From Polarimeter to Contact Angle Goniometer - Inexpensive Conversion of Laboratory Equipment

Kabza, Konrad; Cochran, Kevin

doi:10.1021/ed074p322

Cited by 7 publications

(8 citation statements)

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“…Contact angle measurements were done using deionized water on an FDM‐printed goniometer based on ref. [36]. A coupled digital microscope was used to capture the images of the water droplets and results were analyzed using the contact angle plugin of ImageJ.…”

Section: Methodsmentioning

confidence: 99%

Design of a Bio‐Based Device for Micro Total Analysis Combining Fused Deposition Modeling and Layer‐by‐Layer Technologies

León

Frutos

Molina

2020

Macro Materials & Eng

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Compared to other fabrication methods such as micromolding [7] or soft lithography, [8] objects manufactured via FDM are produced in their final shape without any external template, additional tools, or further postprocessing. Since FDM does not require any mastermold, it allows the fabrication of complex, tailorable lattices with high reproducibility, such as highly hollow or gyroidal structures. [9] FDM feedstock is commodity plastics, avoiding the use of hazard or expensive compounds. Moreover, FDM printers are more economic and relatively easy to use than most of other (micro)fabrication equipment. The printed objects are previously designed using a software and all the information needed for fabrication is contained within a computer assisted design file. These designs can be easily modified to meet the quick changing needs of the market, allowing high flexibility in the product and reducing the product development process. [10] Since 3D printing technologies emerged, polylactic acid (PLA) has become one of the most widely used materials in the FDM technology due to its cost, biodegradability, and good mechanical properties. [11] PLA can be manufactured from natural sources as sugarcane or corn starch and possesses mechanical properties comparable to fossil-fuel derived polystyrene. [12] Among its limitations, it presents a low maximum service temperature (≈60 °C), which narrows its use in engineering applications. [13] However, it can be used as structural matrix when working at room or human body temperature. Bio-based polymers, including PLA, have been printed to fabricate tablets, [14] scaffolds, [15] or even organs individually adapted for each patient. [16] In addition, since additive manufacturing techniques emerged, there is a growing number of initiatives to fabricate different equipment and laboratory supplies in house, [17] which would allow reducing the production chain, saving time and money. Another important factor to consider in the design of micro total analysis systems is the surface modification of the material so it can selectively adsorb the target biomolecule. Among other alternatives, the LbL technology is an interesting option which allows the modification of large surfaces in an inexpensive manner. [18-20] This technology is known since 1997 [21] and consists in the fabrication of thin films via electrostatic or supramolecular interactions of different polymers, which allows In this paper a methodology is presented to fabricate a micropatterned device made of bio-based polymers (polylactic acid, sodium alginate (ALG), and chitosan (CHI)) suitable for micro total analysis. Fused deposition modeling and layer-by-layer technologies are combined to create tailorable devices with submillimetric controlled well size that can be rapidly prepared in house. As proof of concept, the influence of immobilization of ALG/CHI bilayers in the selective adsorption of alkaline phosphatase and its activity is studied. Due to the noncovalent nature of these interactions, it is proven that these devices ...

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Section: Methodsmentioning

confidence: 99%

Design of a Bio‐Based Device for Micro Total Analysis Combining Fused Deposition Modeling and Layer‐by‐Layer Technologies

León

Frutos

Molina

2020

Macro Materials & Eng

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“…[8][9][10][11][12][13] These earlier reports have used microscopes or other more specialized optical equipment to view the droplets. 12,14 In contrast, the heart of our contact angle measurement setup is a webcam connected to a standard personal computer.…”

Section: Experimental Designmentioning

confidence: 99%

Roughness effects on contact angle measurements

Ryan¹,

Poduska²

2008

American Journal of Physics

138

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We have developed a simple and economical procedure to demonstrate the effects of roughness and wetting fraction on the equilibrium contact angles of liquid droplets on solid surfaces. Contact angles for droplets placed on a rough surface, which wet only a portion of the surface, are larger than the contact angles of droplets formed by condensation of steam, which wet the surface more completely. These contact angle data facilitate assessments of changes in true surface area, due to surface roughening, as well as changes in the fractional contact areas of the water droplets, due to the formation of air pockets between the rough surface and the droplet.

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“…Surface phenomena such as surface tension, wettability, and spreading are becoming increasingly important for many areas of applied science and technology. During the last ten years, the Journal of Chemical Education published several papers highlighting fundamentals related to surface tension , and describing the measurement of contact angles using in-house constructed contact-angle goniometers. − Moreover, the Journal published various methods for the determination of CMC, including fluorescence-spectroscopy, , electrical-conductivity, UV-absorption-spectroscopy, , and capillary-rise methods. However, there is a need to develop modern, interactive, and simple educational materials for students to gain proper theoretical and practical knowledge regarding surface phenomena.…”

Section: Introductionmentioning

confidence: 99%

“…However, there is a need to develop modern, interactive, and simple educational materials for students to gain proper theoretical and practical knowledge regarding surface phenomena. Herein, we report a simple, safe, and inexpensive method to measure contact angles of aqueous droplets and to determine a surfactant’s CMC using a portable microscope and the freely available image-processing software ImageJ, unlike previously published related work. − Because this experiment is mainly intended as an undergraduate didactic lab, its suitability for such a purpose was validated by allowing its actual execution by a sample of 12 undergraduate students. This was accompanied by a formative assessment confirming students’ achievement of the intended learning outcomes (ILOs) of this didactic lab.…”

Section: Introductionmentioning

confidence: 99%

Simple Experiment to Determine Surfactant Critical Micelle Concentrations Using Contact-Angle Measurements

et al. 2018

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A simple and reliable didactic laboratory has been developed to illustrate fundamental concepts of hydrophilicity, hydrophobicity, wetting, and spreading phenomena for undergraduate students. The described laboratory includes preparation of surfactant solutions at different concentrations and applying droplets of these solutions on a hydrophobic surface followed by imaging the applied droplets using a cost-effective USB digital microscope connected to a computer. Contact-angle values of droplets were measured using ImageJ, a freely available image-processing software. Students constructed surfactant-concentration−contact-angle plots to determine the surfactant's critical-micelle-concentration value. The feasibility of the described didactic laboratory and the achievement of the intended learning outcomes (ILOs) were evaluated through complementary assessment tools, including lab reports, homework assignments, and students' feedback. The described laboratory was found to be cost-effective, safe, reproducible, and successful in achieving the ILOs.

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From Polarimeter to Contact Angle Goniometer - Inexpensive Conversion of Laboratory Equipment

Cited by 7 publications

References 0 publications

Design of a Bio‐Based Device for Micro Total Analysis Combining Fused Deposition Modeling and Layer‐by‐Layer Technologies

Design of a Bio‐Based Device for Micro Total Analysis Combining Fused Deposition Modeling and Layer‐by‐Layer Technologies

Roughness effects on contact angle measurements

Simple Experiment to Determine Surfactant Critical Micelle Concentrations Using Contact-Angle Measurements

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