High-density Polyethylene Research Articles

Oligo-cyclic loading-induced evolution of stress distribution and apparent amorphous modulus in lamellar stacks of high-density polyethylene

Assessing the resistance of high-density polyethylene (HDPE) against earthquake-like loads involves understanding the changes in structure and properties induced by oligo-cyclic loading at various length scales. To study the evolution of stress distribution and intrinsic properties within lamellar stacks from pristine to oligo-cyclic loading pre-conditioned materials, simultaneous in-situ SAXS/WAXS measurements were performed. During the elastic deformation of each pristine and preconditioned sample, crystal strain was tracked using the in-situ WAXS technique. Based on the established elastic tensor of the crystalline structure in polyethylene, we calculated the microscopic stress values within crystalline lamellae. In the pristine sample, lamellar stacks exhibit closely series-like coupling in the equatorial region and parallel-like coupling in the polar region of the spherulite. In the pre-conditioned sample, stress is primarily concentrated in the intra-fibrillar region, where the crystalline and amorphous phases are series-coupled, and strong strain concentration occurs in the inter-fibrillar region. By combining the local strain in the amorphous layer within the lamellar stacks in the equatorial region of the spherulite and the intra-fibrillar region with series-coupled lamellar stacks, measured by in-situ SAXS tests, the apparent amorphous modulus at the lamellar stack scale can be determined. This modulus changes from 71 to 106 MPa in the equatorial region of pristine spherulites to a notable 2000–7000 MPa in the intra-fibrillar region under the influence of oligo-cyclic pre-loading. Importantly, this apparent modulus is affected by both crystallization conditions and molecular structure, with molecular parameters exerting the primary influence.

Mechanism Study of Removing Sealing Aluminum Contaminates from Waste Packaging High-Density Polyethylene by Eddy Current Separation

Mechanism Study of Removing Sealing Aluminum Contaminates from Waste Packaging High-Density Polyethylene by Eddy Current Separation

The Effects of Microwave Curing on Dielectric Properties of Banana Fiber Reinforced High-Density Polyethylene Composite

The Effects of Microwave Curing on Dielectric Properties of Banana Fiber Reinforced High-Density Polyethylene Composite

Selection of sustainable construction material from recycled waste plastics by q-rung orthopair fuzzy SWARA-MABAC approach

Recycling of waste plastics and agro-industrial waste for the development of sustainable polymeric composites is recognized as a viable approach to overcome the detrimental environmental effects of plastics waste. Despite of immense potential of sustainable composites in the Circular Economy (CE), its implementation is still insignificant due to the lack of an effective material selection approach. The existence of several influencing aspects in the process of material selection considers it a multi-criteria decision making (MCDM) problem. In the present work, an Aggregation Operator (AO) based integrated Stepwise Weight Assessment Ratio Analysis (SWARA) and Multi-attributive Border Approximation Area Comparison (MABAC) has been proposed to deal with the issues of material selection for polymer based sustainable composites. Moreover, q-rung orthopair fuzzy numbers (q-ROPFNs) have been implemented to tackle the uncertainty in the information. The effectiveness of the proposed approach has been confirmed by different comparative and sensitivity investigations. The developed composites have shown excellent properties whereas the responses of the materials vary invariably with compositions. The proposed method has identified the amalgamation of 10 wt percentage of rice husk ash and 10 wt percentage of sand with 80 wt percentage of high-density polyethylene (HDPE) as an appropriate material for the development of sustainable floor tiles as the composites resulted to optimum mechanical performances and minimum abrasive wear. The proposed model gives reliable and robust results and is sensitive to the criteria weights and mathematical parameters. The outcome of the research has exposed that the suggested mathematical approach can be effectively applied for material selection of sustainable polymeric composites for different applications.

Study on the behavior of pulling power and flammability of mold walls mixed with high-density polyethylene plastic waste

Currently, materials used in construction have been continuously developed in terms of quality and efficiency, especially fiber reinforcement in mortar, a form of development used in construction. The development aims to enhance concrete's tensile properties and performance for higher flexibility. Most plaster walls are ordinary mortar and have low elasticity, which is a weak point. Therefore, attempts are being made to improve their properties by using a rigid material as a concrete mixture, namely high-density polyethylene plastic, to increase its ability to bear tensile force. This study examines the tensile strength and flammability tests of walls plastered with mortar, with which high-density polyethylene plastic waste is mixed. The tensile strength of mortar plaster walls mixed with high-density polyethylene plastic is tested by replacing at 2.5%, 5%, and 10% proportions and cured at 7, 14, and 28 days. By comparing general mortar and high-density polyethylene plastic mortar, it is found that the general mortar had the highest tensile strength at 28 days of curing. The obtained value is 45 ksc, and the mortar mixed with polyethylene plastic in the amount of 2.5% at 28 days of curing can withstand the strength of 45 ksc. In addition, the general mortar can produce the same tensile strength as mortar mixed with high-density polyethylene plastic. The flammability test shows that general mortar develops red marks after being burned with fire, while the mortar combined with high-density polyethylene plastic develops black marks. However, neither type of wall is in flames nor spread.

Assessment of transport phenomena in catalyst effectiveness for chemical polyolefin recycling

Since the dawn of agitated brewing in the Paleolithic era, effective mixing has enabled efficient reactions. Emerging catalytic chemical polyolefin recycling processes present unique challenges, considering that the polymer melt has a viscosity three orders of magnitude higher than that of honey. The lack of protocols to achieve effective mixing may have resulted in suboptimal catalyst effectiveness. In this study, we have tackled the hydrogenolysis of commercial-grade high-density polyethylene and polypropylene to show how different stirring strategies can create differences of up to 85% and 40% in catalyst effectiveness and selectivity, respectively. The reaction develops near the H2–melt interface, with the extension of the interface and access to catalyst particles the main performance drivers. Leveraging computational fluid dynamics simulations, we have identified a power number of 15,000–40,000 to maximize the catalyst effectiveness factor and optimize stirring parameters. This temperature- and pressure-independent model holds across a viscosity range of 1–1,000 Pa s. Temperature gradients may quickly become relevant for reactor scale-up.

Modification of high-density polyethylene-based separator to improve lithium-ion battery performance using nano-silica and maleic anhydride

Due to its good mechanical properties and chemical stability, high-density polyethylene (HDPE) has become a fantastic polyolefin for its application in lithium-ion batteries (LIBs) as the separator of electrodes. In this work, nano-silica as a mineral material and maleic anhydride as the compatibilizer of HDPE-silica were used at different combinations to promote the HDPE-based separator efficiency. According to the results, maleic anhydride caused a perfect distribution of nano-silica particles in the polymer media leading to increasing its porosity and reducing the separator heat-shrinkability by 98 %. Also, they improved the compound electrolyte absorption from 49.4 to 94.2 % which led to a decrease in the contact angle value from 65 to 40.2 degrees. The thermal analysis showed a ~10 % reduction in the compound crystallinity without any significant change in the melting point. The obtained data indicated that the HDPE separators made of 5 wt% silica and maleic anhydride are the best candidates for LIBs. The mentioned formulation decreased the separator resistance from 860 and 410 Ω, electrolyte resistance from 13 to 8 Ω, and the increment of the ion conductivity from 0.78 to 1.24 × 10−3 S.cm−1, the LIB capacities from 99.8 to 129.8 mAh/g and 97.8 to 127.59 mAh/g at the charge and discharge processes.

Long-Term Mental Health after High-Density Polyethylene-Based Porous Orbital Implant in Enucleated and Eviscerated Patients

Objectives: To assess the overall mental health of enucleated or eviscerated patients after high-density porous polyethylene OCULFIT implantation and external prosthesis over a 1-year follow-up. Methods: Patients with an indication of enucleation or evisceration with OCULFIT implantation were included in a prospective study. The patients completed four questionnaires regarding mental health at three different visits (baseline, 3–6 months, and 9–12 months post-surgery). The questionnaires used were the following: SF-12 for multidimensional health-related quality of life (scale 0–100); Rosemberg self-esteem scale (scale 0–40); Patients Health Questionnaire-4 (PHQ-4) (scale 0–6); and a Lifetime Major Depression and Anhedonia questionnaire (categorised in groups with/without symptoms). Results: A total of 33 patients (16 enucleations and 17 eviscerations) were included in the study. The physical domain of the SF-12 questionnaire did not change between visits, but the mental domain significantly improved from the baseline to the last visit (41.71 ± 12.72 vs. 46.80 ± 10.68, p = 0.04). The number of patients with high, moderate, and low self-esteem (Rosemberg scale) was similar between the baseline and the last visit. The depression and anxiety scores of the PHQ-4 were not significantly different among visits. The number of patients with no symptoms (depression or anhedonia) improved from the baseline (42.2%) throughout the follow-up (66.7% at the last visit). Conclusions: OCULFIT orbital implant and external prosthesis placement maintained and/or improved the quality of life related to mental health in eviscerated and enucleated eyes. The number of patients with no symptoms improved from the baseline throughout the follow-up. The patients’ self-esteem was already high before implantation and remained stable over the follow-up.

Pharmaceutical residues in plastic tablet containers: Impacts on recycling and the environment

High-density polyethylene tablet containers are potentially very suitable for recycling, but no data are publicly available on active pharmaceutical ingredients’ (API) residues in empty containers and if they affect the recyclability of pharmaceutical packaging. Plastic tablet containers represented 15 % of pharmaceutical primary packages sold in Finland in 2020 and 2021, equalling 350 tons of plastic per year. We studied the residues of six APIs remaining or adsorbed inside plastic tablet containers. The effects of tablet coating and usage in dose-dispensing services versus households on the API residues, and rinsing water’s ability to remove the residues were evaluated. Up to 940,000 µg/kg of carbamazepine was detected in a container of uncoated carbamazepine tablets. The residues from coated tablets containing the other five APIs were 2.4–6,100 µg/kg. Ten times higher paracetamol residues were obtained in containers from household use than from a dose-dispensing unit. Rinsing can remove most API residues, but it leads to environmental emissions. For example, rinsing water can double carbamazepine emissions from a Finnish wastewater treatment plant where plastic packaging waste effluents are processed. Considering the API concentrations, decreasing residues by rinsing and dilution with other plastic packaging waste, the residues of the studied APIs are not considered an obstacle to the recycling of plastic tablet containers. However, further research is needed on more toxic APIs and the fate of APIs in the plastics recycling process.

Optimization and shielding design of a thermal neutron device based on D-D neutron generator with Geant4 toolkit

Neutron activation analysis is a highly sensitive non-destructive testing technique with important applications in industry, geoscience, medical therapy, etc. This work designed and optimized a thermal neutron device that utilized a portable D-D neutron generator, and the Monte Carlo method with the Geant4 toolkit was applied to simulation. The objective of the optimized design is to maximize the thermal neutron flux at the output surface and increase the utilization efficiency of the neutron generator. A parameter K was defined as a measure of the device's slowing capacity for neutrons and was used to determine the optimized device geometry. The simulation considered the contribution of different types and sizes of moderators and reflectors to the thermal neutron intensity to obtain the optimal size. The shielding protection of the device was then designed. The effectiveness of shielding with different thicknesses was evaluated using three dose reference points. The results indicated that the optimized device can achieve a maximum thermal neutron flux of 1.97 × 105 n∙cm−2∙s−1 at the output surface by using high-density polyethylene (HDPE) as the moderator and nickel as the reflector. It was determined that using 45 cm of HDPE and 9 cm of lead protection in sequence along the neutron head axis would reduce the dose rate at the reference point, located 5 cm from the surface of the device, below the safety limit of 2.5 μSv/h.

Application of Pattern Search and Genetic Algorithms to Optimize HDPE Pipe Joint Profiles and Strength in the Butt Fusion Welding Process

The rapid spread of the use of high-density polyethylene (HDPE) pipes is due to the wide variety of methods for connecting them. This study keeps pace with the developments of butt fusion welding of HDPE pipes by exploring the relationship between the performance of the weld joints by studying ultimate tensile strength and exploring the joint welding profiles by studying the shape of the joint at the outer surface of the pipe (height and width of the joint cap) and the shape of the joint at the internal surface (height and width of the joint root). Welding pressure, heater temperature, stocking time, and cooling time were the parameters for the welding process. Regression was analyzed using ANOVA, and an ANN was used to analyze the experimental results and predict the outputs. Two optimization techniques (pattern search and genetic algorithm) were applied to obtain the ideal operating conditions and compare their performance. The results showed that pattern search and genetic algorithms can determine the optimal output results and corresponding welding parameters. In comparison between the two methods, pattern search has a limited relative advantage. The optimal values for the obtained outputs revolved around a tensile strength of 35 MPa (3.45 and 4.5 mm for the cap and root heights, and 8 and 6.98 mm for the cap and root widths, respectively). When comparing the effects of welding parameters on the results, welding pressure had the best effect on tensile strength, and plate surface temperature had the most significant effect on the welding profile geometries.

Impact of Packaging Materials on the Shelf Life of Enriched Aadun (Maize Meal Snack commonly consumed by the Southwestern region of Nigeria)

Optimum condition at 64.80% maize flour, 20% groundnut paste and 13.20 % palm oil was formulated to produced nutritionally enhanced aadun snack. The snack was stored in the different storage materials namely, sweet prayer plant leaves (control) which is usually used by most locals, low density polyethylene (LDPE), high density polyethylene (HDPE) and food grade plastic container (PC). The initial properties (energy, oxidative and sensory properties) of the enhanced aadun (before storage) were investigated and stored in each of the storage materials. The enhanced aadun samples in each storage material were analysed at two weeks interval for eighteen weeks. The results obtained were analysed statistically to examine the effect of the storage material on the aforementioned properties. The results for energy content decreased significantly (P>0.05) in across all the samples stored. The free fatty acid, acid valve and peroxide value increased significantly (P<0.05) in all the storage materials during the storage period but only the samples stored in PC and HDPE were within the recommended limit of FAO (Food and Agricultural Organization) at the end of the storage period. The sensory quality of the control sample was acceptable up to 12 weeks while samples in other storage materials were still acceptable at the end of the storage period under ambient storage condition.

Microplastic Leachate Negatively Affects Fertilization in the Coral Montipora capitata.

Microplastic pollution is an emerging stressor of concern to coral reef ecosystems which are already threatened by additional global and local level anthropogenic stressors. The effects of ingesting microplastics alone on corals have been well studied, but the effects of the chemical composition of these particles have been understudied. Many microplastic-associated chemicals are endocrine disrupters potentially posing a threat to organismal reproduction. Therefore, the goal of this study was to determine if differences exist between the effects of microplastics themselves and plastic leachate on Montipora capitata fertilization due to changes in fatty acid quantity and composition. Assays were conducted two years in a row which exposed M. capitata gamete bundles to either one of four types of recently manufactured, virgin microspheres (nylon, polypropylene, high-density polyethylene, or low-density polyethylene) at three concentrations (50, 100, or 200 particles/L) or microplastic leachates, presumably including plastic additives from these microspheres. Gamete fertilization was not impacted by plastic particles themselves, but some of the microplastic leachate treatments with the same polymer type significantly reduced fertilization rates for M. capitata. Additionally, a total of 17 fatty acids were seen in both years, but neither fatty acid quantity nor composition correlated with observed declines in fertilization. Instead, fertilization and fatty acid data independently varied by concentration and polymer type, likely due to the presence of different chemicals. This study is the first to directly test the toxicity of plastic leachate to coral reproduction. These findings show that microplastic-associated chemicals are an important stressor affecting successful coral fertilization and fatty acid quantity and composition and provide evidence for the negative effects of microplastic leachate to coral reproduction. Thus, plastic additives could pose an additional threat to coral replenishment and persistence in coral reef ecosystems.

Effect of mixing temperature on the dispersion and degradation behaviors of HDPE/UHMWPE blends

Abstract There is currently considerable interest in high-density polyethylene (HDPE)/ultra-high-molecular-weight polyethylene (UHMWPE) blends as recyclable all-polyolefin materials with favorable mechanical properties that can be processed by continuous melt-mixing. Optimal mixing is required to improve the mechanical properties of polymer blends by ensuring their dispersibility and low degradation. In the present study, we investigated the effects of mixing temperature on the dispersion and degradation behaviors of HDPE/UHMWPE blends. Neat HDPE and a HDPE blend comprising 5 % UHMWPE were obtained by melt-mixing while changing the input energy in an internal batch mixer under a nitrogen atmosphere. The temperature of the mixer was set at 200 °C for neat HDPE, and at 180, 200, and 220 °C for the HDPE/UHMWPE blends. Optical microscopy and thermal analysis revealed that the dispersion of UHMWPE in HDPE was accelerated at higher mixing temperatures. However, in the high input energy range, mixing at 200 °C resulted in the most favorable dispersion. Gel permeation chromatography and rheological measurements suggested that chain scission and branching/crosslinking due to degradation were accelerated at higher mixing temperatures, even when mixing in a nitrogen atmosphere. Chemiluminescence measurements suggested that chain scission and branching/crosslinking were caused by an initial oxidation reaction. Furthermore, for the same input energy, the maximum shear stress increased as the mixing temperature decreased, but the mixing time and thermal history increased as the mixing temperature increased. The results suggest that in a blend comprising HDPE and UHMWPE, mixing at the molecular level due to high temperature and fine dispersion of UHMWPE due to shear stress proceed simultaneously. On the other hand, the results also confirmed that degradation was more influenced by the promotion of oxidation due to high temperatures and prolonged mixing than by shear stress.

Sustainable Plastic Waste Management in Thanjavur District: An Evaluation Using Fuzzy AHP and Neutrosophic TOPSIS

Introduction: The amount of plastic garbage has increased in tandem with the steady growth in the use of plastic products worldwide. Since plastics are lightweight, inexpensive, and durable, they are highly appreciated in a variety of industries, including electronics, building, packaging, healthcare, and agriculture). Plastic's cost, adaptability, resistance to corrosion, durability, and ease of production all contribute to its rising demand.With changes to the Plastic Waste Management Rules, India has made managing single-use plastics a top priority. Objectives: The research provides an extensive examination of the methods used to manage plastic garbage in Thanjavur's rural villages. Examining household behaviors and waste production trends, it reveals a wide range of plastic kinds, including polystyrene (PS), polypropylene (PP), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polyethylene terephthalate (PET). Methods: The research uses a Multi-Criteria Decision Making (MCDM) approach that combines the Neutrosophic Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) for alternative ranking with the Fuzzy Analytic Hierarchy Process (FAHP) for criteria weighting. Although it uses fuzzy logic to address ambiguity and uncertainty in decision-making processes, the Fuzzy AHP approach is applied in a manner similar to that of AHP. Results: Egestas diam in arcu cursus euismod quis viverra nibh. Convallis aenean et tortor at risus viverra. Sit amet justo donec enim diam. Sem et tortor consequat id. Purus gravida quis blandit turpis. Consectetur adipiscing elit duis tristique sollicitudin nibh sit amet commodo. Eget duis at tellus at urna condimentum mattis pellentesque. Auctor elit sed vulputate mi sit amet. Conclusions: This study determines that, among the available options, Polyethylene Terephthalate (PET) is the best option by applying the fuzzy analytic hierarchy process (Fuzzy AHP) to balance these criteria. PET exhibits potential because of its economic and environmental advantages, but its effective application necessitates customized strategies that take into account the infrastructure constraints and socioeconomic characteristics of the local area. Programs for raising community knowledge and participation are crucial in promoting sustainable waste management techniques, as the study emphasizes.

Durability Analysis and Cost Efficiency of RCC Beams Using Conventional Concrete Versus Bubble Deck Technique: A Statistical Investigation

A crucial tectonic component in the building of houses and other structures are beams. The structural dead load is substantially reduced by virtually removing the non-structural concrete from the beam's core. A bubble beam is one in which various sized and shaped spheres are used in place of the beam's core. There are benefits to factory-made materials and components, regulated environments, on- and off-site finishing, hollow Bubble Deck technology, and regulated settings. Numerous advantages are offered, such as reduced total expenses, reduced material usage, enhanced structural effectiveness, expedited building, and eco-friendliness. Instead of using concrete, the midsection of the beam in this project is constructed from high density polyethylene balls the content that appears most regularly.

Simulations of neutron activation background for the N[formula omitted]DEx experiment

An extremely low-background environment is a crucial requirement for any neutrinoless double beta decay experiment. Neutrons are very difficult to stop, because they can pass through the shielding and activate nuclei in the detector, even inside the fiducial volume itself. Using Geant4 simulations we have studied the neutron background for NνDEx-100 and the most efficient way to reduce it. Using a 60 cm thick external high-density polyethylene (HDPE) shielding the neutron background can be reduced down to 0.24±0.06 events/year, lower than the background rate due to natural radioactivity (0.42 events/year), which was used as a benchmark for these calculations. The amount of HDPE needed can be significantly reduced by placing a filler in the empty space between the lead shielding and the steel vessel; in this way, it is sufficient to add 20 cm external HDPE shielding to reduce the neutron background down to 0.15±0.05 events/year.

Optimized production of aromatic hydrocarbons via corn stover pyrolysis: Utilizing high-density polyethylene as a hydrogen donor and red mud as a catalyst

Biomass pyrolysis offers a promising route for high-value bio-oil production, yet the process is limited by low deoxygenation efficiency. In this study, high-density polyethylene (HDPE) served as a hydrogen donor, and acid-washed red mud (ACRM) acted as a catalyst to enhance the pyrolysis of corn stover (CS) for producing monocyclic aromatic hydrocarbons (MAHs). The results showed that the addition of ACRM significantly reduced the activation energy for co-pyrolysis, enhanced the reaction rate, and strengthened the synergistic effects between CS and HDPE. Optimal conditions yielded a MAHs selectivity of 64.5 % at 650°C with a CS: HDPE ratio of 1:1. However, excessively high temperatures facilitated the cyclization and polymerization of MAHs into polycyclic aromatic hydrocarbons, while a high HDPE ratio diminished the synergistic effects. Furthermore, recycling tests confirmed the effective reusability of ACRM, with MAHs yields remaining above 40 % after four cycles. This study highlights the potential for valorizing industrial and agricultural wastes.

A step to microplastic formation: Microcracking and associated surface transformations of recycled LDPE, LLDPE, HDPE, and PP plastics exposed to UV radiation

Plastics when exposed to UV radiation start to degrade via photooxidative aging including free radical formation, oxidation, chain scission and/or crosslinking reactions. These chemical changes can cause loss in mechanical strength, surface embrittlement, and eventually surface erosion. The eroded particles are microplastics (MPs), which have been identified as a potentially serious threat to the environment and its inhabitants. In general, photodegradation of virgin plastics has been studied extensively, but there is not much literature on the degradation of recycled plastics. The goal of the study was to investigate the changes caused by photodegradation in recycled plastics and assess the potential risks of MPs formation. And eventually, knowing the chemical and physical transformations occurring on the surface understand the mechanism behind surface microcracking, which is the first step of MPs formation. Pellets of five industrially recycled plastics (low-density polyethylene (rLDPE), linear low-density polyethylene (rLLDPE), high-density polyethylene (rHDPE), and two polypropylenes (rPP)) from different waste sources were analysed. UV irradiation was performed in an accelerated weathering chamber for milled (< 400 µm) plastic powder to ensure homogeneous changes throughout the sample. The properties were investigated by ATR-FTIR, HT-SEC, XPS and DSC. Formation of microcracks was studied on plastic pellets by SEM. The results showed that the degradation significantly differed between the recycled plastics, and the waste source was more important than the plastic type. rLDPE and one of the rPP samples showed a significant increase in carbonyl index as well as decrease in molar mass during the first 500 h of UV exposure. The other rPP and rHDPE samples showed first considerable signs of degradation only after 1000 h of UV exposure. Minor changes were observed for the rLLDPE sample during the whole test. The SEM revealed microcracking on the surface of all samples, which also had noticeable degradation identified by other methods. These recycled plastics can be considered the ones with the highest potential of MPs formation. From the chemical and physical transformations identified on the surface, the mechanism leading to microcracking, which is the first step in the formation of MPs, is proposed.

Experimental detection of marine plastic litter in surface waters by 405 nm LD-based fluorescence lidar

Plastic pollution has become a global challenge, affecting water quality and health. Plastics including polystyrene (PS), polyvinyl chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), and high-density polyethylene (HDPE), are significant contributors to environmental pollution. With the growing need for investigation and detection of plastics found in natural waters, we propose the use of a portable laser diode (LD)-based fluorescence lidar system for in-situ detection of plastic litters in surface waters based on excitation-emission fluorescence spectroscopic data. The experiments were carried out in a controlled environment using a fluorescence lidar system with 405 nm excitation wavelength to determine the fluorescence signals of several plastics at 470 nm emission wavelength. Simultaneous detection of PET plastic and Chlorella vulgaris were also observed to determine the fluorescence influence of chlorophyll in surface waters. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy was employed to study the chemical composition of the plastics used before and after being submerged in the water. Scanning electron microscopy (SEM) and high-resolution camera microscopy were used to analyze the morphology of the submerged PET samples. This study provides a basis for a new in-situ technique using a fluorescence lidar system for submerged or transparent plastics in surface waters.