Low Cost Research Articles

Awareness of Disease Incurability Moderates the Association between Patients’ Health Status and Their Treatment Preferences

Background With advancing illness, some patients with heart failure (HF) opt to receive life-extending treatments despite their high costs, while others choose to forgo these treatments, emphasizing cost containment. We examined the association between patients’ health status and their preferences for treatment cost containment versus life extension and whether their patients’ awareness of disease incurability moderated this association. Methods In a prospective cohort of patients ( N = 231) with advanced HF in Singapore, we assessed patients’ awareness of disease incurability, health status, and treatment preferences every 4 mo for up to 4 y (up to 13 surveys). Using random effects multinomial logistic regression models, we assessed whether patients’ awareness of disease incurability moderated the association between their health status and treatment preferences. Results About half of the patients in our study lacked awareness of HF’s incurability. Results from regression analyses showed that patients with better health status, as indicated by lower distress scores (odds ratio [OR] [95% confidence interval {CI}]: 0.862 [0.754, 0.985]) and greater physical well-being (1.12 [1.03, 1.21]); and who lacked awareness of their disease’s incurability were more likely to prefer higher cost containment/minimal life extension treatments compared with lower cost containment/maximal life extension. Conclusions This study underscores the significance of patients’ awareness in disease incurability in shaping the relationship between their health status and treatment preferences. Our findings emphasize the need to incorporate illness education during goals-of-care conversations with patients and the importance of revisiting these conversations frequently to accommodate changing treatment preferences. Highlights The health status of patients with advanced heart failure was associated with their treatment preferences. Patients whose health status improved and who lacked awareness of their disease’s incurability were more likely to prefer higher cost containment/minimal life extension treatments.

Evaluation of the mechanical characteristics of epoxy resin hybrid composites reinforced with date palm stem fibre and glass fibre

This study investigates the mechanical properties of epoxy resin hybrid composites reinforced with date palm stem fibres (DPSF) and glass fibres (GF). Natural fibres like DPSF offer numerous advantages, including low cost, renewability and biodegradability, making them environmentally friendly alternatives to synthetic fibres. GF, on the other hand, is well-known for its high strength and lightweight properties, making it ideal for various industrial applications. In this research, DPSF and GF were combined to create hybrid composites, aiming to enhance mechanical properties and reduce production costs compared to pure GF composites. The study involved the preparation of DPSF and the fabrication of composites using a hand lay-up approach with varying fibre proportions, followed by mechanical testing that included impact, flexural, tensile test and as well as a water absorption test. The results show that both the flexural and tensile strengths of a composite with epoxy resin containing 10 wt%DPSF and 10 wt%GF improved significantly, resulting in a tensile strength of 17.75 MPa and a flexural strength of 48.13 MPa, along with a favourable reduction in water absorption. The impact strength was significantly increased by the optimal integration of a composite with epoxy resin containing 20 wt% DPSF and 10 wt% GF. These findings suggest that the hybrid composites demonstrate enhanced mechanical properties, revealing the combined benefits of DPSF and GF. This study underscores the potential of DPSF-GF reinforced composites as a cost-effective and mechanically strong alternative to conventional GF composites.

Research on the Advantages and Challenges of Replacing LEDs with Lasers in Functional Near-Infrared Spectroscopy Systems Based on Advanced Signal Processing Algorithms

Abstract: Functional near infrared spectroscopy (fNIRS) has received increasing attention as a non-invasive, portable brain hemodynamic monitoring tool due to its potential for use in natural Settings. Traditional fNIRS systems commonly use light-emitting diodes (LEDs) as light sources, which have become the mainstream choice because of their low cost, easy integration, low heat output, and availability of a variety of near-infrared wavelengths. However, LEDs are limited by their low optical output power and broad wavelength range, which restrict their effectiveness in deep tissue penetration and signal quality. In contrast, Laser Diodes (LD) have the advantages of good monochromaticity and high optical output power, which can provide deeper tissue penetration and higher signal stability. Therefore, this study explores the feasibility of using lasers instead of leds in fNIRS systems and their impact on signal quality and imaging depth. By comparing the performance of LED and laser-based fNIRS systems, it is evident that lasers provide significant improvements in signal quality and imaging depth, although they face challenges in terms of cost, thermal management, and safety. The research in this paper provides an important reference for the future design of fNIRS system, especially in the application scenarios requiring high precision imaging.

Research on Graphitic Carbon Nitride (g-C3N4) prepared by template-based method and its photocatalytic properties

Abstract. The Graphitic Carbon Nitride (g-C3N4), a non-metallic polymer photocatalytic material, has a wide range of raw materials and a simple preparation process. Due to its unique electronic structure and excellent photocatalytic performance, g-C3N4 has attracted wide attention in the field of environmental purification and energy conversion in recent years. However, g-C3N4 faces a lot of challenges, including a wide band gap, many interlayer defects, and poor interlayer electron transport. Nevertheless, its unique semiconductor structure and chemical stability still provide the possibility to explore the effect of its piezoelectric properties on photocatalysis, which paves the way for a novel approach to environmentally friendly hydrogen production. Therefore, the paper delves into the application of different template methods in the preparation of g-C3N4 by reviewing the related literature, and analyzes the role of different template materials in the preparation. In addition, in this paper, the photocatalytic properties of g-C3N4 are explored, which are mainly reflected in the photocatalytic water separation performance and photocatalytic degradation of organic dyes. It is found that the g-C3N4 shows great potential in the fields of photocatalytic water decomposition for hydrogen production and degradation of organic pollutants due to its unique band gap, nontoxicity, low cost and wide range of sources. Future research should continue to explore more kinds of template materials and their preparation processes, with the aim of realizing further enhancement of the performance of g-C3N4 photocatalysts and promoting their practical applications in the fields of environment and energy.

Research on automated defect detection system based on computer vision

Abstract. With the intensification of market competition and consumer demand for product quality enhancement, people's development of industrialization is also more and more in-depth, the production scale and complexity of a variety of products is also increasing. However, in the process of automated production, product defects are unavoidable due to various factors such as equipment, environment, and human influence. The traditional human inspection method is inefficient, costly, and subjective, making it difficult to meet the needs of modern industrial production. Therefore, the need for an efficient, accurate and automated inspection system is urgent. Based on the current social situation, this paper will introduce the automated defect detection system based on computer vision, which is widely used in many fields, and has a great guarantee for people in the production of products with high quality and low cost, based on the needs in these areas, this paper will firstly introduce the relevant algorithms and their main contributions to the application scenarios of computer vision technology, and then introduce the key technologies of computer vision in defect detection in the key technology.

Excellent Wavelength Selectivity of p-AlGaN/n-Ga2O3 Solar-Blind UVC PD.

Due to the advantages of ultrawide bandgap, chemical stability, self-powered, and low cost, gallium oxide (Ga2O3) based photodetectors (PDs) are considered as one of the most promising solar-blind ultraviolet PDs, having garnered significant attention in fields such as missile warning and flame arc detection. High selective ratios and excellent responsivity are important to reduce the false alarm rate in solar-blind detection. However, due to the lack of p-type Ga2O3, existing Ga2O3-based PN PDs utilized heterostructures with narrower bandgap p-type semiconductors (e.g., p-GaN, p-SiC, etc.), inducing poor selective ratios with visible light and ultraviolet-A/B (UVA/B). Therefore, a high Al content AlGaN was used in this study to form a p-AlGaN/n-Ga2O3 solar-blind ultraviolet-C (UVC) PD. Since the bandgap of p-AlGaN aligned with the UVC region, the device exhibited exceptionally high selective ratios with R247nm/R360nm = 3.71 × 105 and R247nm/R300nm = 1.47 × 105 at 0 V, which surpassed the reported Ga2O3-based PN PDs. The formation of the type-II heterojunction facilitated the effective separation and transport of photogenerated carriers, resulting in high responsivity (0.36 A/W) under zero bias. Overall, the high selective ratios and high responsivity of the p-AlGaN/n-Ga2O3 PD in this paper provided a reliable pathway for self-powered solar-blind PDs with a low false alarm rate.

Structural Equation Model of the Variables Affecting the Online Shopping Behavior of Generation-Y

Purpose: 1) To investigate the goodness of fit of the SEM of the variables affecting the online shopping behavior of Generation Y in Thailand. 2) To develop the SEM of the variables affecting the online shopping behavior of Generation Y in Thailand. 3) To study the direct, indirect, and total impact of the variables affecting the online shopping behavior of Generation Y in Thailand. Method: The research applied the literature review, and an analysis on the concepts, theories and principles. This mixed research methodology included a quantitative research method, questionnaire, qualitative research method, and in-depth interview to verify the results from the quantitative research. To collect the data, 300 sets of questionnaires were distributed to consumers who had purchased online products. Data were analyzed by content analysis and Structural Equation Model (SEM). Results and Discussions: The research results showed that the hypothesis test results supported the research with statistical significance. The purchase intention had the highest impact on the online shopping behavior, followed by customer innovation and perceived usefulness, respectively. The structural equation model (SEM) of the purchase intention, customer innovation and perceived usefulness had a direct impact on the online shopping behavior of Generation Y, which was consistent with the goodness of fit. Furthermore, consumers wanted to try new things, needed more challenges, and loved using the Internet that was very convenient and saved their time searching for products. They were able to do the transaction on one platform via social media, which facilitated the entrepreneur to build a business opportunity for efficient competitiveness Research Implications: At present, the Internet has a crucial role and influence on people’s daily routines in terms of learning, studying, entertainment, and business. Thus, the use of the Internet will continue to increase; such as, to search for competitor’s information, communicate with customers, and conduct public relations. The use of the Internet also conveniently facilitates communication and access to new target groups. Everyone can purchase or search for a new product easily from anywhere worldwide at a low cost and in a short time, which greatly generates business opportunities. However, the increase of purchasing via social media has resulted in increased usage of Facebook Pay, Instagram Shopping, and LINE OA (Official Account). Originality/Value: Therefore, social media has simplified the buyer's ability to buy products and be able to do transactions on one platform. Nevertheless, the key concern is the more expensive advertisement costs due to the higher number of sellers. For example, Omnichannel is an inclusive buy-and-sell platform that most retailers are interested in because it supports business growth and provides more payment channels to the customer. Once the customer has the perceived usefulness, enjoys using it, and would like to try the new products via the purchase intention, it would affect the online shopping behavior.

A Survey on Security of UAV Swarm Networks: Attacks and Countermeasures

The increasing popularity of Unmanned Aerial Vehicle (UAV) swarms is attributed to their ability to generate substantial returns for various industries at a low cost. Additionally, in the future landscape of wireless networks, UAV swarms can serve as airborne base stations, alleviating the scarcity of communication resources. However, UAV swarm networks are vulnerable to various security threats that attackers can exploit with unpredictable consequences. Against this background, this paper provides a comprehensive review on security of UAV swarm networks. We begin by briefly introducing the dominant UAV swarm technologies, followed by their civilian and military applications. We then present and categorize various potential attacks that UAV swarm networks may encounter, such as denial-of-service attacks, man-in-the-middle attacks and attacks against Machine Learning (ML) models. After that, we introduce security technologies that can be utilized to address these attacks, including cryptography, physical layer security techniques, blockchain, ML, and intrusion detection. Additionally, we investigate and summarize mitigation strategies addressing different security threats in UAV swarm networks. Finally, some research directions and challenges are discussed.

Hepatotoxic Medicinal Plants in Weight Loss Formulations Sold at Ver-o-Peso Market, Amazon Region, Brazil.

Obesity represents a significant global public health challenge. Various therapeutic strategies for weight reduction are available, including formulations containing medicinal plants, which are favored due to their availability and low cost. The efficacy and safety of these formulations must be evaluated as they can lead to adverse reactions, including severe hepatic injuries. Despite their widespread usage, particularly among residents of the Amazon, there is a considerable gap in knowledge regarding the species of medicinal plants used in these formulations. This study evaluated the labels of natural weight loss products sold from January to October 2022 at the Ver-o-Peso market in Belém, Brazil. A subsequent review of databases was performed to identify plants listed on the labels that were associated with hepatic injuries. In total, 54 plants were identified in these products, primarily in mixed formulations. None of the labels adhered to current legislative standards. Furthermore, nine of these plants were documented in the literature as having hepatotoxic effects, either through invivo or in vitro studies. The presence of medicinal plants that can cause liver injury on the labels of weight loss compounds is a relevant issue requiring rigorous health surveillance intervention.

The Efficacy of a Lower Dose of Everolimus in Patients with Advanced Neuroendocrine Tumors

Background: Everolimus at 10 mg daily is approved to treat patients with advanced grade 1/2 neuroendocrine tumors (NETs), although it may lead to significant toxicity. Grade 3 or higher drug-related adverse events and drug discontinuation occur in approximately one-fourth of cases. However, phase I trials have demonstrated that doses from 5 mg daily efficiently inhibit NET cell signaling. Objectives and Methods: This multicenter retrospective study compared the time to treatment failure (TTF) in patients with NETs who received a mean daily dose of 7–10 mg (higher dose [HD]) or ≤6 mg (lower dose [LD]) of everolimus. Results: Ninety-two patients were included: 74 (80%) in the HD group and 18 (20%) in the LD group. At a median follow-up of 4.2 years, the median time to treatment failure (TTF) was 9.2 months for the HD and 7.2 months for the LD groups (p = 0.85). The TTF did not significantly differ between the LD and the HD groups (HR: 1.24; 95% CI: 0.68–2.25; p = 0.47), even after adjusting for age at treatment initiation, the NET grade, and the treatment line. Conclusion: Everolimus doses from 5 to 6 mg/day seem to be equally as effective as higher doses, but lower doses are potentially associated with less toxicity and lower costs. These findings support validation through a randomized clinical trial.

Leaftronics: Natural lignocellulose scaffolds for sustainable electronics.

The global rise in electronic waste is alarming, driven by the persistent use of glass, epoxy, and plastic substrates owing to their cost, stability, flexibility, and transparency. This underscores the need for biodegradable alternatives with similar properties. This study shows that leaf-derived lignocellulose scaffolds can stabilize bio-sourced, solution-processed polymers by acting as natural sequestering media. Such reinforced films, even when based on gelatin (Tg ~ 60°C), can endure processes over 200°C. We demonstrate dip-coated ethyl cellulose films for commercially viable reflow soldered circuitry. The films offer high flexibility, more than 80% transparency, and surface roughness below 5.5 nm. Advanced OPDs and OECTs fabricated on these films perform comparably to those on glass and the low material cost and simple fabrication process yields a minimal carbon footprint of 1.6 kgCO2/m2. This work thus opens a vista of possibilities for biodegradable polymers heretofore considered unsuitable for making temperature-stable substrates for state-of-the-art electronics applications.

A novel sensing probe based on AuNPs-Apt for the detection of enrofloxacin

Enrofloxacin (ENR), as a synthetic broad-spectrum antibiotic is widely utilized in veterinary medicine to treat animal diseases and promote livestock growth, it can inhibit bacterial DNA gyrase subunit A, thereby preventing bacterial DNA replication and exerting its antibacterial effect. However, excessive use of enrofloxacin poses significant risks to ecological balance and human health due to residual contamination. We have developed a novel ENR aptamer sensor based on the gold nanoparticles/aptamer (AuNPs-Apt) complexes, in which AuNPs were synthesized via the seed method and functionalized with aptamers. The optical properties, particle size, functional groups and morphology of the AuNPs-Apt probe were characterized by transmission electron microscope, Fourier transform infrared spectrometer and UV-vis spectrophotometer, respectively. The aptamer biosensor can specifically identify enrofloxacin, with a wide detection range (0.05-100μg ml-1) and a good linear relationship (R2=0.99) within the detection range. In addition, the biosensor also has the advantages of short detection time, low biological toxicity, good stability, and low detection cost. Therefore, it shows a great prospect for practical application in the field of detecting enrofloxacin residues.

Tightly Coupled LIDAR/IMU/UWB Fusion via Resilient Factor Graph for Quadruped Robot Positioning

Continuous accurate positioning in global navigation satellite system (GNSS)-denied environments is essential for robot navigation. Significant advances have been made with light detection and ranging (LiDAR)-inertial measurement unit (IMU) techniques, especially in challenging environments with varying lighting and other complexities. However, the LiDAR/IMU method relies on a recursive positioning principle, resulting in the gradual accumulation and dispersion of errors over time. To address these challenges, this study proposes a tightly coupled LiDAR/IMU/UWB fusion approach that integrates an ultra-wideband (UWB) positioning technique. First, a lightweight point cloud segmentation and constraint algorithm is designed to minimize elevation errors and reduce computational demands. Second, a multi-decision non-line-of-sight (NLOS) recognition module using information entropy is employed to mitigate NLOS errors. Finally, a tightly coupled framework via a resilient mechanism is proposed to achieve reliable position estimation for quadruped robots. Experimental results demonstrate that our system provides robust positioning results even in LiDAR-limited and NLOS conditions, maintaining low time costs.

A Magnetic Climbing Robot for Steel Bridge Inspection

Abstract. The maintenance of traditional steel bridges presents many significant challenges due to the fact that bridges of different ages and standards vary in design, structural complexity and technical difficulty. In light of these considerations, it is clear that maintenance personnel must possess a wealth of professional expertise and experience in order to effectively address the diverse and intricate maintenance challenges that arise. Moreover, the maintenance process entails high-risk operations such as high-altitude work and welding, which pose a threat to the safety of construction personnel. Therefore, this study introduces a magnetic adsorption robot designed to address the low efficiency and high costs of traditional maintenance methods. This robot features a dual robotic arm mechanism and modeled using the Denavit Hartenberg (D-H) parameter method. Electromagnetic adsorption is utilized to achieve wall adhesion, and direct power supply is provided through DC power to control weight. The robot can perform flexible remote control operations through the HC-05 Bluetooth module. The experimental results show that the robot exhibits robust adhesion and obstacle crossing ability on steel surfaces, thereby enabling unimpeded movement within the steel structure. In addition, the robot is now capable of performing overhaul procedures via remote control.

A Welfare Analysis of Tax Audits Across the Income Distribution

Abstract We estimate the returns to IRS audits of taxpayers across the income distribution. We find an additional ${\$}$1 spent auditing taxpayers above the 90th income percentile yields more than ${\$}$12 in revenue, while audits of below-median income taxpayers yield ${\$}$5. We construct our estimates by drawing from comprehensive internal accounting information and audit-level enforcement logs. We begin by estimating the average initial return to all audits of US taxpayers filing in tax years 2010–2014. On average, ${\$}$1 in audit spending initially raises ${\$}$2.17 in revenue. Audits of high-income taxpayers are more costly, but the additional revenue raised more than offsets the costs. Audits of the 99–99.9th percentile have a 3.2:1 initial return; audits of the top 0.1% return 6.3:1. We then exploit the 40% audit reduction between tax years 2010 and 2014 to examine the returns to marginal audits. We find they exceed the returns to average audits. Revenues remain relatively unchanged but marginal costs fall below average costs due to economies of scale. Next, we use randomly selected audits to examine the impact of an initial audit on future revenue. This individual deterrence effect produces at least three times more revenue than the initial audit. Deterrence effects are relatively consistent across the income distribution. This results in the 12:1 return above the 90th percentile. We conclude by estimating the welfare consequences of audits using the MVPF framework and comparing audits to other revenue-raising policies. We find that audits raise revenue at lower welfare cost.

Performance enhancement of a magnetoactive elastomer actuator through a coupled magnetoelastic topology optimization scheme

Abstract We have found that considering local magnetic fields, large deformations, and magnetoelastic coupling simultaneously significantly affect the resulting shape in magnetoelastic topology optimization in a uniaxial actuator case. In contrast to the work presented here, other works incorporate magnetoelastic formulations that include simplifying assumptions on the local field, and subsequent effects on the magnetization response of the material, or the absence of large deformation mechanics, or both. These assumptions were shown to produce solutions that differ substantively from cases where local fields and large deformations are addressed concurrently. Magnetoelastic topology optimization schemes are needed to optimize magnetoactive elastomer (MAE) devices. MAE devices are magnetic particle-filled polymer matrices designed for specific actuations and controlled remotely by an external magnetic field. They garner considerable research interest as an emerging technology for actuators in soft robots or in applications requiring untethered actuation. The material properties of MAEs are dependent on the volume fraction of particles in the elastomer matrix, where a high-volume fraction increases relative permeability (for soft magnetic particles) but also increases elastic modulus. For optimal actuation, a tradeoff between low stiffness and high magnetic response must be made by adjusting volume fraction and controlling material placement. Using a topology optimization scheme that considers both the magnetic and mechanical properties of the material, the shape and material composition of the device can be tuned to best achieve the desired actuation displacement. In this work, a density-based magnetoelastic multimaterial topology optimization scheme for soft magnetic material is developed in COMSOL Multiphysics. The optimization scheme uses multiphysics coupling that considers local magnetic fields and large deformations at each iteration through a Maxwell stress tensor formulation. A simulated example is then considered to demonstrate the effectiveness and necessity of a coupled optimization. The effect of considering large deformations during optimization is also investigated. It was found that a coupled topology optimization scheme with large deformations produced shapes with modes of actuation not captured by schemes with simplifying assumptions, leading to better performance at lower material cost. Considering large deformations in the coupled scheme offered significantly better performance, with an increase of 81.3% in a side-by-side performance simulation when compared to uncoupled cases.

Impact of Physician Specialty on Treatment Costs of Invasive Melanoma

Introduction: Melanoma is a deadly type of skin cancer that develops from melanocytes and can manifest on the skin or other regions of the body. Its incidence is increasing rapidly, with approximately 100,000 diagnoses and 7000 deaths per year in the US alone. We conducted a cross-sectional study with the aim of determining an association between the cost of care for invasive melanoma and the specialty involved in the treatment to adequately guide future treatment. Methods: We analyzed data from 3817 patients (2013–2018) using the Florida inpatient/outpatient dataset, CMS cost reports, and the National Plan and Provider Enumeration System. Covariates included age, sex, race/ethnicity, insurance type, region, county rurality, the number of procedures, the comorbidity index, obesity, metastatic cancer presence, hospital size, and physician volume. Multivariable mixed linear regression was used to analyze the data, and the cost was adjusted to the 2019 USD. Results: Dermatology had the largest decrease in the overall and outpatient costs compared to general surgery, followed by plastic surgery. The inpatient costs for dermatology and plastic surgery were lower than those for general surgery, but not significantly so. Conclusions: The costs associated with surgical procedures may vary depending on the specialty of the physician treating the patient. Dermatology was associated with lower treatment costs for invasive melanoma compared to other specialties, indicating that physician specialty influences the cost of care.

Interactions Between Bovine Respiratory Syncytial Virus and Cattle: Aspects of Pathogenesis and Immunity

Bovine respiratory syncytial virus (BRSV) is a major respiratory pathogen in cattle and is relevant to the livestock industry worldwide. BRSV is most severe in young calves and is often associated with stressful management events. The disease is responsible for economic losses due to lower productivity, morbidity, mortality, and prevention and treatment costs. As members of the same genus, bovine and human RSV share a high degree of homology and are similar in terms of their genomes, transmission, clinical signs, and epidemiology. This overlap presents an opportunity for One Health approaches and translational studies, with dual benefits; however, there is still a relative lack of studies focused on BRSV, and the continued search for improved prophylaxis highlights the need for a deeper understanding of its immunological features. BRSV employs different host-immunity-escaping mechanisms that interfere with effective long-term memory responses to current vaccines and natural infections. This review presents an updated description of BRSV’s immunity processes, such as the PRRs and signaling pathways involved in BRSV infection, aspects of its pathogeny, and the evading mechanisms developed by the virus to thwart the immune response.

Construction of an Anode Material for Sodium-Ion Batteries with an Ultrastable Structure.

The reserves of sodium resources are much larger than those of lithium resources, and they are widely distributed and easy to produce and can be widely used in photovoltaic energy storage and other industries on the premise of this advantage. However, how to produce hard carbon anodes at a low cost for the preparation of energy storage materials requires continuous exploration and experimentation to find the optimal solution. Here, we used waste sour date shell biomass as a precursor for a hard carbon anode obtained by simple acid treatment and two pyrolyses. It is shown that acid washing after prepyrolysis has a significant effect on the electrochemical performance of the sour date shell-derived hard carbon (ZJ), constructing a stable structure that makes it easier for sodium ions to be embedded and dislodged, and the carbon particles are homogeneous and free of bonding and electrode cracking. The ZJ-1500-HCl pyrolyzed at 1500 °C has a high reversible capacity of 329.1 mAh g-1, 94.1% initial Coulombic efficiency (ICE), 90.54% capacity retention efficiency cycling 300 cycles at a current density of 300 mA g-1, and a resistivity below 10 Ω. It has good cycle stability and a good multiplier performance. It is expected to be used in practical production and photovoltaic energy storage in the future.

In-depth mechanistic insights into Au nanoparticles based polyurethane foams as a selective and efficient dispersive solid phase microextractor for textile dyes from water: performance and reusability study

ABSTRACT Herein, a simple, superhydrophobic, superoleeophilic and low cost microextractor Au nanparticles (Au NPs) based polyurethane (PUFs) solid platform (Au NPs/PUFs) has been developed as a promising sorbent for removal and recovery of Congo red (CR) textile dye from water bodies. The sorbent was characterised using UV-visible and SEM techniques. The procedure relied complete dye retention from the aqueous solution at pH 5.0–5.5 onto an Au NP/PUF extractor. Analytical assessments revealed that the Au NPs/PUFs combination significantly improves mass transfer of dye and enhances creation of active sites for CR retention. CR sorption by the sorbent fitted well with intra-particle diffusion and pseudo first-order kinetic models (R2 = 0.990). The enthalpy change, ΔH (37.8 kJ mol−1) indicates that dye extraction is endothermic whereas the entropy change, ΔS0 (116.6 J mol−1K−1), reveals a significant change in the entropy during dye uptake. The free energy change ΔG (3.12 kJ mol−1 at 298 K) of CR sorption indicated that the dye retention was not spontaneous at all temperatures. A twofold sorption mechanism involving absorption accompanying ‘solvent extraction’ and/or ‘weak ion exchange’, combined with surface adsorption of dye is proposed. Sorbent packed mini column demonstrated effective percent removal and recovery (101.8%) of CR from water samples using acetone or NaOH as an eluting agent. The study expands the utility of Au NPs/PUFs for reusability and spectrophotometric sensing of trace levels of CR in water. The key attention also includes integrating PUFs utility by improving the selectivity and sensing properties towards textile dyes.