Polyethylene Glycol Composites Research Articles

Electrical energy harvesting by connected form stable phase change material composites

Over the years, thermoelectric energy harvesting has been becoming a topic of intensive research and thermoelectric power generator has been utilized in various energy harvesting applications. However, a thermoelectric device is required to harvest energy, which has relatively low efficiency and high cost. To overcome such a common problem, the objective of this study is to generate electrical energy without using thermoelectric devices. To this end, an advanced energy harvester composed of two different phase change material composites was explored. It was hypothesized that based on the well-known Seebeck effect, stable electrical energy output would be feasible without a thermoelectric device, by directly connecting two types of phase change materials with different electrical conductivities and different phase transition temperatures. In this study, polydimethylsiloxane open-cell foam embedded with single walled carbon nanotubes was prepared and utilized as a supporting material to fabricate form stable phase change material composites. Two types of polydimethylsiloxane open-cell foams were prepared by embedding single walled carbon nanotubes, which had a weight fraction of 0.33 % and 0.1 %, respectively, leading to different electrical conductivities. The different electrical conductivities of the supporting foams are vital to cause electron motion. Two types of phase change materials with different phase change temperatures were selected as working materials by filling them into the polydimethylsiloxane open-cell foams. Based on the test results, it is found that direct connection of 1-tetradecanol and polyethylene glycol composites can produce stable electrical voltage and current under different thermal energy inputs: through the change of external temperature from 25 °C to 80 °C, through the light-on/-off process, and through heat flow treatment. The maximum output voltage was up to 1.18 mV with a 50 % energy harvesting efficiency and the harvesting time was maintained for 50 min. To confirm the temperature profiles of the phase change material composites, numerical simulation was conducted and the thermal properties during the phase transition process were estimated, with good agreement. This research would create a new concept of thermoelectric energy harvesting for further development in practical applications.

PEG as versatile mediating agent for sensing heavy metal ions: A mini review

The increasing presence of heavy metal ions in aquatic environments has become a subject of escalating concern in contemporary times. Numerous human-induced activities have contributed to an elevated presence of heavy metal ions in aquatic environments, surpassing the threshold levels established by the World Health Organisation (WHO). Recently, there has been a significant increase in the utilisation of polyethylene glycol (PEG) due to its exceptional characteristics in addressing the pressing issue of aquatic pollution resulting from the presence of heavy metal ions. This mini review evaluates the detection activities in which PEG plays a significant role. The detection strategy utilising PEG composites is thoroughly described, beginning with an examination of the inherent properties of PEG. Furthermore, it concludes with suggestions for future research in this area.

Delving into the properties of nanostructured Mg ferrite and PEG composites: A comparative study on structure, electrical conductivity, and dielectric relaxation

Magnesium ferrite (MgFe2O4) and polyethylene glycol (PEG) are materials known for their versatility in various applications. This study presents a comprehensive comparative analysis of the electrical conductivity and dielectric relaxation of nanostructured MgFe2O4 and its composites with PEG. Through experimentation, it was observed that incorporating PEG into MgFe2O4 did not lead to a high relative observed decrease or increase in electrical conductivity at room temperature. The study revealed that the composites maintained stable electrical behavior at room temperature, with a dielectric constant value of around 9 and a loss tangent value of around 0.1 at high frequency (around 7 MHz). The electron-hole hopping mechanism was identified as the underlying cause for the strong dielectric dispersion with frequency. The low dielectric loss and conductivity of the MgFe2O4 and PEG/ferrite composites make them promising candidates for high-frequency switching applications and microelectronic devices, particularly in scenarios where negligible eddy currents are essential. Additionally, complex impedance data analysis demonstrated that the capacitive and resistive properties of the composites are primarily attributed to grain boundary processes. This study provides a comprehensive analysis of the electrical and dielectric properties of MgFe2O4 and PEG composites and highlights their potential for many applications in materials science, particularly in electrical and electronic devices.

Evaluation of the H2S and NO adsorption and release capacity of PEG-zeolites and PEG-titanosilicates composites

The exogeneous delivery of hydrogen sulfide (H2S) and nitric oxide (NO) has proven to have several therapeutic effects. However, the development of porous materials to be used as drug carries, specifically as carriers of gaseous molecules, is still in its infancy. In here, we synthesized and characterized four polyethylene glycol (PEG) composites obtained from two different kinds of zeolites (4A and Y) and two titanosilicates (ETS-4 and ETS-10). The H2S and NO adsorption capacities are important aspects of the H2S/NO carriers, and they were determined for all the PEG-composites. Additionally, release studies of the H2S/NO loaded composites in aqueous solution at physiological pH revealed a longer NO release than their parent material while for H2S this was not observed, yet the % of released H2S is higher than the parent material. Cytotoxicity studies using HeLa cell line showed that PEG composites at 450 μg/mL have no toxicity. The results indicate that all PEG composites may have potential as NO-carrier, while for H2S only the 4A@PEG may be evaluated.

Programming of micro/nano‐scale information on low switching temperature shape memory film

AbstractShape memory polymer films have been of great interests in storing functional information because of their optical and mechanical variability. High molecular weight polyvinyl acetate (PVAc) is an ideal shape memory material to program micro‐ and nano‐scale patterns on the surface of highly transparent films. By blending PVAc with polyethylene glycol (PEG) plasticizer, lower switching temperatures could be achieved. We develop a shape memory PVAc/PEG blend film system featuring a unique design by taking advantage of multiple switching temperatures. The effect of the PEG composition was studied relative to different surface patterns, switching temperatures and efficiency of information retrieval by utilizing differential scanning calorimetry and UV/Vis analysis. The results indicate that higher contents of PEG enhanced the recovery efficiency of both the micro‐scale and nano‐scale patterns and the corresponding optical properties. Furthermore, a dual switching shape memory film was developed enabling multiple switching temperatures that can lead to versatile applications.

Flexible graphene oxide/poly(ethylene glycol) composite films for lubrication application

For the rotating parts of low-speed heavy machinery, it is difficult to replace and add lubricants, so coating the mechanical surface is an effective method to reduce friction and wear. In this study, a smooth functional film with good mechanical strength was designed and prepared by combining graphene oxide (GO) with polyethylene glycol (PEG). This wachieved by grafting PEG onto the GO surface. The effects of lubrication for the cases of flexible lubricating film, no film, and single film were analysed. The lubrication characteristics of GO–PEG flexible composite film under water lubrication, are discussed in detail. The results show that the mixture of PEG and GO can significantly improve the thermal stability, film forming properties and mechanical properties of GO–PEG composites. The membrane has a good friction limit performance. Compared with the uncoated surface, the friction coefficient is reduced by 74% and the wear rate is reduced by 70%.

Tribological properties of graphene oxide and polyethylene glycol composites under dry friction and oil lubrication conditions

AbstractIn the low speed and heavy load of large machinery rotation or sliding parts, the application of copper base ink plate is very extensive. In this study, the graphene oxide‐polyethylene glycol (GO‐PEG) thin films were prepared on the surface of steel plates by gradient heating, and we simulated the friction and wear state of the solid material when it was brought to the metal surface. And the Fourier transform infrared spectroscopy, X‐ray diffraction, X‐ray energy spectrum analysis, Raman spectroscopy (Raman), and thermogravimetric analysis were used to characterize the structure and properties. The tribological results show that the GO‐PEG composite film prepared by gradient temperature rise method has good lubrication effect. The addition of GO greatly enhances the mechanical properties of the composite films. Compared with the single GO film, the friction coefficient is reduced by 50% and the wear rate is reduced by 85%. The unique characteristics of PEG solved the accumulation phenomenon caused by the strong van der Waals force between GO, then the PEG adhered on GO surfaces caused good lubrication effect. At the same time, the composite film has a broad application prospect in the working environment with little oil and no oil.

Investigation of gamma radiation shielding properties of polyethylene glycol in the energy range from 8.67 to 23.19 keV

The mass attenuation coefficients (μm) of polyethylene glycol (PEG) of different molecular weights (1000–200,000) were measured using single-beam photon transmission. The X-ray fluorescent (XRF) photons from Zinc (Zn), Zirconium (Zr), Molybdenum (Mo), Silver (Ag) and Cadmium (Cd) targets were used to determine the attenuation of gamma radiation of energy range between 8.67 and 23.19 keV in PEG samples. The results were compared to theoretical values using XCOM and Monte Carlo simulation using Geant4 toolkit which was developed to validate the experiment at those certain energies. The mass attenuation coefficients were then used to compute the effective atomic numbers, electron density and half value layers for the studied samples. The outcomes showed good agreement between experimental and simulated results with those calculated theoretically by XCOM within 5% deviation. The PEG 1000 sample showed slightly higher μm value compared with the other samples. The dependence of the photon energy and PEG composition on the values of μm and HVL were investigated and discussed. In addition, the values of Zeff and Neff for all PEG samples behaved similarly in the given photon energy range, and they decreased as the photon energy increased.

Microwave-Induced in Situ Drug Amorphization Using a Mixture of Polyethylene Glycol and Polyvinylpyrrolidone.

The use of a mixture of polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) was investigated for microwave-induced in situ amorphization of celecoxib (CCX) inside compacts. Such amorphization requires the presence of a dipolar excipient in the formulation to ensure heating of the compact by absorption of the microwaves. Previously, the hygroscopic nature of PVP was exploited for this purpose. By exposing PVP-based compacts for set time intervals at defined relative humidity, controlled water sorption into the compacts was achieved. In the present study, PEG was proposed as the microwave absorbing excipient instead of water, to avoid the water sorption step. However, it was found that PEG alone melted upon exposure to microwave radiation and caused the compact to deform. Furthermore, CCX was found to recrystallize upon cooling in PEG-based formulations. Hence, a mixture of PEG and PVP was used, where the presence of PVP preserved the physical shape of the compact, and the physical state of the amorphous solid dispersion. To study the impact of the polymer mixture, different compact compositions of CCX, PEG and PVP were prepared. When exposing the compacts to microwave radiation, it was found that the PEG:PVP ratio was critical for in situ amorphization and that complete amorphization was only achieved above a certain temperature threshold.

Fluorescence Aerosol Flow Tube Spectroscopy to Detect Liquid–Liquid Phase Separation

The phase behavior of atmospheric aerosol particles influences processes like gas-particle partitioning, solar light scattering, and cloud formation, ultimately affecting atmospheric air quality and climate. An important aspect of this phase behavior is whether an individual particle exists in a single homogeneous phase or undergoes liquid–liquid phase separation (LLPS). Herein, fluorescence aerosol flow tube (F-AFT) spectroscopy is developed to characterize LLPS in aerosolized submicron particles of 100–200 nm. A solvatochromic fluorescent probe molecule is incorporated into the particles. The link between its fluorescence emission and the local particle-phase chemical environment is used to determine the separation relative humidity (SRH) at which LLPS occurs. The LLPS behaviors of mixed organic/inorganic particles composed of polyethylene glycol (PEG), ammonium sulfate (AS), and sodium chloride (NaCl) are characterized. PEG/AS particles undergo LLPS at SRH values that vary with PEG composition. By comparison, PEG/NaCl particles continue as a single homogeneous phase to the RH of NaCl crystallization. The SRH values for the submicron particles are lower by >5% RH than those reported in the literature for supermicron particles deposited to substrate surfaces. Possible reasons for the differences are discussed, including kinetic and thermodynamic effects of system size and foreign substrate as well as observation time in the experimental apparatus.

Physical and mechanical properties of hydroxyapatite/polyethylene glycol nanocomposites

The excellent properties of hydroxyapatite [HAp, Ca10(PO4)6(OH)2] have attracted the interest of researchers and engineers for various applications. Instead of using expensive commercial raw materials, we introduced the use of natural minerals for hydroxyapatite synthesis, precisely the calcite rock from Jember, Indonesia. Our study confirmed that the calcium content in the calcite rock was 98.36%. As a bone substitution compound, hydroxyapatite needs to be composited with polymeric materials, such as polyethylene glycol to improve its mechanical properties. The XRD test results showed that variations in the composition of polyethylene glycol (PEG) affect diffraction peak intensities, lattice parameters, and grain size of crystalline HAp/PEG nanocomposites. The density value of the nanocomposites increases with the addition of PEG up to 4.29 g/cm3. In addition, the value of hardness also increases with the addition of PEG up to 78.50 HVN.

Zirconia‐dispersed polyethylene glycol composites with a low temperature‐degradation rate

AbstractThe effect of tetragonal‐zirconia nanoparticle inclusion on the temperature‐dependent storage modulus, or the temperature‐degradation rate, of polyethylene glycol (PEG)‐based composites was investigated using shear‐mode dynamic mechanical analysis (DMA) at temperatures ranging from room temperature up to 75°C. We carried out further investigations in the rubbery area in terms of the characteristic of the degradation rate with temperature and compared it with silica‐quartz‐filled PEG composites, which exhibited a potential as phase‐change materials (PCMs). The investigation began by plotting the shear storage modulus (G′) of the composites and observing the slopes of the curves in the range of the rubbery area, which were assumed to follow a straight‐line equation. Then, we completed the investigation by developing and introducing a temperature‐dependent storage modulus model in the rubbery area for describing the storage modulus of such filler‐dispersed PEG/inorganic composites, to yield the degradation rates of the composites. The new model includes parameters k1 and C that are associated with the degradation rate and the amount of a filler, respectively. The model shows a satisfactory agreement with the experimental data of G′ in the rubbery area, being parameter k1 is associated with a linear degradation rate.

Fabrication of thermal energy storage wood based on graphene aerogel encapsulated polyethylene glycol as phase change material

Thermal energy storage wood (TESW) was fabricated by using graphene aerogel encapsulated polyethylene glycol (PEG) as phase change material and wood as the matrix. The microstructure of TESW was investigated by scanning electron microscope (SEM), the thermal properties of TESW was determined by differential scanning calorimetry (DSC), thermal gravimetric analysis (TG) and laser flash diffusivity apparatus (LFA). The results showed that: (1) graphene aerogel (GA) encapsulated PEG composite was founded in the lumens of wood, there was no apparent interface between PEG and graphene aerogel; (2) the melting and freezing enthalpy of TESW were 11.81 and 27.91 J g−1, respectively. The melting and freezing point were 20 °C and 15 °C, respectively, which were suitable for human comfortable temperature; (3) incorporation of graphene aerogel improved the thermal conductivity of TESW apparently. Thermal conductivity of TESW was 0.374 W (m*K)−1, which increased about 274% compared to pure wood; (4) TG and hygroscopicity test indicated that the TESW had excellent thermal and dimensional stability. The TESW was suggested as energy conservation building material for indoor temperature regulating due to its comfortable phase change temperature and prior latent heat.

Characterization, Thermal and Biological Properties of PCL/PLA/PEG/N-HA Composites

Initially, the use of Additive Manufacturing (AM) technology is mainly for the production of prototypes of a new invention and design. However, the AM technology had extended to the tooling industry, medical scaffolding, and direct part production. This is due to the extensive research and development carried out around the globe regardless of the material, equipment, and technology of AM. In this study, characterization and properties of PCL/PLA/PEG/Nano-HA polymer composites were investigated. Polycaprolactone (PCL), polylactic acid (PLA), polyethylene glycol (PEG), and nano-hydroxyapatite (n-HA) composites were prepared by melting and compounding the mixture using a Brabender machine. The composition of the materials was determined by previous research that it is the optimum recipe, with the ratio of PCL:PLA is 7:3 while the composition of PEG and nano-HA is 5% per hundred resin each. The temperature of the Brabender machine was set at 160°C, and the speed of the mixer was set at 30 rpm. After the mixing, the composites were characterized by using Fourier Transform Infrared Spectroscopy (FTIR) to determine the spectrum and quality of the composite mixed. Based on the spectrum, it can be verified that the characteristic of n-HA powder had been incorporated well into the PCL/PLA/PEG polymer blend. The thermal properties of the composites were investigated by using Thermogravimetry Analyzer (TGA). The results showed that the addition of n-HA lowered the initial degradation temperature and peak degradation temperature. Apparently, the addition of n- HA did not increase the degradation temperature of the composites. Furthermore, Simulated Body Fluid (SBF) test was carried out to access the bioactivity properties of the composites after the addition of n-HA. The results had proved that the addition of n-HA had triggered the growth of apatite layer on the surface of the samples treated with SBF. The growth of the apatite layer was verified by the X-ray Diffraction pattern, and the results proved the initial assumptions.

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).

Palm-based cationic polyurethane membranes for solid polymer electrolytes application: A physico-chemical characteristics studies of chain-extended cationic polyurethane

Polyurethane (PU) having a great potential to be used as a polymeric host in polymer electrolytes. However, it still suffers from low conductivity and high glass transition temperatures (Tg). In this work, chain-extended palm-based cationic PU using polyethylene glycol (PEG) were synthesized at different composition by a polyaddition polymerization reaction. Infrared analysis proved the complete reaction of the limiting monomer by the disappearance of isocyanate peak. The glass transition temperature and crystallinity were decreased to 35 °C. The molecular weight increased by 22 % along with the composition of PEG. Thermal studies proved that all samples are thermally stable up to 190 °C. Further modification on PU structure by alkylation reaction enhanced overall conductivity of the polymeric host up to two orders of magnitude without the presence of charge carriers. These observations indicate this palm-based cationic PU possessed favourable properties and great potential as a polymeric host material for solid-state electrolytes application.

Bio-Based Radish@PDA/PEG Sandwich Composite with High Efficiency Solar Thermal Energy Storage

Phase change materials with desirable light-thermal conversion ability are particularly attractive for solar energy harvesting and storage. Herein, we demonstrate that the combination of efficient light-thermal conversion, excellent thermal property, and reliability can be achieved via the construction of a novel form-stable phase change composite material, that is, Radish@PDA/PEG with a sandwich structure. A 3D porous structure derived from radish via freeze-drying is adopted as the substrate; then, self-polymerization of dopamine is initiated in the surface of Radish to produce a layer of polydopamine (PDA). Finally, polyethylene glycol (PEG) impregnation via vacuum infusion is applied to form the Radish@PDA/PEG composite. These results prove that the incorporation of interlayer PDA can not only improve the strength of the porous structure to protect the PEG from leakage, but also enhance the encapsulation capacity of PEG and light absorption ability of the composite. The preparation method is based on common biomass with green chemicals and thus provides a general way to prepare eco-friendly and biodegradable composite with promising applications in light thermal energy management.

Optimization of Process Parameters using Response Surface Methodology for PCL based Biodegradable Composite Membrane for Water Purification

The biodegradability of polycaprolactone (PCL) and the anti-fouling property of TiO2 are utilized for the preparation of membranes for water treatment. Polyethylene glycol (PEG) is added to the polymeric solution to increase the pore formation in the membranes. The composition of PEG and TiO2 nanoparticles was optimized using the central composite design and response surface methodology. Quadratic models were developed for the responses porosity and contact angle, and the optimum compositions obtained for PEG and TiO2 were 6.24 and 1 wt%, respectively. The competency of the membrane for water treatment is studied using different characterization techniques such as TG analysis, FTIR to determine the chemical interactions, UTM to examine the mechanical strength, AFM for membrane roughness determination and morphological analysis using FESEM. A twofold increase in the overall porosity and a twentyfold reduction (approx.) in pore size were observed for the composite membrane from FESEM images. The anti-fouling ability of TiO2 resulted in a flux recovery of about 90% for the composite membrane compared to the PCL–PEG membrane after bovine serum albumin filtration. Also, the presence of TiO2 increased the reversible fouling component, which can be easily removed by cleaning/backwashing. Thus, the PCL–TiO2 combination would be a better alternative for the membranes used in water treatment applications.

Elimination of toxic metal ion by means of poly m-phenylene (isophthalamide) ultra filtration membranes

Poly m-phenylene (Isophthalamide) (PMIA) Ultrafiltration membranes were synthesized by Non-solvent induced phase inversion technique using Lithium Chloride (LiCl) with various compositions of Poly ethylene glycol (PEG-600) and N-methyl pyrrolidone (NMP) solvent. The effects of compositions of PEG-600, pure water flux and percentage water content of the membranes were studied. The application of PMIA membranes in separation of toxic heavy metal ions from solutions was also attempted and the results were discussed.

Mitigating the anti-nutritional effect of polyphenols on in vitro digestibility and fermentation characteristics of browse species in north western Ethiopia.

Browse species are important sources of forage for livestock in Ethiopia, especially during the dry season, when the quality and quantity of green herbage is limited. However, browse species have anti-nutritional factors, such as polyphenols. This study evaluated the extent to which polyethylene glycol (PEG) can reduce the anti-nutritional effects of polyphenols whose extent is expected to vary depending on the species type and season on the in vitro fermentation of these plant samples. We selected ten browse species commonly used as livestock feed based on their tannin content, and sixty samples of the leaf and twig of these species were collected during the wet and dry seasons. The study was designed as 10 × 2 × 2 factorial arrangement with 10 browse species (Acacia nilotica, Crateva adonsonia, Dombeya torrida, Ekebergia capensis, Ensete ventricosum, Erythrina brucei, Maesa lanceolate, Sesbania sesban, Stereospermum kunthianum, and Terminalia laxiflora), 2 seasons (wet and dry) and 2 states of PEG (with and without PEG). The effects of tannin on the nutritive characteristics were also evaluated by adding PEG as a tannin-binding agent. The chemical composition and in vitro fermentation products of these samples differed significantly (p < 0.001) among browse species. Specifically, total extractable phenol (TEP) ranged from 26.3 to 250.3 g/kg, total extractable tannin (TET) from 22.8 to 210.9 g/kg, and condensed tannin (CT) from 11.1 to 141.3 g/kg, respectively. Season, species, and their interaction have a significant (p < 0.05) effect on the chemical composition and fermentation characteristics of most browse species. The addition of PEG increased gas production (GP), in vitro organic matter digestibility (IVOMD), metabolizable energy (ME) concentration, dry matter degradability (DMD), and volatile fatty acids (VFA), on average, by 76.8%, 47.9%, 42.2%, 21.2%, and 20.2%, respectively. Secondary polyphenols (TEP, TET, CT, and SCT) were significantly (p < 0.001) and negatively correlated with GP, IVOMD, ME, and VFA. Preferable species namely E. ventricosum, S. sesban, M. lanceolata, E. capensis, and A. nilotica were selected for supplementation in terms of their chemical composition, IVOMD, and mitigating effects of PEG on anti-nutritional functions of their secondary compounds. In conclusion, PEG markedly reduced the anti-nutritional effects of polyphenols and improved the in vitro fermentation of browse species harvested in contrasting seasons.