INTERNATIONAL SYMPOSIUM ON NANOTECHNOLOGY FOR SUSTAINABLE DEVELOPMENT

To date, numerous studies have been focused on the self-assembly of petroleum-based block copolymer systems for potential applications in multidisciplinary fields, such as nano-organized films for biosensors, or nanolithography, etc. Such materials are derived from fossil resources that are being rapidly depleted and have negative environmental impacts. In contrast, carbohydrates are abundant, renewable and constitute a sustainable source of materials. This is currently attracting much interest in various sectors and their industrial applications at the nanoscale level will have to expand quickly in response to the transition to a bio-based economy. The self-assembly of carbohydrate BCP systems at the nanoscale level via the bottom-up approach, has allowed only recently the conception of very high-resolution patterning (thin films with sub_10nm resolution) that has never been attained to date by petroleum-based molecules and provides these new materials with novel properties such as: New generation of Nanolithography, Memory devices, OPV, high resolution Biosensors. We will present recent results on the self-assemblies of carbohydrate-based block copolymer leading to highly nanostructured thin films (sub-10nm resolution) using DSA approach in combination of solvent and/or thermal annealing as well as new and ultra-fast microwave “cooking” approach”.(1-6)

High resolution X-ray diffractometry is the primary structural method used in the investigations of epitaxial layers and structures. In high resolution configuration a 4-bounce Ge(220) Bartels monochromator gives an incidence beam divergence of 12 arcsec. In the diffracted beam path, open detector configuration is used for rocking curves (RC) measurements or triple-axis analyser crystal before the detector is used for reciprocal lattice maps (RLM) measurements. Such configurations allow investigations of the single crystals semiconductor structures including: low-dimensional quantum well (QW), quantum dots (QDs) of lasers, LEDs and solar cells structures. The analysis of the results such as RC and RLM allow determination of the basic parameters of the structure: thickness and composition of the layers, degree of relaxation, lattice parameters, size of crystalline blocks and mosaicity of the highly mismatched structures but also dislocations density and strain in the epitaxial layers. In such analysis the main problem is the measurement of planes perpendicular to the sample surface. In standard XRD configuration it is practically impossible to measure such planes for such highly oriented samples. In order to avoid this problem, planes with a large inclination angle, (e.g. over 60 deg) are investigated using the skew geometry. The application of measurements carried out from the edge of the sample allows analysis of such structures, above all, spatial separation of the effects shown in the investigation results. In particular, it allows independently determination of the lattice parameter perpendicular to the growth direction, separation of tilt and twist mosaicity [1], calculation of the edge dislocations density [2] or residual strains in the structure. Furthermore, such type of measurements reveals the difference in lattice parameters of the specific layers [3], which are not always visible with conventional measurements performed from the surface of the sample. This type of measurements were developed in Structural Research Laboratory in Wroclaw University of Science and Technology and has been used in the analysis of epitaxial structures - mainly mismatched III-N materials like (Ga, Al)N, low dimensional structures (QW and QDs) of the III-V materials but also (Zn,Cd)Te superlattices.

Tuning the nanoparticle features by doping iron impurities is an interesting field. It provides a tool for structural and optical characteristics controlling for the material. PVA/PbS nanoparticles synthesized by chemical bath route in the presence of PVA polymer as jell bed stabilizer them Sn and Ag ions injected in material as impurities. Prepared samples investigated by XRD and TEM for criticality and morphology proofing, which were in agreement with each other. Optical spectroscopy of nanocomposites studied by Uv-Vis (300-900 nm) range absorption spectra and by using tach relation bandgap of samples was measured that was obviously a semiconductor (around 2.3-2.8 eV). Studying followed by photoluminescence spectroscopy (PL), we saw in this case for both impurities PL quenched by doping. Nonlinear measurements were done by Z-scan technique with a He-Ne CW laser by 632.8 nm wavelength beam focused by 150mm focal length lens was used for exciting samples which led to thermal nonlinearity mechanism. For nonlinear refractive index and nonlinear absorption, self-focusing and saturable absorber attribute were observed respectively. n2 and β were from the order of 10-9 and 10-3, respectively.

“The world needs to act fast to avoid catastrophe effect on earth”, suggested by the IPCC 2021 report on climate change. It’s a code red for humanity to survive, evidenced by the recent extreme heatwaves, unusual floods, droughts and rise in temperature. The only possible way to stop this by being sustainable in human activities at home, public places, Institutions and at industry. Most of the time, human and industrial activities affect the environment due to large scale and commercial activities. Suppose the precursors are environmentally friendly in chemical industries. In that case, the manufacturing technique and end use of the product can be sustainable, and it can play a significant role in reducing the carbon footprint. The surge in the sustainable synthesis of nanomaterials and methods is recognized in the last couple of years.
In this talk, I will present promising results in graphene synthesis with the help of natural surfactants. The quality of the nanosheets produced is on par and above the quality of commercial samples. The major problem with reported and commercial surfactants resources is its inability to produce micron-sized graphene with fewer defects, a minimal amount of surfactant, and less toxicity [1-2].
After analyzing the samples with electron microscopy and Raman spectroscopy techniques, we found that nanosheets are defect-free, transparent, thin, and laterally with micron-sized dimensions. Exfoliated graphene is impregnated in low-density polyurethane (PU) foam with open-shell structures and demonstrated for strain sensor and oil-water separation applications. In addition, naturally occurring clay minerals are potential 3D precursors with wide varying thermal properties [3].
Our results stress that natural surfactants are feasible and reliable to produce high-quality graphene and 2D materials, essential in sustainable and scalable manufacturing technologies.

“The world needs to act fast to avoid catastrophe effect on earth”, suggested by the IPCC 2021 report on climate change. It’s a code red for humanity to survive, evidenced by the recent extreme heatwaves, unusual floods, droughts and rise in temperature. The only possible way to stop this by being sustainable in human activities at home, public places, Institutions and at industry. Most of the time, human and industrial activities affect the environment due to large scale and commercial activities. Suppose the precursors are environmentally friendly in chemical industries. In that case, the manufacturing technique and end use of the product can be sustainable, and it can play a significant role in reducing the carbon footprint. The surge in the sustainable synthesis of nanomaterials and methods is recognized in the last couple of years.
In this talk, I will present promising results in graphene synthesis with the help of natural surfactants. The quality of the nanosheets produced is on par and above the quality of commercial samples. The major problem with reported and commercial surfactants resources is its inability to produce micron-sized graphene with fewer defects, a minimal amount of surfactant, and less toxicity [1-2].
After analyzing the samples with electron microscopy and Raman spectroscopy techniques, we found that nanosheets are defect-free, transparent, thin, and laterally with micron-sized dimensions. Exfoliated graphene is impregnated in low-density polyurethane (PU) foam with open-shell structures and demonstrated for strain sensor and oil-water separation applications. In addition, naturally occurring clay minerals are potential 3D precursors with wide varying thermal properties [3].
Our results stress that natural surfactants are feasible and reliable to produce high-quality graphene and 2D materials, essential in sustainable and scalable manufacturing technologies.

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