In this paper, the impact performance of a novel resin-infused acrylic thermoplastic matrix-based 3D glass fabric composite (3D-FRC) has been evaluated and compared with thermoset based 3D-FRC under single as well as recurring strike low velocity impact (LVI) events. The single impact tests revealed that the thermoplastic-based 3D-FRC exhibits up to 45% reduced damage area and can have up to 20% higher impact load-bearing capacity (peak force). The damage mode characterization showed that damage transition energy required for micro to macro damage transition is 27% higher, and back face damage extension is up to 3 times less for thermoplastic-based 3D-FRC. Meanwhile, the recurring strike impact test highlights that the thermoplastic-based 3D-FRC experiences a 50% less damaged area, better structural integrity, and survived more strikes. The comparison of single and repeated LVI tests have also allowed us to present a design criterion for estimating the safe number of repeated LVI events for a given impact energy. The superior impact resistance of thermoplastic-based 3D-FRC is attributed to their higher interlaminar fracture toughness, a tougher fiber-matrix interface, matrix ductility, and unique failure mechanism of yarn straining, which is not present in thermoset

Internalization, Subcellular Trafficking, and Cytotoxicity of Nanoparticles

The fabric used in this research work was 3D orthogonal E-glass woven fabric (3D-9871) obtained from TexTech? Industries, USA, as shown in Fig. 1(a). This fabric has three warp layers and four fill layers held together by a through-thickness reinforcement, which travels along the warp direction. The cross-sectional area of a middle layer along the warp direction was twofold to maintain the same areal density and in-plane properties along with both directions (warp and fill direction), as shown in the schematic diagram in Fig. 1(b). The overall thickness of a single-layered dry fabric is ~4.3 mm with an areal density of 5200 GSM. The fabric consists of 49% fibers along the warp and fill direction, and 2% fibers along the thickness direction. The fill and warp count of the 3D fabric is 1.9 PPCM and 2.8 EPCM, respectively. To study the effect of resin toughness, two different resin systems were used to fabricate 3D FRC panels, i.e., a recently developed acrylic thermoplastic liquid resin Elium?188 x 0 (low reactivity) supplied by Arkema and thermoset epoxy resin system Epolam? 5015/5015 supplied by Axson. The Elium?188 x 0 is an acrylic monomer, which was mixed with the peroxide catalyst to initiate the polymerization process at room temperature. The percentage of peroxide may vary between 2% (slow polymerization) to 4% (fast polymerization) depending upon the requirement. In this study, low polymerization time was used (80-100 min). To achieve this, the ratio of Elium? and peroxide used was 100:2.25, i.e., 2.25 gs of peroxide was mixed with 100 gs of Elium? resin. Whereas, in the case of thermoset resin, the epoxy and hardener ratio used was 100:30 by weight. The mechanical properties of Elium? and Epolam? are mentioned in Table 1. A quick look at Table 1 reveals that both resin systems have nearly identical strength and stiffness, however, the toughness of thermoplastic, Elium is more than four times that of the thermoset, Epolam and this leads to significant differences in impact response of the two systems as will be explained in the results and discussion sections.

Material Performance Understanding: The study provides a clear comparison between thermoplastic and thermoset-based 3D-FRCs, showing that thermoplastic-based composites have superior resistance to indentation and damage under recurring impacts. This understanding is crucial for material selection in applications where repeated impacts are expected.

Enhanced Durability:Thermoplastic-based 3D-FRCs demonstrated significantly less indentation depth and damage area, especially under lower impact energy (30 J), indicating higher durability and better performance under repeated stress. This makes them more suitable for applications in industries like aerospace, automotive, and sports equipment, where materials frequently encounter such conditions.

Safety and Reliability: The lower damage area and reduced indentation depth in thermoplastic-based 3D-FRCs imply higher reliability and safety in use. Components made from these materials are less likely to fail catastrophically, which is particularly important in critical structural applications.

Cost-Effectiveness: Although not directly mentioned, the reduced damage and higher durability of thermoplastic-based 3D-FRCs can lead to longer service life and lower maintenance costs. This makes them a cost-effective choice over time, despite possibly higher initial costs.

Comparison of macroscopic damage morphologies at the impact and non-impact face of thermoplastic and thermoset 3D composite under recurring low-velocity impact test. The damage is compared at different impact energies, i.e., 30 J and 50 J. The yellow dashed regions represent damage areas at different impact energies after the fifth successive strike.

Aerospace Industry: Understanding the factors influencing nanoparticle internalization allows for the optimization of drug delivery systems, leading to improved therapeutic outcomes. By modifying nanoparticle properties such as size, surface charge, and shape, researchers can enhance cellular uptake and target specific sites of action within the body, potentially increasing the efficacy of therapeutic agents while minimizing side effects.

Minimization of Side Effects: Tailoring nanoparticle properties to optimize internalization can help minimize off-target effects and reduce the risk of adverse reactions in patients. By enhancing cellular uptake and targeting specific tissues or cells, nanoparticles can deliver therapeutic agents more selectively, thereby minimizing damage to healthy tissues and organs.

Advancements in Drug Delivery: Functionalizing nanoparticles with various proteins or ligands allows for targeted drug delivery, enabling specific interactions with cellular receptors or transport mechanisms. This approach can enhance the rate of transcytosis across epithelial barriers, leading to improved bioavailability and therapeutic efficacy of orally administered drugs.

The ability to modify nanoparticle properties and functionalize them with specific ligands or targeting moieties opens up opportunities for personalized medicine. By targeting specific receptors or cellular pathways, nanoparticles can be tailored to individual patient profiles, potentially improving treatment outcomes and reducing adverse effects.