Pure Polymer Research Articles

Physicochemical analysis of primers and liquid membranes as asbestos’ encapsulant

Asbestos-containing materials pose significant health risks due to the potential dispersion of harmful fibers into the environment. This study presents a comprehensive physicochemical analysis of coatings, including primers and liquid membranes, designed to be applied on asbestos cement roofs, aiming to prevent the release of asbestos fibers and safeguard human health. Primers are normally used during the process of removing asbestos-containing panels to minimize the dispersion of fibers in the environment. By encapsulating the fibers on the surface, the primer helps to reduce the risk of fiber release during handling and removal. On the other hand, the primary goal of a liquid membrane is to encapsulate the asbestos fibers permanently, for long-term protection, preventing the potential health risks associated with asbestos exposure.To assess the reliability of primers and membranes is a matter of great importance especially for developing counties which have recently forbidden or are in the prohibition phase for the use of asbestos fibers. Two primers and two liquid membranes were investigated in a certified laboratory through a series of chemical and physical analysis. A primer was taken from commercial products in Colombia, a country that forbids asbestos but does not have legislation on these products, while two primers and a membrane were taken from a European country with high standards and decades of experience in the production of these materials to prevent asbestos exposure. The solid content, ash content, determination of primary solvents, thermogravimetry, infrared spectrum (FT-IR) of the polymer, infrared spectrum (FT-IR) of powders (fillers and pigments), and density were analyzed in the four products. Additionally, the membranes underwent testing for heat resistance, resistance to rain and freeze-thaw cycles, water impermeability, and accelerated aging (UVA 340, 1000 h). Furthermore, on membranes, adhesion capability (pull-off) was tested before and after heat-rain, freeze-thaw, UV ageing tests to ensure a durable bond between the coating and the asbestos surface.The results of the investigation revealed promising findings for both the primer and liquid membrane formulations. The primer demonstrated its potential applicability during the removal of asbestos panels, offering a preliminary safeguard against fiber dispersion. On the other hand, the liquid membranes exhibited excellent properties in encapsulating asbestos fibers effectively, providing long-term protection to the substrate. The Colombian membrane shown a calcium carbonate basis for the inorganic filler, with an almost pure acrylic polymer, while the second membrane shown a polymer styrene-acrylic matrix. This leads to less elasticity for the first membrane, and a possible exposure to acid rain attacks. Nevertheless, this chemical difference did not alter the results of the aging tests.

Engineering organic solvent reverse osmosis in hybrid AlOxHy / polymer of intrinsic microporosity 1 (PIM-1) membranes using vapor phase infiltration

A solvent-free post-treatment process known as vapor phase infiltration (VPI) is used to engineer the organic solvent reverse osmosis (OSRO) performance of polymer of intrinsic microporosity 1 (PIM-1) membranes via infiltration of trimethylaluminum (TMA) metal-organic vapor. The infiltration of inorganic aluminum constituents hybridizes the pure polymer PIM-1 into an organic-inorganic material (AlOxHy/PIM-1) with enhanced chemical stability. A homogenous distribution of inorganic loading in PIM-1 is achieved due to the reaction-limited infiltration mechanism, and the OSRO performance is enhanced as a result. OSRO separations of ethanol/isooctane mixtures using these membranes are shown to be capable of breaking the azeotropic composition with a separation factor for ethanol over isooctane greater than 5 and an ethanol permeance of 0.1 Lm–2h–1bar–1. Thus, these organic-inorganic hybrid membranes created via VPI show promise as an alternative method for separating azeotropic liquid mixtures.

Mixed Matrix Membranes Using Porous Organic Polymers (POPs)-Influence of Textural Properties on CO2/CH4 Separation.

Mixed matrix membranes (MMMs) provide the opportunity to test new porous materials in challenging applications. A series of low-cost porous organic polymer (POPs) networks, possessing tunable porosity and high CO2 uptake, has been obtained by aromatic electrophilic substitution reactions of biphenyl, 9,10-dihydro-9,10-dimethyl-9,10-ethanoanthracene (DMDHA), triptycene and 1,3,5-triphenylbenzene (135TPB) with dimethoxymethane (DMM). These materials have been characterized by FTIR, 13C NMR, WAXD, TGA, SEM, and CO2 uptake. Finally, different loadings of these POPs have been introduced into Matrimid, Pebax, and chitosan:polyvinyl alcohol blends as polymeric matrices to prepare MMMs. The CO2/CH4 separation performance of these MMMs has been evaluated by single and mixed gas permeation experiments at 4 bar and room temperature. The effect of the porosity of the porous fillers on the membrane separation behavior and the compatibility between them and the different polymer matrices on membrane design and fabrication has been studied by Maxwell model equations as a function of the gas permeability of the pure polymers, porosity, and loading of the fillers in the MMMs. Although the gas transport properties showed an increasing deviation from ideal Maxwell equation prediction with increasing porosity of the POP fillers and increasing hydrophilicity of the polymer matrices, the behavior of biopolymer-based CS:PVA MMMs approached that of Pebax-based MMMs, giving scope to not only new filler materials but also sustainable polymer choices to find a place in membrane technology.

Dielectric behavior and proton conductivity of ultrasound-assisted graphene oxide/sulfonated poly(ether ether ketone) composite electrolytes

This work deals with the evaluation of proton conductivity and dielectric measurements of graphene oxide (GO) doped sulfonated poly(ether ether ketone) (SPEEK) electrolytes for electrochemical devices. SPEEK-GO composite electrolytes were successfully prepared via ultrasound-assisted solution casting method. FTIR, SEM, and TGA analysis were performed to characterize the GO, SPEEK matrix, and current SPEEK-GO electrolytes. Additionally, the effects of GO loading on the proton conductivity and the dielectric behavior were also studied. The effectiveness of the oxy-groups in the GO structure for proton conduction via the Grotthus mechanism was demonstrated, and the SPEEK-GO-(10.0) composite electrolyte had the highest observed proton conductivity value of 4.79 × 10−3 S/cm. This value is roughly four times greater than the proton conductivity value of the pure SPEEK polymer matrix under the same conditions (400 K, 1 MHz), which is 1.23 × 10−3 S/cm. GO was able to increase the dielectric constant (ε′) both through its large surface area and aspect ratio and through its polar functional groups, which can interact with the SPEEK polymer matrix. The decrease in the electric modulus (M′) of the SPEEK-GO-(10.0) composite with increasing temperature could be attributed to both the decrease in the complex modulus and the formation of voids and gap at the interface between the polymer matrix and the GO particles.

Magnetic induction assisted pyrolysis of plastic waste to liquid hydrocarbons on carbon catalyst

Carbon-based catalyst can effectively crack model waste plastic based on polyolefins under contactless induction heating and yield gaseous and liquid hydrocarbons fractions at mild reaction temperatures. High catalytic performances are reached thanks to the stable catalyst bed temperature arising from the high heating rate of the induction setup. By comparison to indirect Joule heating which required much higher temperatures, contactless direct induction heating allows a compensation of the internal temperature loss during such highly endothermic process through direct heat targeting. The single carbon-based catalyst combined a high and stable activity with an extremely high stability as a function of cycling tests with pure or mixed polymers. By comparison to the acid or metal based catalysts used in plastic cracking, such low cost carbon catalyst avoids deactivation within cycling tests and therefore provides an efficient and cost-effective route for waste plastic recycling and also as chemical storage means for renewable energy.

Investigation of Magnetic Electrodes in Conducting Polymeric Materials: Electrochemical Properties of a Fullerene[C60 ]-Pd Polymer and Iron Oxide Magnetic Nanocomposite.

A composite of iron oxide magnetic nanoparticles and coordination fullerene polymer (C60 Pd3 )n is formed by chemical deposition of spherical polymer nanoparticles on iron oxide magnetic nanoparticles in benzene containing C60 and Pd(0) complex. The composition of the composite can be controlled by the amount of magnetite and concentration of polymerization precursors as well as the time of polymerization. The magnetic composite material Fe3 O4 -γFe2 O3 /(C60 Pd3 )n is used as a model system to investigate its deposition on a magnetic electrode and its electrochemical properties. The iron oxide magnetic nanoparticles ensure both the magnetic activity of the composite and its nanostructured morphology. Both of these factors are responsible for the enhancement of the electrochemical activity of the polymer phase forming the composite in comparison to the pure polymer material deposited on the same magnetic electrode. In the magnetic field of the electrode, the composite undergoes permanent and strong bonding with the surface of the electrode. The nanostructured morphology of the Fe3 O4 -γFe2 O3 /(C60 Pd3 )n composite also provides very good capacitive properties.

Effects of core materials on the evolution of products during the pyrolysis of end-of-life wind turbine blades

A wind turbine blade consists of pure glass fiber-reinforced polymer composites (GFRPs) and the sandwich part with core materials. Pyrolysis is a prospective technology to recycle end-of-life blades, but the pyrolysis performance of blades with core materials is still unclear. In this study, three retired blade parts were pyrolyzed, i.e., pure GFRPs, GFRPs filled with polyethylene terephthalate (PET) foam, and GFRPs filled with balsa wood. The results showed that CH4, CO, and CO2 were the majority of the pyrolysis gas when the pure GFRPs part was pyrolyzed at 400ºC, with five typical phenolic products in the pyrolysis oil, containing bisphenol A, phenol, 4-isopropenyl phenol, 4-isopropyl phenol, and o-cresol. As the temperature increased to 550ºC, the content of CH4 reached 48.0 vol% while that of CO2 reduced, raising the calorific value of the pyrolysis gas to 27.2 MJ/Nm3. Meanwhile, the content of bisphenol A in the pyrolysis oil rapidly increased, owing to the enhanced breakage of oligomers. As PET foam was filled, CO2 was dominant in the pyrolysis gas, and the content of benzoic acid became comparable with those of phenols in the pyrolysis oil. Whilst several hydrocarbon substances were detected when balsa wood was filled, making the oil product more complex. In terms of solid products, char residues over the black fibers were formed mainly due to the decomposition of epoxy resin rather than core materials, and the oxidation duration should be extended when recovering the blade parts with sandwich structures. Moreover, elevating the pyrolysis temperature reduced the pyrolytic residues but degraded the recovered fibers’ tensile strengths. The conclusions suggested that the blade parts with sandwich structures should be pyrolyzed separately, considering the core materials and their components.

Study of thermal and mechanical behavior by analyzing reinforcement effect of graphene nanoplatelets on polyamide-66 composite system developed via melt-mixing technique

In the present study, graphene nanoplatelets (GNP) reinforced polyamide 6,6 (PA-66) composite was studied to investigate the thermal and mechanical properties of PA-66/GNP composite. The composites were developed by varying wt% (1, 3, 5, and 10 wt%) of GNP loading using a co-rotating, intermeshing, twin-screw extruder via melt-mixing and injection molding process. In order to understand the thermal and mechanical behavior of PA-66/GNP composite, various thermal (TGA and DSC) and mechanical (tensile, impact, and flexural) tests were carried out. The FTIR spectral analysis was done to identify the presence of different functional groups in the PA-66/GNP composite, indicating the strong enough Vander-Waals interaction between the PA-66 matrix and GNP filler contents. The TGA result shows a significant enhancement in the thermal stability of the composite by increasing wt% of GNP. The DSC analysis exhibits a significant reduction in enthalpy of fusion (∆Hm) and a decrease in the degree of crystallinity with increasing wt% of GNP, reflecting a depressed form of α-crystalline structure. Further, the significant growth in tensile modulus and tensile strength were identified under the mechanical performance of the PA-66/GNP composite. An increasing trend in tensile modulus and tensile strength characteristics was observed, and tensile modulus exhibited an enhancement of ∼96% than pure PA-66 at 10 wt% of GNP. Also, the tensile strength is found to be ∼16% higher than that of pure PA-66 matrix. Similarly, the impact test result shows a decreasing trend in impact strength on increasing wt% of GNP reinforcements, indicating the restriction to the molecular mobility due to improved brittle behavior. Further, the flexural modulus is found to be increased by ∼28% at 10 wt%, and the flexural strength is found to have an enhancement of ∼9% at 3 wt% than pure PA-66 polymer matrix of GNP loadings, respectively. The influence of GNP filler content reinforced PA-66 composite on the thermal and mechanical properties is found to be noteworthy.

Physico-mechanical properties of gamma irradiated polypropylene/ ethylene propylene diene monomer/CaCO3 nanocomposites

ABSTRACT The effect of gamma irradiation on the physico-mechanical properties of nanocomposites-based ethylene propylene diene monomer (EPDM) rubber and polypropylene (PP) blends reinforced with CaCO3 nanoparticles was studied. The nanocomposites were characterized in terms of mechanical, thermal and morphological properties and XRD diffraction. The results indicated, generally, that the elongation at break (E%) was found to decrease by increasing the ratio of PP in the nanocomposite blends and the irradiation dose. The E% values of unirradiated pure EPDM and PP polymers were 1785.0 and 125.0%, respectively. The nanocomposite EPDM/PP (50%)/CaCO3 irradiated to 60 kGy displayed the best properties.

Flax pomace as a substitute for wood raw material in lignocellulosiccomposite technology

Flax pomace as a substitute for wood raw material in lignocellulosic composite technology. In the present study, composites made from flax seed pomace and PE, PP, PLA and modified starch were subjected quality parameter tests. Density, modulus of rapture (MOR), and modulus of elasticity (MOE) were examined, as well as water absorption and swelling to thickness after 2h and 24 h soaking in water, wettability and surface roughness. Addition of flax to different polymers caused significant changes of parameters but the level of influence of the addition varied between polymers. Although the characteristics of the produced biocomposites have been shown to be in general inferior to pure polymers, efforts should be made to improve these characteristics. Agri-food waste products can be a valuable raw material for the production of new type of biomaterials

Deformation kinetics of single-fiber polypropylene composites: Adhesion improvement at the expense of toughness

Despite the maturity of the technology, processing of fiber-reinforced thermoplastic materials remains challenging, and difficulties in processability often result in material formulations with high modulus and strength, yet rather poor ductility compared to the pure polymer matrix. To gain fundamental insight into the deformation mechanisms present in such materials, the complexity of the system is step-wise increased; first, the effect of the most commonly applied adhesion enhancement, the addition of MAH-g-PP compatibilizer, on the bulk properties is assessed. The small-strain tensile properties, i.e., modulus and yield stress, appear to be only marginally affected by the addition of such compatibilization agent, however, the strain-at-break is strongly reduced, even before the addition of the fiber reinforcement. Subsequently, using in-situ X-ray characterization methods upon tensile deformation, the time evolution of crystal structure and lamellar morphology is determined, and at first glance the compatibilizer addition appears to better preserve the crystalline structure. The onset of local failure (cavitation) is quantified at the interface of a single glass fiber. By increasing the adhesive interaction between fiber and matrix the stress concentration at the interface is increased, leading to an acceleration in void formation followed by unstable growth, which in turn strongly embrittles the composite. By the addition of various selective nucleating agents, it is demonstrated that the role of local phase composition and morphology on the deformation kinetics and subsequent failure mechanisms is much more pronounced than the increased adhesion between fiber and matrix by compatibilization or sizing effects. These findings may specify a new route towards tougher fiber-reinforced composites with reduced complexity in the material formulation.

Corn pomace as a substitute for wood raw material in lignocellulosiccomposite technology

Corn pomace as a substitute for wood raw material in lignocellulosic composite technology. Composites made from polymers PE, PP, PLA and modified starch with addition of corn pomace were produced and subjected quality parameters test. There were examined such parameters as: density, static bending strenght and modulus of elasticity and also water absorption and thickness swelling after 2 h and 24 h soaking in water, wettability and surface roughness. In general, the addition of corn pomace to polymers caused changes of parameters and through comparing parameters of different composites and control samples it was possible to indicate corn composite variants that occurs to have similar properties to pure polymer samples. Waste products should be seriously considered as a valuable substitute of wood raw material, but characteristics of composites should be improved through further research.

Со(ІІ) and Ni(II) Removal from Aqueous Solutions by Polymer and Polymer/Silica Adsorbents with Sulfo and Carboxyl groups

Sulfo and carboxyl group-containing polymers and polymer/silica adsorbents poly(acrylonitrile-co-2-acrylamido-2-methylpropane-1-sulfonic acid-co-acrylic acid-co-N,N’-methylene-bis-acrylamide) [poly(AN-co-AMPS-co-AAco-MBA)] and poly(AN-co-AMPS-co-AA-co-MBA)/SiO2 were synthesized by a UV-initiated polymerization or simultaneous UV-initiated polymerization and in situ sol-gel process and used as adsorbents for removal of Co(II) and Ni(II) ions from aqueous solutions. The adsorption capacity and the effect of the pH in the removal process have been studied. The poly(AN-co-AMPS-co-AA-co-MBA) adsorbent exhibited high efficiency: up to 91.8 % removal of Co(II) and 89.7 % removal of Ni(II). Polymer/silica adsorbents showed higher removal capacity as compared to pure polymer. The adsorption kinetics of Co(II) and Ni(II) ions were found to be satisfactorily described by the pseudo-second-order reaction equation of the Lagergren kinetic model, suggesting the ion-exchange nature of the process.

Development and thermal performance of a thermoplastic-graphite-composite based plate heat exchanger for use in corrosive media

Polymer composites based on thermoplastics and thermally conductive fillers can compensate for the disadvantage of poor thermal conductivity of pure polymers and thus serve as feedstock for heat transfer materials in corrosive environments up to 200 °C. This study demonstrates the production of a gasketed plate heat exchanger made of chevron plates based on composites. The novel production process presented allows the transfer of embossing patterns known for metals to polymer composites with processes suitable for mass production. The embossed polypropylene-graphite and polyphenylene sulfide-graphite sheets with a surface area of 0.011 m2 and thicknesses below 2.5 mm achieve thermal conductivities of up to 2 and 2.4 W/mK, respectively. The experimental results show that at wall thicknesses of 0.85 mm, overall heat transfer coefficients of 1280–1850 W/m2K for water-water heat transfer and Reynolds numbers of 600–1600 are achieved. Considering the low density of the thermal plates produced, this ensures comparable performance with metallic materials over a wide range of process conditions (Re = 200–8000) for the same wall thicknesses. A screening of the fouling susceptibility of the materials shows sensitivity to calcium sulfate fouling, however, qualitative analysis indicates that this is due to flow maldistribution and not the actual materials.

Advanced Composite Materials Utilized in FDM/FFF 3D Printing Manufacturing Processes: The Case of Filled Filaments.

The emergence of additive manufacturing technologies has brought about a significant transformation in several industries. Among these technologies, Fused Deposition Modeling/Fused Filament Fabrication (FDM/FFF) 3D printing has gained prominence as a rapid prototyping and small-scale production technique. The potential of FDM/FFF for applications that require improved mechanical, thermal, and electrical properties has been restricted due to the limited range of materials that are suitable for this process. This study explores the integration of various reinforcements, including carbon fibers, glass fibers, and nanoparticles, into the polymer matrix of FDM/FFF filaments. The utilization of advanced materials for reinforcing the filaments has led to the enhancement in mechanical strength, stiffness, and toughness of the 3D-printed parts in comparison to their pure polymer counterparts. Furthermore, the incorporation of fillers facilitates improved thermal conductivity, electrical conductivity, and flame retardancy, thereby broadening the scope of potential applications for FDM/FFF 3D-printed components. Additionally, the article underscores the difficulties linked with the utilization of filled filaments in FDM/FFF 3D printing, including but not limited to filament extrusion stability, nozzle clogging, and interfacial adhesion between the reinforcement and matrix. Ultimately, a variety of pragmatic implementations are showcased, wherein filled filaments have exhibited noteworthy benefits in comparison to standard FDM/FFF raw materials. The aforementioned applications encompass a wide range of industries, such as aerospace, automotive, medical, electronics, and tooling. The article explores the possibility of future progress and the incorporation of innovative reinforcement materials. It presents a plan for the ongoing growth and application of advanced composite materials in FDM/FFF 3D printing.

POLYANILINE, HALLOYSITE NANOTUBES AND THEIR NANOCOMPOSITE AS ADSORBENTS FOR ORGANIC DYES

This work is devoted to the study of the adsorption efficiency of methylene blue and methyl orange dyes by polyaniline base (PANI), halloysite nanotubes (HNTs), and their nanocomposite (HNTs/PANI). PANI and the nanocomposite were prepared by the chemical oxidative polymerization of aniline in the absence and presence of HNTs followed by subsequent dedoping by ammonia solution. The morphology and thermal stability of the adsorbents were explored. In particular, the TEM method showed that the nanocomposite consisted of practically non-agglomerated nanoparticles with a “core-shell” morphology. Particles of pure polymer are quite agglomerated and form massive aggregates. The kinetics of decreasing the concentration of dyes in solutions upon their contact with adsorbent powders was studied by the method of electron spectroscopy. The HNTs/PANI nanocomposite was found to absorb both dyes with slightly higher efficiency than the PANI base probably due to more developed surface of the former. Processing of the obtained results of adsorption of both dyes on the studied adsorbents according to different kinetic models (pseudo-first and pseudo-second order and intraparticle diffusion) showed that in all cases this process is best described by the pseudo-second order model, which indicates the chemical nature of adsorption. The calculated adsorption capacity of the adsorbents under study appeared be quite close to the experimental one. These materials can be used as effective adsorbents for cleaning wastewaters from organic dyes.

Amplified Dielectric Properties of PVDF-HFP/SrTiO3 Nanocomposites for a Flexible Film Capacitor.

A simple solution casting technique was used to fabricate perovskite strontium titanate (SrTiO3)-loaded poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) nanocomposite films for efficient energy storage applications. Various microscopic and spectroscopic methods were used to study the characteristics of the polymer nanocomposite films, like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction technique (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible spectroscopy, thermogravimetric analysis, and mechanical tensile test (stress vs strain). The FTIR, XRD, and FESEM analyses confirmed the incorporation and proper dispersion of SrTiO3 nanoparticles in the PVDF-HFP polymer matrix. An improvement in the optical, thermal, and mechanical behavior of the nanocomposite film was observed compared to the pure polymer. The values of dielectric constant, loss tangent, and AC conductivity of pure PVDF-HFP polymer and PVDF-HFP/SrTiO3 nanocomposites (2, 6, and 10 wt % SrTiO3 loadings) were analyzed in a temperature and frequency span of 30-150 °C and 1-100 kHz, respectively. To better understand the electrical properties of the materials, Nyquist plots were generated, and their related circuit designs were fitted. The 2 wt % SrTiO3 loaded nanocomposite exhibited the highest dielectric enhancement and AC conductivity compared to higher filler-loaded nanocomposites. This exceptional dielectric enhancement at very small filler loading is beneficial for commercialization and economically viable for real-time applications.

Thermo-mechanical analysis of additive manufacturing for material properties estimation of layered polymer composite

This paper proposes a numerical approach for predicting residual stresses induced during the additive manufacturing (AM) of polymer composites and their effect on the deformation behavior of the composites. A finite element (FE) model was developed on Abaqus/Standard for 3D printing of layered polymer composite using three polymers: HDPE, PVC, and ABS. The material properties of pure polymers and their blends were measured through tensile testing of injection-molded specimens. These properties were then used as input data in the FE model for the regions of pure polymers and their interfaces. An uncoupled thermo-mechanical analysis was performed, where a heat transfer analysis was realized first using elements birth (activation/deactivation) technique and a moving cylindrical volumetric heat source as a Fortran subroutine (DFLUX). With temperature input from thermal simulation, a mechanical analysis was carried out to deform the polymer composites along and across the print direction, i.e. under isostrain and isostress conditions, respectively. It was observed that the theoretical models existing in the literature underestimate the material properties as they do not consider the residual stresses developed during fabrication. The FE simulations predicted that the estimated material properties were 10 to 50% different from those calculated by the theoretical models, depending upon the residual stress level and the print direction.

Evaluation of the physical properties and filtration efficiency of PVDF/PAN nanofiber membranes by using dry milk protein

In engineering applications, especially ultrafiltration (UF) applications, it is very important to use polyacrylonitrile (PAN) and poly (vinylidene fluoride) (PVDF) nanofiber membranes. In this study, membrane nanofibers made of pure PAN, PVDF: PAN blends, and pure PVDF (M1, M2, M3, M4, M5, and M6), were produced by the electrospinning technique with different contents of PVDF in each blend. The prepared membranes were characterized by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), contact angle measurements, x-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrophotometry, and differential scanning calorimetry-thermogravimetric analysis (DSC-TGA). In terms of the physical properties, the viscosity of the membranes increased with an increase in the content of PVDF in the blends compared with the viscosity of the pure polymer solutions. This led to increases in nanofiber diameter, pore size, and porosity by 261.664%, 875.107%, and 114.41%, respectively, when the content of PVDF increased from 20% (M2) to 80% (M5); this was also accompanied by an increase in the surface wettability of the membrane depending on its contact angle. In addition, the thermal properties and crystallinity of PAN improved after increasing the PVDF content from 20% (M2) to 60% (M4). Moreover, the filtration efficiency of the membranes was measured to determine the per cent reduction in pure water flux, reduction in mean depth (RMD) before and after using dry milk protein, the flux recovery ratio and porosity, giving values of 15.68%, 82.51%, 84.32%, and 67.79%, respectively, for the M4 membrane.

Ion Solvation Cage Structure in Polymer Electrolytes Determined by Combining X-ray Scattering and Simulations.

Solvation structure plays a crucial role in determining ion transport in electrolytes. We combine wide-angle X-ray scattering (WAXS) and molecular dynamics (MD) simulation to identify the solvation cage structure in two polymer electrolytes, poly(pentyl malonate) (PPM) and poly(ethylene oxide) (PEO) mixed with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. As the salt concentration increases, the amorphous halo in the pure polymers is augmented by an additional peak at low scattering angles. The location of this peak and its height are, however, different in the two electrolytes. By decoupling the total intensity into species contributions and mapping scattering peaks to position-space molecular correlations, we elucidate distinct origins of the additional peak. In PPM, it arises from long-range charge-ordering between solvation cages and anions, while in PEO it is dominated by correlations between anions surrounding the same cage. TFSI- ions are present in the PPM solvation cage, but expelled from the PEO solvation cage.