Engineering Commons^™

Engineering Disorder, Defects, And Electrical Transport For High-Performance Thermoelectric Fe2val Heusler Alloys, James Russell Taylor Iv

Dartmouth College Ph.D Dissertations

Fe₂VAl is a promising low-temperature thermoelectric material for waste-heat energy conversion because it is easily processed and comprised of earth-abundant, non-toxic, and low-cost elements. However, viability for applications faces two major challenges: high thermal conductivity and low p-type Seebeck coefficients. This primarily experimental work aims to address these issues through extrinsic and self-doping, point-defect and disorder generation through thermal and electrical processing, disordered and metastable phase composition quantification, and comparison of transport measurements to modeled electronic features.

An accessible phase quantification method was developed for bulk Fe₂VAl using laboratory X-ray diffraction equipment to compare thermoelectric properties …

Computational Modeling And Machine Learning For The Design Of Polymer-Based Protective Systems Under Dynamic Loading, Jonathan Tate Villada

Open Access Dissertations

Computational modeling and machine learning offer powerful pathways for designing polymer-based protective systems subjected to dynamic loading, particularly for mitigating the early shock-dominated response generated by near-field underwater explosions (UNDEX). As naval, offshore, and submerged infrastructure systems continue to grow in strategic importance, there is an increasing need for lightweight, damage-tolerant protective solutions capable of reducing transmitted pressure, deformation, and energy transfer under extreme impulsive environments. Since large-scale experimental testing under such conditions are costly and limited, validated numerical frameworks provide an efficient means to evaluate polymeric coatings, architected metastructures, and data-driven predictive tools across broad design spaces. The first …

Extending Low-Frequency Traveling-Wave Propagation In A Water-Filled Cylindrical Waveguide Using Active Impedance Control, William Slater

Open Access Dissertations

This dissertation investigates extending the frequency range over which a one-dimensional, plane traveling wave can be generated in a water-filled, steel-walled waveguide under ocean temperature and hydrostatic pressure conditions. The wave guide considered is a thick-walled, steel cylinder filled with a water/glycol mixture with a transducer at each end and a hydrophone array along the length. One transducer excites a plane wave while the other cancels reflections, resulting in a traveling wave in the waveguide. The current (open-loop) measurement system is advertised to generate traveling waves for low frequencies where only 3.4% of a wavelength can be measured (kL …

Waveguide-Assisted Single-Mode Fiber Bragg Gratings In A Highly Multimode Coreless Fiber Via Femtosecond Laser Inscription For Extreme Temperature Quasi-Distributed Thermal Sensing, Farhan Mumtaz, Koustav Dey, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research reports a potential quasi-distributed thermal mapping optical sensing system for extreme temperatures, leveraging femtosecond (fs) laser inscribed single-mode fiber Bragg gratings (FBGs) and a waveguide within coreless, highly multimode optical fiber, resulting in a single-mode structure. Unlike doped single-mode fibers, coreless fibers composed of silica rods prevent issues associated with dopant migration and ensure data accuracy. The strategic placement of point-by-point FBGs in a cascaded formation on the fs-laser inscribed waveguide facilitates localized multipoint sensing. The long-term stability of the proposed waveguide-assisted FBG system was assessed over 24 hours at elevated temperatures (1000°C), showing no hysteresis during heating …

Evaluation And Design Of A Footing Hybrid Connection For Innovative Hollow-Core Fiber-Reinforced Polymer–Concrete–Steel Composite Columns, Mohanad M. Abdulazeez, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To support the advancement of accelerated bridge construction in high-seismic regions, this study investigates a novel prefabricated column-to-footing connection designed for improved resiliency, constructability, and cost efficiency. The socket connection utilizes hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS) columns with embedded corrugated steel pipes (CSPs). The composite HC-FCS column consists of a concrete shell sandwiched between an outer fiber-reinforced polymer tube and an inner steel tube. The inner steel tube is embedded into the footing connection of the HC-FCS column. The same authors tested the innovative socket connection on a large HC-FCS column under seismic loads, showing high ductility, strong moment and drift …

Adversarial Robustness In Biomedical Time-Series Models, Rohan Tiwari

Bioengineering Theses

This study investigates adversarial vulnerabilities in deep learning models for biomedical time-series classification across two clinically important modalities: electrocardiography (ECG) and electroencephalography (EEG). Using the MIT-BIH Arrhythmia and CHB-MIT seizure datasets, I evaluate time-domain attacks (FGSM, PGD), Fourier-domain constrained attacks, and learned spectral perturbations designed to reveal modality-specific sensitivity patterns. Across both tasks, a consistent trend emerges low-frequency components (0–5 Hz) constitute a dominant axis of adversarial vulnerability, with perturbations in this range producing the steepest degradation in classification performance. In ECG models, protecting the physiologically relevant QRS band (5–20 Hz) significantly improves robustness, whereas EEG models remain highly sensitive …

Development And Integration Of A Liquid Rocket Propulsion System For A High-Power Rocket, Matthew A. Dipofi, Christina Griggy, Jonathan Armbrust, Jackson Frame

Williams Honors College, Honors Research Projects

The goal of this project is to integrate the Stinger liquid rocket engine, a regeneratively cooled LOX/ethanol engine developed by the Akronauts Rocket Design Team, into the Copperhead launch vehicle. The objective is to design, build, and test a complete propulsion system including electronics, software, pressurization, tanks, and instrumentation capable of flight. A key innovation is the electronic pressure regulation system, which replaces mechanical regulators with servo-actuated valves running PID loops for precision and an extra degree of control.

The Stinger engine, under development since Fall 2023, has undergone nine hot-fire tests, with further testing planned to qualify the new …

Distilling The Complexity Of Agent-Based Simulations Into Textual Explanations Via Large Language Models, Noé Y. Flandre, Philippe J. Giabbanelli

VMASC Publications

Communicating the design and results of agent-based models (ABMs) to subject matter experts is challenging, which hinders participation and limits trust in simulation-based decision support. Large language models (LLMs) can communicate ABMs as textual summaries, thus complementing traditional disclosure through statistical and visualization techniques. While prior work translated the structure of conceptual models into narratives via LLMs, our extension covers the dynamics of simulation models via an automated simulation-to-text method that extracts contextual information from NetLogo ABMs, performs repeated simulations, and generates narrative descriptions (including the model’s purpose, parameters, and simulation dynamics) using mutimodal LLMs. Furthermore, four summarization algorithms spanning …

Evaluation Of Critical Shear Strength Of Soils In Nebraska Based On Revised Cpt, Chung R. Song, Bashar Al-Nimri, Basil Abu Al Sha'r, Dhurba R. Pandey, Jongwan Eun, Seunghee Kim

Nebraska Department of Transportation: Research Reports

This study evaluated the “Fully Softened Shear Strength (FSSS)” of soils in Nebraska based on a revised Cone Penetration Test(CPT) method. FSSS is a unique strength condition that soils show substantially reduced strength during rainy seasons, eventually causing failure of slopes and other structures.

The revised CPT was adapted to inject water at targeted depths, inducing controlled moisture infiltration and capturing real-time soil softening over designated intervals of 30, 60, or 90 minutes. Through tip resistance (qc) and sleeve friction (fs) measurements under “in-situ” and “wet” conditions, the test effectively identified fully disturbed/low strength zones around the sleeve. Simultaneous sampling …

The Use Of Recycled Plastic In Asphalt Pavements: Feasibility Study, Isabella Bueno, Robert Rea, Jamilla Teixeira

Nebraska Department of Transportation: Research Reports

The plastics industry has been actively exploring new end-market opportunities for the more than 35 million tons of waste plastics generated annually. The use of recycled WP in asphalt presents an opportunity to improve pavement performance while reducing the growing amount of WP being landfilled or released into the environment. However, the use of WP in asphalt mixtures poses challenges due to variations in plastic composition and the presence of non-plastic contaminants. The absence of standardized procedures has resulted in inconsistent integration methods and unclear roles of WP within asphalt concrete (AC) mixtures. Therefore, the goal of this multiphase study …

Development And Evaluation Of Crashworthy Approach Guardrail Transition With Increased Span Length Between Concrete Bridge Rail And First Transition Post – Phase I, Tewodros Yosef, Qusai Alomari, Ronald K. Faller, Robert W. Bielenberg, Scott Rosenbaugh

Nebraska Department of Transportation: Research Reports

This study developed and evaluated a 34-in.-tall Nebraska Department of Transportation (NDOT) thrie-beam approach guardrail transition (AGT) with an increased span between the concrete buttress end and the first transition post. The objective was to accommodate a wide range of common obstructions near bridge ends, including abutments, wing walls, drainage features, and utilities. A survey of NDOT districts identified critical obstruction geometries and informed design criteria. Most NDOT districts indicated that a maximum span of about 4 ft would be sufficient, and some preferred spans up to 6 ft. To accommodate a wider range of obstructions, the first transition post …

Assessment Of Truck Parking Demand And Safety During Normal And Severe Weather Conditions In Nebraska, Nathan Huynh, Li Zhao, Zhenghong Tang, Aida Riahifar, Jahangeer Jahangeer

Nebraska Department of Transportation: Research Reports

This project examined truck parking capacity, demand, and utilization patterns along I-80 in Nebraska. The objectives were to (1) document the capacity of public and private truck parking facilities along I-80, (2) analyze spatial and temporal trends in parking demand, (3) develop models to predict occupancy at parking facilities, (4) identify clusters of undesignated parking during inclement weather, and (5) assess whether truck parking shortages contribute to truck-involved crashes. Within a one-mile buffer of I-80, 21 public facilities and 49 private facilities were identified. The spatiotemporal analysis of these public and private truck parking facilities using the National Agriculture Imagery …

Multi-Objective Optimization Of Energy Costs And Ev Battery Health In V2g Enabled Homes, Dzifa M. Hodey

Theses and Dissertations--Computer Science

Electric vehicles (EVs) and rooftop solar photovoltaic (PV) systems are increasingly being integrated into residential settings, creating new opportunities for vehicle-to-grid (V2G) and vehicle-to-home (V2H) operations. In these systems, the EV battery functions as a controllable energy storage unit that can charge from the grid or PV and discharge energy to supply household load or export to the grid for a profit. By intelligently scheduling this bidirectional power exchange, households can reduce electricity costs and enhance PV utilization. Realizing these benefits requires optimization strategies that balance cost reduction with EV battery health preservation. However, existing V2G/V2H studies largely emphasize cost …

Advancing Task-Oriented Dialog Systems: Scalability, Generalization, And Evaluation, Adib Mosharrof

Theses and Dissertations--Computer Science

Task-oriented dialog (TOD) systems enable conversational interfaces for complex tasks like flight booking and restaurant reservations. However, deploying TOD systems at scale faces three critical barriers: scalability, generalization, and evaluation. Scalability is primarily restricted by the human-annotation bottleneck, as current systems depend on vast quantities of manually labeled data for every new domain, making deployment prohibitively expensive. Generalization remains a persistent challenge, as systems optimized for known domains often suffer significant performance degradation when encountering new, unseen ones. Existing evaluation metrics measure response quality and fluency, but fail to measure functional task success. As TOD systems are deployed across diverse …

Advancing Generative Methods For Multimodal Data Analysis, Rabeya Tus Sadia

Theses and Dissertations--Computer Science

The integration and modeling of high-dimensional, heterogeneous biological data remain central challenges in computational biology due to complex feature dependencies and pervasive missingness. This dissertation addresses these challenges by developing novel generative frameworks for multimodal data reconstruction, imputation, and interaction prediction. In generative modeling, we focus on capturing structural and causal dependencies in sparse biological systems. We first introduce CausalGeD, a causality-aware diffusion framework that leverages Granger-causal attention for biologically coherent spatial gene expression generation. Next, we propose CausalGenDiff, which combines VAE-guided latent representations with causal diffusion to enable robust reconstruction across spatial and single-cell modalities. We further present DepMicroDiff, …

Network-Aware Airline-Specific Flight Delay Prediction Using Tree-Based Ensemble Models, Mary Dufie Afrane

College of Graduate Studies: Theses & Dissertations

Flight delays pose persistent challenges to the efficiency and reliability of air transportation systems, affecting airlines, airports, regulators, and passengers alike. As traffic demand grows and operational environments become increasingly interconnected, accurately predicting both departure and arrival delays has become crucial for effective planning and mitigation. This study presents a network-aware, airline-specific framework for predicting flight delays in U.S. domestic air transportation systems using tree-based ensemble machine learning models. A large-scale dataset of 1.98 million flights, enriched with weather information, is used to develop predictive models for both departure and arrival delays. To capture the structural and operational complexity of …

Roadway Runoff Impacts To Trout Streams Studies For Ms4 Permit, Jobayed Hossain Badhan

College of Graduate Studies: Theses & Dissertations

Roadway runoff from Georgia Department of Transportation (GDOT) highway infrastructure poses measurable, but temporally constrained threats to cold-water trout ecosystems in northern Georgia. This study investigates temperature and dissolved oxygen (DO) dynamics in three secondary trout streams receiving GDOT roadway discharges, with the primary objective of evaluating compliance with Georgia Rule 391-3-6-.03(6)(ii),(v) under the Municipal Separate Storm Sewer System (MS4) permit framework. Field monitoring was conducted from April 2024 through October 2025 across two consecutive summer seasons using a tiered, multi-instrument approach: YSI ProDSS handheld grab sampling provided regulatory-grade reference measurements; HOBO MX-801 optical DO dataloggers recorded continuous 5-minute-interval temperature …

Improving Evacuation Effectiveness On Cruise And Large Passenger Ships : An Analysis Of Human Factors, Safety Culture, And Behavioral Dynamics, Antonios Andreadakis

World Maritime University Ph.D. Dissertations

Maritime trade has long constituted a central pillar of economic development, supporting global commerce and cultural exchange. Nevertheless, the maritime environment is inherently hazardous and therefore the protection of human life has consistently constituted and will continue to remain a central priority (Casson, 1995). An instrumental turning point in maritime safety occurred after the sinking of Titanic in 1912, which prompted in 1914 an International Conference dedicated to the protection of human life at sea; which ultimately led to the adoption of the International Convention on Safety of Life at Sea (SOLAS) (Dalaklis, 2017). This Convention introduced internationally imposed safety …

A Review On Biomass-Derived Hard Carbon Anodes For Sodium-Ion Batteries : From Carbon Precursors To Storage Mechanisms, Anqi Lu, Jiaqian Qin

Journal of Metals, Materials and Minerals

The rapid development of sustainable energy technologies has intensified the demand for cost-effective and high-performance energy storage systems. Sodium-ion batteries (SIBs) are regarded as one of the most promising alternatives to lithium-ion batteries (LIBs) owing to their low cost, abundant sodium resources, and similar electrochemical mechanisms to LIBs. Hard carbon (HC) has attracted significant attention as the predominant anode material for SIBs due to its low cost, structural tunability, and availability from diverse precursors. Nevertheless, challenges remain, including the unclear Na+ storage mechanism, limited rate capability, and strong dependence on precursor type. This review systematically summarizes recent advances in HC …

Mechanical Properties And Crystallization Of Polybutylene Terephthalate Reinforced With Glass Flakes And Aluminum Powder, Nattakarn Hongsriphan, Pajaera Patanathabutr

Journal of Metals, Materials and Minerals

This research investigated mechanical properties and crystallization of poly(butylene terephthalate) composites by adding glass flakes (GF) and aluminum particles (Al). The concentration of the GF was 3 wt% or 5 wt%, and the Al was 0.5 wt% or 1.0 wt%. The stress-strain curves of the PBT-based composites showed yielding and necking. The PBT/GF/Al composites with GF/Al ratios of 3/0.5 wt/wt%, 3/1.0 wt/wt%, 5/0.5 wt/wt%, and 5/1.0 wt/wt% had Young’s moduli of 11.44%, 11.70%, 16.81%, and 19.31% higher than that of neat PBT, respectively. In the presence of Al at 1.0 wt%, the flexural modulus of the PBT/GF/Al composites increased to …

Synthesis, Structure, And Electrochemical Properties Of The Ni(Oh)2/Nimoo4 Composite On The Rgo/Nf Template For Hybrid Battery-Supercapacitor Electrodes, Retno Asih, Haniffudin Nurdiansah, Rogabe Sianipar, Ida Ayu Gayatri, Lukman Noerochim, Diah Susanti, Isao Watanabe, Darminto Darminto

Journal of Metals, Materials and Minerals

The growing demand for renewable and sustainable energy has intensified research on advanced energy-storage systems that can deliver both high energy and power densities. In this study, a Ni(OH)2/ NiMoO4 composite on a reduced graphene oxide/nickel foam (rGO/NF) template was synthesized through a hydrothermal and electrodeposition route to construct a hybrid battery-supercapacitor electrode. The unique hierarchical design combines the pseudocapacitive activity of Ni(OH)2/NiMoO4 with the excellent conductivity of rGO and the high surface area of NF, enabling efficient electron and ion transport. Structural and morphological analyses confirm the successful formation of the Ni(OH)2/NiMoO4/rGO/NF architecture. The electrode exhibits a specific capacitance …

Development Of Poly(Lactic Acid)/Ethylene-Propylene-Diene Monomer/Cellulose Composites Using Cellulose Extracted From Hemp Biomass For Plastic Packaging Applications, Supanicha Alapon, Natthanich Thongmee, Wikoramet Teeka, Pattara Somnuake, Sirirat Wacharawichanant

Journal of Metals, Materials and Minerals

Poly(lactic acid)/ethylene-propylene-diene monomer (EPDM)/cellulose composites using cellulose derived from hemp biomass (CHB) were investigated in this research. Morphology, chemical structures, functional groups, and crystallinity of CHB were characterized, observing a size of 135 ± 32 μm from SEM images with high purity and crystallinity from FT-IR and XRD spectroscopy. The optimized CHB was incorporated at 1 phr, 3 phr, and 5 phr into PLA/EPDM blends at 90/10 w/w. The polymer composites were prepared using an internal mixer, and samples were produced by compression molding for mechanical and thermal testing. The results indicated that the EPDM phase dispersed as droplets in …

Effects Of Gum Additives On Nickel Electroplating For Enhancing Steel Corrosion Resistance, Supitcha Supansomboon, Manatsawee Maneekan, Chanyanut Saenthaweesuk, Duangta Sitthichokcharoen, Natthapong Phinichka

Journal of Metals, Materials and Minerals

Low-carbon steels are widely used across various industries but have limited corrosion resistance, leading to safety hazards and a shortened service life. Nickel plating is a common method for enhancing steel corrosion resistance. The plating bath solution can be modified by adding additives to improve the properties of the coating. In this research, gum arabic, guar gum and gelatin were used as additives in a nickel electroplating bath. SS400 low-carbon steel, as a substrate, was plated with nickel from these different baths at 5 V for 25 min. Nickel coated with green additives showed higher hardness compared to those without …

Effect Of Cu Content On Microstructure, Morphology, And Antibacterial Properties Of Ti-Cu Alloy Thin Films, Chittra Kedkaew, Phalakorn Khwansungnoen, Tanattha Rattana

Journal of Metals, Materials and Minerals

Ti-Cu alloy thin films exhibit considerable potential for the development of advanced antibacterial surfaces, particularly for biomedical applications. In this research, Ti-Cu binary alloy thin films with a wide range of Cu content from 25.8 at% to 77.8 at% were deposited using magnetron co-sputtering with pure Ti and Cu as the targets. The composition of Cu in the films can be controlled by the applied power of Cu targets. This study investigated the effect of Cu content on the microstructural, morphological, and antibacterial properties using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Atomic force microscopy (AFM), X-ray photoelectron …

Contributions Of Carbon Content And Cooling Rate On Phase Transformations And Mechanical Properties Of Sintered Fe-1.5cr-0.2mo-Xc Alloys, Mantana Yaruan, Wantana Koetniyom, Thanyaporn Yotkaew, Nattaya Tosangthum, Ruangdaj Tongsri

Journal of Metals, Materials and Minerals

Microstructural development in sintered Fe-1.5Cr-0.2Mo-xC alloys, produced under different cooling rates of 0.1℃∙s‒1 and 5.4℃∙s‒1, was investigated. It was found that, in slowly sintered Fe-1.5Cr-0.2Mo-xC alloys, the microstructure changed from hypoeutectoid to eutectoid and to hypereutectoid steel microstructural features with increasing carbon content. Under the fast-cooling rate of 5.4℃∙s‒1, the microstructural change with respect to the increase of carbon content involved the competition between the formation of ferrite + carbide mixture and that of martensite-austenite constituent. The increase of tensile strength of slowly cooled sintered Fe-1.5Cr-0.2Mo-xC alloys with increasing carbon content was attributed to …

Synergy Of Ground Granulated Blast-Furnace Slag And Limestone Powder In Ternary Cement: Effects On Heat Of Hydration And Strength Development, Pailyn Thongsanitgarn, Watcharapong Wongkeo, Thanongsak Nochaiya, Arnon Chaipanich

Journal of Metals, Materials and Minerals

This study explores the synergistic effect of ground granulated blast-furnace slag (GGBS) and limestone powder (LS) on the hydration behavior and mechanical performance of ternary cement systems. Calorimetry revealed that 30GGBS mix showed a significantly lower peak of about 2.3 mW∙g‒1 and a delayed response. In contrast, the incorporation of LS enhanced early hydration, with the 30LS mix reaching a peak of approximately 2.8 mW∙g‒1 around 6 h. Among ternary blends, 15GGBS–15LS exhibited the highest and earliest heat flow peak (about 2.55 mW∙g‒1 around 7.5 h), while 25GGBS–5LS showed a slower response (about 2.45 mW∙g‒1 around 9.5 h). Despite differences …

Effect Of Garnet Incorporation On The Functional Properties Of Sunscreens, Parinya Chakartnarodom, Kanyarat Munmani, Sureerat Polsilapa, Duangrudee Chaysuwan, Wichit Prakaypan, Passakorn Sonprasarn, Edward Laitila, Nuntaporn Kongkajun

Journal of Metals, Materials and Minerals

Garnet, a silicate mineral, was investigated as a replacement for the TiO2-based compound in sunscreen formulations. Samples containing garnet were evaluated for color shade, viscosity, sun protection factor (SPF), and water resistance. Substituting the TiO2-based compound with garnet reduced both viscosity and SPF but markedly enhanced water resistance. This improvement is attributed to the physical reinforcement provided by garnet particles, which strengthen the sunscreen film and reduce wash-off under water exposure. Garnet incorporation also altered the product’s appearance from white to a darker brownish-beige tone, improving visual compatibility with a wider range of skin tones.

Synthesis And Photoluminescence Properties Of Graphene Quantum Dots Prepared Via Carbonization Under Pressure Reduction, Sutthipoj Wongrerkdee, Pichitchai Pimpang

Journal of Metals, Materials and Minerals

This study reports the synthesis of graphene quantum dots (GQDs) via a bottom-up carbonization approach using citric acid as a precursor under various reduced pressure conditions. The carbonization process was carried out at 250℃ in an ethanol medium, with atmospheric pressures ranging from normal to 20 inHg below atmospheric pressure. The effects of pressure reduction on the size and optical properties of GQDs were systematically investigated. Dynamic light scattering (DLS), UV–Vis spectroscopy, and fluorescence spectroscopy revealed that pressure reduction during synthesis decreased GQDs size and induced a blue-shift in both absorption and emission spectra. The optical bandgap of GQDs was …

Effects Of Welding Currents On Microstructure And Corrosion Behaviors Of Inconel 625 Cladding On 2.25cr-1mo Steel By Hot-Wire Tig, Supparat Saeheng, Hein Zaw Oo, Prapas Muangjunburee

Journal of Metals, Materials and Minerals

Hot-wire tungsten inert gas (HW-TIG) cladding has been applied to the steam turbine rotor welding repair. This study investigated the effects of welding currents on microstructure, hardness, and corrosion behavior. The experiments were conducted using four different welding currents applied to bead-on-plate Inconel 625 welds on a 2.25Cr-1Mo steel substrate as the steam turbine rotor material. The selected welding currents were 125 A, 150 A, 175 A, and 200 A. The percentages of weld dilution for different welding currents were also evaluated. Higher welding currents increased weld dilution, weld bead width, and HAZ size. As the welding current increased, the …

Development Of 4-Vinylbenzyl Chloride (Vbc) Grafted Onto Branched Polyethylenimine (Pei) Onto Bacterial Cellulose Sheet By Gamma-Induced Irradiation Technique For Cu Ion Adsorption, Methinee Wongwai, Supitchaya Kulratkitiwong, Thitirat Rattanawongwiboon, Sarute Ummartyotin

Journal of Metals, Materials and Minerals

Bacterial cellulose extracted and purified from Nata de coco was employed as a platform for Cu2+ ion adsorption. 4-vinylbenzyl chloride (VBC) was successfully grafted at the hydroxyl position by using gamma irradiation. The optimum was typically related to VBC concentration of 2% (v/v) and a radiation dose of 50 kGy. FTIR significantly reported the functional group of C-Cl related to VBC. No change of crystallinity and morphology was observed. The thermal decomposition was stable up to 200℃. The modification of branched polyethylenimine (PEI) was prepared in order to change the functionality to N‒H stretching. This was expected to adsorb Cu2+ …