Chemical Engineering Commons^™

Evaluation Of Material Request Order To Support Sustainable Construction, Fajar Susilowati, Nur Nahdiah Anggraeni

Makara Journal of Technology

This study was conducted on one of Indonesia’s apartment projects, in which reinforced concrete is the main structure. Based on existing project data, this project experienced a decline in the construction work’s progress, thus reducing the project’s overall progress. This decline occurred because the delivery of concrete reinforcement material was delayed. This study aimed to determine the process of material request order and its relationship with the work implementation, as well as the factors that influenced the delayed arrival of concrete reinforcement material at the project site. The method used in this study was observation and interview. Data were analyzed …

Low-Crystallinity And Heterostructured Aupt-Ru@Cnts As Highly Efficient Multifunctional Electrocatalyst, Tuan-Jie Gan, Jian-Ping Wu, Shi Liu, Wen-Jun Ou, Bin-Ling Bin-Ling, Xiong-Wu Kang

Journal of Electrochemistry

The catalytic activity of the catalysts is strongly dependent on the structure of the catalysts, and the exploration of their correlation and structure-controlled synthesis of the high-performance catalysts are always at the central. Currently, platinum (Pt) is the optimum catalyst for hydrogen evolution reaction (HER), oxygen reduction reaction (ORR) and alcohol oxidation reaction, while ruthenium (Ru) behaves as the champion catalyst for oxygen evolution reaction (OER) during water splitting. Preparing alloy catalysts with these precious metals can modulate the catalytic activity of these catalysts from the perspective of strain effect, ensemble effect and ligand effect. Here, we developed a strategy …

Facile One-Step Solid-State Synthesis Of Ni-Rich Layered Oxide Cathodes For Lithium-Ion Batteries, Jing-Yue Wang, Rui Wang, Shi-Qi Wang, Li-Fan Wang, Chun Zhan

Journal of Electrochemistry

Nickel-rich layered oxide is one of the dominate cathode materials in the lithium ion batteries, due to its high specific energy density meeting the range requirement of the electric vehicles. Typically, the commercial Ni-rich layered oxides are synthesized from co-precipitated precursors, while precision control is required in the co-precipitation process to ensure the atomic level mixing of the cations such as Ni, Co and Mn, et.al. In this work, a one-step solid-state method was successfully applied to synthesize the Ni-rich layered oxide materials with ultra-high Ni content. By choosing the nickel hydroxides as the precursor with layered structure similar to …

Highly Efficient De-Lignification And Reengineering Approach To Modify Wood Into A Bio-Composite And An Adsorbent Material, Ramon Filipe Beims

Electronic Thesis and Dissertation Repository

In this doctoral study, high-value bio-based materials, including a light-weight and high-strength wood-based composite material and a bio-based adsorbent material for removal of heavy metals in water, were developed from natural wood by a novel reengineering approach. In this approach, natural wood was first fractionated into a porous de-lignified wood and lignin. The porous de-lignified wood was then composited by impregnation of an epoxy resin synthesized with the lignin extracted from wood.

The wood-based composite preparation consisted of three main steps: (i) de-lignification of natural wood, (ii) lignin modification and epoxidation, and (iii) impregnation of the de-lignified wood with lignin-based …

Identification Of Lithocholic Acid As A Molecular Glass Host For Room-Temperature Phosphorescent Materials, John J. Flynn, Zachary M. Marsh, Douglas M. Krein, Steven M. Wolf, Joy E. Haley, Erick S. Vasquez, Thomas M. Cooper, Nicholas P. Godman, Tod A. Grusenmeyer

Chemical and Materials Engineering Faculty Publications

Lithocholic acid was identified as a molecular glass host material for room temperature phosphorescent (RTP) chromophores. Differential scanning calorimetry (DSC) was performed on a series of structurally similar, biologically sourced molecules, including lithocholic acid, β-estradiol, cholesterol, and β-sitosterol, in an effort to identify new amorphous molecular glasses independent of plasticizing additives. DSC analysis revealed lithocholic acid and β-estradiol form stable molecular glasses post thermal processing unlike neat cholesterol and β-sitosterol. The ability of lithocholic acid and β-estradiol to stabilize high wt. % loadings of d10-pyrene and a mixture of d10-pyrene and an iridium chromophore, bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate iridium(III) (FIr6), was also investigated. …

Contact Dewatering Of Cellulose Nanofibers For Biopolymer Composite Applications, Alexander Collins

Electronic Theses and Dissertations

Cellulose Nanofibrils (CNFs) are promising materials for reinforcement of polymer matrices attributable to their impressive physical and mechanical properties, as well as their biodegradability. However, the utilization of these materials in composites is made challenging by the water content of CNF slurries, the tendency of CNFs to agglomerate as they dry, and incompatibility between hydrophilic CNFs and hydrophobic polymer matrices. The most commercially viable drying methods to produce small-scale dry CNFs, such as spray drying, are very energy intensive, can only dry the materials down to micron-scale agglomerates, and do not preserve fibrillar aspect ratios. “Contact dewatering,” or the removal …

Biobased Packaging Materials From Cellulose Nanofibrils Produced From Virgin Wood Pulp Or Recycled Cardboard Pulp, Md Ikramul Hasan

Electronic Theses and Dissertations

Self-standing cellulose nanofibril (CNF) films are regarded as one of the promising alternatives to current petroleum-based packaging materials. The mechanical and barrier properties of CNF films are not yet up to the mark for certain applications, especially at high relative humidity. Those properties of CNF films can be tuned by the drying methods of films, degree of fibrillation, cross-linking, and controlled shrinkage. A comprehensive understanding of these processes and their influence on the structure and properties of CNF films have been presented in this thesis.

First, we prepared CNF films from CNF suspensions with two different degrees of fibrillation- standard …

Development Of Anti-Corrosive Polyester Powder Coatings, Marshall Shuai Yang

Electronic Thesis and Dissertation Repository

Powder coatings are green solutions to replace the environmentally unfriendly liquid paints for anti-corrosive purpose. In this study, UV-resistant polyester/TGIC powder coatings for outdoor application were developed instead of the widely used epoxy-based coatings. Three types of additives and functional filler, namely zinc phosphate with passivation effect, zinc powder with sacrificial anode effect, and two nanoclays with barrier effect were incorporated into the coatings to enhance the anti-corrosive performance. The anti-corrosive properties were evaluated by electrochemical techniques and neutral salt spray tests. The combined effects of the additives with a filler barium sulfate were also investigated. The effect of the …

Preface Of Volume 1 Issue 1 On Journal Of Materials Exploration And Findings (Jmef), Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.

Contents, Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.

Synthesis And Consolidation Of Metal Oxide Nanocrystals Via Nonthermal Plasma, Austin Cendejas

McKelvey School of Engineering Theses & Dissertations

Nonthermal plasmas offer a unique nonequilibrium environment that has been leveraged in a wide variety of applications in the fields of material processing, lighting, and waste management to name a few. In all of these cases, the plasma serves as a source of high energy electrons, ions, reactive gas species, and radicals that interact in several ways with surfaces brought into contact with the plasma. Specifically, nonthermal plasmas have been shown to be very successful in achieving continuous, high-throughput, monodisperse nanocrystals of a wide variety of materials. The crystallinity of nanoparticles synthesized in nonthermal plasmas can be attributed to the …

The Optimization Of Failure Risk Estimation On The Uniform Corrosion Rate With A Non-Linear Function, Fernanda Hartoyo, Jaka Fajar Fatriansyah, Imam Abdillah Mas'ud, Farhan Rama Digita, Hanna Ovelia, Datu Rizal Asral

Journal of Materials Exploration and Findings

Failures in the oil and gas pipeline system are conditions that must be avoided and anticipated because the losses due to the failures can occur at a very high level. Internal corrosion is one of the significant causes of the failures in pipeline systems. In addition, this type of corrosion is due to the high content of carbon dioxide and other corrosive substances in crude oil and natural gas. Therefore, an optimal inspection scheduling system is required to prevent the possibility of pipeline failures due to corrosion and to avoid any overspending on the budget due to excessive inspection scheduling. …

The Generation And Transport Of Charged Aerosols: Fundamental Study And Applications In Medicine And Energy Conversion, Hao Zhou

McKelvey School of Engineering Theses & Dissertations

Charged aerosols have significant implications in the field of functional material synthesis, pharmaceutical coating, and drug delivery. Electrospray systems are an effective methodology for generating highly charged monodispersed droplets in the size range from nanometer to micrometer. The prediction of surface charge, size and morphology of nanoparticles resulting from charged droplets are highly required for the precise control of nanoparticle properties and their effective utilization. However, the evolution of charged droplet is not well understood due to the existence of coulombic fission and ion evaporation processes. Thus, the goal of this dissertation is to elucidate how the precursor properties and …

Functional Bottlebrush Polymer Additives For Thin Films And Coatings, Travis S. Laws

Doctoral Dissertations

Bottlebrush polymers are a class of highly branched polymers consisting of polymeric side chains that are densely grafted to a linear backbone. Their highly branched architecture results in surface enrichment across a broad range of materials. The goal of my research has been centered around the design of functional bottlebrush polymers and their use as surface active additives in blend films and coatings.

In the first chapter, we examine the segregation behavior of polystyrene bottlebrushes that are blended with linear polystyrene. We systematically vary the lengths of the bottlebrush backbone (Nb), side-chain (Nsc), and the linear matrix (Nm) in order …

Quantifying The Workability Of Calcium Sulfoaluminate Cement Paste Using Time-Dependent Rheology, Sukanta K. Mondal, Adam Welz, Carrie Clinton, Kamal Khayat, Aditya Kumar, Monday Uchenna Okoronkwo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Poor workability is a common feature of calcium sulfoaluminate (CSA) cement paste. Multiple chemical admixtures, such as set retarders and dispersants, are frequently employed to improve the workability and delay the setting of CSA cement paste. A quantitative assessment of the compatibility, efficiency, and the effects of the admixtures on cement paste workability is critical for the design of an appropriate paste formulation and admixture proportioning. Very limited studies are available on the quantitative rheology-based method for evaluating the workability of calcium sulfoaluminate cement pastes. This study presents a novel and robust time-dependent rheological method for quantifying the workability of …

Fabrication Of Nb3Sn By Magnetron Sputtering For Superconducting Radiofrequency Application, Md Nizam Sayeed

Electrical & Computer Engineering Theses & Dissertations

Particle accelerators are considered as an important device that has wide applications in cancer treatment, sterilizing waste, preserving foods, ion implantation in semiconductor industry, and in production of isotopes for medical applications. Superconducting radiofrequency (SRF) cavities are the building blocks of a linear particle accelerator. Current particle accelerators use niobium (Nb) superconductors as the sheet material to fabricate a single SRF cavity for particle acceleration. With better superconducting properties (critical temperature T_c ~ 18.3 K, superheating field H_sh~ 400 mT), Nb₃Sn is considered a potential candidate in SRF technology. Magnetron sputtering is a promising deposition …

Study Thermodynamics Of The Magnetite Sulfidation In Copper Smelting Processes, A S. Khasanov, Q T. Ochildiyev, B T. Berdiyarov, Sh T. Khojiev, S T. Matkarimov

Technical science and innovation

The article discusses the problem of reducing the amount of magnetite in the impregnation of copper in the slag generated after the conversion process in copper production in the furnace to reduce slag. Accordingly, a method of lowering magnetite by sulfidation has been proposed, using elemental sulfur as a local and relatively inexpensive sulfiding-reducing agent. The mechanism of chemical phenomena occurring in the interaction regions of magnetite and elemental sulfur has been developed. Based on the mechanism of chemical reactions produced, each chemical reaction that occurs in the process is analysed from a thermodynamic point of view. According to the …

Obtaining Wrapping Paper Used In Furniture Wrapping And Quality Delivery And Determining Its Quality Indicators, E A. Egamberdiyev, A R. Makhkamov, G R. Rakhmonberdiev

Technical science and innovation

Composite materials samples have been obtained from cellulose and bazalt fibers based on cellulose-containing plants. The properties of paper samples have been studied: the amound of cellulose, the amound of ash, water absorption and breaking load. Gained results show that the composite material with the addition of basalt fibers is more durable. Half-finished cellulose fibers obtained from basalt, straw and wastepaper are more prouse than ones obtained from cotton plant

New Solid Polymer Electrolytes For Lithium, Sodium, And Calcium-Based Batteries, Francielli Silva Genier

Dissertations - ALL

The establishment of sustainable energy sources highly depends on efficient storage devices to guarantee a consistent power supply. The growing demand for lithium-ion batteries (LIBs) for this purpose, combined with concerns about lithium availability, has motivated the search for viable storage alternatives, such as sodium and calcium. While several studies have investigated different lithium-free liquid electrolytes, the transport of these alternative ions in their polymer counterparts remains understudied. The advantages of solid polymer electrolytes include the possibility of higher energy density in solid-state devices and the elimination of safety concerns associated with liquid electrolytes, such as flammability, leakage, and dendrite …

Effect Of Dispersions Of Al2o3 On The Physical And Mechanical Properties Of Pure Copper And Copper-Nickel Alloy, Samah El-Khatib, A. H. Elsayed, A. Y. Shash, A. El-Habak

Future Engineering Journal

This paper illustrates the mechanical and physical properties of pure Cu and Cu-Ni (50-50 wt. %) alloy mixed with Al₂O₃ (1-4 wt. %) as micro-particles reinforcement materials. The attained composite alloy specimens' characteristics were estimated such as microstructure, relative density, electrical and thermal conductivity, hardness, and compression yield stress properties to adjust the suitable optimum percentage of reinforcing material which has the best physical and mechanical properties with different main matrix materials whether pure Cu powder or Cu-Ni mechanical alloy. The micron-sized Al₂O₃ was added to enhance the mechanical and physical properties of the …

Effect Of Process Control Agents Used In Mechanochemical Synthesis On Properties Of The Prepared Composite Reactive Materials, Mehnaz Mursalat

Dissertations

The study explores synthesis and reactivity of new reactive materials prepared by ball milling. High-energy ball milling became a ubiquitous mechano-chemical tool to manufacture diverse powders, from pharmaceuticals or foods to alloys to new solid rocket propellants. It enabled a dramatic expansion of the range of chemical compositions obtainable; however, it did not so far, allowed one to fine-tune morphology or interfaces in the generated powders. It is shown in this work how different process control agents (PCAs) can serve to tune the powder morphology and reactivity. Commonly used as lubricants and cooling agents during milling, liquid PCAs can be …

Electrochemical Synthesis Of Acetylpyrazine, Lin Mao, Dong-Fang Niu, Shuo-Zhen Hu, Xin-Sheng Zhang

Journal of Electrochemistry

Acetylpyrazine is naturally presented in hazelnuts, peanuts, and sesame seeds. As an important food additive, it is widely used in baked foods, meat, sesame and tobacco. At the same time, acetylpyrazine is also an important pharmaceutical intermediate, which is used in the syntheses of anti-tuberculosis drugs, anti-tumor, anti-malaria, anti-viral, antibacterial and treatments of epilepsy, pain and Parkinson’s drugs. At present, the synthesis methods of acetylpyrazine include oxidation method, multi-step method and Grignard reagent method, which have the disadvantages of low yield, cumbersome process, severe reaction conditions and high cost. In this study, acetylation of pyrazine was used to synthesize acetylpyrazine …

Electrocatalytic “Volcano-Type” Effect Of Nano-Tio2 (A)/(R) Phase Content In Pt/Tio2-CnX Catalyst, Ai-Lin Cui, Yang Bai, Hong-Ying Yu, Hui-Min Meng

Journal of Electrochemistry

The relationship between the electrochemical activity of fuel cell catalysts and Pt particle size, as well as the catalyst support and co-catalyst is still unclear. In this work, FESEM, XRD, BET, TEM and CV techniques were adopted to investigate the effects of TiO₂ anatase (A)/rutile (R) phases content on the electrochemical activity of Pt electrocatalyst. The results showed that the anatase-rutile phase transformation occurred during the heat treatment of TiO₂ at 700 ~ 900 ^oC accompanied by the growth of two-phase crystalline size, and anatase was completely transformed into rutile at 900 ^oC. TEM results revealed …

Preparation And Properties Of Gcp-Supported Palladium Particles Composite Towards Electrochemical Ammonia Synthesis, Ying-Chao Wang, Zi-Zai Ma, Yi-Fan Wu, Xiao-Guang Wang

Journal of Electrochemistry

Ammonia (NH₃) plays an essential role in agriculture and modern industries. Electrochemical fixation of nitrogen (N₂) to ammonia (NRR) under ambient conditions with renewable electricity is a promising strategy to replace the industrial Haber-Bosch method. However, it usually suffers from extremely poor ammonia yield and low Faraday efficiency due to the poor electrocatalysts. Therefore, intensive studies have been devoted to developing efficient NRR catalysts till now. Among them, palladium (Pd) can capture protons in the aqueous phase to form stable α-PdH, which balances the competitive adsorption between nitrogen and protons as well as reduces the …

Study And Improvement On Expansion Property Of Silicon Oxide, Wei-Chuan Qiao, Fang-Ru Li, Jin-Lin Xiao, Li-Juan Qu, Xiao Zhao, Meng Zhang, Chun-Lei Pang, Zi-Kun Li, Jian-Guo Ren, Xue-Qin He

Journal of Electrochemistry

The silicon-based anode materials have the potential to meet the ever-increasing demand for energy density in lithium-ion batteries market owing to their high theoretical specific capacity. Unfortunately, their commercialization was hindered by the continuous volume expansion. Herein, the expansion characteristics and corresponding mechanism of the silicon oxide and graphite-silicon oxide composites were investigated by in-situ displacement detection systematically. The results showed that the expansion property was improved by material process modifications. During the de/lithiation processes of graphite, the expansion ratio in 30% ~ 50% SOC changed little because of the small interlayer spacing variation of the intercalated graphite. …

A Circular Economy Approach To Improve E-Waste Recycling In California: Economic Potential And Policy Options, Kripa Shah

Master's Projects and Capstones

The higher consumption rates of electronic devices along with their short life cycles and few repair options poses a huge challenge for E-waste industries to manage them effectively. E-waste comprises of hazardous materials and toxic constituents that can affect the environment and public health through improper disposal. However, they also contain few valuable materials that, if recovered, can reduce the dependence on virgin raw materials. Circular economy has the potential to utilize these valuable materials and gain environment and socio-economic benefits. The research explains how the adoption of a circular economy approach can help improve the E-waste recycling in California …

Receptor-Doped Organic Transistors: Transducing Anion Binding From Mixed Ionic-Electronic Transport, Anthony Benasco

Dissertations

Organic semiconductors based on π-conjugated polymers show remarkable properties such as high tolerance to structural defects, low processing temperature requirements, biocompatibility, ease of fabrication, and tunable properties. Conjugated polymers integrated into device arrays can exhibit collective properties sensitive to minor perturbations in the surrounding media. However, these devices rely on serendipitous sensitivity to the analyte of interest, and strategies for specific detection remain a considerable change. There remains a compelling, global need for technologies to monitor phosphate due to its prevalence in agricultural runoff, leading to fish kills and economic decline for commercial and recreational fisheries. The strong hydration energies …

Preparation, Cure, And Characterization Of Cyanate Ester-Epoxy Blends, Donald A. Klosterman

Chemical and Materials Engineering Faculty Publications

Cyanate ester resins are often blended with lower cost epoxy monomers in order to modify the cost, toughness, and processing characteristics. There are also several choices of catalysts that can be used to improve processing, namely by reducing the cure temperature. This study was undertaken to illustrate how a designed experiment approach can be used to systematically investigate a wide range of material combinations and illuminate the basic cure behavior of some simple cyanate ester – epoxy blend combinations. Two commercial cyanate ester resin products were obtained. Each was blended with a bisphenol F based epoxy resin at two different …

Oligodimethylsiloxanes With Charged Chain Ends: Synthesis, Characterization, And Properties, Tianyu Li

Doctoral Dissertations

Charged polymers have been intensively studied because of their scientific and industrial importance. In certain cases, a single charged group in the chain end can alter the structure and properties of a polymer dramatically. On the other hand, oligomers, which are different from both discrete small molecules and higher molecular weight polymers, have become an emergent class of materials. There are several charged chain-end functionalized oligomers reported, but this area has been largely unexplored. The work described in this dissertation is aimed at using well-characterized end-group functionalized oligodimethylsiloxane (oDMS) as model materials to understand the effects of charged end groups …

Isolation And Production Of Tandem Collagen Binding Domain From Clostridial Collagenase Colg And Developments In C1q Reagent Production For Future Molecule Characterization Work, Stephanie Beitle

Chemical Engineering Undergraduate Honors Theses

This thesis covers a two part project: the production methods to create a double collagen binding domain molecule with a growth factor for wound healing applications and the development of a new in-house production method for isolating C1q from bovine blood. The wound healing molecule was created using transformation, sonication, and purification before being tested via electrophoresis SDS page and Western blots to confirm the molecule’s presence. The C1q in-house production method utilizes an ultrafiltration flow cell rather than dialysis at a critical point in the process, allowing for researchers to not only be able to use a single small …