Waste Expanded Polystyrene Foam Research Articles

Sustainable fabrication of fluorescent carbon quantum dots as an optical amplifier in modern agriculture, anti-counterfeiting, food packing and intelligent pH detection

Carbon quantum dots (CQDs) have received a great deal of attention due to their distinctive luminescent features and exciting potential applications in the fields of agronomy, enhanced anti-counterfeiting, drug tracking and intelligent sensing and detection. The focus of the current effort is on easily transforming toxic, non-biodegradable waste expanded polystyrene foam (WEPS) into extremely luminescent CQDs and investigating their various applications. As a nano-priming agent for Cajanus cajan (L.), the green pigeon pea (GPP), WEPS derived CQDs are used. The outcomes showed that seed priming had beneficial effects at all CQDs concentrations (100–900 mg/L), including accelerated seed germination rate, increased shoot and root length, augmented root vigour, higher chlorophyll content and biomass accumulation in comparison to the control groups. The most crucial data coding can be protected under 365 nm UV light using the optimized CQDs concentration (700 mg/L) blue fluorescent ink. In addition, a straightforward sensing platform with high sensitivity and selectivity is needed for the detection of dual metal ions, as well as one with a "turn-on and turn-off" fluorescence (FL) response. Additionally, a composite film containing well-dispersed CQDs (700 mg/L) in polyvinyl alcohol and strong hydrogen-bond interaction is successfully developed to alleviate the FL quenching caused by CQD aggregation. The resulting film had extraordinary FL performance, good mechanical flexibility and high transparency (transmittance of 90 %). Even more remarkably, this luminescent film showed sensitive pH responsiveness, signifying that when pH is stimulated, the FL intensity changed. A smart pH-detector based on this luminescent film is logically created as a proof-of-concept for real-time sensing and detection of pH changes in human sweat. These results show that WEPS derived CQDs have enormous potential as nano-priming agents for seed germination, seedling development, anti-counterfeiting ink, food packaging and intelligent pH-detector in wearable, real-time health monitoring.

Improvised centrifugal spinning for the production of polystyrene microfibers from waste expanded polystyrene foam and its potential application for oil adsorption

A straightforward approach to recycle waste expanded polystyrene (EPS) foam to produce polystyrene (PS) microfibers using the improvised centrifugal spinning technique is demonstrated in this work. A typical benchtop centrifuge was improvised and used as a centrifugal spinning device. The obtained PS microfibers were characterized for their potential application for oil adsorption. Fourier transform infrared spectroscopy results revealed similarity on the transmission bands of EPS foam and PS microfibers suggesting the preservation of the EPS foam’s chemical composition after the centrifugal spinning process. Scanning electron microscopy displayed well-defined fibers with an average diameter of 3.14 ± 0.59 μm. At the same time, energy dispersive X-ray spectroscopy revealed the presence of carbon and oxygen as the primary components of the fibers. Contact angle (θCA) measurements showed the more enhanced hydrophobicity of the PS microfiber (θCA = 100.2 ± 1.3°) compared to the untreated EPS foam (θCA = 92.9 ± 3.5°). The PS microfiber also displayed better oleophilicity compared to EPS foam. Finally, the fabricated PS microfibers demonstrated promising potential for oil removal in water with a calculated sorption capacity value of about 15.5 g/g even at a very short contact time. The fabricated PS fiber from the waste EPS foam may provide valuable insights into the valorization of polymeric waste materials for environmental and other related applications.

Studies on the adsorption of dyes, Methylene blue, Safranin T, and Malachite green onto Polystyrene foam

Many researchers focus on the conversion of waste into reusable materials in recent years. In this study, waste expanded polystyrene foam (WEPS) and 1,2,4-benzenetricarboxylic anhydride (BTA) were used as raw materials to prepare recyclable acylating waste expanded polystyrene adsorbent (WEPS-BTA) by Friedel-Crafts reaction and to recover dyes effectively. The WEPS-BTA was characterized by FT-IR, TGA, BET and SEM. WEPS-BTA showed good performance in a wide range of pH (2–12) and high concentration brine (0.2 M). The maximum adsorption capacity to methylene blue, safranine T, and malachite green were 859.9, 1036.7, and 1197.3 mg/g, respectively. It was found that Freundlich model and pseudo-second-order kinetics could describe the adsorption behavior. This is a heterogeneous, endothermic, and spontaneous multiple adsorption process. The plausible adsorption mechanism was explained by kinetic model, thermodynamic discussion, SEM-EDS, XPS and FT-IR. In addition, WEPS-BTA showed satisfactory reusability without significant loss of the removal efficiency of the three dyes after 5 cycles. Therefore, WEPS-BTA has the advantages of simple synthesis, efficient adsorption, easy recycling and reuse, and stable performance in a harsh environment. Converting waste polystyrene foam to an adsorbent is an economic way of handling waste and providing material for wastewater remediation simultaneously.

Conversion of waste polystyrene foam into sulfonated hyper-crosslinked polymeric adsorbents for cadmium removal in a fixed-bed column

In this paper, the sulfonated hyper-crosslinked polystyrene (SHCP) adsorbents derived from the waste expanded polystyrene foam (WEPS) were prepared by the simple one-step Friedel–Crafts reaction and the subsequent sulfonation. The prepared SHCP adsorbents were used for the first time in the fixed-bed dynamic adsorption experiments for the removal of cadmium (Cd) ions. The maximum adsorption capacity of SHCP for Cd ion reached 0.7mmol/g at the pH of 7 at the temperature of 25°C. The influencing factors of the actual industrial wastewater including initial Cd ion concentration, height-to-diameter (H/d) ratio, ionic strength and co-existing ions on Cd ion adsorption breakthrough curve were examined in a fixed-bed column with the SHCP adsorbents. Furthermore, Thomas model was employed to fit the adsorption breakthrough curve and the simulated adsorption capacity ranged from 68.90 to 80.46mg/g, with the correlation coefficient higher than 0.97. It was found that the decrease of the ionic strength and the Cd ion initial concentration, as well as the increase of the H/d ratio would increase the adsorption capacity and the breakthrough point in the Cd ion column adsorption. In addition, the SHCP showed good Cd ion selectivity over Na ions in the column adsorption.

CBR Properties of Sand Mixed with Modified Waste Expanded Polystyrene Foams (EPS)

CBR Properties of Sand Mixed with Modified Waste Expanded Polystyrene Foams (EPS)

Transforming waste expanded polystyrene foam into hyper-crosslinked polymers for carbon dioxide capture and separation

A novel facile and one-pot approach was developed for the preparation of hyper-crosslinked polymers (HCPs) via the Friedel-Crafts reaction between the waste expanded polystyrene foam (WEPS) and 1,2-dichloroethane in this study. 1,2-dichloroethane as a cost-effective chemical agent was used as both the solvent and the cross-linker for HCPs. The obtained HCPs showed large specific surface areas and good thermal stability. The highest CO2 adsorption capacity (1.987mmol/g) and the adsorption selectivity ratio (CO2 over N2) of 23.4 at 273K and 1.13bar were achieved among the prepared HCPs. This study provides a simple and cost-effective method to convert WEPS into value-added adsorbents for the capture and storage of carbon dioxide as the greenhouse gas.

The effects of apricot resin addition to the light weight concrete with expanded polystyrene

In this paper, the employability of waste Expanded Polystyrene Foam (EPS) as aggregate in production of concrete with apricot resin-added cement has been examined. The EPS ratios were determined as 20, 40, 60 and 80% of the total volume in the mixtures. The amount of the resin in the mixture is 1% of the weight of the total cement and EPS. At the end of 28 days of drying period, the samples were subjected to certain tests to find out their physical properties. It was seen that the porosity had increased 3.0–26.38% times compared to the case with no resin. Similarly, with increasing the EPS ratio in the mixture from 20 to 80%, the density, thermal conductivity and compressive strength had decreased in the percentages of 14.66–17.61%, 15.49–17.43% and 17.58–40.32% respectively. The rate of water absorption of sample was less than 30%. From this results, it is concluded that these materials can be used as partition walls, floorings, ceiling concretes, briquettes or bricks and plaster instead of building-carrier systems such as columns or beams.

Thermal and mechanical properties of gypsum plaster mixed with expanded polystyrene and tragacanth

In this paper, the employability of waste Expanded Polystyrene Foam (EPS) as filling material in the plaster with resin added gypsum by means of revaluation has been examined. After waste EPS is collected as packaging material and disintegration according to 0–3mm particle diameters and mixed with the gypsum of percentages; 20%, 40%, 60% and 80%. Tragacanth is added to each of this binder at 0.5%, 1% and 1.5% of the weight of the mixture in order to create artificial pores on gypsum block. The samples of 16 different combinations are produces. They are subjected to some tests to find out their properties. It is found that; the thermal conductivity, the compression and tensile strength decreases with increasing amount of EPS and tragacanth in the mixture. Produced samples must not be used in external plaster which is subjected to water against the danger of freezing as the water absorption rate was found higher than 30%. With this study, it is recommended that the samples should be used as internal plaster, insulation plaster and decoration material due to their canal opening and paint sustention features. If this plaster and decoration material is used, (i) the waste EPS will be evaluated and environmental pollution will be prevented, (ii) building heating and cooling energy will be saved.

Evaluation of Shear Strength Properties of Modified Expanded Polystyrene Aggregate

The paper presents the results of series of direct shear tests made on recycled waste expanded polystyrene foams (EPS). Waste EPS were thermally modified in an oven at 130 ̊C through 15minutes and crushed into aggregate size before tested. Heat treatment of the EPS increased its density from 15kg/m3 to nearly 200kg/m3. Shear strength behavior of modified EPS were investigated in loose and dense states under three different normal stresses. The test results showed that shear strength behavior of modified EPS is similar to that of sand. Internal friction angle of modified waste EPS in the dense state is higher than of loose state.

Compaction Properties of Sand Mixed with Modified Waste EPS

The paper presents the results of the study which influence the use of recycled waste expanded polystyrene foams (EPS), as a lightweight material used with river sand. In this study, thermally modified waste EPS have been used. The waste EPS were put in an oven at 130 °C through 15 min to obtain modified expanded polystyrene (MEPS). The influences of MEPS on compaction properties such as maximum dry density and optimum moisture content were investigated. For this purpose, five series of compaction tests were carried out. MEPS were added to river sand at 5, 10, 15, and 20 % by weight. The test results showed that addition of 20 % MEPS in sand reduces the density of mixture almost 50 %. MEPS can be an alternative light weight fill material for geotechnical applications.

Development of Biodegradable Wood Fiber Foam Packaging Material

. In daily life, expanded polystyrene foams (EPS) are widely used as packaging material and waste EPS has caused lots of environmental pollutions because it cannot be decomposed in nature. In this study, the machining process is developed of a reinforced foam packaging material by hot press molding, potato starch and birch fiber as the main raw materials. Analysis of the dosage of the birch fiber, starch adhesive and foaming agent and how do they affect the mechanical properties. Experiments show that material compressive strength is good and foam well-distributed, when the birch fiber content is 20%-25%, adhesive content is 30%-35%, and birch fiber amount is 10%-15%, the material has fine performance, and the cells are well distribute.

Paints Based on Waste Expanded Polystyrene

A formula for making paint was developed using waste expanded polystyrene foam (EPS) as a binder. This method replaces the alkyd resin in most commercial paint, which is derived from the byproducts of refining crude oil. Experimental results showed that 27% waste polystyrene foam can be incorporated in the paint formulation. Basic performance tests for EPS paint were conducted and evaluated, and the developed formulation was compared with commercial paint containing modified alkyd resin as a binder. Test results showed that EPS-based paint has some advantages such as excellent abrasion resistance, water resistance, alkali resistance, hardness, and adhesion characteristics.

A novel material for lightweight concrete production

Abstract This paper presents the results of an experimental study on the effects of using recycled waste expanded polystyrene foam (EPS), as a potential aggregate in lightweight concrete. In this study, thermally modified waste EPS foams have been used as aggregate. Modified waste expanded polystyrene aggregates (MEPS) were obtained by heat treatment method by keeping waste EPS foams in a hot air oven at 130 °C for 15 min. Effects of MEPS aggregate on several properties of concrete were investigated. For this purpose, six series of concrete samples were prepared. MEPS aggregate was used as a replacement of natural aggregate, at the levels of 0%, 25%, 50%, 75%, and 100% by volume. The density of MEPS is much less than that of natural aggregate; MEPS concrete becomes a lightweight concrete with a density of about 900–1700 kg/m3. The 28-d compressive strengths of MEPS concrete range from 12.58 MPa to 23.34 MPa, which satisfies the strength requirement of semi-structural lightweight concrete.