Highly curable self-healing vitrimer-like cellulose-modified halloysite nanotube/epoxy nanocomposite coatings

Surface chemistry of halloysite nanotubes controls the curability of low filled epoxy nanocomposites

Novel hybrid halloysite nanotubes (HHNTs) were developed and used as smart carriers for corrosion protection of steel. For this purpose, as-received halloysite nanotubes (HNTs) were loaded with a corrosion inhibitor, imidazole (IM), by vacuum encapsulation. In the next step, a layer by layer technique was employed to intercalate another inhibitor, dodecylamine (DDA), in the polyelectrolyte multilayers of polyethylenimine and sulfonated polyether ether ketone, leading to the formation of HHNTs. During this process, IM (5 wt %) was successfully encapsulated into the lumen of HNTs, while DDA (0.4 wt %) was effectively intercalated into the polyelectrolyte layers. Later, the HHNTs (3 wt %) were thoroughly dispersed into the epoxy matrix to develop smart hybrid self-healing polymeric coatings designated as hybrid coatings. For a precise evaluation, epoxy coatings containing as-received HNTs (3 wt %) without any loading denoted to as reference coatings and modified coatings containing HNTs loaded with IM-loaded HNTs (3 wt %) were also developed. A comparative analysis elucidates that the hybrid coatings demonstrate decent thermal stability, improved mechanical properties, and promising anticorrosion properties compared to the reference and modified coatings. The calculated corrosion inhibition efficiencies of the modified and hybrid coatings are 92 and 99.8%, respectively, when compared to the reference coatings. Noticeably, the superior anticorrosion properties of hybrid coatings can be attributed to the synergetic effect of both the inhibitors loaded into HHNTs and their efficient release in response to the localized pH change of the corrosive medium. Moreover, IM shows an active release in both acidic and basic media, which makes it suitable for the protection of steel at the early stages of damage, while DDA being efficiently released in the acidic medium may contribute to impeding the corrosion activity at the later stages of deterioration. The tempting properties of hybrid coatings demonstrate the beneficial role of the development of novel HHNTs and their use as smart carriers in the polymeric matrix for corrosion protection of steel.

Hybrid Halloysite Nanotubes as Smart Carriers for Corrosion Protection.

Epoxy-clay fiber reinforced plastics are employed in myriad applications. They, however, are brittle with less impact strength/related properties. There has been tremendous amount of research on pr...

Advancements in multi-scale filler reinforced epoxy nanocomposites for improved impact strength: A review

Synergistic toughen epoxy resin by incorporation of polyetherimide and amino groups grafted MWCNTs

The particulate filled epoxy composites show lower mechanical properties than neat composites due to lack strength of uniform dispersion of particles leading to poor in interfacial strength between matrix and fillers. In this study, ultrasonification dispersion technique is employed to achieve a homogenous dispersion of halloysite nanotubes (HNTs) in epoxy resin. The nanocomposites are fabricated by solution casting method and specimens are prepared as per ASTM standards. The various test has been conducted as per ASTM procedure to evaluate the mechanical properties viz. density, hardness, tensile, flexural, ILSS and impact strength of the nanocomposites consisting of different weight (wt)% of HNTs varying in the range of 0–4 with the interval of 1. As per the experimental investigation, the selected dispersion techniques enhances the mechanical properties of the nanocomposite by the loading of HNT. Further, the study revealed that the 3 wt% of HNT with ultrasonic homogenized nanocomposite shows superior mechanical strength as compared to other nanocomposites. Hence it is evident that the properties of the nanocomposite depends on the quantity of filler present and dispersion condition. The dispersion condition and fractured surfaces are analyzed through the SEM micrographs.

/pdf/enhancement-of-mechanical-properties-of-epoxy-halloysite-2gwa1vox0k.pdf

Enhancement of mechanical properties of epoxy/halloysite nanotube (HNT) nanocomposites

Effect of heat treated HNT on physico-mechanical properties of epoxy nanocomposites

Brassica juncea (BJ) is a familiar edible crop, which has been used as a dietary ingredient and to prepare anti-inflammatory/anti-arthritic formulations in Ayurveda. But, the scientific validation ...

Brassica juncea (L.) Czern. leaves alleviate adjuvant-induced rheumatoid arthritis in rats via modulating the finest disease targets - IL2RA, IL18 and VEGFA

A limited number of overexpressed transcription factors are associated with cancer progression in many types of cancer. BTB and CNC homology 1 (BACH1) is the first mammalian heme-binding transcription factor that belongs to the basic region leucine zipper (bZIP) family and a member of CNC (cap 'n' collar). It forms heterodimers with the small musculoaponeurotic fibrosarcoma (MAF) proteins and stimulates or suppresses the expression of target genes under a very low intracellular heme concentration. It possesses a significant regulatory role in heme homeostasis, oxidative stress, cell cycle, apoptosis, angiogenesis, and cancer metastasis progression. This review discusses the current knowledge about how BACH1 regulates cancer metastasis in various types of cancer and other carcinogenic associated factors such as oxidative stress, cell cycle regulation, apoptosis, and angiogenesis. Overall, from the reported studies and outcomes, it could be realized that BACH1 is a potential pharmacological target for discovering new therapeutic anticancer drugs.

Regulatory mechanisms of heme regulatory protein BACH1: a potential therapeutic target for cancer.

Fatigue failure is an important factor in most of the engineering applications, especially in steel materials, and among the steel materials, it is an important phenomena in medium carbon steels like EN8, which is very commonly used in components like shaft, gears etc., since it is prone to fatigue failure. Hence, without changing the composition, an attempt is made to enhance the fatigue strength by different heat treatment techniques. In this study, the investigation is carried out on heat treatment of EN8 steel material. Various kinds of heat treatment techniques like quench and temper, normalizing and annealing are performed on EN8 steel. After exposure to the heat treatment, the EN 8 steel material specimens are machined as per the ASTM standards and are subjected to RR MOORE test and SN-curves are plotted from the obtained results; the obtained results from the fatigue tests are further analyzed with the help of ANSYS software. Fatigue life and Factor of Safety (FOS) comparisons for EN 8 steel material is made with the structural steel material and it is found from the comparisons, that the heat treatment process enhances the fatigue strength and endurance limit.

https://iopscience.iop.org/article/10.1088/1757-899X/1013/1/012009/pdf

G. Ravichandran

Papers

Enhancement of mechanical properties of epoxy/halloysite nanotube (HNT) nanocomposites

Effect of heat treated HNT on physico-mechanical properties of epoxy nanocomposites

Brassica juncea (L.) Czern. leaves alleviate adjuvant-induced rheumatoid arthritis in rats via modulating the finest disease targets - IL2RA, IL18 and VEGFA

Regulatory mechanisms of heme regulatory protein BACH1: a potential therapeutic target for cancer.

Effect of Heat Treatment on Fatigue Characteristics of En8 Steel