Showing papers by "Joydeep Dutta published in 2019"

Visible light photocatalytic degradation of microplastic residues with zinc oxide nanorods

Abstract: Microplastics have recently become a major environmental issue due to their ubiquitous distribution, uncontrolled environmental occurrences, small sizes and long lifetimes. Actual remediation methods include filtration, incineration and advanced oxidation processes such as ozonation, but those methods require high energy or generate unwanted by-products. Here we tested the degradation of fragmented, low-density polyethylene (LDPE) microplastic residues, by visible light-induced heterogeneous photocatalysis activated by zinc oxide nanorods. The reaction was monitored using Fourier-transform infrared spectroscopy, dynamic mechanical analyser and optical imaging. Results show a 30% increase of the carbonyl index of residues, and an increase of brittleness accompanied by a large number of wrinkles, cracks and cavities on the surface. The degree of oxidation was directly proportional to the catalyst surface area. A mechanism for polyethylene degradation is proposed.

Introduction to Nanoscience

Abstract: Perspectives Introduction Nanoscience and Nanotechnology-The Distinction Historical Perspectives Advanced Materials Tools of Nano Nature's Take on Nano and the Advent of Molecular Biology The Nano Perspective Societal Implications of Nano Introduction to Societal Issues Ethical Implications Legal Implications Environmental Implications Public Perception Future of Nanotechnology Nanotools Characterization Methods Characterization of Nanomaterials Electron Probe Methods Scanning Probe Microscopy Methods Spectroscopic Methods Nonradiative and Nonelectron Characterization Methods Fabrication Methods Fabrication of Nanomaterials Top-Down Fabrication Bottom-Up Fabrication Computational Chemistry and Molecular Modeling Physics: Properties and Phenomena Materials, Structure, and the Nanosurface Importance of the Surface Engineering Materials Particle Shape and the Surface Surface and Volume Atomic Structure Particle Orientation Energy at the Nanoscale Surface Energy Basic Thermodynamics Liquid State Surface Energy (and Stress) of Solids Surface Energy Minimization Mechanisms The Material Continuum Material Continuum Basic Quantum Mechanics and the Solid State Zero-Dimensional Materials One-Dimensional Materials Two-Dimensional Materials Hierarchical Structures Quantum Size Effects and Scaling Laws Nanothermodynamics Thermodynamics and Nanothermodynamics Classical Equilibrium Thermodynamics Statistical Mechanics Other Kinds of Thermodynamics Nanothermodynamics Modern Nanothermodynamics Chemistry: Synthesis and Modification Carbon-Based Nanomaterials Carbon Fullerenes Carbon Nanotubes Diamondoid Nanomaterials Chemical Interactions at the Nanoscale Bonding Considerations at the Nanoscale Electrostatic Interactions Hydrogen Bonding Van der Waals Attractions Hydrophobic Effect Supramolecular Chemistry Chemistry of Nanomaterials Supramolecular Chemistry Design and Synthesis of Selected Supramolecular Species Extended Supramolecular Structures Chemical Synthesis and Modification of Nanomaterials Chemistry and Chemical Modification Self-Assembly Revisited Synthesis and Chemical Modification of Nanomaterials Template Synthesis Polymer Chemistry and Nanocomposites Natural and Bionanoscience Natural Nanomaterials Natural Nanomaterials Inorganic Natural Nanomaterials Nanomaterials from the Animal Kingdom Nanomaterials Derived from Cell Walls Nanomaterials in Insects Gecko Feet: Adhesive Nanostructures More Natural Fibers Summary Biomolecular Nanoscience Introduction to Biomolecular Nanoscience Material Basis of Life Cellular Membranes and Signaling Systems DNA, RNA, and Protein Synthesis Concluding Remarks

Chlorination disadvantages and alternative routes for biofouling control in reverse osmosis desalination

Abstract: With an ever-increasing human population, access to clean water for human use is a growing concern across the world. Seawater desalination to produce usable water is essential to meet future clean water demand. Desalination processes, such as reverse osmosis and multi-stage flash have been implemented worldwide. Reverse osmosis is the most effective technology, which uses a semipermeable membrane to produce clean water under an applied pressure. However, membrane biofouling is the main issue faced by such plants, which requires continuous cleaning or regular replacement of the membranes. Chlorination is the most commonly used disinfection process to pretreat the water to reduce biofouling. Although chlorination is widely used, it has several disadvantages, such as formation of disinfection by-products and being ineffective against some types of microbes. This review aims to discuss the adverse effect of chlorination on reverse osmosis membranes and to identify other possible alternatives of chlorination to reduce biofouling of the membranes. Reverse osmosis membrane degradation and mitigation of chlorines effects, along with newly emerging disinfection technologies, are discussed, providing insight to both academic institutions and industries for the design of improved reverse osmosis systems.

Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications

Abstract: Worldwide, millions of tons of crustaceans are produced every year and consumed as protein-rich seafood. However, the shells of the crustaceans and other non-edible parts constituting about half of ...

Enhanced Visible Light Photodegradation of Microplastic Fragments with Plasmonic Platinum/Zinc Oxide Nanorod Photocatalysts

Abstract: Microplastics are persistent anthropogenic pollutants which have become a global concern owing to their widespread existence and unfamiliar threats to the environment and living organisms. This stu ...

Dynamic Langmuir Model : A Simpler Approach to Modeling Capacitive Deionization

Abstract: Capacitive deionization (CDI) is emerging as an environment-friendly and energy-efficient water desalination option for meeting the growing global demand for drinking water. It is important to deve ...

An Easy-to-Use Tool for Modeling the Dynamics of Capacitive Deionization.

Abstract: Capacitive deionization is an emerging method of desalinating brackish water that has been presented as an alternative to the widely applied technologies such as reverse osmosis However, for the technology to find more widespread use, it is important not only to improve its efficiency but also to make its modeling more accessible for researchers In this work, a program has been developed and provided as an open-source with which a user can simulate the performance of a capacitive deionization system by simply entering the basic experimental conditions The usefulness of this program was demonstrated by predicting how the effluent concentration in a continuous-mode constant-voltage operation varies with time, as well as how it depends on the flow rate, applied voltage, and inlet ion concentration Finally, the generality of the program has been demonstrated using data from reports in the literature wherein various electrode materials, cell structures, and operational modes were used Thus, we conclude that the model, termed the dynamic Langmuir model, could be an effective and simple tool for modeling the dynamics of capacitive deionization

Plasmonic Photocatalyst Design: Metal-Semiconductor Junction Affecting Photocatalytic Efficiency.

Abstract: Silver-zinc oxide nanorods (Ag-ZnO NRs) and gold-zinc oxide nanorods (Au-ZnO NRs) plasmonic photocatalysts were fabricated by the deposition of Ag and Au nanoparticles on ZnO NRs. The photocatalyst ...

Chlorination disadvantages and alternative routes for biofouling control in reverse osmosis desalination (vol 2, 2, 2019)

Abstract: Chlorination disadvantages and alternative routes for biofouling control in reverse osmosis desalination (vol 2, 2, 2019)

Nanocomposite functionalized membranes based on silica nanoparticles cross-linked to electrospun nanofibrous support for arsenic(V) adsorption from contaminated underground water

Abstract: Fil: Yohai del Cerro, Lucia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingenieria. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales; Argentina

Low-Cost Integrated Zinc Oxide Nanorod-Based Humidity Sensors for Arduino Platform

Abstract: Realization of a simple integrated and low-cost intensity modulation/direct detection-based humidity and vapor detection system utilizing zinc oxide (ZnO) nanorods as the active material is demonstrated. The sensing device comprises of ZnO nanorods optimally grown on a glass substrate and mounted on 3D printed platform for the alignment with a green light-emitting diode setup for an edge excitation. An Arduino platform was used for the signal processing of the detection of the transmitted light. Both forward and backward scattering are affected due to light leakage while propagating through the glass substrate which are further attenuated in the presence of humidity. In this paper, backward scattering was found to be dominant, and thus, with increasing humidity, a reduction in the transmitted light was monitored. When the sensor was tested in a humidity controlled environment, it was found that the output voltage drops by approximately 750 mV upon changing the relative humidity (RH) level from 35% to 90% in a non-linear fashion. The average sensitivity of the sensor was observed to be −12 mV/% throughout the tested RH levels. Sensitivity was found to be higher at −24.6 mV/% for RH’s beyond 70%. An average response time of 3.8 s was obtained for RH levels of 85% with respect to the standard ambient humidity conditions (RH 50%), which showed a quicker recovery time of 2.2 s. The proposed sensor device provides numerous advantages, including low-cost production, simplicity in design, ease of use, and stability during handling.

Graphene Oxide/Polyethylene Glycol-Stick for Thin Film Microextraction of β-Blockers from Human Oral Fluid by Liquid Chromatography-Tandem Mass Spectrometry.

Abstract: A wooden stick coated with a novel graphene-based nanocomposite (Graphene oxide/polyethylene glycol (GO/PEG)) is introduced and investigated for its efficacy in solid phase microextraction techniques. The GO/PEG-stick was prepared and subsequently applied for the extraction of β-blockers, acebutolol, and metoprolol in human oral fluid samples, which were subsequently detected by liquid chromatography tandem mass spectrometry (LC-MS/MS). Experimental parameters affecting the extraction protocol including sample pH, extraction time, desorption time, appropriate desorption solvent, and salt addition were optimized. Method validation for the detection from oral fluid samples was performed following FDA (Food and Drug Administration) guidelines on bioanalytical method validation. Calibration curves ranging from 5.0 to 2000 nmol L−1 for acebutolol and 25.0 to 2000 nmol L−1 for metoprolol were used. The values for the coefficient of determination (R2) were found to be 0.998 and 0.996 (n = 3) for acebutolol and metoprolol, respectively. The recovery of analytes during extraction was 80.0% for acebutolol and 62.0% for metoprolol, respectively. The limit of detections (LODs) were 1.25, 8.00 nmol L−1 for acebutolol and metoprolol and the lower limit of quantifications (LLOQ) were 5.00 nmol L−1 for acebutolol and 25.0 nmol L−1 for metoprolol. Validation experiments conducted with quality control (QC) samples demonstrated method accuracy between 80.0% to 97.0% for acebutolol and from 95.0% to 109.0% for metoprolol. The inter-day precision for QC samples ranged from 3.6% to 12.9% for acebutolol and 9.5% to 11.3% for metoprolol. Additionally, the GO/PEG-stick was demonstrated to be reusable, with the same stick observed to be viable for more than 10 extractions from oral fluid samples.

Antifouling properties of chitosan coatings on plastic substrates

Abstract: In the current study, chitosan coatings were fabricated on plastic substrata and investigated for their antifouling activities. Scanning Electron Microscopy (SEM) and water contact angle measurement (WCA) of the fabricated chitosan films showed smooth and hydrophilic surface with WCA below 60°. Chitosan coating on plastic substrate showed 88% reduction in settlement of bryozoan Bugula neritina larvae compare to the control after 3 hours incubation in dark conditions with no larval mortality during the experiment. The antimicrobial activity of chitosan was evaluated by coating of plastic panels with the prepared chitosan solution and immersing the coated samples in seawater with controlled environmental conditions. Biofilms scraped from immersed chitosan coated panels showed no bacteria after 1 week immersion. After the second week of immersion, less than 1500 bacteria/mm 2 was observed on the chitosan-coated panels compared to more than 10 5 bacteria/mm 2 on uncoated ones. Thus, this study prove the efficiency of chitosan coatings against micro- and macro-fouling.

Electrochemical Parameters of Aluminum Oxide Film in Situ During Anodization of Aluminum by White Light-Optical Interferometry

Abstract: Both of Fabry-Perot interferometry and the DC electrochemical method have been simultaneously used for the first time to measure in situ the anodic current density (J) of aluminum oxide films in 0, ...