Materials Science and Engineering Commons^™

Active Packaging Film Based On Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) Blends Incorporated With Tannic Acid And Gallic Acid For The Prolonged Shelf Life Of Cherry Tomato, Shubham Sharma, Kalpani Perera, Dileswar Pradhan, Brendan Duffy, Amit Jaiswal, Swarna Jaiswal

Articles

The antimicrobial property is the key feature of active packaging. Biological macromolecules such as tannic and gallic acids are naturally found in plants such as tea, fruits, berries, and grapes. The incorporation of tannic acid (TA) and gallic acid (GA) in the biodegradable polymer blend Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) (PLA-PBAT) was used in this study to assess the potential of active packaging. TA and GA (10 wt%) composite films showed a 65%–66% increase in the UV barrier property. The tensile strength value increased after the incorporation of TA and GA (10 wt%), respectively. Overall, 1.67 and 2.2 log reductions in …

A Flexible Dual-Mode Pressure Sensor With Ultra-High Sensitivity Based On Bto@Mwcnts Core-Shell Nanofibers, Bangze Zhou, Chenchen Li, Yanfen Zhou, Zhanxu Liu, Xue Gao, Xueqin Wang, Liang Jiang, Mingwei Tian, Feng-Lei Zhou, Stephen Jerrams, Jianyong Yu

Articles

Wearable flexible sensors have developed rapidly in recent years because of their improved capacity to detect human motion in wide-ranging situations. In order to meet the requirements of flexibility and low detection limits, a new pressure sensor was fabricated based on electrospun barium titanate/multi-wall carbon nanotubes (BTO@MWCNTs) core-shell nanofibers coated with styrene-ethylene-butene-styrene block copolymer (SEBS). The sensor material (BTO@MWCNTs/SEBS) had a SEBS to BTO/MWCNTs mass ratio of 20:1 and exhibited an excellent piezoelectricity over a wide range of workable pressures from 1 to 50 kPa, higher output current of 56.37 nA and a superior piezoresistivity over a broad working range …

Implementation Of Multiscale Mechanisms In Finite Element Analysis Of Active Composite Structures, Amany Micheal, Yehia Bahei-El-Din

Centre for Advanced Materials

Interrogation of composite structures for inherent damage is investigated by implementing a three-tier analysis scheme. The analysis starts at the structure level where a general-purpose Finite Element code ABAQUS is employed to obtain the stress field in the second level of analysis which is the composite laminate. A special material routine is prepared to propagate the local fields to the individual plies and hence to the third level of analysis which is the microstructure modeling of the composite. Through the third level of analysis, interface damage between fiber and matrix is checked implementing a certain failure criteria. The interaction between …

Modeling Isothermal Reduction Of Iron Ore Pellet Using Finite Element Analysis Method: Experiments & Validation, Amogh Meshram, Joe Govro, Ronald J. O'Malley, Seetharaman Sridhar, Yuri Korobeinikov

PSMRC Faculty Research

Iron ore pellet reduction experiments were performed with pure hydrogen (H₂) and mixtures with carbon monoxide (CO) at different ratios. For direct reduction processes that switch dynamically between reformed natural gas and hydrogen as the reductant, it is important to understand the effects of the transition on the oxide reduction kinetics to optimize the residence time of iron ore pellets in a shaft reactor. Hence, the reduction rates were studied by varying experimental parameters such as the temperature (800, 850 & 900 degrees C), reactant gas flow rate (100, 150 & 200 cm³/min), pellet size and …

Monitoring Of State Transitions In Extreme Environment Application Materials Using Fiber Bragg Grating Sensors, Sabuj Khadka

Electronic Theses and Dissertations

By embedding both a single fiber Bragg grating (FBG) sensor and a thermocouple (TC) during the manufacturing for extreme environment applications of certain classes of materials such as metals and polymers, a novel in-situ approach was developed to precisely monitor their entire manufacturing processes. This novel monitoring technique was able to identify many characteristic points during the curing of room and high-temperature epoxies and the solidification processes of metal alloys composed of tin and bismuth which were selected in this research purely for verification purposes. Some of the characteristic points identified for the epoxies were: (i) the gel point, (ii) …

Pilot-Scale Spinning And Sucrose-Tetra-Aldehydes-Crosslinking Of Feather-Derived Protein Fibers With Improved Mechanical Properties And Water Resistance, Bingnan Mu, Faqrul Hassan, Qianmei Wu, Yiqi Yang

Department of Textiles, Merchandising and Fashion Design: Faculty Publications

Pliable and water-resistant protein fibers from feathers were developed via continuous one-step spinning and crosslinking using sucrose-tetra-aldehydes. Though flexible protein fibers from feathers were developed, poor wet stability and low tenacity still limit the large and high-end applications of feather-derived fibers. Despite that saccharide aldehydes are considered as an efficient and sustainable crosslinker, substantial concerns such as generation of formaldehyde, high consumption of modifiers, loss of mechanical properties, yellowing, and decline in dyeability of fibers, exist after crosslinking. In this work, we controlled structures of crosslinkers and incorporated disaccharide-tetra-aldehydes into a continuous wet-spinning line. No formaldehyde was generated in the …

Carbon Nanotube Coated Fibrous Tubes For Highly Stretchable Strain Sensors Having High Linearity, Chenchen Li, Bangze Zhou, Yanfen Zhou, Jianwei Ma, Fenglei Zhou, Shaojuan Chen, Stephen Jerrams, Liang Jiang

Articles

Strain sensors are currently limited by an inability to operate over large deformations or to exhibit linear responses to strain. Producing strain sensors meeting these criteria remains a particularly difficult challenge. In this work, the fabrication of a highly flexible strain sensor based on electrospun thermoplastic polyurethane (TPU) fibrous tubes comprising wavy and oriented fibers coated with carboxylated multiwall carbon nanotubes (CNTs) is described. By combining spraying and ultrasonic-assisted deposition, the number of CNTs deposited on the electrospun TPU fibrous tube could reach 12 wt%, which can potentially lead to the formation of an excellent conductive network with high conductivity …

Improving The Performance And Durability Of Metal Contacts In Crystalline Silicon Solar Cells Using Advanced Characterization, Nafis Iqbal

Electronic Theses and Dissertations, 2020-2023

Solar energy is one of the fastest growing forms of energy generation due to its low cost, lack of emissions, minimal maintenance, and excellent durability. However, like any other technology, it is also not free from defects and degradation, which limit its performance in the real world. Most of the degradation is related to metal contacts, which also happens to be one of the most expensive items in manufacturing, comprising almost half of the cost of converting a silicon wafer into a photovoltaic (PV) cell. Therefore, studying contact degradation to make them reliable and free of defects is the key …

Synchronous Raman Microspectroscopy And Laser Beam Induced Current Measurements As A Metrology Tool For Solar Cells And Optoelectronic Devices, Jeya Prakash Ganesan

Electronic Theses and Dissertations, 2020-2023

This works developed synchronous Raman microspectroscopy with laser beam induced current (LBIC) measurements to generate insights into structure-property correlations in finished solar cell modules. Raman spectroscopy is a powerful, non-destructive technique to examine phase and composition of materials where a laser beam excites characteristic vibrational modes of chemical bonds in a material. Conducting Raman spectroscopy under a microscope (i.e., Raman microspectroscopy) with confocal capabilities allows the chemical constituents to be mapped with high spatial resolution in the x, y and z directions. Simultaneously, the excitation laser from Raman can also generate photocarriers in a semiconductor. In a solar cell, these …

Davydov-Split Aggregates Of Cyanine Dyes For Bovine Serum Albumin Detection, Yiping Ma

Electronic Theses and Dissertations, 2020-2023

The p-conjugated supramolecular aggregates have gained significant interest in recent years. The cyanine dye aggregates are particularly interesting due to their unique optical and excitonic properties, which cannot be found in individual molecules. Cyanine dyes can form different kinds of aggregates. H-aggregates are formed when dye molecules are packed in a face-to-face fashion, which gives rise to a blue-shift absorption band and strong emission quenching compared to the monomer. J-aggregates are composed of individual dye molecules in a head-to-tail stacking, which leads to a red-shift absorption band and a sharp intense emission band with a small Stoke shift compared with …

Influence Of Growth Parameters On The Synthesis Of Mos2 Films, Victor Okonkwo

Honors Undergraduate Theses

Information processing is crucial in modern society, placing a great emphasis on the performance of optoelectronic devices to match ever increasing processing and memory needs. Within these devices, MoS₂ has demonstrated great potential as transistors due to its enhanced electrostatic control. As increased layer thickness of quality MoS₂ films have been shown to boost the performance of its transistors, growth parameters for the synthesis of ideally uniform and large area multilayered films via chemical vapor deposition were investigated. By increasing the flow pressure in the system and the growth time, increasing levels of thickness and nucleation density was …

Engineering The Electrode Properties For Developing High Performance Supercapacitors, Kowsik Sambath Kumar

Electronic Theses and Dissertations, 2020-2023

Rising global warming concern demands the need for a rapid transition to renewable energy sources. The intermittent nature of these sources emphasizes the requirement of developing highly efficient electrochemical energy storage devices like supercapacitors and batteries. Supercapacitors are at the forefront of powering various devices spanning from electric cars to aircraft. Here, we have engineered the electrode material properties for developing supercapacitors with high capacitance, energy density and cycle life. Among the electrode materials, we have focused on improving the energy storage performance of 2D materials like graphene oxide (GO) and tungsten disulfide (WS2), in addition to metal oxides such …

Processing-Microstructure-Property Correlation For 316l Stainless Steel Manufactured By Laser Powder Bed Fusion, Nathalia Diaz Vallejo

Electronic Theses and Dissertations, 2020-2023

The microstructural development of 316L stainless steel (316L SS) was investigated over a wide range of systematically varied laser powder bed fusion (LPBF) parameters, such as laser power, laser scan speed, hatch distance, and volumetric energy density. The use of volumetric energy density between 46 and 127 J/mm3 produced samples with relative density above 99.8% demonstrating that even in the optimized range of processing parameters the pores are unavoidable. Shifting from this range through a variation of laser scan speed produced two types of flaws, lack of fusion (LoF) and keyhole (KH) porosity leading to a decrease in the relative …

Effect Of The Extended Rigid Flapping Trailing Edge Fringe On An S833 Airfoil, Hongtao Yu, Zifeng Yang

Mechanical and Materials Engineering Faculty Publications

A 2D numerical simulation was conducted to investigate the effect of an extended rigid trailing edge fringe with a flapping motion on the S833 airfoil and its wake flow field, as an analogy of an owl’s wing. This study aims to characterize the influence of the extended flapping fringe on the aerodynamic performance and the wake flow characteristics downstream of the airfoil. The length (Le) and flapping frequencies (fe) of the fringe are the key parameters that dominate the impact on the airfoil and the flow field, given that the oscillation angular amplitude is fixed at 5◦. The simulation results …

From Field To Failure: Detecting And Understanding Reliability Defects In Crystalline Silicon Photovoltaics, Dylan Colvin

Electronic Theses and Dissertations, 2020-2023

Severe pollution levels and the growing influence of climate change have shown that dirty energy sources need renewable and sustainable replacements. The field of photovoltaics (PV) has grown substantially over the years from a niche space solar market to a commodity in large part due to improvements in reliability. Reliability of all materials in a PV module must be considered. The industry has seen an explosion of innovation in cell interconnection technologies with significant market penetration in the past several years. These emerging, less mature technologies require more reliability information to guide improvements. Degradation studies of long-term outdoor exposure and …

Molten Steel Interactions With Tundish Linings And Refractory Glazes, Tyler Michael Richards

Doctoral Dissertations

"In the final stages of casting, molten steel is in contact with two main types of refractories: the working lining of the tundish used to serve as an intermediate vessel between the ladle and copper mold, and the various glazed carbon-bearing refractories used to control the flow of steel from the ladle to the tundish and from the tundish to the mold. If steel interacts with these refractories in such a way as to result in the formation of inclusions, it may be too late to remove them, leading to degradation of the steel’s mechanical properties. Understanding these interactions and …

Fundamental Effects Of Al And Ta On Microstructure And Phase Transformations In The Al–Cr–Mo–Ta–Ti Refractory Complex Concentrated Alloy System, Austin E. Mann, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

The effect of aluminum and tantalum concentrations on a refractory metal complex concentrated alloy is reported, particularly with respect to their effect on microstructure and phase composition of the alloy in cast and annealed form. Alloys with an equiatomic composition, (AlCrMoTaTi), an aluminum-lean composition (Al0.75CrMoTaTi), and a tantalum-lean composition (AlCrMoTa0.75Ti) are produced via arc melting. The alloys exhibit multiphase structures, confirmed by X-ray diffraction, microstructural characterization, and thermal analysis. The minor off-equiatomic adjustments of aluminum and tantalum in this alloy system did not drastically alter the prevalence of the Cr–Ta-based Laves phase. Correlations between thermodynamic predictions and observed phase transformations …

The Role Of Microstructure On High-Temperature Oxidation Behavior Of Hafnium Carbide, Jonathan A. Scott, Xiaoqing He, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Microstructure development of the products formed upon oxidation of hafnium carbide (HfCx, x = 0.65, 0.81, or 0.94) at 1300°C and 0.8 mbar oxygen pressure was investigated using Raman spectroscopy, X-ray diffraction, electron microscopy, and electron energy-loss spectroscopy. For all specimens a multilayered oxide scale was observed featuring an outermost porous hafnia layer and an interlayer adjacent to the parent carbide containing hafnia interspersed with carbon. The outermost hafnia features coarse pores presumably formed during initial stages of oxidation to allow rapidly evolving gaseous products to escape from the oxidation front. As the oxidation scale thickens, diffusional resistance results in …

Effect Of Spallation On Oxidation Kinetics Of Heat-Resistant Cr–Ni Austenitic Steels On Air And Combustion Atmosphere, Simon N. Lekakh, Oleg Neroslavsky, Mei Li, Larry Godlewski, Wenhui Zhu

Materials Science and Engineering Faculty Research & Creative Works

Thin-walled castings made from Cr–Ni austenitic steels offer a combination of light weight of a near-net component with significant high temperature corrosion protection by forming a surface oxide layer. However, above critical service conditions (temperature, atmosphere, thermal cycling), oxidized surface can result in intensive surface degradation due to scale spallation. Scale spallation can decrease the wall thickness which could be detrimental to the in-service life of thin-walled castings. Experiments and stochastic simulations of spallation assisted oxidation were performed with three cast austenitic heat-resistant steels having different Cr–Ni concentrations at temperatures between 900 and 1000 ℃ on air and water vapor …

On The Effect Of Hot Rolling On Inclusion Size And Distribution In A Cast Aisi 1070 Steel Railroad Wheel, Jacob M. Summers, Soumava Chakraborty, Laura Bartlett, Ronald J. O'Malley, Mario F. Buchely, Richard Pilon

Materials Science and Engineering Faculty Research & Creative Works

The goal of this work is to examine the effect of hot deformation on shrinkage porosity and nonmetallic inclusions in an AISI 1070 grade steel industrially produced wheel casting. Steel cleanliness is an important consideration as it influences the mechanical properties of the final product. A high density of porosity and inclusions have been shown to be detrimental for mechanical properties, especially during hot rolling. Using a laboratory-scale rolling mill, cast preforms were subjected to a 66% cumulative reduction to determine the effect of thermomechanical processing on void closure and inclusions that may produce anisotropy in mechanical properties. Quantitative automated …

The Effects Of Mixing Multi-Component Hlw Glasses On Spinel Crystal Size, C. (Charmayne) E. Lonergan, J. Rice, C. Skidmore, M. J. Schweiger, P. Hrma

Materials Science and Engineering Faculty Research & Creative Works

The Hanford Waste Treatment and Immobilization Plant will vitrify radioactive waste into borosilicate glass. The high-level waste (HLW) glass formulations are constrained by processing and property requirements, including restrictions aimed at avoiding detrimental impacts of spinel crystallization in the melter. To understand the impact of glass chemistry on crystallization, two HLW glasses precipitating small (∼5 μm) spinel crystals were individually mixed and melted with a glass that precipitated large (∼45 μm) spinel crystals in ratios of 25, 50, and 75 wt.%. The size of spinel crystals in the mixed glasses varied from 5 to 20 μm. Small crystal size was …

Stimuli-Responsive Chitosan-Based Hydrogels For Antibiotic Delivery, Tu Tran Vo Minh

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to investigate hydrogels fabricated via green approaches for drug delivery application. Biocompatible polymer-based drug delivery systems (DDS) have gained popularity in recent years because of their ability to improve the efficacy and safety of drug delivery by providing targeted and sustained release of drugs to reduce the frequency of dosing, making it more convenient for patients. Chitosan is one of the polymers commonly used for this purpose due to their higher water retention and porosity, which create space for loading medicine into the matrix. However, the potential utilization of endogenous and exogenous stimuli controlling drug release still …

การเตรียมและการวิเคราะห์ลักษณะสมบัติผ้าไหมที่เคลือบผิวด้วยไคโตซาน/ซิลเวอร์/มอนต์มอริลโลไนต์คอมโพสิต, ลักษณารีย์ มาละ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ศึกษาการเคลือบผิวผ้าไหมด้วยไคโตซาน/ซิลเวอร์/มอนต์มอริลโลไนต์คอมโพสิต โดยซิลเวอร์คอลลอยด์ถูกสังเคราะห์ด้วยกระบวนการรีดักชันทางเคมี และกระบวนการรีดักชันด้วยแสงยูวี ผลการศึกษาพบว่าภาวะที่เหมาะสมสำหรับการเคลือบซิลเวอร์คอลลอยด์สีน้ำเงินที่เตรียมด้วยวิธีรีดักชันทางเคมี โดยใช้โซเดียมโบโรไฮไดรด์ (NaBH4) เป็นตัวรีดิวซ์ (ความเข้มข้นของซิลเวอร์ไนเตรต 0.2 มิลลิโมลาร์) บนผ้าไหมอย่างสมบูรณ์ด้วยกระบวนการจุ่มแช่และกวน โดยใช้อัตราส่วนโดยน้ำหนักของซิลเวอร์คอลลอยด์ : น้ำหนักผ้าไหม เท่ากับ 1 : 200 คือ ที่อุณหภูมิในการเคลือบ 100 องศาเซลเซียส เป็นเวลา 90 นาที โดยซิลเวอร์คอลลอยด์ถูกปรับค่าความเป็นกรด-ด่าง เท่ากับ 5 ด้วยกรดแอซิติก ซึ่งผ้าไหมที่ถูกเคลือบด้วยซิลเวอร์คอลลอยด์และไคโตซานแสดงสมบัติการต้านแบคทีเรียชนิด S. aureous ได้ดีเยี่ยม และเมื่อนำไปเคลือบทับด้วยมอนต์มอริลโลไนต์ด้วยกระบวนการบีบอัดโดยใช้เครื่องบีบอัด พบว่าช่วยเพิ่มสมบัติการหน่วงไฟให้กับผ้าไหม แต่สมบัติการต้านแบคทีเรียลดลง การสังเคราะห์ซิลเวอร์คอลลอยด์โดยวิธีรีดักชันด้วยแสงยูวี โดยการฉายแสงยูวีบนสารละลายซิลเวอร์ไนเตรตที่เตรียมร่วมกับไคโตซาน พบว่าที่เวลา 2 ชั่วโมง เป็นเวลาที่เหมาะสมที่สุดในการเตรียม ซึ่งแสดงสเปกตรัมการดูดกลืนแสงที่แสดงสมบัติ Localized surface plasmon resonance (LSPR) บ่งชี้การเกิดอนุภาคซิลเวอร์นาโนหลังการฉายแสงยูวี และเมื่อนำไปวิเคราะห์โครงสร้างจุลภาค พบการกระจายของอนุภาคซิลเวอร์นาโนบนพื้นผิวของผ้าไหม หลังจากนั้นนำไปเตรียมเป็นคอมโพสิตร่วมกับมอนต์มอริลโลไนต์ และเคลือบบนผ้าไหมด้วยกระบวนการบีบอัดโดยใช้เครื่องบีบอัด พบว่าผ้าไหมที่ผ่านการเคลือบด้วยไคโตซาน/ซิลเวอร์ และไคโตซาน/ ซิลเวอร์/มอนต์มอริลโลไนต์คอมโพสิต ด้วยการรีดิวซ์ด้วยแสงยูวี ให้ผลการทดสอบสมบัติการต้านแบคทีเรียและการหน่วงไฟในทำนองเดียวกันกับวิธีรีดักชันทางเคมี

Rational Design Of Flexible And Stretchable Electronics Based On 3d Printing, Yuanhang Yang

Theses and Dissertations

Flexible and stretchable electronics have been considered as the key component for the next generation of flexible devices. There are many approaches to prepare the devices, such as dip coating, spin coating, Mayer bar coating, filtration and transfer, and printing, etc. The effectiveness of these methods has been proven, but some drawbacks cannot be ignored, such as lacking pattern control, labor consuming, requiring complex pretreatment, wasting conductive materials, etc.

In this investigation, we propose to adopt 3D printing technology to design flexible and stretchable electronics. The objective is to rationally design flexible and stretchable sensors, simplify the preparation process, form …

Nanomechanical Characterization And Comparison Of Additively Manufactured Grcop-42 Alloy, Trupti Suresh Mali

Electronic Theses and Dissertations

In an aggressive thermomechanical environment, the superior mechanical as well as thermal properties of materials play an essential role. GRCop which is a copper-based alloy developed by NASA has the potential to fulfill the requirements necessary for hightemperature applications such as the combustion chamber of liquid rocket engines. The first alloy of this family, GRCop-84 (Cu-8 wt.% Cr-4 wt.% Nb) was discovered followed with the development of GRCop-42 (Cu-4 wt.% Cr, 2 wt.% Nb). The reduction in alloying element percentage enhanced thermal conductivity with less built time while maintaining the strength of the material. The conventional fabrication is replaced with …

Moisture Content Prediction In Polymer Composites Using Machine Learning Techniques, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Rassel Raihan

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

The principal objective of this study is to employ non-destructive broadband dielectric spectroscopy/impedance spectroscopy and machine learning techniques to estimate the moisture content in FRP composites under hygrothermal aging. Here, classification and regression machine learning models that can accurately predict the current moisture saturation state are developed using the frequency domain dielectric response of the composite, in conjunction with the time domain hygrothermal aging effect. First, to categorize the composites based on the present state of the absorbed moisture supervised classification learning models (i.e., quadratic discriminant analysis (QDA), support vector machine (SVM), and artificial neural network-based multilayer perceptron (MLP) classifier) …

Uio-Type Metal-Organic Framework Derivatives As Sorbents For The Detection Of Gas-Phase Explosives, Matthew Ryan Sherrill

Legacy Theses & Dissertations (2009 - 2024)

The detection of energetic compounds – better known to the public as explosives – has is an important cornerstone of counterterrorism and homeland security . While significant advances have been achieved for the detection of trace explosives in various matrices such as soil, wastewater, and clothing, the detection of explosives in the gas phase remains challenging due to their infamously low vapor pressures. In this thesis, we leverage the high sensitivity of direct analysis in real-time mass spectrometry (DART-MS) and the microporosity of metal-organic frameworks (MOFs) to adsorb and therefore concentrate explosives from the vapor phase and subsequently detect them …

Microscale Transverse Compression Modeling: A Comparative Study Of The Analytical Mac/Gmc Methods To Experimental Results, Emily Zeitunian

Dissertations, Master's Theses and Master's Reports

Composite materials require a multi-scale approach to fully understand its behavior. At the micro level, material behavior analysis is conducted most often using numerical or analytical approaches. These models, however, require validation from experimental data to ensure material predictions are accurate. This study compares a semi-analytical micromechanical analysis tool, MAC/GMC, to experimental results of in-situ microscale transverse compression testing conducted at AFRL facilities. Effective properties, stress-strain curves, stress and strain fields, and damage predictions are compared with experimental outputs. Both generalized method of cells (GMC) and high-fidelity generalized method of cells (HFGMC) theories implemented within MAC/GMC show results that agree …

The Influence Of Different Crystal Modifiers On Ultra-Low Embodied Energy Curing Fiber-Reinforced Cement Composites, Passakorn Sonprasarn, Wichit Prakaypan, Sureerat Polsilapa, Nuntaporn Kongkajun, Edward A. Laitila, Nutthita Chuankrerkkul, Parinya Chakartnarodom

Michigan Tech Publications, Part 1

Fiber-reinforced cement composites (FRCC) are widely used in the construction of houses and commercial buildings in many countries such as the United States, the United Kingdom, the European countries, and the Asian countries such as China, India, and Thailand. Conventionally, the FRCC is manufactured from Portland cement, silica sand, and cellulose fiber using the so-called autoclaved curing under a designate hydrothermal condition to accelerate the hydration reaction resulting in superior properties. However, the autoclave-curing process needs a huge investment and generates highly environmental impact specially greenhouse gases due to its heavy energy consumption. Hence, this research aims to develop the …

3d Printing And Shape Memory Of Silicone Acrylate Polymers, Aphiwat Pongwisuthiruchte

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this research is to develop a novel UV curable resin as a 3D printing material which possesses shape memory properties. The first part of the study focuses on formulating acrylate-based resins by combining low-cost polypropylene glycol (PPG) with a commercial acrylate-based resin. The effects of PPG content on the printability, thermal, mechanical, and thermomechanical properties of the formulated resins were studied. The results show that the mechanical properties of the printed parts were successfully enhanced at a small loading of 5%vol. However, a higher PPG content leads to printing failure and reduced mechanical properties. The degree of …