Mixture Of PS Research Articles

Size- and surface charge-dependent hormetic effects of microplastics on bacterial resistance and their interactive effects with quinolone antibiotic

The facilitation of microplastics (MPs) on bacterial resistance has attracted wide concern, due to the widespread presence of MPs in environmental media and their ubiquitous contact with bacteria strains. Furthermore, MPs possibly co-exist with antibiotics to trigger combined stress on bacterial survival. Therefore, it is significant to reveal the dose-responses of MPs and MP-antibiotic mixtures on bacterial endogenous and exogenous resistance. In this study, 0.1 and 5 μm polystyrenes with no surface functionalization (PS-NF, no charge), surface functionalized with amino groups (PS-NH2, positive charge) and carboxyl groups (PS-COOH, negative charge) were selected as the test MPs, and norfloxacin (NOR) was set as the representative of antibiotics. It was found that six types of PS all inhibited the growth of Escherichia coli (E. coli) but induced hormetic dose-responses on the mutation frequency (MF) and conjugative transfer frequency (CTF) of RP4 plasmid in E. coli. Moreover, these hormetic effects exhibited size- and surface charge-dependent features, where 0.1 μm PS-NH2 (100 mg/L) triggered the maximum stimulatory rates on MF (363.63 %) and CTF (74.80 %). The hormetic phenomena of MF and CTF were also observed in the treatments of PS-NOR mixtures, which varied with the particle size and surface charge of PS. In addition, the interactive effects between PS and NOR indicated that the co-existence of PS and NOR might trigger greater resistance risk than the single pollutants. Mechanistic exploration demonstrated that the increase of cellular reactive oxygen species and the variation of cell membrane permeability participated in the hormetic effects of PS and PS-NOR mixtures on bacterial resistance. This study provides new insights into the individual effects of MPs and the combined effects of MP-antibiotic mixtures on bacterial resistance, which will promote the development of environmental risk assessment of MPs from the perspective of bacterial resistance.

Biofuel Production Through Co-Pyrolysis Process By Utilizing Waste Raw Materials Of Palm Oil and Plastic Waste

Oil, natural gas, and coal are non-renewable fossil energy sources. The limited availability of non-renewable fossil fuels has prompted countries worldwide to develop technologies that harness energy from renewable sources. One of these renewable energy sources is biofuel, which includes bioethanol and biodiesel. Currently, the Co-Pyrolysis method has been widely developed for waste processing. The Co-Pyrolysis method aims to extract energy content from a mixture of raw materials. The varying percentage of raw material mixtures can significantly influence the resulting products. Obtaining the characteristics of raw materials, the differences in temperature distribution graphs for each percentage of the raw material mixture, and achieving optimum product yield are the objectives of the Co-Pyrolysis process. Based on the data from the heating process, it has been found that an excellent product can be obtained from heating a mixture of TKKS (30%) and PS (70%) at 500 °C for 1 hour, resulting in a product yield of 68%.

Toward time resolved dynamic light scattering microscopy: Retrieving particle size distributions at high temporal resolutions.

Dynamic light scattering (DLS) is a widely applied technique in multiple scientific and industrial fields for the size characterization of nanoscale objects in solution. While DLS is typically applied to characterize systems under static conditions, the emerging interest in using DLS on temporally evolving systems stimulates the latent need to improve the time resolution of measurements. Herein, we present a DLS microscopy setup (micro-DLS) that can accurately characterize the size of particles from autocorrelation functions built from sub-100ms time windows, several orders of magnitude faster than previously reported. The system first registers the arrival time of the scattered photons using a time-correlated single photon counting module, which allows the construction of the autocorrelation function for size characterization based on a time window of freely chosen position and width. The setup could characterize both monomodal (60 or 220nm polystyrene particles; PS) and multimodal size distributions (e.g., mixture of 20nm LUDOX and 80nm PS) with high accuracy in a sub-100ms time window. Notably, the width of the size distribution became narrower as a shorter time window was used. This was attributed to the ability of the system to resolve the sub-ensemble of the broad size distribution, as the broad distribution could be reconstructed by accumulating the distribution obtained by consecutive 80ms time windows. A DLS system with high temporal resolution will accelerate the expansion of its application toward systems that evolve as a function of time beyond its conventional use on static systems.

Pyrolysis of mixed plastic fractions – Development of predictive models for yield and oil quality

Pyrolysis of plastic mixtures has shown to form complex mixtures of oil, which is difficult to predict. Interaction effects between plastics have shown to affect both the oil composition and the yield distribution of oil, char, and gas. This work aims to generate models for the prediction of oil and char yield, acid number, and viscosity based on the feed composition. Besides the oil composition based on the reactor feed was mapped. Pyrolysis was performed in a batch reactor with a mixture of PP, PE, EVA, PET, PS and PA, where the content of PET, PS and PA were varied from 0% to 15%. The developed models showed a decrease in oil yield of 10% when 15% PS was interchanged with PET. Char content, acid number, and viscosity were shown to increase with the content of PET and lowered with the content of PS. PA caused an increase in char yield and viscosity, while it did not affect the acid number. The models R2-values varied from 0.87 to 0.96, showing that most of the variation in the responses can be explained by the differences in feed composition. The oil composition was found to mainly consist of hydrocarbons (C10 +), naphta and aromatics with only a small precense of alcohol and acid. The content of aromatic hydrocarbons is increased by the presence of PS, due to formation of styrene and toluene while the acid content increases with the PET content.

Microstructure and flexural performances of glass fibers reinforced phosphate sludge based geopolymers at elevated temperatures

The focus of this study is the development of innovative and sustainable geopolymer composites with improved elevated temperatures performances. To minimize production related costs and support a circular economy model, phosphate sludge and MK are chosen as precursors for alkaline activation, and glass fibers as reinforcement material. The geopolymer composites were prepared by incorporating glass fibers in a geopolymer matrix based on a mixture of metakaolin and PS in a ratio of 50% and with amounts ranging from 0.25% to 1% of fibers. The developed composites were assessed in terms of physical characteristics, microstructural properties and flexural strength prior to and after introduction to higher temperatures. The findings demonstrated that PS based geopolymer matrix flexural strength decreased in the region of temperature between 25 and 600 °C, but increased progressively at higher temperatures, achieving a gain of 3.2% at 1000 °C. The same trend was followed after glass fiber incorporation, leading to a more significant gain of about 16.5% with a 1% fiber content up to 1000 °C. This behavior was assigned to the decomposition of carbonate content of PS at 600 °C as well as to the crystallization of the geopolymer matrix at higher temperatures.

EFFECTS OF MOLECULAR WEIGHT ON MICROFLUIDIC SEPARATION

the molecular weight effects the diffusion of molecules in the interface of laminar flow form in a microfluidic channel. Two mixtures of PS with anisole and PEG were used to evaluate the molecular weight effect on the microfluidic separation. Also, the separation of a low molecular weight substance of anisole from the mixture with a high molecular weight substance of PS is proved experimentally. However, the separation of PEG from the mixture with PS remained difficulty. More information about diffusion in microfluidic channel and can be applied to polymer science and separation fields.

Simply Fabricated Inexpensive Dual-Polymer-Coated Fabry-Perot Interferometer-Based Temperature Sensors with High Sensitivity.

We designed simply fabricated, highly sensitive, and cost-effective dual-polymer-coated Fabry–Perot interferometer (DFPI)-based temperature sensors by employing thermosensitive polymers and non-thermosensitive polymers, as well as different two successive dip-coating techniques (stepwise dip coating and polymer mixture coating). Seven sensors were fabricated using different polymer combinations for performance optimization. The experiments demonstrated that the stepwise dip-coated dual thermosensitive polymer sensors exhibited the highest sensitivity (2142.5 pm °C−1 for poly(methyl methacrylate)-polycarbonate (PMMA_PC) and 785.5 pm °C−1 for poly(methyl methacrylate)- polystyrene (PMMA_PS)). Conversely, the polymer-mixture-coated sensors yielded low sensitivities (339.5 pm °C−1 for the poly(methyl methacrylate)-polycarbonate mixture (PMMA_PC mixture) and 233.5 pm °C−1 for the poly(methyl methacrylate)-polystyrene mixture (PMMA_PS mixture). Thus, the coating method, polymer selection, and thin air-bubble-free coating are crucial for high-sensitivity DFPI-based sensors. Furthermore, the DFPI-based sensors yielded stable readouts, based on three measurements. Our comprehensive results confirm the effectiveness, reproducibility, stability, fast response, feasibility, and accuracy of temperature measurements using the proposed sensors. The excellent performance and simplicity of our proposed sensors are promising for biomedical, biochemical, and physical applications.

Subchronic toxicity of dietary sulfamethazine and nanoplastics in marine medaka (Oryzias melastigma): Insights from the gut microbiota and intestinal oxidative status

Antibiotics and nanoplastics are two prevalent pollutants in oceans, posing a great threat to marine ecosystems. As antibiotics and nanoplastics are highly bioconcentrated in lower trophic levels, evaluating their impacts on marine organisms via dietary exposure route is of great importance. In this study, the individual and joint effects of dietborne sulfamethazine (SMZ) and nanoplastic fragments (polystyrene, PS) in marine medaka (Oryzias melastigma) were investigated. After 30 days of dietary exposure, 4.62 mg/g SMZ decreased the Chao1 index (60.86% for females and 26.85% for males) and the Shannon index (68.95% for females and 65.05% for males) and significantly altered the structure of gut microbial communities in both sexes. The female fish exposed to 4.62 mg/g SMZ exhibited higher intestinal sod (43.5%), cat (38.5%) and gpx (39.6%) transcripts, indicating oxidative stress in the gut. PS alone at 3.45 mg/g slightly altered the composition of the gut microbiota. Interestingly, the mixture of SMZ and PS caused more modest effects on the gut microbiota and intestinal antioxidant physiology than the SMZ alone, suggesting that the presence of PS might alleviate the intestinal toxicity of SMZ in a scenario of dietary co-exposure. This study helps better understand the risk of antibiotics and nanoplastics to marine ecosystems.

Parental exposure to sulfamethazine and nanoplastics alters the gut microbial communities in the offspring of marine madaka (Oryzias melastigma)

The individual and combined toxicity of antibiotics and nanoplastics in marine organisms has received increasing attention. However, many studies have been mostly focused on the impacts on the directly exposed generation (F0). In this study, intergenerational effects of sulfamethazine (SMZ) and nanoplastic fragments (polystyrene, PS) on the growth and the gut microbiota of marine medaka (Oryzias melastigma) were investigated. The results showed that parental exposure to dietary SMZ (4.62 mg/g) alone and PS (3.45 mg/g) alone for 30 days decreased the body weight (by 13.41% and 34.33%, respectively) and altered the composition of gut microbiota in F1 males (two months after hatching). Interestingly, parental exposure to the mixture of SMZ and PS caused a more modest decrease in the body weight of F1 males than the PS alone (15.60% vs 34.33%). The hepatic igf1 level and the relative abundance of the host energy metabolism related phylum Bacteroidetes for the SMZ + PS group were significantly higher than those for the PS group (igf1, increased by 97.1%; Bacteroidetes, 2.876% vs 0.375%), suggesting that the parentally derived mixture of SMZ and PS might influence the first microbial colonization of gut in a different way to the PS alone. This study contributes to a better understanding of the long-term risk of antibiotics and nanoplastics to marine organisms.

The influence of PET and PBT contamination during transportation fuel production via pyrolysis

The pyrolysis of plastic waste is a promising method to reduce waste accumulation while it could provide value-added transportation fuels. The main goal of this study is to investigate the influence of PET and PBT contamination during plastic pyrolysis oil production utilizing HDPE, LDPE, PP, and PS mixtures as these plastics are good candidates for transportation fuel production via pyrolysis and distillation. Seven different waste blends were prepared and pyrolyzed in a laboratory-scale batch reactor equipped with reflux. Mass balance, gas analysis, thermogravimetric analysis, and deposit formation were evaluated. It was concluded that by increasing the PET or PBT concentration in the initial solid waste mixtures, the oil production decreases while the amount of gases increases. Additionally, either PET or PBT generates operational difficulties due to they form deposits in piping system in form of benzoic acid. The maximum concentration of these plastic waste materials was 20% (PET) and 25% (PBT) in this study as further increase blocked the cross-section of piping, causing operational difficulties. Based on the obtained results the concentration of PET and PBT should be limited in waste mixtures when transportation fuel production is desired.

Phase behavior in thin films of weakly segregated block copolymer/homopolymer blends.

We have demonstrated the phase behavior of substrate-supported films of a symmetric weakly segregated polystyrene-block-poly (methyl methacrylate), P(S-b-MMA), block copolymer and its blends with homopolymer polystyrene (PS) at different compositions. Upon increasing the content of added PS in the blends, lamellae (L), perforated layers (PL), double gyroid (DG) and cylinders (C) are obtained in sequence for films. Among these nanodomains, PL and DG only exist in a narrow ϕPS region (ϕPS denotes the volume fraction of PS). At ϕPS = 64%, tuning film thickness and annealing temperature can produce parallel PL or DG with {121}DG lattice planes being parallel to the substrate surface. The effects of annealing temperature and film thickness on the formation of PL and DG are examined. In thin films with n ≈ 3 (n denotes the ratio of initial film thickness to inter-domain spacing), the PL phase solely exists regardless of temperature. However, for thick films with n ≈ 6 and 10, thermal annealing at the most accessible temperature produces films containing both PL and DG of various fractions, but a low temperature tends to favor a greater fraction of PL. The PL phase becomes the only discernible phase if thick films are shortly annealed at 230 °C.

Kinetic study for the co-pyrolysis of water hyacinth biomass with waste polystyrene

Co-pyrolysis behavior of water hyacinth (WHC) and waste PS using thermogravimetric analysis to determine kinetic parameters was investigated. TG and DTG results indicated that the pyrolysis of WHC and mixture of WHC and waste PS could be divided into three stages. It was found that co-pyrolysis of WHC and waste PS delayed the pyrolysis process with a wider decomposition temperature range, when compared with the pyrolysis of PS. The results compared with the pyrolysis of individual components revealed a positive synergistic interaction between WHC and waste PS according to the difference in weight loss. Coats-Redfern method was applied in the second stage to evaluate the activation energy (Ea) and pre-exponential factor (A) from the data of weight loss using three major reaction mechanisms. Two conversion temperature zones, zone I of 240-400 °C and zone II of 400-530 °C, were identified and a best-fit model describing the co-pyrolysis behavior of mixture was achieved. The addition of waste PS to WHC led to a slight decrease in the activation energy in the first zone and then the activation energy significantly reduced in the second zone. Chemical reaction and diffusion-controlled reaction mechanisms could be kinetically examined and enabled good explanation of the co-pyrolysis behavior of the mixture of WHC and waste PS as well as individual pyrolysis.

Nonspherical Nanoparticles in Block Copolymer Composites: Nanosquares, Nanorods, and Diamonds

A hybrid block copolymer(BCP) nanocomposite computational model is proposed to study nanoparticles(NPs) with a generalised shape including squares, rectangles and rhombus. Simulations are used to study the role of anisotropy in the assembly of colloids within BCPs, ranging from NPs that are compatible with one phase, to neutral NPs. The ordering of square-like NPs into grid configurations within a minority BCP domain was investigated, as well as the alignment of nanorods in a lamellar-forming BCP, comparing the simulation results with experiments of mixtures of nanoplates and PS-\textit{b}-PMMA BCP. The assembly of rectangular NPs at the interface between domains resulted in alignment along the interface. The aspect ratio is found to play a key role on the aggregation of colloids at the interface, which leads to a distinct co-assembly behaviour for low and high aspect ratio NPs.

Investigation on regulation mechanism of red mud on the ash fusion characteristics of high ash-fusion-temperature coal

Red mud (RM) used as a flux to decrease coal ash fusion temperature (AFT) has great economic and environmental attractions. The effects of Bayer RM (BRM) and Sintering RM (SRM) on the AFTs of high silicon-aluminum coal (Jiaozuo coal (ZJ)) or high aluminum coal (Pingsuo coal (PS)) were investigated by X-ray fluorescence analysis, X-ray diffraction, and FactSage calculation. With increasing BRM/SRM mass ratio, the AFTs of JZ or PS mixture firstly decreased quickly and then slowly. When ash flow temperatures were decreased to <1400 °C, for ZJ mixtures, the mass ratio of BRM or SRM should not be <1.38% or 0.65%; while for PS, BRM or SRM should not be <2.76% or 1.81%, respectively. SRM lower AFT’s of two coals compared to the addition of BRM resulted from that SRM higher CaO content (20.12 wt%) than that of BRM (8.87 wt%), and its lower A/B value (1.15) than BRM (1.53). The increasing contents of Na2O, Fe2O3, and CaO inhibited high melting-point (MP) mullite formation and prompted the formations of low MP albite, hercynite, and anorthite with increasing RM mass ratio. This caused the respective decrease in the AFTs. The mineral evolution based on FactSage calculation could explain the AFT changing trend with increasing BRM or SRM mass ratio.

Nanoporous Polymer Networks of N-Vinylpyrrolidone with Triethylene Glycol Dimethacrylate and Sorption of Macromolecules

Nanoporous polymer networks with different composition are obtained by the 3D radical copolymerization of N-vinylpyrrolidone and triethylene glycol dimethacrylate in the presence of a branched copolymer that acts as a macromolecular template and a pore-forming agent. The processes of adsorption of polyvinylpyrrolidone, poly(methyl methacrylate), and polystyrene from their mixtures in chloroform by the N‑vinylpyrrolidone-based nanoporous polymer network and their desorption are studied. The molecular-weight distribution and composition of PVP–PMMA and PVP–PS mixtures (before and after adsorption) and macroobjects (after desorption) are studied by GPC and IR spectroscopy. A high selectivity of the nanoporous polymer network for the adsorption of polyvinylpyrrolidone from its mixture with nonpolar polystyrene is shown.

Effect of Mixing on the Optical Parameters of Polymer Blend (PMMA:PVC:PS) Thin Films

The thin films have been prepared using casting method at normal weather conditions of pressure and temperature. The films treated thermally for three hours at 45 °C. The UV-VIS double beam technique used to determine absorption and reflection spectrum. The thickness of the prepared thin films is measured using a handheld gauge of coating thickness measurement. Excel and MATLAB program used to calculate and simulate parameters and figures. The optical properties of PMMA:PVC:PS mixtures have been investigated. There is a clear change in the optical parameters due to mixing ratio. The result shows the indirect energy gap values reduced from 1.58 to 1.9 electron-volts. Mix a ratio of PMMA, PVC & PS leads to enhance some of the optical parameters like optical energy gap, absorbance, extinction coefficient and optical conductivity. The four kinds of thin films have different properties: The polymer blend (50%PMMA:25%PVC:25%PS) has the smallest values of the energy gap and linear refractive index, and the highest extinction coefficient values. The polymer blend (25%PMMA:25%PVC:50%PS) has a small value of energy gap and the best optical conductivity. The polymer blend (25%PMMA:50%PVC:25%PS) has the highest Urbach energy and absorption for the short wavelength (370 to 620 nm). The polymer blend (50%PVC:50%PS) has a good reflection, linear refractive index and skin depth, but it has the lowest values of extinction coefficient and optical conductivity.

Investigation on the feasibility of coffee husk (endocarp) as efficient filler material for enhancing physical and mechanical properties of styrofoam based particleboard

This research focuses on introducing a coffee husk as viable and efficient filler for enhancing physical and mechanical properties of Styrofoam based particleboard. Heat treatment method was adopted to produce the particleboard from the mixture of coffee husk (CH) with Styrofoam (PS). Styrofoam is material derived from polystyrene. The aim of this research is to get the appropriate weight composition between coffee husks with PS and to identify the physical and mechanical properties of the produced particleboard. The composition of coffee husk varies between 0-90%wt. The manufacture of particleboard i.e. coffee husk milled with size 20/10 mesh then soak with 10% NaOH for 2 hours, rinsed with clean water and dried and weight according to the composition. The mixture of CH and PS is inserted into mold and put into hot-press. The result shows from physical properties that density, water absorption and thick development test corresponding with SNI 03-2105-2006 standard, the mechanical properties shows MOR test meets the standard on the addition of CH 10-50%, while the MOE test has not meet the standard.

Data including GROMACS input files for atomistic molecular dynamics simulations of mixed, asymmetric bilayers including molecular topologies, equilibrated structures, and force field for lipids compatible with OPLS-AA parameters

In this Data in Brief article we provide a data package of GROMACS input files for atomistic molecular dynamics simulations of multicomponent, asymmetric lipid bilayers using the OPLS-AA force field. These data include 14 model bilayers composed of 8 different lipid molecules. The lipids present in these models are: cholesterol (CHOL), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylethanolamine (POPE), 1-stearoyl-2-oleoyl-sn-glycero-3-phosphatidyl-ethanolamine (SOPE), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (POPS), 1-stearoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (SOPS), N-palmitoyl-D-erythro-sphingosyl-phosphatidylcholine (SM16), and N-lignoceroyl-D-erythro-sphingosyl-phosphatidylcholine (SM24). The bilayers׳ compositions are based on lipidomic studies of PC-3 prostate cancer cells and exosomes discussed in Llorente et al. (2013) [1], showing an increase in the section of long-tail lipid species (SOPS, SOPE, and SM24) in the exosomes. Former knowledge about lipid asymmetry in cell membranes was accounted for in the models, meaning that the model of the inner leaflet is composed of a mixture of PC, PS, PE, and cholesterol, while the extracellular leaflet is composed of SM, PC and cholesterol discussed in Van Meer et al. (2008) [2]. The provided data include lipids׳ topologies, equilibrated structures of asymmetric bilayers, all force field parameters, and input files with parameters describing simulation conditions (md.mdp). The data is associated with the research article “Interdigitation of Long-Chain Sphingomyelin Induces Coupling of Membrane Leaflets in a Cholesterol Dependent Manner” (Róg et al., 2016) [3].

Structure and Lipid Binding Preferences of the Alternatively Translated Region of PTEN-Long

PTEN-Long is a 576-amino acid translational variant of phosphatase and tension homolog on chromosome ten (PTEN), a tumor suppressor gene and antagonist to phosphoinositide-3-kinase (PI3K) signaling.PTEN-Long (PTEN-L) exhibits an alternative translation region (ATR) with additional 173 N-terminal amino acids to the normal PTEN open reading frame.Several studies have demonstrated that PTEN-Long is secreted from cells, can exist outside the cell and can enter other cells via a yet to be determined mechanism. PTEN-L may have therapeutic uses by restoring a functional tumor suppressor protein to tumor cells. A computational analysis reported that the N-terminal ATR part of PTEN-L is largely unstructured and has the potential to interact with a variety of proteins. The ATR region of PTEN-L is evolutionary conserved and contains a polyarginine stretch with homology to cell permeable peptides. Using CD and FTIR spectroscopy, we confirmed that the ATR region of PTEN-L is intrinsically disordered. It is not very well understood if PTEN-L ATR shares the same protein-protein, protein-lipid activity and mechanism of regulation as normal PTEN. Our FTIR studies with lipid mixtures of PC, PS, and PI(4,5)P2 did not reveal an observable structural change to PTEN-L ATR upon lipid binding. We are currently delineating the lipid binding preferences of the ATR part of PTEN-L as well as the full-length protein.

GS0908 PSとABSからなるプラスチック混合物の静電選別

GS0908 PSとABSからなるプラスチック混合物の静電選別