Surfaces

17 pages, 3326 KiB

Open AccessArticle

Development of a Portable Device for Surface Traction Characterization at the Shoe–Floor Interface

by Shubham Gupta, Ayush Malviya, Subhodip Chatterjee and Arnab Chanda

Surfaces 2022, 5(4), 504-520; https://doi.org/10.3390/surfaces5040036 - 10 Dec 2022

Cited by 7 | Viewed by 1903

Slip and fall accidents are widespread in workplaces and on walkways. Slipping is generally initiated by a sudden change in the flooring properties or due to a low available traction at the shoe–floor interface. To measure shoe-floor traction, mechanical slip and fall risk [...] Read more.

Slip and fall accidents are widespread in workplaces and on walkways. Slipping is generally initiated by a sudden change in the flooring properties or due to a low available traction at the shoe–floor interface. To measure shoe-floor traction, mechanical slip and fall risk estimation devices are typically employed. However, to date, such existing devices are lab-based, bulky, and are unable to simulate realistic slip biomechanics and measure whole footwear traction in realistic contaminated floorings at the same time. Moreover, these devices are expensive and not available in low- or lower-middle-income countries with limited awareness regarding slip testing. To overcome these challenges, in this work, a biofidelic, portable, and low-cost slip testing device was developed. A strategic three-part subassembly was designed for the application of normal load, slipping speed, and heel strike angle for its modularity. The developed slip tester was extensively tested and validated for its performance using 10 formal footwears and two floorings, under dry and wet conditions. The results indicated that the slip tester was accurate, repeatable, and reliable in differentiating traction measurements across varying combinations of shoes, contaminants, and floorings. The instrumentation performance of the slip tester was found to also capture the differences between different shoe tread patterns in the presence of fluid films. The developed device is anticipated to significantly impact the clinical, industrial, and commercial performance testing of footwear traction in realistic slippery flooring conditions, especially in the low- or middle-income countries. Full article

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15 pages, 4998 KiB

Open AccessArticle

Traction Performance of Common Formal Footwear on Slippery Surfaces

by Shubham Gupta, Subhodip Chatterjee, Ayush Malviya and Arnab Chanda

Surfaces 2022, 5(4), 489-503; https://doi.org/10.3390/surfaces5040035 - 17 Nov 2022

Cited by 7 | Viewed by 2106

Abstract

Traumatic injuries caused due to slipping and falling are prevalent in India and across the globe. These injuries not only hamper quality of life but are also responsible for huge economic and compensation burdens. Unintentional slips usually occur due to inadequate traction between [...] Read more.

Traumatic injuries caused due to slipping and falling are prevalent in India and across the globe. These injuries not only hamper quality of life but are also responsible for huge economic and compensation burdens. Unintentional slips usually occur due to inadequate traction between the shoe and floor. Due to the economic conditions in low and middle-income countries, the public tends to buy low-cost footwear as an alternative to costly slip-resistant shoes. In this study, ten high-selling formal shoes under $25 were considered. These shoes were tested on three commonly available dry floorings and across contaminated common floor surfaces (i.e., water and floor cleaners). The traction performance of the shoes was quantified by using a biofidelic slip tester. The majority of formal shoes were not found to produce the slip-resistant performance across common slippery surfaces. Shoes with softer outsoles exhibited increased slip-resistant performance (R² = 0.91). Shoe outsoles with less-to-no treads at the heel region showed poor traction performance as compared to other shoes. The apparent contact area was found as an important metric influencing the slip risks in dry and wet slipping conditions (R² = 0.88). This research is anticipated to help the public and footwear manufacturers select safer shoes to reduce slip-and-fall incidents. Full article

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8 pages, 3439 KiB

Open AccessCommunication

Green Composites from Thiophene Chalcones and Rice Husk Lignin: An Alternative of Powder for Latent Fingermark

by Bruno Nunes da Rosa, Marcelo Pereira da Rosa, Tais Poletti, Nathalia Pereira Koltz de Lima, Guilherme Kurz Maron, Bruno Vasconcellos Lopes, Kristiane de Cássia Mariotti, Paulo Henrique Beck, Neftali Lenin Villarreal Carreno and Claudio Martin Pereira de Pereira

Surfaces 2022, 5(4), 481-488; https://doi.org/10.3390/surfaces5040034 - 16 Nov 2022

Cited by 1 | Viewed by 1932

Abstract

This study reports a route to obtaining a novel and cost-effective rice husk-derived lignin/thiophene chalcone green composite for application in forensic science as a fingermark developer through high energy milling. The material was properly characterized by UV-Vis, IR, fluorescence, X-ray diffraction and scanning [...] Read more.

This study reports a route to obtaining a novel and cost-effective rice husk-derived lignin/thiophene chalcone green composite for application in forensic science as a fingermark developer through high energy milling. The material was properly characterized by UV-Vis, IR, fluorescence, X-ray diffraction and scanning electron microscopy. The product provided clear and sharp images of latent fingermarks with minimal background staining, revealing all ridge details. Thus, the composite presented good performance as a fingermark developer, becoming an interesting alternative to being applied as a technological, reproducible and renewable product. Full article

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25 pages, 4414 KiB

Open AccessReview

A Review on the Fabrication and Characterization of Titania Nanotubes Obtained via Electrochemical Anodization

by Syeda Ammara Batool, Muhammad Salman Maqbool, Muhammad Awais Javed, Akbar Niaz and Muhammad Atiq Ur Rehman

Surfaces 2022, 5(4), 456-480; https://doi.org/10.3390/surfaces5040033 - 09 Nov 2022

Cited by 6 | Viewed by 2898

Abstract

Recently, titania nanotubes (TNTs) have been extensively studied because both their functional properties and highly controllable morphology make them important building blocks for understanding nanoscale phenomena and realizing nanoscale devices. Compared with sol–gel and template-assisted methods, electrochemical anodization is a simple, cost-effective, and [...] Read more.

Recently, titania nanotubes (TNTs) have been extensively studied because both their functional properties and highly controllable morphology make them important building blocks for understanding nanoscale phenomena and realizing nanoscale devices. Compared with sol–gel and template-assisted methods, electrochemical anodization is a simple, cost-effective, and low-temperature technique offering additional advantages such as straightforward processing and ease of scale-up. This review focuses on the process modalities and underlying mechanism of electrochemical anodization to achieve a different set of TNTs for a variety of applications. Finally, important applications of TNTs are highlighted including biomedical devices, water purification, and solar cells. Full article

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11 pages, 2124 KiB

Open AccessArticle

Technological Peculiarities of Epsilon Ferrite Epitaxial Stabilization by PLD

by Polina A. Dvortsova and Sergey M. Suturin

Surfaces 2022, 5(4), 445-455; https://doi.org/10.3390/surfaces5040032 - 21 Oct 2022

Cited by 1 | Viewed by 1614

Abstract

The present paper describes the technological peculiarities relevant to the nucleation and further epitaxial growth of the metastable epsilon phase of iron oxide by means of pulsed laser deposition (PLD). The orthorhombic epsilon ferrite ε-Fe₂O₃ is an exotic member of [...] Read more.

The present paper describes the technological peculiarities relevant to the nucleation and further epitaxial growth of the metastable epsilon phase of iron oxide by means of pulsed laser deposition (PLD). The orthorhombic epsilon ferrite ε-Fe₂O₃ is an exotic member of a large family of iron oxide polymorphs, which attracts extensive attention nowadays due to its ultra-high magneto-crystalline anisotropy and room temperature multiferroic properties. Continuing the series of previous publications dedicated to the fabrication of ε-Fe₂O₃ films on GaN, this present work addresses a number of important requirements for the growing conditions of these films. Among the most sensitive technological parameters, the growth temperature must be high enough to aid the nucleation of the orthorhombic phase and, at the same time, low enough to prevent the thermal degradation of an overheated ε-Fe₂O₃/GaN interface. Overcoming the contradicting growth temperature requirements, an alternative substrate-independent technique to stabilize the orthorhombic phase by mild aluminum substitution is proposed. The advantages of this technique are demonstrated by the example of ε-Fe₂O₃ films PLD growth carried out on sapphire—the substrate that possesses a trigonal lattice structure and would normally drive the nucleation of the isostructural and energetically more favorable trigonal α-Fe₂O₃ phase. The real-time profiling of high-energy electron diffraction patterns has been extensively utilized throughout this work to keep track of the orthorhombic-to-trigonal balance being the most important feed-back parameter at the growth optimization stage. Full article

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16 pages, 1901 KiB

Open AccessArticle

Ternary Metal-Alginate-Chitosan Composites for Controlled Uptake of Methyl Orange

by Bernd G. K. Steiger and Lee D. Wilson

Surfaces 2022, 5(4), 429-444; https://doi.org/10.3390/surfaces5040031 - 24 Sep 2022

Cited by 7 | Viewed by 1947

Abstract

Three ternary metal composites (TMCs) with iron nitrate, aluminum nitrate, and copper nitrate (Fe-TMC-N, Al-TMC-N, Cu-TMC-N) were synthesized and their physicochemical properties were investigated. Characterization of the TMCs was achieved by elemental analysis (XPS), infrared (IR) spectroscopy and thermogravimetric analysis (TGA). The surface [...] Read more.

Three ternary metal composites (TMCs) with iron nitrate, aluminum nitrate, and copper nitrate (Fe-TMC-N, Al-TMC-N, Cu-TMC-N) were synthesized and their physicochemical properties were investigated. Characterization of the TMCs was achieved by elemental analysis (XPS), infrared (IR) spectroscopy and thermogravimetric analysis (TGA). The surface charge of the TMCs was estimated from the point-of-zero-charge (PZC), which depended on the type of metal nitrate precursor. The adsorption properties of the TMCs showed the vital role of the metal center, where methylene blue (MB) is a cationic dye probe that confirmed the effects of surface charge for effective methyl orange (MO) anion dye uptake. MB uptake was negligible for Al-TMC-N and Cu-TMC-N, whereas moderate MB uptake occurs for Fe-TMC-N (26 mg/g) at equilibrium. The adsorption capacity of MO adopted the Langmuir isotherm model, as follows: Al-TMC-N (422 mg/g), Cu-TMC-N (467 mg/g) and Fe-TMC-N (42 mg/g). The kinetic adsorption profiles followed the pseudo-second order model. Generally, iron incorporation within the TMC structure is less suitable for MO anion removal, whereas Cu- or Al-based materials show greater (10-fold) MO uptake over Fe-based TMCs. The dye uptake results herein provide new insight on adsorbent design for controlled adsorption of oxyanion species from water. Full article

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16 pages, 5392 KiB

Open AccessArticle

Removal of Model Aromatic Hydrocarbons from Aqueous Media with a Ferric Sulfate–Lime Softening Coagulant System

by Deysi J. Venegas-García and Lee D. Wilson

Surfaces 2022, 5(4), 413-428; https://doi.org/10.3390/surfaces5040030 - 22 Sep 2022

Cited by 1 | Viewed by 1820

Abstract

The removal of model hydrocarbon oil systems (4-nitrophenol (PNP) and naphthalene) from laboratory water was evaluated using a ferric sulfate and a lime-softening coagulant system. This study addresses the availability of a methodology that documents the removal of BTEX related compounds and optimizes [...] Read more.

The removal of model hydrocarbon oil systems (4-nitrophenol (PNP) and naphthalene) from laboratory water was evaluated using a ferric sulfate and a lime-softening coagulant system. This study addresses the availability of a methodology that documents the removal of BTEX related compounds and optimizes the ferric-based coagulant system in alkaline media. The Box–Behnken design with Response Surface Methodology enabled the optimization of the conditions for the removal (%) of the model compounds for the coagulation process. Three independent variables were considered: coagulant dosage (10–100 mg/L PNP and 30–100 mg/L naphthalene), lime dosage (50–200%), and initial pollutant concentration (1–35 mg/L PNP and 1–25 mg/L naphthalene). The response optimization showed a 28% removal of PNP at optimal conditions: 74.5 mg/L ferric sulfate, 136% lime dosage, and initial PNP concentration of 2 mg/L. The optimal conditions for naphthalene removal were 42 mg/L ferric sulfate, 50% lime dosage, and an initial concentration of naphthalene (16.3 mg/L) to obtain a 90% removal efficiency. The coagulation process was modeled by adsorption isotherms (Langmuir for PNP; Freundlich for Naphthalene). The surface properties of flocs were investigated with pH_pzc, solid-state UV absorbance spectra, and optical microscopy to gain insight into the role of adsorption in the ferric coagulation process. Full article

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Surfaces, Volume 5, Issue 4 (December 2022) – 7 articles

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