Recent advances in designing and developing efficient sillenite-based materials for photocatalytic applications.

Sillenite materials have been the subject of intense investigation for recent years due to their unique characteristics. They possess a distinct structure with space group I23, allowing them to exhibit distinctive features, such as an electronic structure ideal for certain applications such as photocatalysis. The present research delves into the structure, synthesis, and properties of sillenites, highlighting their suitability for photocatalysis. It explores also advanced engineering strategies for designing sillenite-based photocatalysts, including heterojunction formation, morphology modification, doping, and hybrid processes. Each strategy offers advantages and limitations that are critically discussed. The review then lists and discusses the photocatalytic performance of various sillenite-based systems recently developed for common applications, such as removing hazardous organic and inorganic contaminants, and even infrequent applications, such as microbial inactivation, H2 generation, CO2 reduction and N2 fixation. Finally, valuable insights and suggestions are put forward for future research directions in the field of sillenite-based photocatalysis. This comprehensive overview would provide a valuable resource for the development of efficient photocatalytic systems to address environmental and energy challenges.

Recent progression in MXene-based catalysts for emerging photocatalytic applications of CO2 reduction and H2 production: A review.

The development of advanced materials for efficient photocatalytic H2 production and CO2 reduction is highly recommended for addressing environmental issues and producing clean energy sources. Specifically, MXenes have emerged as two-dimensional (2D) materials extensively used as high-performance cocatalysts in photocatalyst systems owing to their outstanding features of structure and properties such as high conductivity, large specific surface area, and abundant active sites. Nevertheless, there is a lack of deep and systematic studies concerning the application of these emerging materials for CO2 reduction reaction (CRR) and H2 production (HER). This review first outlines the essential features of MXenes, encompassing the synthesis methods, composition, surface terminations, and electronic properties, which make them highly active as cocatalysts. It then examines the recent progress in MXene-based photocatalysts, emphasizing the synergy achieved by coupling MXenes as co-catalysts with semiconductors, utilizing MXenes as a support for the consistent growth of photocatalysts, leading to finely dispersed nanoparticles, and exploiting MXene as exceptional precursors for creating MXene/metal oxide photocomposite. The roles of engineering surface terminations of MXene cocatalysts, MXene quantum dots (QDs), and distinctive morphologies in MXenes-based photocatalyst systems to enhance photocatalytic activity for both HER and CRR have been explored both experimentally and theoretically using DFT calculations. Challenges and prospects for MXene-based photocatalysts are also addressed. Finally, suggestions for further research and development of effective and economical MXenes/semiconductors strategies are proposed. This comprehensive review article serves as a valuable reference for researchers for applying MXenes in photocatalysis.

Gold-Deposited Graphene Nanosheets for Self-Cleaning Graphene Surface-Enhanced Raman Spectroscopy with Superior Charge-Transfer Contribution.

The interaction of graphene with metals initiates charge-transfer interaction-induced chemical enhancements, which critically depend on the doping effect from deposited metallic configurations. In this paper, we have explored the gold nanoparticle-decorated monolayer graphene nanosheets for the large graphene-induced Raman enhancement of adsorbed analytes, indicating the surface-enhanced Raman spectroscopy (SERS) capabilities of metal-doped graphene (G-SERS). Here, the systematically sputtered Au thickness optimization procedure revealed noticeable modifications in the graphene Raman spectra and photoluminescence (PL) background quenching, which indicated favorable charge transfer through n-type doping of chemical vapor deposition-grown graphene nanosheets. The highly consistent, individually distributed morphology of the gold nanoislands over graphene nanosheets depicted a reproducibly uniform G-SERS signal with excellent relative standard deviation values (<5%), resulting in the strongest Raman intensity enhancement factors of ∼108 (MB) (methylene blue) and 107 (DPA) (2,6-pyridinedicarboxylic acid) composed of the weakest PL background. The combined charge-transfer-induced chemical enhancement and electromagnetic enhancement from individual Au nanoislands result in a lowering of detectability down to 10-16 M (MB) and 10-11 M (DPA) concentrations with efficient time-dependent signal stability. Additionally, the GAu demonstrated its effective (∼94.4%) photocatalytic degradation capabilities by decomposing MB dye molecules from a concentration of 1 µM to 2.52 fM within 60 min. Therefore, the prominent charge-transfer contribution through controlled Au decoration over graphene nanosheets provides a potential strategy for fabricating superior SERS sensors and photocatalysts exhibiting adequate signal consistency, stability, and photodegradation efficiency through overcoming the limitations of the traditional sensing platforms.

Comparative study of two indoor microbial volatile pollutants, 2-Methyl-1-butanol and 3-Methyl-1-butanol, on growth and antioxidant system of rice (Oryza sativa) seedlings.

2-Methyl-1-butanol (2MB) and 3-Methyl-1-butanol (3MB) are microbial volatile organic compounds (VOCs) and found in indoor air. Here, we applied rice as a bioindicator to investigate the effects of these indoor microbial volatile pollutants. A remarkable decrease in germination percentage, shoot and root elongation, as well as lateral root numbers were observed in 3MB. Furthermore, ROS production increased by 2MB and 3MB, suggesting that pentanol isomers could induce cytotoxicity in rice seedlings. The enhancement of peroxidase (POD) and catalase (CAT) activity provided evidence that pentanol isomers activated the enzymatic antioxidant scavenging systems, with a more significant effect observed in 3MB. Furthermore, 3MB induced higher activity levels of glutathione (GSH), oxidized glutathione (GSSG), and the GSH/GSSG ratio in rice compared to the levels induced by 2MB. Additionally, qRT-PCR analysis showed more up-regulation in the expression of glutaredoxins (GRXs), peroxiredoxins (PRXs), thioredoxins (TRXs), and glutathione S-transferases (GSTUs) genes in 3MB. Taking the impacts of pentanol isomers together, the present study suggests that 3MB exhibits more cytotoxic than 2MB, as such has critical effects on germination and the early seedling stage of rice. Our results provide molecular insights into how isomeric indoor microbial volatile pollutants affect plant growth through airborne signals.

Signaling pathways involved in microbial indoor air pollutant 3-methyl-1-butanol in the induction of stomatal closure in Arabidopsis.

Indoor air pollution is a global problem and one of the main stress factors that has negative effects on plant and human health. 3-methyl-1-butanol (3MB), an indoor air pollutant, is a microbial volatile organic compound (mVOC) commonly found in damp indoor dwellings. In this study, we reported that 1 mg/L of 3MB can elicit a significant reduction in the stomatal aperture ratio in Arabidopsis and tobacco. Our results also showed that 3MB enhances the reactive oxygen species (ROS) production in guard cells of wild-type Arabidopsis after 24 h exposure. Further investigation of 24 h 3MB fumigation of rbohD, the1-1, mkk1, mkk3, and nced3 mutants revealed that ROS production, cell wall integrity, MAPK kinases cascade, and phytohormone abscisic acid are all involved in the process of 3MB-induced stomatal. Our findings proposed a mechanism by which 3MB regulates stomatal closure in Arabidopsis. Understanding the mechanisms by which microbial indoor air pollutant induces stomatal closure is critical for modulating the intake of harmful gases from indoor environments into leaves. Investigations into how stomata respond to the indoor mVOC 3MB will shed light on the plant's "self-defense" system responding to indoor air pollution.

Uncovering molecular mechanisms involved in microbial volatile compounds-induced stomatal closure in Arabidopsis thaliana.

Microbial volatile compounds (mVCs) may cause stomatal closure to limit pathogen invasion as part of plant innate immune response. However, the mechanisms of mVC-induced stomatal closure remain unclear. In this study, we co-cultured Enterobacter aerogenes with Arabidopsis (Arabidopsis thaliana) seedlings without direct contact to initiate stomatal closure. Experiments using the reactive oxygen species (ROS)-sensitive fluorescent dye, H2DCF-DA, showed that mVCs from E. aerogenes enhanced ROS production in guard cells of wild-type plants. The involvement of ROS in stomatal closure was then demonstrated in an ROS production mutant (rbohD). In addition, we identified two stages of signal transduction during E. aerogenes VC-induced stomatal closure by comparing the response of wild-type Arabidopsis with a panel of mutants. In the early stage (3 h exposure), E. aerogenes VCs induced stomatal closure in wild-type and receptor-like kinase THESEUS1 mutant (the1-1) but not in rbohD, plant hormone-related mutants (nced3, erf4, jar1-1), or MAPK kinase mutants (mkk1 and mkk3). However, in the late stage (24 h exposure), E. aerogenes VCs induced stomatal closure in wild-type and rbohD but not in nced3, erf4, jar1-1, the1-1, mkk1 or mkk3. Taken together, our results suggest that E. aerogenes mVC-induced plant immune responses modulate stomatal closure in Arabidopsis by a multi-phase mechanism.

Antifungal mechanism of volatile compounds emitted by Actinomycetota Paenarthrobacter ureafaciens from a disease-suppressive soil on Saccharomyces cerevisiae.

Increasing evidence suggests that in disease-suppressive soils, microbial volatile compounds (mVCs) released from bacteria may inhibit the growth of plant-pathogenic fungi. However, the antifungal activities and molecular responses of fungi to different mVCs remain largely undescribed. In this study, we first evaluated the responses of pathogenic fungi to treatment with mVCs from Paenarthrobacter ureafaciens. Then, we utilized the well-characterized fungal model organism Saccharomyces cerevisiae to study the potential mechanistic effects of the mVCs. Our data showed that exposure to P. ureafaciens mVCs leads to reduced growth of several pathogenic fungi, and in yeast cells, mVC exposure prompts the accumulation of reactive oxygen species. Further experiments with S. cerevisiae deletion mutants indicated that Slt2/Mpk1 and Hog1 MAPKs play major roles in the yeast response to P. ureafaciens mVCs. Transcriptomic analysis revealed that exposure to mVCs was associated with 1,030 differentially expressed genes (DEGs) in yeast. According to gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses, many of these DEGs are involved in mitochondrial dysfunction, cell integrity, mitophagy, cellular metabolism, and iron uptake. Genes encoding antimicrobial proteins were also significantly altered in the yeast after exposure to mVCs. These findings suggest that oxidative damage and mitochondrial dysfunction are major contributors to the fungal toxicity of mVCs. Furthermore, our data showed that cell wall, antioxidant, and antimicrobial defenses are induced in yeast exposed to mVCs. Thus, our findings expand upon previous research by delineating the transcriptional responses of the fungal model. IMPORTANCE Since the use of bacteria-emitted volatile compounds in phytopathogen control is of considerable interest, it is important to understand the molecular mechanisms by which fungi may adapt to microbial volatile compounds (mVCs). Paenarthrobacter ureafaciens is an isolated bacterium from disease-suppressive soil that belongs to the Actinomycetota phylum. P. ureafaciens mVCs showed a potent antifungal effect on phytopathogens, which may contribute to disease suppression in soil. However, our knowledge about the antifungal mechanism of mVCs is limited. This study has proven that mVCs are toxic to fungi due to oxidative stress and mitochondrial dysfunction. To deal with mVC toxicity, antioxidants and physical defenses are required. Furthermore, iron uptake and CAP proteins are required for antimicrobial defense, which is necessary for fungi to deal with the thread from mVCs. This study provides essential foundational knowledge regarding the molecular responses of fungi to inhibitory mVCs.

Enhanced photocatalytic and SERS performance of Ag nanoparticles functionalized MoS2 nanoflakes.

We report the preparation of Ag nanoparticles functionalized MoS2 nanoflakes by using the chemical reduction method followed by the hydrothermal method. Field emission scanning electron microscopy and elemental mapping reveals the uniform functionalization of Ag nanoparticles with MoS2 nanoflakes. High density of Ag plasmonic nanoparticles onto MoS2 nanoflakes demonstrates tremendously improved charge separation behavior in Ag-MoS2 nanohybrids. Photodecomposition capability of plasmonic Ag-MoS2 nanohybrids was explored by the decomposition of industrial pollutant molecules, showing a direct correlation between the Ag content over the MoS2 surface with their photodecomposition ability. The SERS-based detection profiles of the plasmonic were investigated by the ultra-low detection of MB molecules. The Ag-MoS2 nanohybrids SERS substrate manifests the detection of MB molecules solution up to a concentration of 10-9 M with an enhancement factor of 107. In the current study, we proposed and elucidated the probable efficient charge transfer mechanism for improved photocatalytic behavior and SERS-based sensing performance.

Recent Development of Polyhydroxyalkanoates (PHA)-Based Materials for Antibacterial Applications: A Review.

The diseases caused by microorganisms are innumerable existing on this planet. Nevertheless, increasing antimicrobial resistance has become an urgent global challenge. Thus, in recent decades, bactericidal materials have been considered promising candidates to combat bacterial pathogens. Recently, polyhydroxyalkanoates (PHAs) have been used as green and biodegradable materials in various promising alternative applications, especially in healthcare for antiviral or antiviral purposes. However, it lacks a systematic review of the recent application of this emerging material for antibacterial applications. Therefore, the ultimate goal of this review is to provide a critical review of the state of the art recent development of PHA biopolymers in terms of cutting-edge production technologies as well as promising application fields. In addition, special attention was given to collecting scientific information on antibacterial agents that can potentially be incorporated into PHA materials for biological and durable antimicrobial protection. Furthermore, the current research gaps are declared, and future research perspectives are proposed to better understand the properties of these biopolymers as well as their possible applications.

SARS-CoV-2 and its new variants: a comprehensive review on nanotechnological application insights into potential approaches.

SARS-CoV-2 (COVID-19) spreads and develops quickly worldwide as a new global crisis which has left deep socio-economic damage and massive human mortality. This virus accounts for the ongoing outbreak and forces an urgent need to improve antiviral therapeutics and targeted diagnosing tools. Researchers have been working to find a new drug to combat the virus since the outbreak started in late 2019, but there are currently no successful drugs to control the SARS-CoV-2, which makes the situation riskier. Very recently, new variant of SARS-CoV-2 is identified in many countries which make the situation very critical. No successful treatment has yet been shown although enormous international commitment to combat this pandemic and the start of different clinical trials. Nanomedicine has outstanding potential to solve several specific health issues, like viruses, which are regarded a significant medical issue. In this review, we presented an up-to-date drug design strategy against SARS-CoV-2, including the development of novel drugs and repurposed product potentials were useful, and successful drugs discovery is a constant requirement. The use of nanomaterials in treatment against SARS-CoV-2 and their use as carriers for the transport of the most frequently used antiviral therapeutics are discussed systematically here. We also addressed the possibilities of practical applications of nanoparticles to give the status of COVID-19 antiviral systems.

The involvement of AtMKK1 and AtMKK3 in plant-deleterious microbial volatile compounds-induced defense responses.

KEY MESSAGE: Plant-deleterious microbial volatiles activate the transactivation of hypoxia, MAMPs and wound responsive genes in Arabidopsis thaliana. AtMKK1 and AtMKK3 are involved in the plant-deleterious microbial volatiles-induced defense responses. Microbial volatile compounds (mVCs) are a collection of volatile metabolites from microorganisms with biological effects on all living organisms. mVCs function as gaseous modulators of plant growth and plant health. In this study, the defense events induced by plant-deleterious mVCs were investigated. Enterobacter aerogenes VCs lead to growth inhibition and immune responses in Arabidopsis thaliana. E. aerogenes VCs negatively regulate auxin response and transport gene expression in the root tip, as evidenced by decreased expression of DR5::GFP, PIN3::PIN3-GFP and PIN4::PIN4-GFP. Data from transcriptional analysis suggests that E. aerogenes VCs trigger hypoxia response, innate immune responses and metabolic processes. In addition, the transcript levels of the genes involved in the synthetic pathways of antimicrobial metabolites camalexin and coumarin are increased after the E. aerogenes VCs exposure. Moreover, we demonstrate that MKK1 serves as a regulator of camalexin biosynthesis gene expression in response to E. aerogenes VCs, while MKK3 is the regulator of coumarin biosynthesis gene expression. Additionally, MKK1 and MKK3 mediate the E. aerogenes VCs-induced callose deposition. Collectively, these studies provide molecular insights into immune responses by plant-deleterious mVCs.

Rapid Assessment of Biological Activity of Ag-Based Antiviral Coatings for the Treatment of Textile Fabrics Used in Protective Equipment Against Coronavirus.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants have rapidly spread worldwide, causing coronavirus disease (COVID-19) with numerous infected cases and millions of deaths. Therefore, developing approaches to fight against COVID-19 is currently the most priority goal of the scientific community. As a sustainable solution to stop the spread of the virus, a green dip-coating method is utilized in the current work to prepare antiviral Ag-based coatings to treat cotton and synthetic fabrics, which are the base materials used in personal protective equipment such as gloves and gowns. Characterization results indicate the successful deposition of silver (Ag) and stabilizers on the cotton and polypropylene fiber surface, forming Ag coatings. The deposition of Ag and stabilizers on cotton and etched polypropylene (EPP) fabrics is dissimilar due to fiber surface behavior. The obtained results of biological tests reveal the excellent antibacterial property of treated fabrics with large zones of bacterial inhibition. Importantly, these treated fabrics exhibit an exceptional antiviral activity toward human coronavirus OC43 (hCoV-OC43), whose infection could be eliminated up to 99.8% when it was brought in contact with these fabrics after only a few tens of minutes. Moreover, the biological activity of treated fabrics is well maintained after a long period of up to 40 days of post-treatment.

Graphitic carbon nitride based immobilized and non-immobilized floating photocatalysts for environmental remediation.

In solar photocatalysis, light utilization and recycling of powder from reaction solution are the main obstructions that hinder the photocatalytic efficacy of any photocatalyst. In this respect, a floatable system is effective for efficient solar photocatalysis by light utilization. Due to the maximum solar light absorption property, floating nanocomposite photocatalyst is an appealing substitute for effective wastewater treatment. Floating photocatalysts are a non-oxygenated and non-stirred solution that is a good light harvester, stable, non-toxic, biodegradable, naturally abundant in nature. They also have low density, a simple preparation process, no need to stir, and high porosity. Due to these characteristics, floating photocatalysts are widely favored and ideal candidates for practical environmental remediation. Several researchers have come up with new and innovative ways for immobilizing capable photocatalyst on a floatable substrate to produce floating nanocomposite photocatalytic material. In recent decades, g-C3N4-based floating photocatalysts have gained a lot of attention as g-C3N4 is a visible light active photocatalyst with unique and exceptional properties. It also has good photocatalytic activity in waste water treatment and environmental remediation. Many previous reports have studied the logical design and manufacturing method for heterojunction floating photocatalysts and immobilized floating photocatalysts. Based on those studies, we have focused on the g-C3N4 based immobilized and non-immobilized floating photocatalysts for pollutant degradation. We have also categorized immobilized floating photocatalyst based on several lightweight substrates such as expanded perlite and glass microbead. In addition, future challenges have been discussed to maximize solar light absorption and to improve the efficiency of broadband response floating photocatalysts. Floating photocatalysis is an advanced technique in energy conversion and environmental remediation thus requires special consideration.

Advanced Functional Materials for Intelligent Thermoregulation in Personal Protective Equipment.

The exposure to extreme temperatures in workplaces involves physical hazards for workers. A poorly acclimated worker may have lower performance and vigilance and therefore may be more exposed to accidents and injuries. Due to the incompatibility of the existing standards implemented in some workplaces and the lack of thermoregulation in many types of protective equipment that are commonly fabricated using various types of polymeric materials, thermal stress remains one of the most frequent physical hazards in many work sectors. However, many of these problems can be overcome with the use of smart textile technologies that enable intelligent thermoregulation in personal protective equipment. Being based on conductive and functional polymeric materials, smart textiles can detect many external stimuli and react to them. Interconnected sensors and actuators that interact and react to existing risks can provide the wearer with increased safety, protection, and comfort. Thus, the skills of smart protective equipment can contribute to the reduction of errors and the number and severity of accidents in the workplace and thus promote improved performance, efficiency, and productivity. This review provides an overview and opinions of authors on the current state of knowledge on these types of technologies by reviewing and discussing the state of the art of commercially available systems and the advances made in previous research works.

Recent progress in air treatment with combined photocatalytic/plasma processes: A review.

Nowadays, air pollution is an increasingly important topic, as environmental regulations require limiting pollutant emissions. This problem requires new techniques to reduce emissions by either improving the current emission control systems and processes or installing new hybrid treatment systems. These are of broad diversity, and every system has its advantages and disadvantages. The tendency is, accordingly, to combine various techniques to achieve more acceptable and suitable treatment. Recent studies suggest that the combination of photocatalysis and plasma in a reactor can offer attractive pollutant treatment efficiency with a minimum of partially oxidized by-products than that of these processes taken separately. However, there is little review of the capability of this pairing to treat different brands of pollutants. Besides, available data concerning reactor design with flows treated 10 to 1000 times higher than those studied at the lab scale. This review paid particular attention to determine the reaction mechanisms in terms of engineering and design of combination reactors (plasma and catalysis). Likewise, we developed the effect of critical parameters such as pollutant load, relative humidity, and flow rate to understand the degradation kinetics of specific pollutants individually by using plasma and photocatalysis. Additionally, this review compares different designs of cold plasma reactors combination with heterogeneous catalysis with special attention on synergistic and antagonistic effects of using plasma and photocatalysis processes at the laboratory, pilot, and industrial scales. Therefore, the elements discussed in this review stick well to the first theme on pollution prevention of the special issue concerning pollution prevention and the application of clean technologies to promote a circular (bio) economy.

Effects of radiation and role of plants in radioprotection: A critical review.

Radiation can be lethal at high doses, whereas controlled doses are useful in medical applications. Other applications include power generation, agriculture sterilization, nuclear weapons, and archeology. Radiation damages genetic material, which is reflected in genotoxicity and can cause hereditary damage. In the medical field, it is essential to avoid the harmful effects of radiation. Radiation countermeasures and the need for radioprotective agents have been explored in recent years. Considering plants that evolve in radiative conditions, their ability to protect organisms against radiation has been studied and demonstrated. Crude extracts, fractioned extracts, isolated phytocompounds, and plant polysaccharides from various plants have been used in radioprotection studies, and their efficiency has been proven in various in vitro and in vivo experimental models. It is important to identify the mechanism of action to develop a potent plant-based radioprotective agent. To identify this protective mechanism, it is necessary to understand the damage caused by radiation in biological systems. This review intends to discuss the effects of ionizing radiation on biological systems and evaluate plant-based radioprotectants that have tested thus far as well as their mechanism of action in protecting against the toxic effects of radiation. From the review, the mechanism of radioprotection exhibited by the plant-based products could be understood. Meanwhile, we strongly suggest that the potential products identified so far should undergo clinical trials for critically evaluating their effects and for developing an ideal and compatible radioprotectant with no side-effects.

Editorial for the Special Issue: Functional Polymer Composites.

Functional polymer composites are now making significant strides in synthesis, design, preparation, processing, and promising applications [...].

Artificial neural network modeling of cefixime photodegradation by synthesized CoBi2O4 nanoparticles.

CoBi2O4 (CBO) nanoparticles were synthesized by sol-gel method using polyvinylpyrrolidone (PVP) as a complexing reagent. For a single phase with the spinel structure, the formed gel was dried and calcined at four temperatures stages. Various methods were used to identify and characterize the obtained spinel, such as X-ray diffraction (XRD), scanning electron micrograph (SEM-EDX), transmission electron microscope (TEM), Fourier transform infrared (FT-IR), X-ray fluorescence (XRF), Raman, and UV-Vis spectroscopies. The photocatalytic activity of CBO was examined for the degradation of a pharmaceutical product cefixime (CFX). Furthermore, for the prediction of the CFX degradation rate, an artificial neural network model was used. The network was trained using the experimental data obtained at different pH with different CBO doses and initial CFX concentrations. To optimize the network, various algorithms and transfer functions for the hidden layer were tested. By calculating the mean square error (MSE), 13 neurons were found to be the optimal number of neurons and produced the highest coefficient of correlation R2 of 99.6%. The relative significance of the input variables was calculated, and the most impacting input was proved to be the initial CFX concentration. The effects of some scavenging agents were also studied. The results confirmed the dominant role of hydroxyl radical OH• in the degradation process. With the novel CoBi2O4/ZnO hetero-system, the photocatalytic performance has been enhanced, giving an 80% degradation yield of CFX (10 mg/L) at neutral pH in only 3 h.

Graphene Oxide-Induced Interfacial Transcrystallization of Single-Fiber Milkweed/Polycaprolactone/Polyvinylchloride Composites.

Understanding the interfacial crystallization is crucial for semi-crystalline polymer/natural fiber composites because it links to the final properties. This work reports, for the first time, the interfacial crystallization of a miscible blend between polycaprolactone (PCL) and polyvinylchloride (PVC) with milkweed fibers. We have first described the morphology of the fibers and the chemical composition of waxes covered on its surface. Our findings show that the transcrystallization (TC) layer of PCL/PVC could appear at the interface by simply coating with a layer of graphene oxide (GO) on the milkweed fiber. In our study, atomic force microscopy-infrared spectroscopy analysis shows that the crystallinity of the blends is higher at the vicinity of the interface compared to that in the bulk. The kinetic of the interfacial crystallization in terms of spherulite morphology and crystal growth rates at the nanoscale is examined. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy were used to analyze the prepared GO and evaluate its relationship with the interfacial crystallization behavior of the blends.

DFT Prediction of Factors Affecting the Structural Characteristics, the Transition Temperature and the Electronic Density of Some New Conjugated Polymers.

Conjugated polymers are promising materials for various cutting-edge technologies, especially for organic conducting materials and in the energy field. In this work, we have synthesized a new conjugated polymer and investigated the effect of distance between bond layers, side-chain functional groups (H, Br, OH, OCH3 and OC2H5) on structural characteristics, phase transition temperature (T), and electrical structure of C13H8OS using Density Functional Theory (DFT). The structural characteristics were determined by the shape, network constant (a, b and c), bond length (C-C, C-H, C-O, C-S, C-Br and O-H), phase transition temperatures, and the total energy (Etot) on a base cell. Our finding shows that the increase of layer thickness (h) of C13H8OS-H has a negligible effect on the transition temperature, while the energy bandgap (Eg) increases from 1.646 eV to 1.675 eV. The calculation of bond length with different side chain groups was carried out for which C13H8OS-H has C-H = 1.09 Å; C13H8OS-Br has C-Br = 1.93 Å; C13H8OS-OH has C-O = 1.36 Å, O-H = 0.78 Å; C13H8OS-OCH3 has C-O = 1.44 Å, O-H =1.10 Å; C13H8OS-OC2H5 has C-O = 1.45 Å, C-C = 1.51Å, C-H = 1.10 Å. The transition temperature (T) for C13H8OS-H was 500 K < T < 562 K; C13H8OS-Br was 442 K < T < 512 K; C13H8OS-OH was 487 K < T < 543 K; C13H8OS-OCH3 was 492 K < T < 558 K; and C13H8OS-OC2H5 was 492 K < T < 572 K. The energy bandgap (Eg) of Br is of Eg = 1.621 eV, the doping of side chain groups H, OH, OCH3, and OC2H5, leads to an increase of Eg from 1.621 eV to 1.646, 1.697, 1.920, and 2.04 eV, respectively.