Single‐walled carbon nanotube absolute‐handedness chirality assignment confirmation using metalized porphyrin's supramolecular structures via STM imaging technique

Carbon Nanomaterial Fluorescent Probes and Their Biological Applications

Fluorescent carbon nanomaterials have broadly useful chemical and photophysical attributes that are conducive to applications in biology. In this review, we focus on materials whose photophysics allow for the use of these materials in biomedical and environmental applications, with emphasis on imaging, biosensing, and cargo delivery. The review focuses primarily on graphitic carbon nanomaterials including graphene and its derivatives, carbon nanotubes, as well as carbon dots and carbon nanohoops. Recent advances in and future prospects of these fields are discussed at depth, and where appropriate, references to reviews pertaining to older literature are provided.

Effect of the Simultaneous Addition of Polycaprolactone and Carbon Nanotubes on the Mechanical, Electrical, and Adhesive Properties of Epoxy Resins Cured with Ionic Liquids

Electrically-conductive epoxy nanocomposites (NCs) with improved mechanical and adhesive properties were achieved through the combined addition of poly(ε-caprolactone) (PCL) and carbon nanotubes (CNTs). Three different ionic liquids (ILs) were used as dual role agents, i.e., as both curing and dispersing agents. Regardless of the IL used, the epoxy/PCL matrix of the NCs showed a single-phase behaviour and similar glass transition (Tg) and crosslinking density (νe) values to the unfilled epoxy/PCL/IL systems. Although the CNTs were more poorly dispersed in the epoxy/PCL/CNT/IL NCs than in the reference epoxy/CNT/IL NCs, which led to slightly lower electrical conductivity values, the epoxy/PCL/CNT/IL NCs were still semiconductive. Their low-strain mechanical properties (i.e., flexural modulus and flexural strength) were similar or better than those of the reference epoxy/IL systems and their high-strain mechanical properties (i.e., deformation at break and impact strength) were significantly better. In addition, the positive effects of the PCL and the CNTs on the adhesive properties of the epoxy/IL system were combined. The substitution of ILs for traditional amine-based curing agents and biodegradable PCL for part of the epoxy resin represents an important advance on the road towards greater sustainability.

Identification of Supramolecular Structures of Porphyrin Polymer on Single-Walled Carbon Nanotube Surface Using Microscopic Imaging Techniques

Although the supramolecular structure of porphyrin polymers on flat surfaces (i.e., mica and HOPG) has been extensively studied, the self-assembly arrays of porphyrin polymers on the SWNT (as curved nanocarbon surfaces) have yet to be fully identified and/or investigated, especially using microscopic imaging techniques, i.e., scanning tunneling microscopy (STM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). This study reports the identification of the supramolecular structure of poly-[5,15-bis-(3,5-isopentoxyphenyl)-10,20-bis ethynylporphyrinato]-zinc (II) on the SWNT surface using mainly AFM and HR-TEM microscopic imaging techniques. After synthesizing around >900 mer of porphyrin polymer (via Glaser-Hay coupling); the as-prepared porphyrin polymer is then non-covalently adsorbed on SWNT surface. Afterward, the resultant porphyrin/SWNT nanocomposite is then anchored with gold nanoparticles (AuNPs), which are used as a marker, via coordination bonding to produce a porphyrin polymer/AuNPs/SWNT hybrid. The polymer, AuNPs, nanocomposite, and/or nanohybrid are characterized using 1H-NMR, mass spectrometry, UV-visible spectroscopy, AFM, as well as HR-TEM measuring techniques. The self-assembly arrays of porphyrin polymers moieties (marked with AuNPs) prefer to form a coplanar well-ordered, regular, repeated array (rather than wrapping) between neighboring molecules along the polymer chain on the tube surface. This will help with further understanding, designing, and fabricating novel supramolecular architectonics of porphyrin/SWNT-based devices.

Hybrid Nano Flake-like Vanadium Diselenide Combined on Multi-Walled Carbon Nanotube as a Binder-Free Electrode for Sodium-Ion Batteries

As the market for electric vehicles and portable electronic devices continues to grow rapidly, sodium-ion batteries (SIBs) have emerged as energy storage systems to replace lithium-ion batteries (LIBs). However, sodium-ion is heavier and larger than lithium-ion, resulting in volume expansion and slower ion transfer. It is necessary to find suitable anode materials with high capacity and stability. In addition, wearable electronics are starting to be commercialized, requiring a binder-free electrode used in flexible batteries. In this work, we synthesized nano flake-like VSe2 using organic precursor and combined it with MWCNT as carbonaceous material. VSe2@MWCNT was mixed homogenously using sonication and fabricated film electrodes without a binder and substrate via vacuum filter. The hybrid electrode exhibited high-rate capability and stable cycling performance with a discharge capacity of 469.1 mAhg-1 after 200 cycles. Furthermore, VSe2@MWCNT exhibited coulombic efficiency of ~99.7%, indicating good cycle stability. Additionally, VSe2@MWCNT showed a predominant 85.5% of capacitive contribution at a scan rate of 1 mVs-1 in sodiation/desodiation process. These results showed that VSe2@MWCNT is a suitable anode material for flexible SIBs.

Synthesis and applicability of reduced graphene oxide/porphyrin nanocomposite as photocatalyst for waste water treatment and medical applications

This study presents the synthesis and doping of reduced graphene oxide (rGO) with synthesized porphyrin (5,15-bisdodecyl porphyrin, C12P) nanoparticles to fabricate reduced graphene oxide-porphyrin (rGO-P) nanocomposite as well as demonstrates their outstanding removal activity of azo dye and antimicrobial potential. The synthesized porphyrin, rGO, and rGO-P nanocomposites were characterised using SEM, HRTEM, Raman spectroscopy, XRD, ¹H-NMR, mass spectrometry, and UV-Visible spectroscopy. The ability of the synthesized rGO-P nanocomposite was then investigated (as catalyst and/or adsorbent) to impact its removal efficacy against Congo red (CR) as a well-known toxic, mutagenic and carcinogenic synthetic dye. The findings indicated that 0.01 g of rGO-P nanocomposite achieved 78.0% removal of CR at pH 3.0. Besides, the removal efficacy was evaluated while studying many aspects i.e. pH, CR initial concentration, and rGO-P nanocomposite amount. Moreover, the minimum inhibitory concentration (MIC) and zone of inhibition (ZOI) of antimicrobial activity against pathogenic bacteria and yeast were evaluated. The antimicrobial results showed that rGO-P nanocomposite revealed the greatest antimicrobial activity against Candida albicans, Enterococcus faecalis, and Staphylococcus aureus with ZOI values of 24.3, 21.8, and 22.1 mm, respectively. Consequently, it demonstrates the substantial potential of rGO-P nanocomposite in the effective removal of pollutant dyes as well as significant antibacterial and antifungal properties.

Intrinsic helical twist and chirality in ultrathin tellurium nanowires

Robust atomic-to-meso-scale chirality is now observed in the one-dimensional form of tellurium. This enables a large and counter-intuitive circular-polarization dependent second harmonic generation response above 0.2 which is not present in two-dimensional tellurium. Orientation variations in 1D tellurium nanowires obtained by four-dimensional scanning transmission electron microscopy (4D-STEM) and their correlation with unconventional non-linear optical properties by second harmonic generation circular dichroism (SHG-CD) uncovers an unexpected circular-polarization dependent SHG response from 1D nanowire bundles - an order-of-magnitude higher than in single-crystal two-dimensional tellurium structures - suggesting the atomic- and meso-scale crystalline structure of the 1D material possesses an inherent chirality not present in its 2D form; and which is strong enough to manifest even in the aggregate non-linear optical (NLO) properties of aggregates.