DOST Balik Scientist Dr. Caldona’s Works Focuses on Corrosion Science; Shares to Fellow Researchers
by Faith P. Macatangay
Dr. Eugene B. Caldona’s stint as a DOST Balik Scientist may have been short, but truly very sweet. Thanks to the series of webinars he conducted, external participants, as well as the researchers at the DOST-MIRDC, learned much about surface engineering.
Dr. Caldona brought his laboratory closer to Filipinos as he shared his group’s research projects and activities during the last of the five-part seminar series entitled ‘High Performance Thermosets, Semi-Fluorinated Polymers, Thin Films, Composite Coatings, and 3D Printed Materials,’ held on July 17, 2023.
Dr. Caldona gave a brief background on the State of Dakota in the United States of America, the North Dakota State University, and its Department of Coatings and Polymeric Materials, where he is currently affiliated as an Assistant Professor. He also shared about his research group that specializes in the fabrication of advanced protective coatings, the development of new groups of coating materials and corrosion-preventing materials, and the utility of electrochemical approaches to evaluate the protection efficiencies of coating materials.
By definition, corrosion is the deterioration of a substance of its properties as a result of an undesirable reaction with the environment. Dr. Caldona emphasized that “the damage we encounter from corrosion can be minimized by using a coating that can function as a layer of physical barrier.” According to Dr. Caldona, this coating serves as a protection by slowing down the transport of aggressive substances that harm and damage metal surfaces.”
In his presentation, he enumerated the following coatings to minimize corrosion: organic polymer coatings, stand-alone polymer barrier coatings, and additively manufactured coatings.
Organic polymer coatings are the most widely used corrosion barriers due to ease of application, high-performing capabilities, and effective functionalities. Adding micro and nano-size fillers can further enhance the overall coating performance. Their surface may also be roughened to improve the anti-wetting properties of coatings.
Stand-alone polymer barrier coatings are also utilized because of their simplicity and ease of preparation. They are proven effective as they act as an insulating layer that blocks electron transfer between the metal and corrosive medium to prevent the electrochemical oxidation process.
Additive manufacturing or 3D printing was also applied for coating purposes. 3D printing in coating preparation is beneficial mainly due to its automation and digital design availability. The 3D printing approach helps solve failures in many coating materials.
A slide presented by Dr. Caldona shows the results of a study about rubber-modified polybenzoxazine-based (PBZ)/ polyaniline (PANI)coatings. PBZ is an example of an organic polymer coating.
Meanwhile, corrosion inhibitors are different from coatings. These compounds are added in minimal quantity to a corrosive medium to slow down the corrosion rate - their inhibiting abilities lie in their molecular structure and ability to absorb and form a protection barrier across the metallic surface. Organic compounds that contain combinations of sulfur, oxygen, phosphorus, nitrogen, aromatic rings, and multiple bonds have been shown to function effectively as corrosion inhibitors.
Superhydrophobic surfaces are applied for the best possible protection of metals from being rotten. They stand out due to their anti-wettability property. Only two requirements are required to achieve super hydrophilicity – surface roughness on micro and nanoscale and low surface energy materials.
“[In] Every research that deals with coatings, [it] is important to consider the effect of damages on the coating and integrity and performance during their intended use,” Dr. Caldona noted.
The resource person, Dr. Eugene B. Caldona, discusses to the onsite and online participants.
To know more about the research and development activities and the trainings and seminar offerings of the Center, visit the DOST-MIRDC’s website and Facebook page.
DOST Balik Scientist Dr. Caldona: How to Make Polymeric Materials ‘Speak’
by Faith P. Macatangay
“You can’t talk about materials without talking about polymers. Now is the polymer age.” – Dr. Eugene B. Caldona
A polymer is any natural or synthetic large molecule made by repeating small molecules called monomers. Polymerization is the process that links monomers together using heat and pressure.
We all use polymers - in fact, a famous example of these are the plastics that we use daily.
Plastic is a synthetic polymeric (made of polymers) material derived from crude oil and natural gas. Plastics became the name of polymers because of their booming demand across almost every sector, including packaging, building and construction, consumer products, transportation, and industrial machinery.
The techniques for measuring polymers' properties were the center of DOST Balik Scientist Dr. Caldona’s seminar entitled ‘Conventional and Modern Approaches to Characterizing Polymeric Materials’ on July 12, 2023.
In purchasing polymers to be used, Dr. Caldona shared that researchers must consider fundamental properties such as molecular weight and distribution. The minimum molecular weight for good physical and mechanical properties for the most important polymers is 25,000 grams per molecule. In measuring molecular weights, he highlights the commonly used Gel Permission Chromatography (GPC) analysis and the detectors used in its system.
Polymers have other properties that influence their characteristics. Making polymers ‘speak’ is like asking them what their properties are so that they can be understood and used in appropriate applications.
Crystallinity is one of their properties. It refers to the alignment of molecular chains, which influences the hardness of polymers. X-ray diffraction (XRD) can determine a sample's degree of crystallinity.
Chemical structure is another property of polymers. Dr. Caldona shared some spectroscopic techniques to probe the chemical structures of polymers: infrared (IR) spectroscopy to measure the interactions between molecules and IR light; Surface-Enhanced Raman Scattering (SERS) spectroscopy for finding the functional groups of atoms or bonds that are not seen using IR spectroscopy; and X-ray photoelectron spectroscopy (XPS) to identify the quantitative atomic composition and chemistry.
The behavior of polymers under controlled temperature programs is also part of a better understanding of polymer performance. Thermal analysis techniques include
thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA measures the changes of sample mass with temperature or time under programmed
temperature. DSC, on the other hand, measures the energy absorption of a sample as it is subjected to a specified thermal profile.
The resource person, Dr. Eugene B. Caldona, discusses to the onsite and online participants.
According to Dr. Caldona, “in terms of resistance to fracture, it is always very useful to fabricate polymer composites for demanding applications.”
The resistance to fracture of polymers is comparable to that of metals, ceramics, and composites. Other mechanical behaviors, such as strength and toughness, can be increased by incorporating different materials into polymers, such as composites and rubber.
The DOST Balik Scientist further shared that the relationship between the change in mechanical properties and temperature of the polymer can be determined using thermomechanical characteristics analysis (TMA). Rheology, meanwhile, measures a material's flow behavior through an oscillatory test mode.
In summary, the discussion imparts to the participants that performing the recommended techniques to assess the characteristics of polymers is an advantage in synthesizing or fabricating polymeric materials.
This seminar was the third of the five-part seminar series of Dr. Caldona about materials engineering. The seminars were in connection with Dr. Caldona’s engagement with the DOST-Metals Industry Research and Development Center as a DOST Balik Scientist.
Visit the DOST-MIRDC's Facebook page for regular updates about the Center’s activities that enhance skills of the metals, engineering, and allied industries.
DOST Balik Scientist Dr. Caldona: Surface Electrochemical Approaches May Save Materials and Equipment From Corrosion
By: Ella Vanesa Lopez
Corrosion, the silent killer in the metals and engineering industries, is a major concern worldwide. The good news is that this threat can actually be minimized, according to DOST Balik Scientist Dr. Eugene B. Caldona.
“Corrosion is a serious economic problem, and it takes its toll on national landmarks, works of art, historical artifacts, and businesses,” Dr. Caldona said during his talk. He added, “Corrosion is a difficult phenomenon to understand; it may seem simple, but the study of it is a difficult but interesting pursuit for everybody.”
Corrosion can be defined as the progressive and gradual deterioration of metals as a result of chemical or electrochemical reactions with their surroundings. As it gradually happens, more often than not, people become aware of it after it has already spread and caused significant problems.
Official poster of Dr. Eugene B. Caldona, DOST Balik Scientist, for his talk on “Surface Electrochemical Approaches to Evaluating Corrosion Preventive Materials”
Most businesses and industries heavily rely on machines and equipment that are made of metal. The fact that we reside in an archipelagic and tropical country makes us more susceptible to this issue. As corrosion attacks metals, it is no wonder that it causes catastrophic effects on the safety, health, and conservation of materials.
Fortunately, Dr. Caldona is here to assist people in protecting their investments.
Dr. Caldona shared various techniques on how to minimize the damage of corrosion
Attendees of the seminar “Surface Electrochemical Approaches to Evaluating Corrosion Preventive Materials” by Dr. Eugene Caldona held on July 11, 2023.
A scientific solution to a scientific problem
Dr. Eugene B. Caldona has a dedicated team researching the development of new groups of corrosion-preventive materials and the use of electrochemical approaches to evaluating corrosion-preventive materials.
He shared various techniques to fight the damage of corrosion. The most widely used is the organic polymeric coating - it functions as a physical barrier that prevents the metal surface from coming into contact with the corrosive environment. Paints, urethane, epoxy, acrylic, and silicone are considered organic coatings.
Dr. Caldona did point out, however, that an organic coating is not an impenetrable barrier as substances, such as water and oxygen, can still pass through and cause damage.
Aside from organic coatings, he also introduced five electrochemical techniques, namely: Open Circuit Potential, Scanning Electrochemical Microscopy, Potentiodynamic Polarization, Electrochemical Noise, and Electrochemical Impedance Spectroscopy. Among these five techniques, the most highlighted is the quantitative technique known as Electrochemical Impedance Spectroscopy (EIS), as the anti-corrosion effectiveness of protective coatings can be quickly evaluated using the EIS. Further, EIS measurements deliver reliable data quickly, enabling the prediction of the coatings' long-term performance.
Knowing which technique to use is the key to successful corrosion protection, as each has its own advantages and disadvantages. Dr. Caldona reminded the attendees to select based on their target objectives. For business owners whose bread and butter are their machines and equipment, knowing these techniques will surely be handy.
DOST-MIRDC, as the sole government agency that caters to the requirements of the metals, engineering, and allied industries, is dedicated to improving the quality and performance of the industry's products, processes, and operations through its testing and calibration services. Companies may avail of the Center’s corrosion testing service to determine the corrosion resistance of coatings used in their metal products.
The recently concluded seminar is the second of the seminar series by Dr. Caldona for the DOST Balik Scientist Program. For more details on his next seminars, stay tuned to DOST-MIRDC’s Facebook page.
DOST Balik Scientist, Unimpressed by 3D Printing Years Ago But Amazed at How It Is Making Waves in Various Industries Now
By: Ella Vanesa L. Lopez
“Ten years ago, sabi ko isip ko, ‘ano naman ang magagawa ng 3D printing na ‘to sa research?’ I was looking at 3D printing from a chemist’s point of view. Eh, para sa mga hobbyist lang ito, but look at what happened now. May AMCen tayo at marami na ring papers ang napa-publish sa 3D printing.”
Dr. Eugene Caldona mentioned this fond memory during his presentation on "Additive Manufacturing of Engineering and High-Performance Polymeric Materials" on July 13, 2023. The DOST Balik Scientist shared his perception then of additive manufacturing (AM) impacting product development far-off from reality.
Official poster for Dr. Eugene Caldona’s talk on “Additive Manufacturing of Engineering and High-Performance Polymeric Materials.”
Façade of the Advanced Manufacturing Center (AMCen) of the DOST-MIRDC, the largest 3D printing facility in the country.
AM or 3D printing technology was first introduced in the 1980s, and has significantly advanced in recent years. 3D printing is now being utilized to create simple do-it-yourself items as well as large-scale structures such as a house or a building. This just clearly shows that there is no limit to technology.
Dr. Caldona explained all about the different high-performance materials that are now being used in 3D printing during his talk.
Dr. Caldona discussed polymers and the rising trend of AM across the globe. Further, he talked about the challenges and tips on how to effectively 3D print high-performance materials, which include polyetheretherketone (PEEK), polyphenylene sulfide (PPS), Kevlar, polypropylene, fluoropolymer, and Epoxy-based materials.
The Philippines has ventured into AM to be at par with its ASEAN neighbors, who have long been implementing this technology. A manifestation of the country’s venture into AM is the Advanced Manufacturing Center (AMCen) of the Department of Science and Technology – Metals Industry Research and Development Center (DOST-MIRDC). The AMCen embarks on initiatives to enhance the aerospace, defense, biomedical, healthcare, and automotive industries, among others, through 3D printing.
Dr. Caldona expounded on the different polymers that are currently being used by the 3D printing industry, some of which are also offered by the AMCen. In AMCen, clients have a variety of materials to choose from depending on their requirements, such as (1) Standard Polymers: polymethylmethacrylate (PMMA) standards, polyvinyl chloride (PVC), polystyrene (PS), polyethylene terephthalate (PET, PETE, PETG), acrylonitrile butadiene styrene (ABS), and polypropylene (PP); (2) Engineering Polymers: polycarbonate (PC), thermoplastic polyurethane (TPU), and polyamides (PA) or nylon; and (3) High-Performance Polymers: polyethyleneimine (PEI), and polyetherketone (PEEK).
Some of the different additive manufacturing technologies that are available at the Advanced Manufacturing Center (AMCen).
According to Dr. Caldona, the rapid and systematic fabrication approach offered by this cutting-edge technology is what commonly appeals to people. However, others might not realize that 3D printing will not only accelerate the product development phase but also improve supply chain efficiency.
The continuous rise of the use of 3D printing for research, innovation, and manufacturing is now very obvious and very different from what Dr. Caldona perceived many years ago. Soon, more people are expected to create things differently from the conventional methods that we are used to.
The recently concluded seminar is the fourth in the seminar series by Dr. Caldona for the DOST Balik Scientist Program (DOST-BSP). The DOST-BSP encourages Filipino experts abroad to return home and impart their expertise in order to foster the advancement of science, technology, and innovation in the country. Dr. Caldona’s engagement with the DOST-MIRDC as a DOST Balik Scientist is focused on the Center’s Surface Engineering R&D Program.
DOST Balik Scientist Gives Scientific Paper Writing Skills of Researchers a Boost
by Faith P. Macatangay
Click here to download a PDF copy of this file.
“The aim of writing is not only to make yourself understood but to make sure you are not misunderstood,” said Dr. Eugene B. Caldona.
This was said during the seminar entitled, ‘“Writing and Publishing a Scientific Paper,” conducted by Dr. Caldona on July 7, 2023.
Dr. Caldona first emphasized the most important reason for conducting research and writing a scientific paper is to build up scientific competence; this will allow the researcher to know about the relevant methods and understand research publications in their area of expertise.
Clear communication, according to Dr. Caldona, is a requirement in conducting research, and writing scientific papers is the best way of communicating research.
Writing is often viewed as a difficult task. As an encouragement, Dr. Caldona pointed out the possible outcome of writing scientific papers, he said “Writing can be fun. The fruits of your labor can have substantial benefits if you transform it into writing. Find inspiration.”
Sharing of ideas is a way to achieve immortality
Submitting a research paper for publication is to share ideas. Thus, a published paper will remain forever attached to the researcher’s name.
Dr. Caldona laid down tips on where o submit scientific papers, the importance of becoming aware of the predatory journals that only seek profit, and to not disseminate high-quality research. Moreover, he reminded the participants about the misconduct and breaches in writing and publishing papers.
Before concluding his seminar, Dr. Caldona left his audience with some motivational words, “There is a researcher within all of us. It is waiting to be unleashed. When that happens, you should be ready with your diligence and patience.”
The Balik-Scientist
Dr. Caldona is an Assistant Professor in the Department of Coatings and Polymeric Materials at North Dakota State University (NDSU), USA – one of the premier coatings institutions in the world.
He is currently engaged as a Short-term Balik Scientist under the DOST Balik Scientist Program (DOST-BSP), with DOST-Metals Industry Research and Development Center (DOST-MIRDC) as the host agency. Dr. Caldona will assist in the Center's surface engineering research and development program.
The recently concluded seminar is part of the online seminar series about materials engineering that will be conducted this month of July. We invite researchers from the academe, industry, and aspiring individuals who are interested in the said fields to avail of these free seminars.
To be updated on the training and seminar schedules by Dr. Caldona, visit DOST-MIRDC's Facebook page.
The resource person, Dr. Eugene B. Caldona, discusses to the onsite and online participants.
