Journal of Composites Science

12 pages, 1349 KB

Open AccessArticle

Influence of Non-Staining Chitosan-Based Nano-Silver Fluoride on Shear Bond Strengths of Dental Restorations

by Bennett T. Amaechi, Sima Abdollahi, Tejal Gohil, Amos C. Obiefuna, Temitayo Omoniyi, Temitope O. Omosebi, Thais S. Phillips and Noha Elhabashi

J. Compos. Sci. 2025, 9(10), 518; https://doi.org/10.3390/jcs9100518 - 26 Sep 2025

Abstract

Objective: To investigate the influence of chitosan-based nano-silver fluoride (CNSF) treatment of tooth tissues on shear bond strength (SBS) of resin composite (RC) and resin-modified glass ionomer (RMGI) restorations. Methods: 90 extracted human molars were collected. Specimens were randomly assigned to three groups [...] Read more.

Objective: To investigate the influence of chitosan-based nano-silver fluoride (CNSF) treatment of tooth tissues on shear bond strength (SBS) of resin composite (RC) and resin-modified glass ionomer (RMGI) restorations. Methods: 90 extracted human molars were collected. Specimens were randomly assigned to three groups (n = 30): non-pretreated (NPT) pretreated with either CNSF or silver diamine fluoride (SDF). Each group was subdivided into two restorative subgroups (n = 15): RC and RMGI. Specimens in CNSF and SDF groups were pretreated with CNSF or SDF per their manufacturer’s instructions. Then specimens in RC subgroups were etched, treated with chlorhexidine cleanser, followed by adhesive application. Specimens in RMGI subgroups were treated with cavity conditioner only. A cylindrical restoration (2.38 mm θ × 2 mm height) of RC or RMGI restoration was fabricated with a standardized mold and light-cured on all specimens. After 5000 times of thermocycling between 5 °C and 55 °C with dwell times of 30 s intervals, SBS was measured using the Ultradent UltraTester. Data was analyzed statistically (α = 0.05) using ANOVA/Tukey’s comparisons. Results: No statistically significant difference in SBS among RC restorations in the three treatment groups: NPT (17.48 ± 3.96), CNSF (18.38 ± 5.59), and SDF (14.03 ± 6.56). For RMGI restorations, SBS was significantly (p < 0.05) higher in NPT (15.99 ± 3.59) compared to CNSF-treated (11.45 ± 5.48), but there was no significant difference between NPT and SDF-treated (14.27 ± 2.17) or between SDF- and CNSF-treated groups. Conclusions: No difference in SBS of resin composite restorations when the dentin tissue is pretreated with either chitosan-based nano-silver fluoride or silver diamine fluoride. However, SBS of RMGI was lowered when the dentin tissue was pretreated with CNSF. Full article

(This article belongs to the Section Biocomposites)

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22 pages, 5442 KB

Open AccessArticle

Redesigning UAV Vertical Tail Structures with Lightweight Eco-Friendly Carbon-Reinforced Polymers: A Generative Design-Based Approach

by Giovanni Maisto, Antonio Garofano, Valerio Acanfora and Aniello Riccio

J. Compos. Sci. 2025, 9(10), 517; https://doi.org/10.3390/jcs9100517 - 26 Sep 2025

Abstract

The increasing adoption of additive manufacturing in applications requiring high strength, stiffness, and lightness has highlighted the need to outclass the classical design methodologies. As a matter of fact, traditional design approaches often fail to exploit additive manufacturing’s full potential. To address this [...] Read more.

The increasing adoption of additive manufacturing in applications requiring high strength, stiffness, and lightness has highlighted the need to outclass the classical design methodologies. As a matter of fact, traditional design approaches often fail to exploit additive manufacturing’s full potential. To address this need, this research presents an innovative design of a vertical tail for an unmanned aerial vehicle by integrating the generative design optimization strategy for additive manufacturing and engineered technopolymers reinforced with chopped carbon fiber. The proposed iterative method, combined with a high strength carbon fiber material, led to significant mass reductions, up to 71.2%, compared with a metallic design. Full article

(This article belongs to the Section Carbon Composites)

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24 pages, 2067 KB

Open AccessReview

Coconut Coir Fiber Composites for Sustainable Architecture: A Comprehensive Review of Properties, Processing, and Applications

by Mohammed Nissar, Chethan K. N., Yashaswini Anantsagar Birjerane, Shantharam Patil, Sawan Shetty and Animita Das

J. Compos. Sci. 2025, 9(10), 516; https://doi.org/10.3390/jcs9100516 - 26 Sep 2025

Abstract

The growing need for sustainable materials in architecture has sparked significant interest in natural-fiber-based composites. Among these, coconut coir, a by-product of the coconut industry, has emerged as a promising raw material owing to its abundance, renewability, and excellent mechanical properties. The promise [...] Read more.

The growing need for sustainable materials in architecture has sparked significant interest in natural-fiber-based composites. Among these, coconut coir, a by-product of the coconut industry, has emerged as a promising raw material owing to its abundance, renewability, and excellent mechanical properties. The promise of coir-based composites in architecture is highlighted in this review, which also looks at their problems, advantages for the environment, manufacturing processes, and mechanical, thermal, and acoustic performances. The fibrous shape of the coir provides efficient thermal and acoustic insulation, while its high lignin concentration guarantees stiffness, biological resistance, and dimensional stability. Fiber-matrix adhesion and durability have improved owing to advancements in treatment and environmentally friendly binders, opening up the use of cement, polymers, and hybrid composites. In terms of the environment, coir composites promote a biophilic design, reduce embodied carbon, and decrease landfill waste. Moisture sensitivity, inconsistent fiber quality, and production scaling are obstacles; however, advancements in hybridization, grading, and nanotechnology hold promise. This review provides comprehensive, architecture-focused review that integrates material science, fabrication techniques, and real-world architectural applications of coir-based composites. Coir-based composites have the potential to be long-lasting, sustainable substitutes for conventional materials in climate-resilient architectural design if they are further investigated and included in green certification programs and the circular economy. Full article

(This article belongs to the Special Issue Composites: A Sustainable Material Solution, 2nd Edition)

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11 pages, 2008 KB

Open AccessArticle

Corrosion-Resistant Plasma Electrolytic Oxidation Composite Coatings on Ti6Al4V for Harsh Acidic Environments

by Michael Garashchenko, Yuliy Yuferov and Konstantin Borodianskiy

J. Compos. Sci. 2025, 9(10), 515; https://doi.org/10.3390/jcs9100515 - 23 Sep 2025

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Abstract

Titanium alloys are widely employed in structural and electrochemical applications owing to their excellent mechanical properties and inherent corrosion resistance. However, their stability in harsh acidic environments, such as those encountered in energy storage systems, remains a critical issue. In this study, composite [...] Read more.

Titanium alloys are widely employed in structural and electrochemical applications owing to their excellent mechanical properties and inherent corrosion resistance. However, their stability in harsh acidic environments, such as those encountered in energy storage systems, remains a critical issue. In this study, composite ceramic coatings were synthesized on a Ti6Al4V alloy using plasma electrolytic oxidation (PEO) in silicate-, phosphate-, and sulfate-based electrolytes, with and without the addition of α-alumina nanoparticles. The resulting coatings were comprehensively characterized to assess their surface morphology, chemical and phase compositions, and corrosion performance. Thus, the corrosion current density decreased from 9.7 × 10⁴ for bare Ti6Al4V to 143 nA/cm² for the coating fabricated in phosphate electrolyte with alumina nanoparticles, while the corrosion potential shifted anodically from –0.68 to +0.49 V vs. silver chloride electrode in 5 M H₂SO₄. Among the tested electrolytes, coatings produced in the phosphate-based electrolyte with Al₂O₃ showed the highest polarization resistance (113 kΩ·cm²), outperforming those fabricated in silicate- (71.6 kΩ·cm²) and sulfate-based (89.0 kΩ·cm²) systems. The composite coatings exhibited a multiphase structure with reduced surface porosity and the incorporation of crystalline oxide phases. Notably, titania–alumina nanoparticle composites demonstrated significantly enhanced corrosion resistance. These findings confirm that PEO-derived composite coatings provide an effective surface engineering strategy for enhancing the stability of the Ti6Al4V alloy in aggressive acidic environments relevant to advanced electrochemical systems. Full article

(This article belongs to the Special Issue Metal Composites, Volume II)

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33 pages, 5997 KB

Open AccessArticle

Crown-Tulip Trigger Mechanisms to Improve Crashworthiness Design of Composite Tubular Structures

by Rohin Padayachee and Hessam Ghasemnejad

J. Compos. Sci. 2025, 9(10), 514; https://doi.org/10.3390/jcs9100514 - 23 Sep 2025

Viewed by 165

Abstract

Background: This article presents the design development of a new crown-tulip trigger mechanism to initiate progressive failure and reduce initial collapse load in comparison with the existing trigger designs of bevel and tulip in tubular composite structures. Objectives: Through experimental impact testing, comparisons [...] Read more.

Background: This article presents the design development of a new crown-tulip trigger mechanism to initiate progressive failure and reduce initial collapse load in comparison with the existing trigger designs of bevel and tulip in tubular composite structures. Objectives: Through experimental impact testing, comparisons are drawn to the existing designs, such as the 45° bevel and 4T90° tulip trigger mechanism. Methods: This experimental testing design phase demonstrated a significant improvement in the crush force efficiency of crown-tulip trigger mechanisms compared to the previously established Tulip trigger design (4T90°). The experimental results were utilised to develop equivalent numerical models in LS-DYNA. Results: The validated models were employed for further design development, studying the influence of increased bevel angles (30°, 45°, and 60°), tulip angles (90°, 100°, 120°, 140°, and 160°), crown notch depth, crown notch angle, and number of tulip tips/crown notches on the crashworthiness and force response. Conclusions: This culminated in the numerical design development of the 4T160°-40°-2 mm crown-tulip trigger, which achieved 20% higher specific energy absorption, a 22% increase in crush force efficiency, and a 36% higher mean force compared with the 4T90° Tulip-triggered specimen. The outcomes of this research will be implemented in automotive, aerospace, and defence sub-structures. Full article

(This article belongs to the Special Issue Functional Composites: Fabrication, Properties and Applications)

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25 pages, 4216 KB

Open AccessArticle

Epoxy and Bio-Based Epoxy Glass Fiber Composites: Taguchi Design of Experiments and Future Applications

by Svetlana Risteska, Ivan Vasileski, Evgenija Gjorgjieska Angelovska and Aleksandar Pižov

J. Compos. Sci. 2025, 9(10), 513; https://doi.org/10.3390/jcs9100513 - 23 Sep 2025

Viewed by 93

Abstract

Epoxidized soybean oil (ESO) is the oxidation product of soybean oil with hydrogen peroxide and either acetic or formic acid obtained by converting the double bonds into epoxy groups, which is non-toxic and of higher chemical reactivity. Oxidized soybean oil (ESO) has gained [...] Read more.

Epoxidized soybean oil (ESO) is the oxidation product of soybean oil with hydrogen peroxide and either acetic or formic acid obtained by converting the double bonds into epoxy groups, which is non-toxic and of higher chemical reactivity. Oxidized soybean oil (ESO) has gained significant attention as a renewable and environmentally friendly alternative to petroleum-based epoxy resins. Derived from soybean oil through epoxidation of its unsaturated fatty acids, ESO offers a bio-based platform with inherent flexibility, low toxicity, and excellent chemical resistance. When used as a reactive diluent or primary component in epoxy formulations, ESO enhances the sustainability profile of coatings, adhesives, and composite materials. This study explores the mechanical properties of ESO-based epoxy systems, with particular attention to formulation strategies, crosslinking agents, and performance trade-offs compared to conventional epoxies. The incorporation of ESO not only reduces the reliance on fossil resources but also imparts tunable thermal and mechanical properties, making it suitable for a range of industrial and eco-friendly applications. The results underscore the potential of ESO as a viable component in next-generation green materials, contributing to circular economy and low-impact manufacturing. For the application of these materials in pultrusion and FW technologies, the Taguchi method is used to determine the most influential process parameters. Full article

(This article belongs to the Special Issue Sustainable Biocomposites, 3rd Edition)

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22 pages, 16594 KB

Open AccessArticle

Innovative Flexible Conductive Polymer Composites for Wearable Electrocardiogram Electrodes and Flexible Strain Sensors

by María Elena Sánchez Vergara, Joaquín André Hernández Méndez, Carlos Ian Herrera Navarro, Marisol Martínez-Alanís, Selma Flor Guerra Hernández and Ismael Cosme

J. Compos. Sci. 2025, 9(10), 512; https://doi.org/10.3390/jcs9100512 - 23 Sep 2025

Viewed by 184

Abstract

This work reports the fabrication of innovative flexible conductive polymer composites (FCPCs), composed of poly (2,3-dihydrothieno-1,4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS), polypyrrole (PPy) and copper phthalocyanine (CuPc). These FCPCs were deposited by the drop-casting technique on flexible substrates such as polyethylene terephthalate (PET), Xuan paper and [...] Read more.

This work reports the fabrication of innovative flexible conductive polymer composites (FCPCs), composed of poly (2,3-dihydrothieno-1,4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS), polypyrrole (PPy) and copper phthalocyanine (CuPc). These FCPCs were deposited by the drop-casting technique on flexible substrates such as polyethylene terephthalate (PET), Xuan paper and ethylene–vinyl acetate (EVA) foam sheets. Wearable photoactive electrocardiogram (ECG) electrodes and flexible strain sensors were fabricated. Morphological characterization by SEM revealed a stark contrast between the smooth, continuous PEDOT:PSS films and the rough, globular PPy films. EDS confirmed the successful and homogeneous incorporation of the CuPc, evidenced by the strong spatial correlation of the nitrogen and copper signals. The highest mechanical resistance was present in the FCPCs on PET with a limit of proportionality between 4074–6240 KPa. Optical parameters were obtained by Ultraviolet–Visible Spectroscopy and their Reflectance is below 15% and could be used as photoelectrodes. Three Signal Quality Indexes (SQIs) were used to evaluate the ECG signal obtained with the electrodes. The results of all the SQIs demonstrated that the obtained signals have a comparable quality to that of a signal obtained from commercial electrodes. To evaluate the flexible strain sensors, the change in output voltage caused by mechanical deformation was measured. Full article

(This article belongs to the Special Issue Biomedical Composite Applications)

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J. Compos. Sci., Volume 9, Issue 10 (October 2025) – 7 articles

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