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41.
Tapas K. Paira Sanjib Banerjee Tarun K. Mandal 《Journal of polymer science. Part A, Polymer chemistry》2012,50(11):2130-2141
Well‐defined peptide‐poly(ε‐caprolactone) (Pep‐PCL) biohybrids were successfully synthesized by grafting‐from ring‐opening polymerization (ROP) of ε‐caprolactone (CL) using designed amine‐terminated sequence‐defined peptides as macroinitiators. MALDI‐TOF‐MS and 1H NMR analyses confirmed the successful attachment of peptide to the PCL chain. The gel permeation chromatography (GPC) measurement showed that the Pep‐PCL biohybrids with controllable molecular weights and low polydispersities (PDI <1.5) were obtained by this approach. The aggregation of Pep‐PCL hybrid molecules in THF solution resulted in the formation of micro/nanospheres as confirmed through FESEM, TEM, and DLS analyses. The circular dichroism study revealed that the secondary structure of peptide moiety was changed in the peptide‐PCL biohybrids. The crystallization and melting behavior of Pep‐PCL hybrids were somewhat changed compared with that of neat PCL of comparable molecular weight as revealed by DSC and XRD measurements. In Pep‐PCL biohybrids, extinction rings were observed in the PCL spherulites, in contrast with the normal spherulite morphology of the neat PCL. There was a substantial decrease (4–5 folds) in the spherulitic growth rate after the incorporation of peptide moiety at the end of PCL chain as measured by polarizing optical microscopy. Pseudomonas lipase catalyzed enzymatic degradation was studied for Pep‐PCL hybrids and neat PCL. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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Over exploitation of natural resources and human activities are relentlessly fueling the emission of CO2 in the atmosphere. Accordingly, continuous efforts are required to find solutions to address the issue of excessive CO2 emission and its potential effects on climate change. It is imperative that the world looks towards a portfolio of carbon mitigation solutions, rather than a single strategy. In this regard, the use of CO2 as a C1 source is an attractive strategy as CO2 has the potential to be a great asset for the industrial sector and consumers across the globe. In particular, the reduction of CO2 offers an alternative to fossil fuels for various organic industrial feedstocks and fuels. Consequently, efficient and scalable approaches for the reduction of CO2 to products such as methane and methanol can generate value from its emissions. Accordingly, in recent years, metal-free catalysis has emerged as a sustainable approach because of the mild reaction conditions by which CO2 can be reduced to various value-added products. The metal-free catalytic reduction of CO2 offers the development of chemical processes with low cost, earth-abundant, non-toxic reagents, and low carbon-footprint. Thus, this perspective aims to present the developments in both the reduction and reductive functionalization chemistry of CO2 during the last decade using various metal-free catalysts.This review article documents the key developments in the metal-free catalytic reduction of CO2 into various energy intensive chemicals and fuels, and reductive functionalization of CO2 for the formation of new C–N bonds. 相似文献
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Priyabrata Das Suvra Mandal Sudeshna Gangopadhyay Kalipada Das Arpita Ghosh Mitra Swati Dasgupta 《Natural product research》2016,30(4):474-477
Methylphophorbide a (MPa) has been isolated from the ethanol extract of the wheat grass plant. Its antioxidative efficacy is evaluated by hydroxyl radical scavenging activities and reducing capacity which are significantly up regulated in comparison with aqueous extract of the plant. The compound shows iron-binding capacity where the Fe2+ binds with MPa by two types of binding patterns with dissociation constants 157.17 and 27.89. It has antioxidative and cytotoxic effects on HeLa and Hep G2 cells. The cancerous cell survivability decreases with increasing concentration of MPa. These findings have provided evidence for the traditional use of the wheat grass plant in the treatment of cancers, oxidative stress and iron overloaded disorders. 相似文献
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Facile synthesis of novel ibuprofen bearing polyurethane 1 has been achieved for the first time and found to display the release pattern of ibuprofen based on the easy cleavage of ester linkages. Thorough characterizations (FT‐IR, UV‐Vis, NMR, and elemental analysis) were performed to ascertain the structure of polyurethane 1. 相似文献
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Vethathiri Pakkirisamy Sridhar Mahadevan Surianarayanan Suthangathan Paramashivan Sivapirakasam Asit Baran Mandal 《Journal of Thermal Analysis and Calorimetry》2013,112(3):1335-1341
The objective of this article is to generate thermal decomposition data on fireworks tip mixture, a mixture used to coat the tip of fireworks, for easy ignition. This mixture has reportedly involved in triggering many accidents in fireworks industry. Different quantities of water were added to the mixture and its thermal characteristics were studied. Differential scanning calorimeter was used for screening tests and accelerating rate calorimeter was used for detailed studies in adiabatic and isothermal modes. The self-heat rate data obtained showed onset temperature for different quantity of water, at a range of 80–170 °C. The mixture with 40 % water wt/wt had onset at 80 °C in adiabatic mode. The same mixture on isoaging at 40 °C exhibited exothermic characteristics with a substantial rise in system pressure (57 bar). The heats of exothermic decomposition and Arrhenius kinetics were also computed. 相似文献
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Biman B. Mandal Eun Seok Gil Bruce Panilaitis David L. Kaplan 《Macromolecular bioscience》2013,13(1):1-1
Front Cover: Highly aligned 3D silk scaffolds using directional freezing in a custom designed chamber was demonstrated. The method is versatile and holds potential to produce complex, multicomponent aligned structures for various tissue engineering and biomedical applications, needing immediate cell alignment to mimic native tissue hierarchy and function. Further details can be found in the article by B. B. Mandal, E. S. Gil, B. Panilaitis, and D. L. Kaplan* on page 48 .