•Selective functionalization of ferrocenyl Cp rings using rice husk ash (RHA) as solid support.•Fluorescence based sensing and signaling behavior with metal cations in the intracellular matrix.•Mode ...of interaction of the unsymmetrical ferrocene based rhodaminyl organometallic receptor has been established by DFT study.
Selective funtionalization of ferrocenyl species with fluorescent active rhodamine moiety using a solvent free solid state method led to the synthesis of 1,1’- unsymmetrical ferrocene based turn-on fluorescent hydrazone molecular system, 1,1’-CH3C(O)(η5-C5H4)Fe{(η5-C5H4)C(CH3)N-NC(O)-X}, (X = Rhodamine-6G) (1) and 1,1’-HC(O)(η5-C5H4)Fe{(η5-C5H4)C(H)N-NC(O)-X}, (X = Rhodamine-6G (2), Rhodamine-B (3)). The unsymmetrical molecular system was structurally characterized by single crystal X-ray diffraction crystallography. Their fluorescence based signaling and sensing behavior has been explored with metal cations to observe remarkable fluorescence enhancement capabilities in the intracellular matrix. The interaction behavior of the unsymmetrical ferrocene based rhodaminyl organometallic receptor has been established by DFT study and spectroscopic analysis. The study showed some significant intracellular metal recognition and imaging characteristics to understand their potential in applications related to bioimaging of heavy metal ions. Molecular logic Gate property was also studied corresponding to INHIBIT, OR and a combinational logic operations using the fluorometric molecular compound.
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•Synthesis of fluorophoric 1,1′-unsymmetrical bi-functionalized ferrocenyl molecular receptor using two different solid supported condensation reactions.•Intracellular metal ...recognition and imaging characteristics has been explored for their potential in applications related to bioimaging of heavy metal ions.•The bioimaging study of the THP‐1 cancer cell line revealed considerable bioaccumulation of the receptor compounds.•Distinct interaction of the metal ion leading to a change in structural conformation due to the rotational flexibility within the ferrocenyl axis.
Unsymmetrically bi-functionalized ferrocenyl compounds are significant class of multifunctional molecule having unique structural features, varied conformational orientations, tunable electrochemical behavior and wide functional prospects. Strategic design of these unsymmetrical derivatives involving multifunctional components containing sandwich based electroactive fragment, heterocyclic moieties and a highly emissive photo-responsive unit can create flexible, biocompatible fluorescent single molecule - probe for sensor and signaling based molecular devices. Therefore, synthesis of fluorophoric 1,1′-unsymmetrical bi-functionalized ferrocenyl molecular receptor have been carried out using two different types of solid supported condensation reactions, one using Schiff base condensation reaction to link hydrazone based heterocyclic moieties and the other involving a Knoevenagel condensation to link cyano-vinyl based donor–acceptor system, to obtain 1,1′-ferrocenyl rhodaminyl-pyridyl hydrazones and 1,1′-ferrocenyl hydrazone-cyanovinylester derivatives. The unsymmetrical nature of the molecules has been established by single crystal diffraction study and explored for their fluorescence and electrochemical based signaling and sensing behavior of metal cations in solution and subcellular level. The study showed significant intracellular metal recognition and imaging characteristics for their potential in applications related to bioimaging of heavy metal ions. DFT study revealed distinct interaction of the metal ion leading to a change in structural conformation due to the rotational flexibility within the ferrocenyl axis. Molecules were also explored for their cytotoxic behavior and protein binding interaction to understand their biological potential.
•Redmud supported solid state synthesis of unsymmetrical bi-functionalized ferrocenyl hydrazone enone molecular compounds.•Investigation of phosgene and metal ion sensing properties using multi-probe ...spectroscopic and electrochemical methods.•Intracellular metal recognition and imaging study for their potential in bioimaging of heavy metal ions.
A series of 1,1′-unsymmetrical bi-functionalized ferrocenyl hydrazone – enone molecular compounds (3–7) have been synthesized using a facile redmud supported solid state synthetic method. These unsymmetrical bi-functionalized derivatives involving fluorescent active group have been explored for their fluorescence based signaling and sensing behavior of metal cations in the subcellular level. The study showed significant intracellular metal recognition and imaging characteristics for their potential in applications related to bioimaging of heavy metal ions. Sensing behavior has also been studied to understand their scope in the detection of toxic phosgene gas using multi-probe spectroscopic and electrochemical methods.
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•Solid state synthetic approach to design multi-pyridine based ferrocenyl scaffold.•Unusual 1,4-Michael addition leading to selective bis-pyridyl functionalization.•Significant amyloid inhibition ...against fibrillation in amyloidogenic BSA protein.•Molecular dynamics simulation study to explore inhibitor–BSA interaction
Destabilization of protein's native conformation to intermediates rich in β-sheet structure may lead to amyloid fibrillation involving a complex process of aggregation that are primarily responsible for various neurodegenerative disorders. Design of flexible, functional molecules capable of disruption or inhibition of fibrillar aggregates at their initial stages can be an effective approach to restrict or prevent amyloid related diseases. In this perspective, strategic association of ferrocenyl based electro-active moiety with heterocyclic rings can generate flexible, biocompatible molecular system with significant role in protein interactions, electrochemical monitoring and improved biological activity. Therefore, synthesis of molecules containing multi-pyridine ring framework conjugated to a ferrocenyl scaffold have been explored using a unique solid state, redmud supported, solvent free reaction method which led to the formation of ferrocenyl bis-pyridylenone (2) and a rare class of ferrocene based 1,4-Michael addition compound (3). The 1,4-Michael addition attack at an olefinic carbon with bulkier, electron donating ferrocenyl substituent has been unprecedented. Inhibitory potential of di-functionalized ferrocenyl-bispyridylenone conjugate (2) against amyloid fibrillation and its ability to serve as electrochemical probe on the disaggregation process of BSA have been explored. The study revealed significant inhibition of amyloid fibrils during aggregation process and also showed disruption of pre-formed BSA fibrils. The redox active inhibitor molecule was also used as potential electrochemical probe to monitor the inhibition of the fibrillation process. Molecular dynamics simulation confirmed distinct hydrogen bond interactions between the inhibitor compound and the A chain of BSA and revealed enough conformational stability of the protein-inhibitor complex.
Solid state synthetic approach using redmud support to design molecules containing ferrocenyl scaffold conjugated to multi-pyridine ring framework. Inhibition study against fibrillation in amyloidogenic BSA protein showed significant amyloid inhibition. Display omitted
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•Disorder of cellulosic H-bonds during pre-treatment developed amorphous Cellulose II.•EmimOAc pre-treatment reduced the activation energy of biomass pyrolysis.•Presence of amorphous ...Cellulose II in treated biomass enhanced dehydration reaction.•Enhanced dehydration of treated biomass during pyrolysis increased furans yield.•Cleavage of β-O-4 bonds of lignin during pre-treatment enhanced phenols yield.
Slow pyrolysis of regenerated cellulose-rich material (RCRM) and recovered lignin produced from imidazolium-based ionic liquid (IL) pre-treatment of sugarcane straw (SCS) was investigated employing a Thermogravimetric Analyser (TGA) instrument coupled with a Fourier-Transform Infrared (FTIR) spectroscopy. 1-ethyl-3-methylimidazolium acetate (EmimOAc) pre-treatment of SCS altered the hydrogen bonds of cellulose and produced amorphous Cellulose II structure in RCRM. FTIR spectroscopic analysis of liquid products showed that the IL pre-treatment increased the production of furans from the pyrolysis of RCRM, because the presence of amorphous Cellulose II in RCRM enhanced the dehydration reaction during pyrolysis. Moreover, the recovered lignin from IL pre-treatment enhanced the production of phenol-rich pyrolysis oil due to the cleavage of β-O-4 ether bonds of lignin during pre-treatment. Scanning electron microscope (SEM) analysis indicated highly porous structure of both RCRM and recovered lignin derived biochars. The kinetic analysis using a hybrid approach (a combination of model-fitting and model-free methods) indicated a reduction in the activation energy for both RCRM and recovered lignin pyrolysis. It is concluded that IL pre-treatment of lignocellulosic biomass followed by low-temperature pyrolysis can be an efficient route for biorefinery production.
•Slow pyrolysis of biosolids was studied in a Bubbling Fluidised Bed Reactor.•Established comparison with low cost bed materials such as lime, biochar and activated char.•Bed materials produced high ...surface area biochar between the temperature of 700 and 900 °C.•Bed materials reduced nitrogenated, oxygenated, PACs and aliphatic compounds in bio-oil.
Slow pyrolysis of biosolids was investigated employing a laboratory scale fluidised bed reactor maintaining the bubbling mode of fluidisation where the primary product was biochar. Low cost bed materials such as natural lime, biosolids derived biochar and activated char of biosolids origin were employed in the investigation. The pyrolysis experiments were mainly conducted in a batch mode at a constant heating rate of 35 °C/min, a solids residence time of 60 min and a biosolids to bed material ratio of 1. Experiments were conducted by varying pyrolysis temperatures (500, 700 and 900 °C) and bed material. The product characterisation was performed employing various analytical instruments including Scanning Electron Microscope (SEM), Fourier-Transform Infrared (FTIR) spectrometer, Gas Chromatography–Mass Spectrometry (GC/MS) and Brunauer–Emmett–Teller (BET) analyser. The objectives of this work were to identify the most suitable bed material and optimum operating temperature for generating biochar of superior quality as well as cracking down unwanted nitrogenated, oxygenated, polycyclic aromatic compounds (PACs) and aliphatic compounds as these species are difficult to combust or have the potential to cause secondary emissions. The temperature between 700 and 900 °C as well as biochar and activated char as bed materials were found to be favourable in obtaining biochar of high porosity and high surface area and in reducing nitrogenated, oxygenated, PACs and aliphatic compounds.
Biofouling, the unwanted growth of microorganisms on submerged surfaces, has appeared as a significant impediment for underwater structures, water vessels, and medical devices. For fixing the ...biofouling issue, modification of the submerged surface is being experimented as a non-toxic approach worldwide. This technique necessitated altering the surface topography and roughness and developing a surface with a nano- to micro-structured pattern. The main objective of this study is to review the recent advancements in surface modification and hydrodynamic analysis concerning biofouling control. This study described the occurrence of the biofouling process, techniques suitable for biofouling control, and current state of research advancements comprehensively. Different biofilms under various hydrodynamic conditions have also been outlined in this study. Scenarios of biomimetic surfaces and underwater super-hydrophobicity, locomotion of microorganisms, nano- and micro-hydrodynamics on various surfaces around microorganisms, and material stiffness were explained thoroughly. The review also documented the approaches to inhibit the initial settlement of microorganisms and prolong the subsequent biofilm formation process for patterned surfaces. Though it is well documented that biofouling can be controlled to various degrees with different nano- and micro-structured patterned surfaces, the understanding of the underlying mechanism is still imprecise. Therefore, this review strived to present the possibilities of implementing the patterned surfaces as a physical deterrent against the settlement of fouling organisms and developing an active microfluidic environment to inhibit the initial bacterial settlement process. In general, microtopography equivalent to that of bacterial cells influences attachment via hydrodynamics, topography-induced cell placement, and air-entrapment, whereas nanotopography influences physicochemical forces through macromolecular conditioning.
The conversion of low-value plastic waste into high-value products such as carbon nanomaterial is of recent interest. In the current study, the non-condensable pyrolysis gases, produced from ...Polypropylene Copolymer (PPC) feedstock, was converted into bamboo-type carbon nanotubes (BCNTs) through catalytic chemical vapour deposition using biochar. Experiments were conducted in a three-zone furnace fixed bed reactor, where PPC was pyrolysed in the second zone and carbon nanotubes (CNTs) growth was eventuated in the third zone. The effects of different growth temperatures (500, 700, 900 °C) and biochar particle sizes (nanoparticle as well as 0–100 and 100–300 μm) were investigated to optimise the production of hydrogen and the yield of carbon nanotubes on the biochar surface. Biochar samples used in the synthesis of CNTs were obtained from the pyrolysis of saw dust at 700 °C in a muffle furnace. Analyses performed by using Scanning electron microscopy, Transmission electron microscopy, X-ray diffraction, and Raman spectroscopy techniques suggested that the best crystalline structure of CNTs were obtained at 900 °C with nano-sized biochar as a catalyst. The strong gas-solid contact and void fraction of nano-sized particles enhances the diffusion–precipitation mechanism, leading to the growth of CNTs. The nano-sized biochar increased hydrogen production at 900 °C and reduced the polycyclic aromatic hydrocarbons content in oil to only 1%, which is advantageous for further utilisation. Therefore, the production of high-value CNTs from waste plastic using low-cost biochar catalyst can be a sustainable approach in the management of waste plastic while participating in the circular economy.
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•Carbon nanotubes were produced from waste plastic using low-cost biomass-derived biochar.•Carbon deposition at 900 °C for biochar nanoparticles was 15.6 times higher than 500 °C.•Carbon deposition increased by ∼66% for nanoparticle biochar compared to 100–300 μm at 900 °C.•Biochar nanoparticles significantly reduced polycyclic aromatic hydrocarbons in oil.•Synthesis of carbon nanotubes from waste plastic can be a sustainable route of circular economy.
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•Pre-treatment severity greatly affected delignification and oak wood dissolution.•Oak wood dissolution in IL occurred through diffusion in the early stage.•The later stage of ...dissolution was governed by surface chemical reaction.•Activation energy of first and later stage was ~ 24.2 and 40.3 kJ/mol, respectively.•The developed mass transfer correlation was well fitted with experimental value.
Lignocellulosic biomass processing employing ionic liquids is of recent research interest for the biorefinery industry. The data on biomass dissolution kinetics in ionic liquids is important for designing scale-up pre-treatment reactor design. In this study, the reaction mechanism and kinetics of oak wood dissolution in aqueous choline chloride was investigated. In an extended effort, a correlation of dimensionless numbers was developed for the estimation the mass transfer coefficient. The analyses suggested that oak wood dissolution in choline chloride occurred in two stages. The diffusion of ionic liquid through the product layer was the dominating rate-controlling step in the first stage of dissolution followed by the surface chemical reaction in the second stage. The diffusivity of choline chloride into the oak wood matrix was ranging between 2.96E−14 and 2.84E−13 m2/s. The activation energy of the diffusion controlled stage and surface chemical reaction controlled stage was approximately 24.2 and 40.3 kJ mol−1, respectively. The proposed mathematical correlation for mass transfer coefficient fitted well with the experimental mass transfer coefficient values.
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