonyl groups and ester linkages in the PHA polymer was established by Fourier transform infrared analysis. The polymer's crystalline nature was validated by X‐ray powder diffraction measurement. Scanning electron microscope study revealed thread‐like forms with a rough surface while energy dispersive X‐ray analysis revealed a low impurity content that was primarily composed of carbon and oxygen with traces of other elements. Overall, the findings indicate C. cellulans potential as an ideal candidate for efficient PHA synthesis supporting its commercial potential in diverse applications.

Removal of phenol from aqueous solution using montmorillonite-Fe3O4-humic acid (MFH) nanocomposite

Abstract Phenol is a highly toxic pollutant commonly found in industrial wastewater. Its removal is crucial to protect the environment and human health. Various methods are available for phenol removal, but adsorption is the most widely used and effective approach. Fe3O4 nanoparticles (NP) have emerged as a promising adsorbent due to their cost-effectiveness, high surface area, and exceptional adsorption capabilities. However, its small size can lead to issues such as oxidation, aggregation, and difficulty in separation. This study introduces a new approach for phenol removal using a montmorillonite-Fe3O4-humic acid (MFH) nanocomposite. The synthesis of the MFH nanocomposite involved dispersing Fe3O4 nanoparticles onto montmorillonite clay and coating the surface with humic acid to enhance stability and adsorption efficiency. The prepared MFH nanocomposite was thoroughly characterized to find the morphology, composition and functional group. FTIR spectroscopy revealed the presence of Fe-O, O-Si and C=O vibrations which confirmed the successful formation of the nanocomposite. The average crystal size of the synthesized nanoparticles is obtained from XRD analysis as 10.99 nm. The Fe3O4: montmorillonite ratio was found to influence the adsorption performance, with a Fe3O4:montmorillonite ratio of 1:4 exhibiting the highest removal efficiency. Batch experiments were performed to assess the phenol removal effectiveness of the MFH nanocomposite. At optimum operating conditions of pH 4 and contact time 150 minutes, the phenol removal efficiency was found to decrease from 98% to 87% when the concentration of phenol in influent increased from 10 to 100 mg/L. The adsorption kinetics of phenol on MFH followed the pseudo-second-order kinetic model, indicating a chemisorption process with strong correlation and agreement between experimental and predicted results. The Langmuir and Freundlich isotherm models both provided suitable descriptions of the adsorption behaviour. The maximum adsorption capacity (qm) was determined to be 11.14 mg/g. The presence of carbonyl groups(C=O), Hydroxyl groups (-OH) and silanol groups (Si-O) in MFH offers a significant advantage for enhancing the removal efficiency of phenol. The phenol sorption capacity of MFH nanocomposites was found to be significantly greater compared to that of magnetite. The results showed that the developed MFH nanocomposite offers a promising solution for the efficient removal of phenol from wastewater.

Thermo-Oxidative Aging Effect on Charge Transport in Polypropylene/Ultra-High Molecular Weight Polyethylene Nanocomposites

This study investigates the impact of magnesium oxide (MgO) nanoparticles on the thermo-oxidative aging behavior of blends of polypropylene (PP) and ultra-high molecular weight polyethylene (UHMWPE). The samples, both unfilled and filled with MgO, were aged at 120 °C for varying durations of up to 672 h. The observed structural changes are not monotonic; recrystallization leads to the increased crystallinity and melting temperature of UHMWPE until 336 h. Beyond this, the consumption of the antioxidant leads to chain scission which, in turn, results in decreased crystallinity. The presence of carbonyl groups indicates chemical changes and, as such, the carbonyl index is used as an indicator of aging, with subsequent changes to charge transport. During thermal aging, the interaction between PP and UHMWPE chains at interfaces is enhanced, leading to improved compatibility and the emergence of a new single crystallization peak in PP/UHMWPE blends. Although MgO does not show evidence of elevating the crystallization temperature, implying the absence of enhanced nucleation, it acts as a compatibilizer, improving interfacial interaction compared with the unfilled blend counterparts. MgO hinders the breakage of molecular structures and impedes the diffusion of oxygen. This, in turn, results in nanocomposites filled with MgO having reduced their charge accumulation and conductivity, thus delaying the aging process compared to PP/UHMWPE blends without nanofiller.

Preparation and Characterization of Carbon Nanotubes Enhanced Canola Protein Isolate (CNT/CPI) Bio-Adhesive for Wood Application

The current wood adhesives technologies rely mainly on formaldehyde-based adhesives produced from petrochemicals. Moreover, these adhesives are derived from non-renewable sources is known to be carcinogenic together with other serious health effects. Therefore, there is an increasing interest in the use of renewable and biodegradable sources for the evolution of an environmentally friendly adhesives for interior wood applications.The canola meal (the remnant after oil extraction from the canola seed) contains about 36 – 39% (8.5% moisture basis) can be used as a low value feed for the animals. Moreover, its protein content is currently exploring other applications such as in the adhesive technology and it can be used as an alternative to the widely used formaldehyde-based adhesives. Canola proteins (CP) as adhesives have many unique properties such as ease of handling, low cost, low pressing temperatures, and the ability to bind wood with relatively high moisture content. On the other hand, it has relatively low adhesion strength and low water resistance which are the major drawbacks. This study will address these issues by modifying CP adhesive with carbon nanotubes (CNT). CNT are one of the most encouraging strengthening nanofillers with the extraordinary tensile modulus and strength, it has been proved to significantly improve the physical and mechanical properties of the nanocomposites. Generally, this study will intend to improve the water resistance and adhesive strength of the CP adhesive by incorporating different concentrations of the CNT into the protein matrix.This study is made up of two parts: incorporation of CNT and functionalized CNT (FCNT) into the CP matrix. Incorporation of CNT at 1% (w/w) enhanced the adhesive strength from 5.98, 1.80, and 5.42 to 9.20, 5.64, and 7.44 at percentage increment of 53.85, 213.33, and 37.27% for dry, wet, and soaked strength respectively. The presence of carbonyl group in the CNT after purification as well as the polyvinylpyrrolidone (PVP) helped to attain this improvement in the water resistance and adhesion.In the second part, functionalization of the CNT greatly improved the shear strength at 1% FCNT concentration to 10.62, 8.10, and 8.13 at 77.59, 350, and 50% increase for dry, wet, and soaked strength respectively. The introduction of the carboxylic group by functionalization significantly improved the mechanical and thermal properties of the CP due to a proper dispersion giving rise for a better hydrophobic and cohesive interactions between the wood and adhesive.These results proved an enhanced water resistance and adhesion of the CP contributed by the CNT and its functionalization.

Potential of Phytomolecules in Alliance with Nanotechnology to Surmount the Limitations of Current Treatment Options in the Management of Osteoarthritis.

Osteoarthritis (OA), a chronic degenerative musculoskeletal disorder, progressively increases with age. It is characterized by progressive loss of hyaline cartilage followed by subchondral bone remodeling and inflammaging. To counteract the inflammation, synovium releases various inflammatory and immune mediators along with metabolic intermediates, which further worsens the condition. However, even after recognizing the key molecular and cellular factors involved in the progression of OA, only disease-modifying therapies are available such as oral and topical NSAIDs, opioids, SNRIs, etc., providing symptomatic treatment and functional improvement instead of suppressing OA progression. Long-term use of these therapies leads to various life-threatening complications. Interestingly, mother nature has numerous medicinal plants containing active phytochemicals that can act on various targets involved in the development and progression of OA. Phytochemicals have been used for millennia in traditional medicine and are promising alternatives to conventional drugs with a lower rate of adverse events and efficiency frequently comparable to synthetic molecules. Nevertheless, their mechanism of action in many cases is elusive and uncertain. Even though many in vitro and in vivo studies show promising results, clinical evidence is scarce. Studies suggest that the presence of carbonyl group in the 2nd position, chloro in the 6th and an electron- withdrawing group at the 7th position exhibit enhanced COX-2 inhibition activity in OA. On the other hand, the presence of a double bond at the C2-C3 position of C ring in flavonoids plays an important role in Nrf2 activation. Moreover, with the advancements in the understanding of OA progression, SARs (structure-activity relationships) of phytochemicals and integration with nanotechnology have provided great opportunities for developing phytopharmaceuticals. Therefore, in the present review, we have discussed various promising phytomolecules, SAR as well as their nano-based delivery systems for the treatment of OA to motivate the future investigation of phytochemical-based drug therapy.

Understanding the compositional changes of organic matter in torrefied olive mill pomace compost using infrared spectroscopy and chemometrics

Composting olive mill pomace (OMP), the major by-product of the olive oil industry, is an attractive waste management practice in the context of sustainable food production. Thermal treatment of compost at mild temperatures (torrefaction) can aid to improve its characteristics as a soil amendment. This study aims to understand the chemical changes occurring during torrefaction of olive mill pomace-based (OMP) compost, as well as to evaluate the treatment effects on compost at different stages of maturation. Here, treatments at different temperatures (175, 225, and 275 °C) and duration (from 1 to 5 h) have been employed to obtain a sort of torrefied samples. In general, the H/C and O/C atomic ratios of compost samples decreased with torrefaction temperatures, which suggests an incipient coalification of the organic matter. Furthermore, the results showed that a combination of FT-NIR and FT-MIR spectroscopy using a low-level data fusion strategy is very sensitive to the molecular changes occurring both in the composting process and during heating. Principal Component Analysis (PCA) of the merged spectra revealed that the changes at 175 °C are mainly the loss of water (O–H contributions at 3300 and 5169 cm−1) together with the degradation of proteins (observed in the decrease of amide I and II characteristic bands). Furthermore, the samples heated at this temperature can still be differentiated by their initial maturation stage. On the other hand, thermochemical changes occurring at higher temperatures are more intense and make the samples more alike, independently of the composting time. When heating above 225 °C, the loss of O–H happens together with the decrease of aliphatic moieties, reflected in the bands 2920 and 2850 cm−1 (FT-MIR) and 4258, 4323, 5665, and 5781 cm−1 (FT-MIR). This can be attributed to the thermal degradation of cellulosic materials and, additionally, to the degradation of the residual oil in the case of poorly composted samples. Heated samples are characterized by the presence of carbonyl groups (1709 cm−1) and humic-like complex and polymerized aromatic structures (1579 cm−1). Since the characteristics of the torrefied compost at 275 °C are very similar regardless of the initial maturation stage, torrefaction may be a very interesting way to reduce the composting time of olive mill pomace to obtain a high-quality organic amendment for soil application.

Distinct Bacterial and Fungal Communities Colonizing Waste Plastic Films Buried for More Than 20 Years in Four Landfill Sites in Korea.

Plastic pollution has been recognized as a serious environmental problem, and microbial degradation of plastics is a potential, environmentally friendly solution to this. Here, we analyzed and compared microbial communities on waste plastic films (WPFs) buried for long periods at four landfill sites with those in nearby soils to identify microbes with the potential to degrade plastics. Fourier-transform infrared spectroscopy spectra of these WPFs showed that most were polyethylene and had signs of oxidation, such as carbon-carbon double bonds, carbon-oxygen single bonds, or hydrogen-oxygen single bonds, but the presence of carbonyl groups was rare. The species richness and diversity of the bacterial and fungal communities on the films were generally lower than those in nearby soils. Principal coordinate analysis of the bacterial and fungal communities showed that their overall structures were determined by their geographical locations; however, the microbial communities on the films were generally different from those in the soils. For the pulled data from the four landfill sites, the relative abundances of Bradyrhizobiaceae, Pseudarthrobacter, Myxococcales, Sphingomonas, and Spartobacteria were higher on films than in soils at the bacterial genus level. At the species level, operational taxonomic units classified as Bradyrhizobiaceae and Pseudarthrobacter in bacteria and Mortierella in fungi were enriched on the films. PICRUSt analysis showed that the predicted functions related to amino acid and carbohydrate metabolism and xenobiotic degradation were more abundant on films than in soils. These results suggest that specific microbial groups were enriched on the WPFs and may be involved in plastic degradation.

The Practical Utility of Imidazolium Hydrogen Sulfate Ionic Liquid in Fabrication of Lignin-Based Spheres: Structure Characteristic and Antibacterial Activity.

In this study, lignin-based spherical particles (Lig-IL) with the use of 1-(propoxymethyl)-1H-imidazolium hydrogen sulfate were prepared in different biopolymer and ionic liquid (IL) weight ratios. The application of IL during the preparation of spherical particles is an innovative method, which may be beneficial for further applications. The particles were obtained with the use of the soft-templating method and their chemical, structural and morphological characterization was performed. The spherical shape of products and their size (91–615 nm) was confirmed with the use of scanning electron microscopy (SEM) images and the particle size distribution results. The attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra were analyzed to identify functional groups of all precursors and produced material and it was confirmed, that all materials exhibit characteristic hydroxyl and carboxylic groups, but the presence of carbonyl group was detected. Moreover, the zeta potential analysis was performed to evaluate the electrokinetic behavior of obtained materials. It was confirmed, that all materials are colloidally stable in pH above 4. Produced lignin-based spherical particles were used for evaluation of their antibacterial properties. Particles were tested against Staphylococcus aureus (S. aureus), a gram-positive bacterium, and Escherichia coli (E. coli), a gram-negative one. It was observed, that only the material with the highest addition of IL showed the antibacterial properties against both strains. A reduction of 50% in the number of microorganisms was observed for particles with the addition of hydrogen sulfate ionic liquid in a 1:1 ratio after 1 h. However, all prepared materials exhibited the antibacterial activity against a gram-positive bacterium.

Screening of Aqueous Extract of Persea americana Seeds for Alpha-Glucosidase Inhibitors.

Activity of α-glucosidase enzyme in the gastrointestinal tract has been implicated in postprandial hyperglycaemia. If not properly controlled, postprandial hyperglycaemia might progress to diabetes mellitus, a metabolic syndrome. Diabetes is associated with many complications such as retinopathy, heart attack, nephropathy, neuropathy, stroke, and lower limb amputation. Antidiabetic medications presently in use have little effect on postprandial glycaemic excursion and hence do not bring down the blood glucose level to baseline. This study extracted, fractionated, and screened the aqueous extract of Persea americana seeds for hypoglycaemic potential. Inhibitory effects of the fractions and subfractions of the extract on α-glucosidase activity were investigated. The most active subfraction was subjected to Fourier transform infrared (FTIR) and gas chromatography mass spectroscopy (GC-MS) analysis to elucidate the active components. The active subfraction showed a significant inhibition (p < 0.05) on α-glucosidase. The subfraction competitively inhibits α-glucosidase (with IC50 = 09.48 ± 0.58 μg/mL), though less potent than the standard drug, acarbose (IC50 = 06.45 ± 0.47 μg/mL). FTIR analysis of the subfraction showed the presence of carbonyl group, hydroxy group, carboxyl group, double bonds, methylene, and methyl groups. GC-MS analysis suggests the presence of cis-11,14-eicosadienoic acid, catechin, and chlorogenic acid as the active components. In conclusion, the components obtained from this study can be synthesised in the laboratory to further confirm their hypoglycaemic activity. The most active subfraction can be explored further to confirm its inhibitory activity against the enzyme and to determine its extent in the treatment of diabetes mellitus in vivo.

Biochar from microwave co-pyrolysis of food waste and polyethylene using different microwave susceptors – Production, modification and application for metformin removal

Biochar (BC) production by microwave (MW) co-pyrolysis of food waste (FW) with polyethylene (PE) (mixed in a ratio of 8:1) was performed in the present study using different MW susceptors, i.e. granular activated carbon (G), silica gel (S), cement (C) and flyash (F). BC yield varied from 37 wt% to 45 wt%. The highest yield of 45 wt% was obtained with flyash as MW susceptor. All BC exhibited increased carbon content (57.1–69.0 wt%), fixed carbon (76.0–85.3 wt%), and porous structure with improved thermal stability than the feedstock. The inferential plot exhibited an inverse relationship between yield and carbon of BC with loss tangent (tan δ) and specific surface area (SSA) of the MW susceptor. Alkali (potassium phosphate) modified F-BC (K-F-BC) showed further improvement in porous structures with a good cavity and presence of carbonyl group (CO) and hydroxide group (O–H) on its surface, which showed good adsorptive removal of metformin (MET). Alkali modification of F-BC improved the adsorption capacity by ∼8 times; thus, resulting in ∼62% MET removal within 5 min. Kinetic models suggested the MET adsorption on BC predominantly controlled by intra-particle diffusion (R2 = 0.72–0.98). Adsorption of MET with S-BC and F-BC followed Langmuir isotherm (R2 = 0.99). On the other hand, G-BC, C-BC and K-F-BC followed Freundlich isotherm (R2 = 0.99). Maximum MET adsorption of 0.17 mg/g, 0.23 mg/g, 0.26 mg/g and 0.27 mg/g were observed with F-BC, G-BC, S-BC and C-BC respectively. Alkali modification of F-BC (K-F-BC) improved its adsorption capacity up to 0.34 mg/g. The Surface deposition, pore filling, π-π interaction and chemical bonding of functional groups with K-F-BC were the predominant mechanisms of MET removal by K-F-BC.

Fluorescent “OFF–ON” Sensors for the Detection of Sn2+ Ions Based on Amine-Functionalized Rhodamine 6G

These structurally isomeric rhodamine 6G-based amino derivatives are designed to detect Sn2+ ions. The receptors exhibit rapid fluorescent “turn-on” responses towards Sn2+. The absorption (530 nm) and fluorescent intensity (551 nm) of the receptors increase when increasing the concentration of Sn2+. The hydrazine derivative exhibits more rapid sensitivity towards Sn2+ than the ethylene diamine derivative, indicating that the presence of an alkyl chain in the diamine decreases the sensitivity of the receptors towards Sn2+. The presence of carbonyl groups and terminal amino groups strongly influences the sensitivity of the chemosensors toward Sn2+ by a spirolactam ring-opening mechanism. The receptors exhibit 1:1 complexation with Sn2+ as evidenced by Job plot, and the corresponding limit of detection was found to be 1.62 × 10−7 M. The fluorescence images of the receptors and their complexes reveal their potential applications for imaging of Sn2+ in real/online samples.

Synthesis and Docking Studies of Novel Bis(2-(Substituted(methyl)amino)-4-phenylthiazol-5-yl)methanone

A new series of novel synthesis of bis(2-(substituted(methyl)amino)-4-phenylthiazol-5-yl)methanone (PVS 1-9) is reported. The carbonyl isothiocyanate (3) was synthesized by a para-cleavage of C–Cl bond of benzoyl chloride (1) with ammonium thiocyanate (2). The presence of carbonyl group in acyl isothiocyanates enhance the reactivity of acyl isothiocyanates upon reaction with substituted secondary amine (4) give n-alkylated adduct (5), which upon the reaction with dichloro acetone give target compound 7. Substituted derivatives as inhibitors against lungs, breast and EJFR assist cancer based on virtual screening cellular evaluations with NSCLC H1975 harboring EGFR L858R/T790M double mutations indicated that the most active compound PVS-7 could inhibit the proliferation of two cell lines in one digital micromolar scale. The enzymatically results indicated that compounds PVS-2, PVS-4 and PVS-9 were the most active inhibitor against EGFR T790M and above cancer activity with a ~82%. All compounds were well characterized by spectroscopic techniques and their purity was confirmed by UV-HPLC.

Ambient, tunable room temperature phosphorescence from a simple phthalimide phosphor in amorphous polymeric matrix and in crystalline state

Harvesting triplet excitons via room temperature phosphorescence (RTP) from purely organic chromophores has been a formidable challenge, which has a potential applications in displays, lighting, and bio-imaging. Herein, a simple phthalimide phosphor derivative is reported, which exhibits visible cyan emissive phosphorescence in solution-processable thin films and orange-red emitting phosphorescence in the crystalline state. Presence of carbonyl group and the bromine atom in the molecular design effectively increases the inter-system crossing (ISC) and spin-orbit coupling efficiency (SOC) between singlet and triplet states, which play a crucial role in achieving efficient phosphorescence under ambient conditions.

The utilization of vehicle waste-oil as a material source for preparing carbon dots

Synthesis of carbon dots (c-dots) from vechile waste-oil is one of the alternatives for reducing the burden of environmental pollution. This study aimed to develop a green and economical strategy to produce C-dots by using motor oil waste. C-dots were synthesized by heating motor oil waste in the various percentage of sulfuric acid solution (95, 70, 30, and 0% H2SO4). The synthesized C-dot was characterized by UV-Vis spectrophotometry and Fourier Transform Infrared (FT-IR) spectroscopy. The result showed that the carbon dot produces blue color at 365 nm of UV light. This color was attributed to the oxidation of chemical content in motor oil waste. Therefore, four peaks were obtained at 203 nm, 204 nm, 215 nm, and 210 nm for all samples. Based on FT-IR spectra, the most prominent sample difference was observed at peak 1630 cm−1. The characteristic band of the carbonyl group was identified at the c-dot concentration (70 and 95%) but was not observed in the c-dot concentration (0 and 30%). The presence of carbonyl groups caused the fluorescent color to gradually shift from dark blue to light blue.

Degradation of primary nanoplastics by photocatalysis using different anodized TiO2 structures

In recent years, plastic pollution has become an environmental problem requiring urgent attention. Recently, the release of nano-sized plastics (<1 µm) into the environment has raised concern due to the possible adverse effects that their small size can have on the trophic web. Advanced oxidation processes are efficient at removing organic pollutants such as dyes and pharmaceuticals, making them a viable approach for treating these hazardous materials. This study proposes the use of photocatalysis as an alternative for removing polystyrene nanoparticles (PS-NPs) from aqueous media. A comparative study was carried out to determine the photocatalytic activity of three different TiO2 photocatalysts synthesized by anodization. Elimination and degradation were monitored by turbidimetry, TOC, FTIR, and GC/MS, and the presence of carbonyl groups and intermediate products was recorded to confirm PS-NP degradation. Statistical analysis revealed that PS-NP elimination using TiO2/T and TiO2/M as photocatalysts was more efficient than with photolysis. The results indicate that the mixed structure (nanotubes/nanograss) reduces the concentration of PS-NPs in dispersion 2 times more efficiently than photolysis with UV light does. Despite the challenges posed by nanoplastic contamination, this study provides a useful remediation approach; a technique that, to date, has received little attention.

Green synthesis of Fe-ZnO nanoparticles with improved sunlight photocatalytic performance for polyethylene film deterioration and bacterial inactivation

Massive utilization and improper handling of plastics urge us to seek an applicable and efficient treatment method to reduce the plastic wastes. Herein, iron-doped ZnO (Fe-ZnO) nanoparticle was synthesized via a hibiscus rosa-sinensis leaf-assisted green method, and subsequently employed for low density polyethylene (LDPE) plastic degradation as well as Escherichia coli (E. coli) inactivation under sunlight irradiation. Myriad characterization techniques were used to investigate the structural, optical and electronic properties of green synthesized samples. The weight loss results presented that the photocatalytic performance of the LDPE/Fe-ZnO film was higher than those of pure LDPE and LDPE/un-doped ZnO films. The Fe-ZnO (2 wt%) nanoparticle demonstrated a greater photocatalytic deterioration of LDPE owing to its boosted optical absorption and the effective suppression of photogenerated charge carriers. The presence of carbonyl groups as the degradation product of LDPE was confirmed by Fourier transform infrared (FTIR) analysis. Field-emission scanning electron microscopy (FESEM) images also witnessed the formation of pores at the interface between polymer matrix and Fe-ZnO. Additionally, the LDPE/Fe-ZnO film exhibited an obvious antibacterial effect against E. coli as compared to LDPE/un-doped ZnO film. The current work put forward the construction of eco-friendly photocatalyst as a green strategy to tackle the challenges of plastic pollution.

Hydrothermal Synthesis of Multi-Color Fluorescent Carbon Dots from Sappan Wood (Caesalpinia sappan) as an Acid-Base Indicator

Caesalpinia sappan L., known as sappan wood, has been extensively explored by many researchers because it contains various structural types of phenolic compounds. This study objectives are to investigate the effect of pH on the flourescent color of carbon dots (CDs) from sappan wood and its application as an acid-base indicator under UV light for the first time. CDs were synthesized through the hydrothermal route in ethanol solvents. The synthesized CDs were further characterized by UV-Vis spectrophotometry, fluorescence and Fourier Transform Infrared (FT-IR) spectroscopy. Based on the results, CD solutions performed multiple flourescent colors (yellow, orange and green) under UV light at 365 nm when the pH was adjusted to be 1, 3, 5, 7, 9 and 11. These multiple colors were produced because of the instability of phenolic compounds in the sample, especially brazilin which was easily oxidized to brazilein in alkaline condition. According to the FT-IR spectra, the most prominent differences of the sample before and after the treatment process was observed in the peak region ranging from 1500-1700 cm-1. The characteristic band of carbonyl groups was identified at 1697 cm-1 in the treated sample (pH 9), but it was unobserved in the spectrum of sappan wood and the treated sample (pH 5). The presence of carbonyl group can be assumed that brazilin has been oxidized to brazilein after the alkaline treatment process and making the flourescent color was gradually shifted from yellow to green. Under normal light, the sappan wood�s extract and CD solution produced yellow and red colors in acidic and alkaline conditions, respectively. However, only CD solutions which have yellow, orange and green emissions in different pH conditions under UV light. Therefore, the synthesized CDs can be used as an acid-base indicator in both different light conditions.

Lignocellulosic pretreatment-mediated phenolic by-products generation and their effect on the inhibition of an endo-1,4-β-xylanase from Thermomyces lanuginosus VAPS-24

The inhibitory effect of eight model lignin derivatives (ferulic acid, guaiacol, kraft lignin (alkali, low sulfonate content), p-coumaric acid, gallic acid, syringic acid, vanillin and vanillic acid) on XynA activity was evaluated. The model lignin derivatives viz. gallic acid, vanillic acid and vanillin were inhibitory to XynA activity, with an over 50% reduction in activity at concentrations as low as 0.5mg/ml. However, enzyme deactivation studies in the absence of substrate showed that these pretreatment by-products do not interact with the enzyme except when in the presence of its substrate. The effect of the main structural properties of the pretreatment-derived phenolics, for example their hydroxyl and carbonyl group types, on XynA enzyme inhibition was investigated. The presence of carbonyl groups in phenolics appeared to confer stronger inhibitory effects than hydroxyl groups on XynA activity. The hydrolytic potential of XynA was not inhibited by a mixture of phenolics derived after steam pretreatment of woody biomass (Douglas fir and Black wattle). It appears as if the liquors from steam-pretreated woody biomass did not possess high enough phenolic content to confer XynA inhibition. The xylanase (XynA from Thermomyces lanuginosus) is, therefore, a striking choice for application in biofuel and fine chemical industries for the xylan degradation in steam-pretreated biomass.

Graphite Nanoplatelets from Waste Chicken Feathers.

Graphite nanoplatelets (GNPs), a functional 2D nanofiller for polymer nanocomposites, utilize natural graphite as a raw material due to its stacked graphene layers and outstanding material properties upon successful exfoliation into nano-thick sheets. However, the increasing demand for natural graphite in many industrial applications necessitates the use of graphite from waste resources. We synthesized GNPs from waste chicken feathers (WCFs) by graphitizing carbonized chicken feathers and exfoliating the graphitic carbon by high-speed homogenization and sonication. We then separated GNP from non-exfoliated carbon by centrifugation. This paper describes the morphology, chemical, and crystalline properties of WCF and its carbon derivatives, as well as the structural features of WCF-derived carbons. We obtained GNPs that have a 2D structure with huge variations in particle size and thickness. The GNP shows the presence of carbonyl groups, which are mostly attached at the edges of the stacked graphene sheets. Defects in the GNP are higher than in graphene synthesized from direct exfoliation of natural graphite but lower than in graphene oxide and reduced graphene oxide. To produce GNP of high quality from WCF, restacking of graphene sheets and concentration of carbonyls must be minimized.