Copolymerization and Dark Polymerization Studies for Photopolymerization of Novel Acrylic Monomers

The copolymerization behavior and the dark polymerization kinetics of highly reactive novel acrylic monomers were compared to traditional acrylate monomers. Copolymerization of thiol functionalities with novel acrylic monomers was characterized, and it was observed that the inclusion of secondary functionalities such as carbamates, carbonates, and cyclic carbonates, in acrylic monomers significantly alters the relative reactivity of the novel acrylates with thiols. While traditional aliphatic acrylates exhibited propagation to chain transfer ratios ranging between 0.8 (±0.1) and 1.5 (±0.2), the novel acrylates characterized by secondary functionalities exhibited much higher propagation to chain transfer ratios ranging from 2.8 (±0.2) to 4 (±0.2). In the dark polymerization studies, the kinetics of the novel acrylates were evaluated following cessation of the UV light. The novel acrylates exhibited extensive polymerization in the dark compared to most traditional acrylates and diacrylates. For instance, cyclic carbonate acrylate was observed to attain 35% additional conversion in the dark when the UV light was extinguished at 35% conversion, whereas traditional acrylates such as hexyl acrylate attained only 3% additional conversion when the UV light was extinguished at 35%, and a diacrylate such as HDDA attained 15% additional conversion when the UV light was extinguished at 40% conversion. Also, through choice of appropriate monomers, the dark polymerization studies were performed such that the polymerization rate was approximately the same at the point the light was extinguished for all these monomers. The copolymerization and dark polymerization studies support the hypothesis that the nature of the propagating species in the novel acrylates is altered as compared to traditional acrylic monomers and polymerizations.     

Ionic liquid-assisted synthesis of tri-functional ruthenium oxide nanoplatelets for electrochemical energy applications

Journal of Materials Science - Nanostructured crystalline metal oxides are in great demand in industrial processes due to their unique physicochemical properties and ionic liquids (ILs) are...     

Carlson’s Index,a poor cursor of trophic status assessment of Pulicat Lagoon,southeast coast of India

Pulicat Lagoon is a productive coastal lagoon on the southeast coast of India. Several studies of its physico‐chemical and biological characteristics have been undertaken. This project was the first to attempt to represent the lagoon’s ecological status in the form of a trophic state index. The investigation applied Carlson’s Trophic State Index (TSI) to determine the trophic status of Pulicat lagoon over the years 2005 and 2006. The observations corresponding to the TSI scores for the transparency of the water column (represented by Secchi Disk Depth, an important parameter for calculating TSI) were compared with observations obtained during field sampling. Discrepancies were observed in the representation of the transparency of the water column as well as the trophic condition and those predicted by the TSI. These discrepancies suggested that TSI was not an effective index of the trophic status of Pulicat lagoon. The study thus proves the fallibility of classical indices for a case‐specific scenario. The investigation points out that there is a need to develop newer and more accurate indices to represent water quality in a lagoon.     

CXCR‐4 Targeted,Short Wave Infrared (SWIR) Emitting Nanoprobes for Enhanced Deep Tissue Imaging and Micrometastatic Cancer Lesion Detection

Realizing the promise of precision medicine in cancer therapy depends on identifying and tracking cancerous growths to maximize treatment options and improve patient outcomes. This goal of early detection remains unfulfilled by current clinical imaging techniques that fail to detect lesions due to their small size and suborgan localization. With proper probes, optical imaging techniques can overcome this by identifying the molecular phenotype of tumors at both macroscopic and microscopic scales. In this study, the first use of nanophotonic short wave infrared technology is proposed to molecularly phenotype small lesions for more sensitive detection. Here, human serum albumin encapsulated rare‐earth nanoparticles (ReANCs) with ligands for targeted lesion imaging are designed. AMD3100, an antagonist to CXCR4 (a classic marker of cancer metastasis) is adsorbed onto ReANCs to form functionalized ReANCs (fReANCs). fReANCs are able to preferentially accumulate in receptor positive lesions when injected intraperitoneally in a subcutaneous tumor model. fReANCs can also target subtissue microlesions at a maximum depth of 10.5 mm in a lung metastatic model of breast cancer. Internal lesions identified with fReANCs are 2.25 times smaller than those detected with ReANCs. Thus, an integrated nanoprobe detection platform is presented, which allows target‐specific identification of subtissue cancerous lesions.     

Hydrogen Storage in Partially Exfoliated Magnesium Diboride Multilayers

Metal boride nanostructures have shown significant promise for hydrogen storage applications. However, the synthesis of nanoscale metal boride particles is challenging because of their high surface energy, strong inter- and intraplanar bonding, and difficult-to-control surface termination. Here, it is demonstrated that mechanochemical exfoliation of magnesium diboride in zirconia produces 3–4 nm ultrathin MgB₂ nanosheets (multilayers) in high yield. High-pressure hydrogenation of these multilayers at 70 MPa and 330 °C followed by dehydrogenation at 390 °C reveals a hydrogen capacity of 5.1 wt%, which is ≈50 times larger than the capacity of bulk MgB₂ under the same conditions. This enhancement is attributed to the creation of defective sites by ball-milling and incomplete Mg surface coverage in MgB₂ multilayers, which disrupts the stable boron–boron ring structure. The density functional theory calculations indicate that the balance of Mg on the MgB₂ nanosheet surface changes as the material hydrogenates, as it is energetically favorable to trade a small number of Mg vacancies in Mg(BH₄)₂ for greater Mg coverage on the MgB₂ surface. The exfoliation and creation of ultrathin layers is a promising new direction for 2D metal boride/borohydride research with the potential to achieve high-capacity reversible hydrogen storage at more moderate pressures and temperatures.     

Experimental,Numerical and Microscopic Analysis of Contaminated Clay with Precipitated Silica

Silicon - Petrol-contaminated clay (PCC) is a severe environmental risk and has a detrimental effect on the engineering properties of soil. Since precipitated silica has a powerful adsorption...