Employing Polyethylene Glycol Research Articles

Experimental Investigations on Shear Thickening Fluids as "Liquid Body Armors": Non-Conventional Formulations for Ballistic Protection.

Shear thickening fluids (STFs) have garnered attention as potential enhancers of protective capabilities and for the optimization of Kevlar® armor design. To assess the possible shear thickening properties and potential application in ballistic protection, ten formulations were developed by employing polyethylene glycol (PEG) or polypropylene glycol (PPG), along with fumed silica or Aerosil HDK®. Rheological characterization facilitated the identification of formulations displaying shear thickening behavior. The potential integration of the selected shear thickening fluids (STFs) into Kevlar®-based composites was investigated by studying the impact resistance of Kevlar® soft armor structures. Also, high-velocity impact testing revealed that the distance between aramid layers plays a crucial role in the impact resistance effectiveness of Kevlar®-STF composite structures and that there is a very narrow domain between optimal and undesired scenarios in which STF could facilitate the penetration of Kevlar. The introduction of STF between the Kevlar sheets disrupted this packing and the energy absorption capacity of the material was not improved. Only one formulation (PEG400, Aerosil 27 wt.%) led to a less profound traumatic imprint and stopped the bullet when it was placed between layers no.1 and no.2 from a total of 11 layers of Kevlar XP. These experimental findings align with the modeling and simulation of Kevlar®-STF composites using Ansys simulation software (Ansys® AutoDyn 2022 R2).

Investigating the Presence of Rotavirus in Wastewater Samples of Bhopal Region, India, by Utilizing Droplet Digital Polymerase Chain Reaction.

Rotavirus-induced viral gastroenteritis outbreaks result in over two million hospitalizations globally yearly. Wastewater-based epidemiology (WBE) has emerged as a crucial tool for detecting and monitoring viral outbreaks. The adoption of WBE has been instrumental in the early detection and surveillance of such viral outbreaks, providing a non-invasive method to assess public health. This study aims to utilize droplet digital polymerase chain reaction (ddPCR) technology to detect and quantify Rotavirus in wastewater samples collected from the Bhopal region of India, thereby contributing to the understanding and management of viral gastroenteritis outbreaks through environmental surveillance. In this study, we used ddPCR to detect and quantify Rotavirus in wastewater samples collected from the Bhopal region of India. We monitored its viral presence in municipal sewage treatment plants bi-weekly using an advanced ddPCR assay. Targeting the rotavirus non-structural protein 3 (NSP-3) region with custom primers and TaqMan probes, we detected virus concentration employing polyethylene glycol (PEG). Following RNA isolation, complementary DNA (cDNA) synthesis, and ddPCR analysis, our novel method eliminated standard curve dependence, propelling virus research and treatment forward. Out of the 42 samples collected, a 16.60% positivity rate was observed, indicating a moderate presence of Rotavirus in Bhopal. The wastewater treatment plants (WWTP) attached to a hospital exhibited a 42.85% positivity rate, indicating the need for targeted monitoring. Leveraging ddPCR, precise quantification of rotavirus concentrations (ranging from 0.75 to 28.9 copies/µL) facilitated understanding and supported effective remediation. This study emphasizes the importance of vigilant wastewater surveillance, especially in WWTPs with higher rotavirus prevalence. The significance of ddPCR in comparison to conventional and real-time PCR lies in its superior sensitivity and specificity in detecting and quantifying positive samples. Furthermore, it can identify positive samples even in the smallest quantities without the need for a standard curve to evaluate. This makes ddPCR a valuable tool for accurate and precise detection and quantification of samples.

Improvement of liraglutide release from PLGA microspheres by a porous microsphere-gel composite system

In the current work, we aimed to prepare a liraglutide-loaded porous microsphere-gel composite system. By employing polyethylene glycol (PEG) as a porogenic agent and poly (lactic-co-glycolic acid) copolymer (PLGA) as a carrier, the liraglutide microspheres were prepared and dispersed in a temperature-sensitive gel made of poloxamer 407 (F-127) and poloxamer 188 (F-68), which served as the gel matrix, to construct the composite system. The porous microsphere-gel composite system demonstrated prolonged and steady drug release, with a reduction to 4.7% in the initial release within 1 d, according to data from in vitro release tests. The drug release from the porous microspheres decreased from 53% to 29% during the rapid release phase as the PEG concentration increased and the release rate slowed down. In vivo experiments in rats revealed that the composite system prolonged the release period by about 10 d. The pharmacokinetic parameter AUC0-1 was decreased by 24.78 ng/ml*h, the initial burst release was decreased, and the blood drug concentration fluctuation was lessened. The construction of a porous microsphere-gel composite matrix offers a novel approach to the systems with a sustained, long-lasting release that utilizes rational design.

Screening of Chickpea (Cicer arietinum L.) Genotypes against Drought Stress Employing Polyethylene Glycol 6000 as Selecting Agent

Chickpea (Cicer arietinum L.) stands as a prominent legume crop globally, renowned for its elevated protein content. The primary challenges to chickpea cultivation emanate from abiotic stressors, with drought reigning as the most pivotal contributor to diminished growth and production output. To select putative drought tolerant genotype (s), an in vitro screening method was deployed, utilizing different concentration of Polyethylene Glycol (PEG 6000) as selecting agent along with control. Seeds of twenty different genotypes were treated with different concentrations of PEG6000 and observations were recorded for shoot length (cm), root length (cm), germination percentage, relative water content, seedling vigour index and stress tolerance index (STI). Evidently, all assessed attributes exhibited a significant reduction commensurate with the augmentation of PEG6000. This trend detrimentally influenced germination and the entirety of seedling growth-related metrics. Furthermore, the distinction in variability across genotypes concerning germination percentage, vigour index, and stress tolerance index (STI) emerged as vigorous and informative standards for discriminating drought-tolerant chickpea genotype (s) during both germination and seedling phases. Investigative findings spotlighted the drought-tolerant disposition of genotypes, where genotypes viz., SAGL152252, ICC4958, and JG315 found to be putative drought tolerant based on different parameters investigated.

Structurally Colored Inks from Synthetic Melanin-Based Crosslinked Supraparticles

Structurally colored supraparticles, formed from dispersed nanoparticle building blocks through self-assembly, have tremendous potential for applications in displays, coatings, paints, inks, and cosmetics. Mechanical stability and solvent compatibility of supraparticles is critical in these applications. Here, we describe the scalable synthesis of supraparticles via the assembly of nanoparticles composed of synthetic melanin cores with silica shells (SM@SiO2 NPs) using a vortex-assisted reverse emulsion method. We use a hydrogen-bond driven crosslinking strategy employing polyethylene glycol to lock the SM@SiO2 NP building blocks together. This approach yields multicolor photonic supraparticles stable both in organic and aqueous solvents and in the dry state. Supraparticles crosslinked via 4-arm PEG2k withstand at least a 10-fold increase in compressive force when compared to noncrosslinked versions. Capitalizing on the enhanced stability of crosslinked supraparticles, we directly blend them with painting media and apply them as inks.

RETRACTED: Synthesis of hollow maghemite (-Fe2O3) particles for magnetic field and pH-responsive drug delivery and lung cancer treatment

Abstract The development of smart stimuli-responsive materials for drug delivery offers new opportunities for precise drug release and cancer chemotherapy. A combination of more than one stimuli is highly desirable to further maximize the therapy by taking the advantages of various unique merits. Herein, we employed polyethylene glycol (PEG) functionalized γ-Fe2O3 particles (γ-Fe2O3/PEG) as a novel magnetic drug carrier for doxorubicin (DOX) delivery. The results showed that the γ-Fe2O3/PEG exhibited excellent thermal effects under alternating magnetic field (AMF), high magneto-thermal stability, and large DOX loading capacity. Furthermore, the effects of pH and AMF on the DOX drug release were studied. It was discovered that DOX loaded γ-Fe2O3/PEG carriers were highly responsive to both AMF and pH, resulting in significantly improved cancer cell killing capability over a single stimulus. The magnetic and pH responsive drug delivery system provided a new opportunity to minimize the side effects and maximize the therapeutic efficiency of lung cancer treatment.

Enhancement of proton conduction in carboxymethyl cellulose-polyvinyl alcohol employing polyethylene glycol as a plasticizer

The present study deals with the enhancement of proton transport and conduction properties of solid polymer electrolyte (SPE)-based carboxymethyl cellulose (CMC) blended with polyvinyl alcohol (PVA) doped with ammonium nitrate (NH4NO3) and plasticized with various compositions of polyethylene glycol (PEG). The SPE system was successfully prepared using an economical method, the solution casting technique, and analysed by Fourier transform infrared spectroscopy and electrical impedance spectroscopy. The infrared spectra show that interaction had occurred at O–H and COO− from CMC when PEG was added which prevailed the enhancement of ion dissociation. Glass transition measurement highlighted that the interaction between CMC–PVA–NH4NO3 and ethylene carbonate at 8 wt% give the most plasticization effect that achieved the lowest Tg. The highest conductivity of the SPE system achieved at ambient temperature was 1.70 × 10−3 S cm−1 for a non-plasticized sample, and further enhanced to 3.00 × 10−3 S cm−1 when 8 wt% PEG was incorporated into the SPE system. The sample with the highest conductivity was found to obey the Arrhenius behaviour with a function of temperature. The ionic conductivity of the SPE system was shown to be primarily influenced by a number of ions (η), ion mobility (μ) and diffusion coefficient (D).

Pharmabiotic beads with improved encapsulation and gut survival for management of colonic inflammation associated gut derangements

Encapsulation techniques and materials, explored for addressing compromised probiotic gut survival, report significant production losses resulting in <10% entrapment. Presently, we report three-time enhanced entrapment (30 ± 1.2%) of Lactobacillus acidophilus (LAB) in calcium-alginate beads, by modifying process parameters and employing polyethylene glycol (PEG). Water-loving, viscolysing and osmotic-building effects of PEG create numerous, fine voids in the alginate gel allowing efficient diffusion of crosslinking calcium ions, resulting in less leaky beads. Eudragit S100 overcoat improved LAB survival by 690 times in simulated GIT stresses.In DMH-DSS induced colitis and precancerous lesions in rats, while free LAB failed to show any protection, pharmabiotic beads significantly (p < .05) reduced lipid peroxidation, increased antioxidant levels; decreased serum inflammatory burden; downregulated COX-2, iNOS, and c-Myc expression; elevated levels of the selected gut bacteria and SCFAs especially butyrate, all of which add up to antioxidant, anti-inflammatory, balanced gut biota, and ultimately anticancer effects.

Design and development of 1,3,4-thiadiazole based potent new nano-fungicides

Being the important organic reaction intermediates and biological scaffolds, a series of 2-alkyl/aralkyl/heterocyclyl sulfanyl-5-amino/methyl-1,3,4-thiadiazoles have been synthesized by suitable synthetic route and characterized by analytical and spectral data. The evaluation of these compounds for their bioefficacy against two phyto-pathogenic fungi revealed their fungicidal potency against Rhizoctonia bataticola (ED50 values, 3.9–300.4 μg/mL) and Rhizoctonia solani (ED50 values, 4.2–228.5 μg/mL). To further augment their fungicidal efficacy, the potent five fungicidal compounds were nano-sized. The protocol for preparing 1,3,4-thiadiazole based nano-fungicide employing polyethylene glycol was developed and standardized. Characterization of nano-forms of 1,3,4-thiadiazole derivatives by particle size analyzer and electron microscopy (TEM) techniques confirmed the <100 nm average particle sizes of all nano-fungicides. The 2–4 times higher fungicidal activity was observed with nano-forms than the corresponding conventional sized 1,3,4-thiadiazole derivatives against phytopathogenic fungi, namely, Rhizoctonia solani and R. bataticola.

Polyethylene glycol (PEG-400): An efficient one-pot green synthesis and anti-viral activity of novel α-diaminophosphonates

An efficient and eco-friendly protocol has been accomplished for a series of novel α-diaminophosphonates by a one-pot, three-component system via Kabachnik-Fields reaction of 4,4′-methylenedianiline, a variety of aryl/heteroaryl aldehydes and diphenylphosphite employing polyethylene glycol (PEG-400) as a green solvent at 80 °C. All products were obtained in good to excellent yields (80–95%). The identity of the new synthesized compounds was confirmed by IR, 1H, 13C, and 31P NMR, LC-MS and elemental analysis. In vivo anti-viral activity was evaluated against tobacco mosaic virus (TMV). Compounds 4b, 4c, 4j and 4k exhibited the highest anti-viral activities against tobacco mosaic virus (TMV) when compared with the standard drug ningnanmycin.

Using Peg As a Suppressor for High Speed Copper Filling of Microvias

Copper electroplating has been widely used for the metallization process of the inner conducting lines in printed circuit boards (PCBs). Short plating process time, which means that the electrochemical deposition is operated at a high current density is always expected because of high yield consideration. However, it is difficult to fill a microvia using copper electroplating at a high current density. The microvias of PCBs have to be fully filled by copper electroplating without void, and the organic plating additives have to overcome breakdown (i.e., electrochemical oxidation) on anode. In this work, we find out a formula employing polyethylene glycol (PEG) as the suppressor can fill the microvias within 20 minutes. The filling performance was assessed through the cross-sections of the filled microvias using optical microscope (OM). Both cyclic voltammetry (CV) and linear sweep voltammetry (LCV) were carried out to explain the fast filling mechanism. Keywords: High speed copper filling, Microvia, Printed circuit board, Polyethylene glycol. References W. P. Dow, M. Y. Yen, S. Z. Liao, Y. D. Chiu and H. C. Huang, Electrochim. Acta, 53, 8228 (2008).

FCLIP-seq for transcriptomic footprinting of dsRNA-binding proteins: Lessons from DROSHA.

CLIP-seq (crosslinking immunoprecipitation and sequencing) is widely used to map the binding sites of a protein of interest on the transcriptome, and generally employs UV to induce the covalent bonds between protein and RNA, which allows stringent washing. However, dsRNA is inefficiently crosslinked by UV, making it difficult to study the interactions between dsRNA binding proteins and their substrates. A dsRNA endoribonuclease DROSHA initiates the maturation of microRNA (miRNA) by cleaving primary miRNA (pri-miRNA). Despite the importance of DROSHA in miRNA maturation and sequence determination, accurate mapping of DROSHA cleavage sites has not been feasible due to rapid processing, modification, and degradation of the cleaved products in cells. Here, we present a high-throughput sequencing method that allows the mapping of in vivo DROSHA cleavage sites at single nucleotide resolution, termed formaldehyde crosslinking, immunoprecipitation, and sequencing (fCLIP-seq). The fCLIP-seq protocol has been improved significantly over the standard CLIP-seq methods by (1) using formaldehyde for efficient and reversible crosslinking, (2) employing polyethylene glycol and adaptors with randomized sequences to enhance ligation efficiency and minimize bias, and (3) performing ligation after elution, which exposes the RNA termini for efficient ligation. fCLIP-seq successfully captures the nascent products of DROSHA, which allows precise mapping of the DROSHA processing sites. Moreover, from the analysis of the distinctive cleavage pattern, we discover previously unknown substrates of DROSHA. fCLIP-seq is a useful tool to obtain transcriptome-wide information on DROSHA activity and can be applied further to investigate other dsRNA-protein interactions.

Preparation of sponge-like macroporous PVA hydrogels via n-HA enhanced phase separation and their potential as wound dressing

Polyvinyl alcohol (PVA) hydrogels have been widely studied for biomedical applications due to their water solubility, non-toxicity, non-carcinogenicity, and biocompatibility. However, PVA hydrogels prepared by the physical crosslinking method usually do not exhibit a macroporous structure, which limits their application when PVA hydrogels are used alone as a wound dressing. Here, we reported a sponge-like macroporous PVA hydrogel (SPH) prepared by employing polyethylene glycol and nano-hydroxyapatite (n-HA) to enhance phase separation. After being fabricated through cyclic freezing/thawing, the resulting PVA hydrogels possessed macroporous structures. The swelling ratio could reach nearly 1500%, resulting from the excellent water absorption capacity, and the sample could rapidly restore to the original state after being pressed, suggesting a sponge-like characteristic. Furthermore, cell experiments showed that macroporous PVA hydrogels exhibited good biocompatibility and the results of wound closure and H&E analysis consistently indicated that SPHs could significantly promote the wound healing process.

Solvent-free preparation and performance of novel xylitol based solid-solid phase change materials for thermal energy storage

Novel polymeric solid-solid phase change materials (SSPCMs) were prepared through solvent-free bulk polymerization by employing polyethylene glycol (PEG) as phase change functional segments, diphenylmethane diisocyanate (MDI) as coupling agent and xylitol as curing agent. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), polarizing optical microscopy (POM), differential scanning calorimetry (DSC), accelerated thermal cycling testing and thermogravimetric analysis (TG) were conducted to study the chemical structure, crystalline properties, phase change properties, thermal reliability and stability of SSPCMs, respectively. The crosslinked structure gave the obtained SSPCMs solid-solid phase change process. XRD and POM results showed that SSPCMs have the same crystalline structure, lower degree of crystallinity and smaller crystal size with pure PEG. DSC results indicated that SSPCMs are capable of reversible storing and releasing latent heat in the temperature of −10 to 60°C through phase transitions. Thermal cycling tests demonstrated that SSPCMs have good thermal reliability and chemical stability. TG results testified the thermal stability of SSPCM. The obtained SSPCMs exhibited great potential application in the field of thermal energy storage.

Polyethylene Glycol-Mediated Synthesis of Cubic Iron Oxide Nanoparticles with High Heating Power.

Iron oxide magnetic nanoparticles (IOMNPs) have been successfully synthesized by means of solvothermal reduction method employing polyethylene glycol (PEG200) as a solvent. The as-synthesized IOMNPs are poly-dispersed, highly crystalline, and exhibit a cubic shape. The size of IOMNPs is strongly dependent on the reaction time and the ration between the amount of magnetic precursor and PEG200 used in the synthesis method. At low magnetic precursor/PEG200 ratio, the cubic IOMNPs coexist with polyhedral IOMNPs. The structure and morphology of the IOMNPs were thoroughly investigated by using a wide range of techniques: TEM, XRD, XPS, FTIR, and RAMAN. XPS analysis showed that the IOMNPs comprise a crystalline magnetite core bearing on the outer surface functional groups from PEG200 and acetate. The presence of physisorbed PEG200 on the IOMNP surface is faintly detected through FT-IR spectroscopy. The surface of IOMNPs undergoes oxidation into maghemite as proven by RAMAN spectroscopy and the occurrence of satellite peaks in the Fe2p XP spectra. The magnetic studies performed on powder show that the blocking temperature (TB) of IOMNPs is around 300 K displaying a coercive field in between 160 and 170 Oe. Below the TB, the field-cooled (FC) curves turn concave and describe a plateau indicating that strong magnetic dipole-dipole interactions are manifested in between IOMNPs. The specific absorption rate (SAR) values increase with decreasing nanoparticle concentrations for the IOMNPs dispersed in water. The SAR dependence on the applied magnetic field, studied up to magnetic field amplitude of 60 kA/m, presents a sigmoid shape with saturation values up to 1700 W/g. By dispersing the IOMNPs in PEG600 (liquid) and PEG1000 (solid), it was found that the SAR values decrease by 50 or 75 %, indicating that the Brownian friction within the solvent was the main contributor to the heating power of IOMNPs.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-1091-0) contains supplementary material, which is available to authorized users.

Formulation and Evaluation of Amoxicillin Trihydrate Lozenges

In the present investigation an attempt has been made to formulate medicated lozenges containing amoxicillin trihydrate. There are several amoxicillin trihydrate dosage forms in the market such as tablet, capsule, suspension and syrup. Still there is a need for more variant dosage forms which acts effectively and locally. The benefits of the present research work is to increase the retention of the dosage form in oral cavity for increased bioavailability, reduction in gastric irritation and bypassing first pass metabolism. The lozenges were prepared by heating and congealing method employing polyethylene glycol 1500 as matrix base, saccharin sodium (artificial sweetener), stevia (natural sweetener), xanthan gum (polymer), sodium carboxymethyl cellulose (polymer) as other exciepients. The prepared medicated lozenges were characterized for drug content uniformity, hardness, thickness, weight variation, friability and dissolution by standard pharmacopeal methods. The results of the evaluation tests obtained were within the limits. Accelerated stability studies were conducted as per ICH guidelines and found that there wasn’t any substantial interaction among the drug, flavour and colour and the prepared formulations were found to be stable. Formulations were tested for drug exciepients interactions subjecting to IR spectral and DSC analyses. The results revealed that there was no major interactions between the drug and polymers used for the preparation of lozenges.Dhaka Univ. J. Pharm. Sci. 14(1): 61-70, 2015 (June)

Pd-doped β-Bi2O3/Bi2Sn2O7 hybrid nanocomposites for photocatalytic fluorene oxidation: A green approach for the synthesis of fluorenone/fluorenol mixture

Bismuth oxide, tin oxide and Pd metal (Pd/SnBi3SG) hybrids, synthesized via sol–gel technique while employing polyethylene glycol template at a ratio of 3 (Bi/Sn=3) were tested toward the photocatalytic oxidation of fluorene under ultraviolet and visible light irradiations in comparison with Pd/BiSG and Pd free SnBi3SG photocatalysts. These catalysts were characterized using X-ray diffraction (XRD), UV–vis diffuse reflectance (DRUV–vis), N2 sorptiometry, Raman spectroscopy, transmission electron microscopy (TEM) and GC–MS technique, which used for analyzing the photo-oxidation products. The actual photocatalyst exhibited the highest activity (100% conversion, TOF≈9.4×10−6s−1, fluorenone/fluorenol=3/1) following oxygen flushing for 30min (35ml/min) before UV irradiation. This was mainly due to the close proximity between β-Bi2O3 and Bi2Sn2O7 heterojunction as well as increasing the mesoporosity margin comparatively. On the other hand, the Pd/BiSG catalyst that exhibited smaller crystallite size (20nm vs. 44nm) and higher surface area (21.0 vs. 12.0m2/g) than Pd/SnBi3SG indicated lower activity (Pd/BiSG, 72% conv.). This highlights the importance of the modified electronic structure of Pd/SnBi3SG in designing efficient charge separation as well as high quantum yield value (Φ∼0.1±0.05) exceeding that of Pd/BiSG (3×10−2) and SnBi3SG (10−2) photocatalysts. The catalytic behavior and mechanism, reactivity–structure relationship and recyclable use of the hybrid photocatalysts have been thoroughly examined. An indirect chemical probe method using active species scavengers elucidated that the photo-oxidation mechanism was proceeded via holes and O2− moieties rather than singlet oxygen moieties.

Electrical, optical, photocatalytic, and bactericidal properties of polyethylene glycol-assisted sol–gel synthesized ZnTiO3-implanted ZnO nanoparticles

ZnTiO3-implanted ZnO nanoparticles were prepared by sol–gel method employing polyethylene glycol (PEG) 4000 and 20 000. The high resolution transmission electron micrographs, selected area electron diffraction pattern, energy dispersive x-ray spectra and powder x-ray diffractograms show the prepared materials as core/shell nanoparticles. Increase of the molecular mass of PEG decreases the d-spacing in ZnO of ZnTiO3-implanted ZnO and pristine ZnO nanoparticles. The charge transfer resistances of ZnTiO3-implanted ZnO nanoparticles are larger than those of pristine ZnO and precursor ZnTiO3 nanoparticles. The optical properties of ZnTiO3/ZnO nanoparticles are similar to those of pristine ZnO nanoparticles. The photocatalytic activity of ZnO is enhanced by the presence of ZnTiO3 core in the ZnO lattice. The bactericidal activity of core/shell ZnTiO3/ZnO nanoparticles is not less than that of ZnO nanoparticles.

Polymer-assisted sol–gel process for the preparation of photostimulable core/shell structured SiO2/Zn2SiO4:Mn2+ particles

In this study the SiO2/Zn2SiO4:Mn2+ core/shell particles with diameters of about 200 nm were prepared by a modified Pechini sol–gel method. The focus of the study was on the investigation of the shell formation mechanism and on the determination of key synthesis parameters. A precise adjustment of the particle structure is crucial for optical properties. The influence of the organic additives, the pH value of the coating solution and the annealing temperature on the properties of the resulting particles was evaluated. The roles of the influential factors were studied in detail using transmission electron microscopy, X-ray diffraction, Fourier transform infrared and nuclear magnetic resonance spectroscopy. The most homogeneous coating was achieved by employing polyethylene glycol (PEG) at a pH value of 1. The application of citric acid in combination with PEG caused the formation of inhomogeneous shells. The particles showed photoluminescence and photostimulable luminescence of increasing intensities with rising annealing temperatures (1100 °C). These core/shell structured particles have the potential to serve as luminescent labeling agents for biomedical applications.

Vanadium pyrophosphate oxides: The role of preparation chemistry in determining renewable acrolein production from glycerol dehydration

Efficient acrolein production through selective dehydration of biomass-derivable glycerol was investigated over the vanadium pyrophosphate oxide (VPO) catalysts. Employing polyethylene glycol (PEG) additive in the preparation media and activating the VPO precursors in the butane–air atmosphere considerably enhanced catalyst performance for the target reaction. An acrolein yield of 70.1mol% can be achieved over the as-synthesized VPO catalyst using an aqueous glycerol solution (36.5wt.%) feed and a liquid hourly space velocity (LHSV) of 4h−1 at 320°C. Moreover, the derived VPO catalyst can handle heavy loading of reaction feed, such as a concentrated glycerol solution (50.0wt%) or a notably high LHSV of 12h−1, and still retain reasonable acrolein yields (45–65mol%), giving acrolein formation rate up to 35.3mmolgcat−1h−1. Techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and hydrogen temperature programmed reduction (H2-TPR) were employed to explore the nature of catalysts. Type of alcohol and addition of PEG adopted in catalyst preparation showed significant impact on sample crystallinity/morphology, surface V5+/V4+ ratio, VO bonding strength, and Brønsted surface acidity. Balanced surface V5+/V4+ ratio and suitable density of medium strong acid sites are found to be critical to accomplish superior activity.