Graphene-Modified Polycaprolactone Nanofibers for Biomedical Applications: Enhancing Mechanical Strength and Biocompatibility Sankar Thangavel, Kannan Thanneerpanthalpalayam Kandasamy, Rajasekar Rathanasamy, Balakrishnan Nanjappan Journal of Biomedical Materials Research Part B Applied Biomaterials, 2026 Electrospun nanofiber scaffolds met a pressing need for degradable matrices that matched the architecture and mechanics of soft tissues, yet neat poly(ε‐caprolactone) (PCL) fibers often exhibited low surface energy, modest stiffness, and a loss of strength after sterilization and hydration. Graphene additives were expected to provide interfacial reinforcement and wettability improvements, but the effects of specific functional groups at low loading and under clinically relevant conditioning conditions had not been clarified. This study aimed to engineer sterilization‐resistant, water‐stable PCL scaffolds by comparing carboxyl‐ and hydroxyl‐functionalized graphene (CFG and HFG) and defining an operating window via response surface methodology. PCL was electrospun with 0.5–2.0 wt% CFG or HFG while varying voltage; dispersion and chemistry were verified by FTIR and Raman mapping, thermal behavior by DSC/TGA, mechanics by tensile and DMA including cyclic loading, stability by EtO and γ sterilization with wet testing, surface energetics by contact angles and Owens–Wendt analysis, protein adsorption by BSA/fibronectin assays, cytocompatibility by human dermal fibroblasts, and aging by PBS degradation with GPC. The 1 wt% composites increased ultimate tensile strength by ~45%–55% and modulus by ~40%–55% relative to neat PCL, with modest reductions in elongation; storage modulus increased across −20°C to 60°C, and the composite retained ~98% stiffness after 50 cycles compared with ~90% for PCL. After γ‐sterilization, strength retention was ~90%–92% for composites versus ~80% for PCL; wet‐state modulus retention approached ~95%. Tc shifted upward by 2°C–3°C and crystallinity increase by ~5%–8%, while TGA showed a ~10°C onset increase; Raman maps confirmed uniform dispersion with ≈ 1.1 (CFG) and ≈1.0 (HFG). Contact angle fell from ~130° (PCL) to ~90°–95°, fibronectin adsorption increased and correlated with Day‐7 viability ( R ≈ 0.95), hemolysis stayed near 1%–2%, and bacterial attachment decreased to ~70%–80% of PCL. Response‐surface analysis identified a practical region around 1.2–1.3 wt% graphene and 16–18 kV that balanced strength and sterilization retention. These findings supported use in soft‐tissue scaffolds requiring robust handling and rapid cell coverage, and suggested extension to scale‐up studies and in vivo validation, including sterilization dose mapping and sustained‐release add‐ons.
Sustainable Phoenix sp. Chopped-Fiber Epoxy Composites: Length–Loading Optimization via ASTM Testing and Diffusion Kinetics Wasurat Bunpheng, Hariharan Vaggeeram, Sankar Thangavel, Ratchagaraja Dhairiyasamy, Xianpeng Wang, Subhav Singh Polymer Composites, 2026 Sustainable natural‐fiber‐reinforced epoxy composites are attractive for lightweight components, yet their design is constrained by the coupled effects of the chopped‐fiber architecture on mechanical performance and moisture ingress. In Phoenix sp. for fiber/epoxy systems, a unified work linking fiber length, fiber loading, and water‐uptake kinetics under consistent processing and standardized testing has remained limited. This work establishes a design window for chopped Phoenix sp. fiber–reinforced epoxy composites by quantifying the combined effects of fiber length and fiber weight fraction on mechanical response and immersion‐driven transport descriptors. Alkali‐treated Phoenix fibers (10–30 mm) were incorporated into a DGEBA epoxy using hand lay‐up, followed by compression consolidation and staged curing. Specimens were characterized using ASTM tensile, flexural, impact, and hardness tests, and ASTM D570 immersion testing at controlled temperatures with diffusion‐kinetic fitting. A distinct optimum was obtained at 15 mm and 20 wt%, where tensile strength increased from 35.2 ± 2.1 MPa for neat epoxy to 58.7 ± 2.8 MPa and impact strength reached 24.3 ± 1.9 kJ·m −2 . At higher fiber packing, reduced wetting continuity and defect sensitivity were reflected by a decline in tensile strength to 44.6 ± 3.8 MPa at 50 wt% (15 mm). Water uptake increased strongly with fiber fraction, with saturation rising from 0.45% for neat epoxy to 9.58% at 50 wt% under the reported immersion condition. These results define an actionable length–loading window for selecting Phoenix fiber/epoxy formulations and provide transport descriptors for durability screening in moisture‐exposed service conditions.
Optimization of graphene-functionalized polycaprolactone nanofibers: enhancing mechanical, thermal, and biocompatibility properties for biomedical applications Department of Mechanical Engineering, Paavai College of Engineering, Namakkal, Tamilnadu, India-637018, T. Sankar, T. K. Kannan, Department of Mechanical Engineering, Gnanamani College of Technology, Namakkal, Tamilnadu, India-637018, R. Rajasekar, Department of Mechanical Engineering, Kongu Engineering College, Erode, Tamilnadu, India-638060, N. Balakrishnan, Department of Mechanical Engineering, Gnanamani College of Technology, Namakkal, Tamilnadu, India-637018 Digest Journal of Nanomaterials and Biostructures, 2025 The development of biocompatible materials with enhanced properties is critical for biomedical applications. However, polycaprolactone (PCL), a widely used biodegradable polymer, exhibits insufficient mechanical and thermal properties for demanding applications. This study addresses the challenge by incorporating carboxyl-functionalized graphene (CFG) and hydroxyl-functionalized graphene (HFG) derivatives into PCL nanofibers using electrospinning. The objective is to optimize graphene content to improve the mechanical strength, thermal stability, and biocompatibility of the nanocomposites. Electrospun nanofibers with varying graphene concentrations (0.5, 1, and 2 wt%) were characterized for morphology, mechanical properties, thermal behavior, and cell viability. Results demonstrated that 1 wt% graphene content provided optimal performance, significantly enhancing tensile strength (5.5 MPa for CFG, 5.4 MPa for HFG) and Young's modulus while maintaining uniform, bead-free fibers. Thermal analysis revealed improved crystallinity and degradation temperature, while MTT assays showed superior cell viability (up to 93%) at 1 wt% graphene. These highlight the potential of PCL/graphene nanocomposites as high-performance biomaterials for tissue regeneration. Future research should explore in vivo performance and long-term biological effects to confirm their clinical viability
Optimizing graphene-enhanced polycaprolactone nanofibers for superior biomedical properties Sankar Thangavel, Kannan Thanneerpanthalpalayam Kandasamy, Rajasekar Rathanasamy, Ratchagaraja Dhairiyasamy Polimeros, 2025 Electrospun polycaprolactone (PCL) nanofibers are widely studied for biomedical applications due to their biodegradability and processability, but their limited mechanical strength and bioactivity restrict advanced use. This study addresses these challenges by incorporating four types of functionalized graphene—carboxyl (CFG), hydroxyl (HFG), amine (AFG), and sulfonic (SFG)—into PCL at varying concentrations. Nanocomposite fibers were fabricated via electrospinning and characterized using SEM, FTIR, Raman, DSC, TGA, tensile testing, and MTT assay. Among all, PCL reinforced with 1 wt% SFG showed superior properties, including a tensile strength of 5.8 MPa, 34% thermal residue at 600°C, and 93% cell viability at 72 hours, outperforming pure PCL by over 60% in strength and 9% in biocompatibility. The enhancement is attributed to improved dispersion and strong interfacial bonding from polar functional groups. These results highlight the potential of functionalized graphene to engineer high-performance nanofibers for tissue engineering and regenerative medicine applications.
Synergistic Enhancement of Automotive Radiator Performance Using Coated Surfaces and Hybrid Nanofluids: Experimental Evaluation of Heat Transfer and Hydraulic Characteristics Ratchagaraja Dhairiyasamy, J. Narendran, Alagarasan Ilango, M. Sathishkumar, Sankar Thangavel, C. Jothinath, T. Kaneesh, S. Balasubramanian, T. Chinnamadhan, Deekshant Varshney, Subhav Singh Journal of Environmental Nanotechnology, 2025 Nanofluids have emerged as promising alternatives to conventional coolants in automotive and industrial heat transfer applications due to their superior thermal conductivity and enhanced convective performance. However, ensuring long-term stability while achieving significant thermal gains without increasing pumping losses remains a critical challenge. This study addresses this gap by evaluating the effects of nanoparticle concentration and boron nitride (BN) surface coating on the thermophysical behavior of AlCeO₃ and CuFe₂O₄ nanofluids in radiator systems. The objective is to investigate how BN coating influences heat-transfer efficiency, stability, and pressure drop characteristics across different nanofluid loadings. AlCeO₃ and CuFe₂O₄ nanoparticles were synthesized, dispersed at 2% and 4% volume fractions, and tested in coated and uncoated radiators. Key metrics, including thermal conductivity, viscosity, zeta potential, heat-transfer coefficient (HTC), and pressure drop, were experimentally analyzed. Results show that thermal conductivity increased from 0.61 W/m·K (base fluid) to 0.86 W/m·K (4% AlCeO₃) and 0.83 W/m·K (4% CuFe₂O₄). The zeta potential values greater than 35 mV confirmed strong colloidal stability. BN-coated radiators achieved HTC values of up to 6200 W/m²·K, compared to 4600 W/m²·K in uncoated systems, and reduced pressure drops by 15–20% at higher Reynolds numbers. Additionally, coated systems exhibited stability over 30 days, outperforming uncoated counterparts that destabilized after 10–15 days. The study concludes that combining optimized nanofluid concentration with BN-coated radiators significantly boosts thermal performance while mitigating pressure losses. Future research could explore higher flow rates, scaling effects, and hybrid coatings for commercial adoption.
Enhancing thermal and mechanical properties of polycaprolactone nanofibers with graphene and graphene oxide reinforcement for bio-medical applications Sankar Thangavel, Kannan Thanneerpanthalpalayam Kandasamy, Rajasekar Rathanasamy, Ratchagaraja Dhairiyasamy Revista Materia, 2024 This study aimed to enhance the mechanical, thermal, and biocompatibility properties of polycaprolactone (PCL) nanocomposite nanofibers by incorporating graphene and graphene oxide (GO) using the electrospinning technique. PCL nanocomposite nanofibers were synthesized with varying concentrations of graphene (0.5%, 1%, and 1.5%) and GO (0.5%, 1%, and 1.5%). Mechanical properties were evaluated through tensile strength tests, showing significant enhancements. Graphene increased tensile strength by 10%, 20%, and 30%, while GO improved it by 15%, 25%, and 35% for respective concentrations. Thermal stability was assessed via thermogravimetric analysis (TGA), revealing that the onset degradation temperature increased by 5%, 10%, and 15% for graphene and by 7%, 12%, and 18% for GO. The maximum weight loss temperature improved by up to 20% for GO-reinforced nanocomposites. Results indicated that graphene enhanced cell viability by 8%, 12%, and 15%, and GO by 10%, 15%, and 20%. The thermal stability and biocompatibility improvements were attributed to the better dispersion and stronger interfacial bonding of GO within the PCL matrix. GO-reinforced nanocomposites showed a 20% improvement in cell viability, suggesting their suitability for biomedical applications. These findings indicate that incorporating graphene and GO significantly enhances the properties of PCL nanocomposites, making them suitable for demanding biomedical applications.
RECENT SCHOLAR PUBLICATIONS
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Operational Hazop Study for API in Pilot Plant SK Srinivasan K,Sankar T International Journal of Modern Trends in Engineering and Science 3 (10) , 2016 2016
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MOST CITED SCHOLAR PUBLICATIONS
Enhancing thermal and mechanical properties of polycaprolactone nanofibers with graphene and graphene oxide reinforcement for biomedical applications S Thangavel, KT Kandasamy, R Rathanasamy, R Dhairiyasamy Matéria (Rio de Janeiro) 29 (3), e20240324 , 2024 2024 Citations: 10
The Effect of Oxy-Hydrogen (HHO) on the Performance and Emission Characteristics of Diesel and Karanj in Single Cylinder Four Stroke Diesel Engine. S Thangavel Journal of Multidisciplinary Scientific Research 2 (1), 12-18 , 2014 2014 Citations: 6
Investigating the effect of cashew nutshell liquid and aluminum powder on the mechanical and thermal properties of epoxy resins RD Dineshkumar Jayaraman , Parthiban Alagesan , Sankar Thangavel Matéria (Rio de Janeiro) 29 (4), e20240719 , 2024 2024 Citations: 1
Desirability-Based Multiobjective Optimization of Layer Thickness, Infill Density, and Print Speed in Sustainable Carbon–Polylactic Acid Fused Deposition Modeling XW Chongkol Sungoum, Kiruthika Gnanavel , Ratchagaraja Dhairiyasamy ,Sankar ... Journal of Materials Engineering and Performance 35 (19), 1-25 , 2026 2026
Sustainability Assessment of Internal Microchannel Cooling with Nanofluid MQL in Hastelloy B3 Turning RD Murali T, Elango V,Sankar Thangavel Transactions of the Indian Institute of Metals 79 (5), 71 , 2026 2026
Sustainable Phoenix sp. Chopped‐Fiber Epoxy Composites: Length–Loading Optimization via ASTM Testing and Diffusion Kinetics SS Wasurat Bunpheng,Hariharan Vaggeeram,Sankar Thangavel,Ratchagaraja ... Polymer Composites 47 (6), 1-13 , 2026 2026
Graphene-Modified Polycaprolactone Nanofibers for Biomedical Applications: Enhancing Mechanical Strength and Biocompatibility BN Sankar Thangavel, Kannan Thanneerpanthalpalayam Kandasamy, Rajasekar ... Journal of Biomedical Materials Research Part B: Applied Biomaterials 114 (3 … , 2026 2026
Trust-Based Security for IoT Networks CV A.Sujitha,Sankar Thangavel 2026
Synergistic Enhancement of Automotive Radiator Performance Using Coated Surfaces and Hybrid Nanofluids: Experimental Evaluation of Heat Transfer and Hydraulic Characteristics SS Ratchagaraja Dhairiyasamy,J. Narendran, Alagarasan Ilango,M.Sathishkumar ... Journal of Environmental Nanotechnology 14 (4), 54-71 , 2025 2025
Optimizing graphene-enhanced polycaprolactone nanofibers for superior biomedical properties S Thangavel, KT Kandasamy, R Rathanasamy, R Dhairiyasamy Polímeros 35 (4), e20250042 , 2025 2025
Eco-Friendly Polymer Synthesis Method and Composition for Biodegradable Packaging Materials R Madham Padma,Ponsuriyaprakash S,Vipin Vijayan,Baskaran R, Sankar T IN Patent App. 202541078471 A , 2025 2025
Optimization of graphene-functionalized polycaprolactone nanofibers: enhancing mechanical, thermal, and biocompatibility properties for biomedical applications. T Sankar, TK Kannan, R Rajasekar, N Balakrishnan Digest Journal of Nanomaterials & Biostructures (DJNB) 20 (2) , 2025 2025
Integrated Structural and Drivetrain Engineering for Enhanced Efficiency in Electric Three-Wheel Freight Vehicles DP T. Sankar, J. Narendran, C. Saran, P. Logesh, S. Kabilan Journal of Thermal and Sustainable Energy Systems 1 (1), 1-12 , 2025 2025
Fabrication of Mini Electrical Cart MR Sankar.T,Hariharan.K,Mohamedfaizalhaq.S,Thilaksundar.N.S INTERNATIONAL JOURNAL OF CREATIVE RESEARCH THOUGHTS 12 (5), h90-h96 , 2024 2024
Operational Hazop Study for API in Pilot Plant SK Srinivasan K,Sankar T International Journal of Modern Trends in Engineering and Science 3 (10) , 2016 2016
Control of Specific Gaseous Pollutants for Environmental Safety S Seshalin Anand.S,Sankar T International Journal of Modern Trends in Engineering and Science 3 (9) , 2016 2016
