Environmental Friendly Materials Research Articles

Carbonization of golden shower pods to high surface area biochar for decontamination of cationic dyes and regeneration study by gamma radiations

Detoxification of water resources is the need of the hour and a number of environment friendly materials are proposed by scientist to deal with water pollution issues. The present study deals with preparation and characterization of porous activated carbon from golden shower pods, a waste ligno-cellulosic biomass, for the removal of dye contaminants from aqueous solution. The synthesized material, golden shower biochar (GSBC) was characterized using various analytical techniques to confirm the presence of active sites. The BET analysis of GSBC revealed high surface area of 1120 m2/g with total pore volume of 1.099 cm3/g and average pore radius 19.618 Å. Operational parameters were optimized using batch studies by taking GSBC dose of 50 mg which showed complete removal of target dyes with an initial dye concentration of 200 mg/L with just 60 min interaction time; based on these results, a fixed bed column of GSBC was designed and column studies were performed. Adsorption isotherm studies were carried out using Langmuir and Freundlich models, of which Langmuir model was found to be best-fit with maximum adsorption capacities of 208.86 mg/g, 284.35 mg/g and 327.56 mg/g for Crystal violet, Brilliant green and Methylene blue dyes respectively. Analysis of kinetics and thermodynamics revealed that the best-fit model was pseudo second-order with spontaneous reaction course and exothermic nature. Regeneration was carried out using gamma irradiation of dye loaded GSBC, followed by leaching in alcohol. It was observed that a 30 KGy dose was just sufficient to completely degrade the dye on the adsorbent surface. GSBC has shown immense potential for eradication of dyes from water effluents and it is easily recovered with negligible loss in efficacy.

Hydroxyapatite Derived from Eggshell Embedded on Functionalized g-C3N4 for Synergistic Extraction of U(VI) from Aqueous Solution

In this paper, we report hydroxyapatite derived from egg-shell biowaste embedded on diglycolamic acid functionalized graphitic carbon nitride nanocomposite (abbreviated as HAp@D-gCN). The compositional and morphological characteristics of HAp@D-gCN were evaluated using scanning electron microscopy, X-ray diffraction, BET, FTIR techniques and surface charge using zeta potential measurement. The sorption of U(VI) species on HAp@D-gCN was investigated through batch studies as a function of pH, contact time, initial U(VI) concentration, adsorbent dosage and ionic strength. The adsorption of U(VI) onto HAp@D-gCN was confirmed by FTIR, XRD and EDS elemental mapping. Adsorption kinetics follows pseudo second order model and it attains equilibrium within 20 minutes. Adsorption isotherm data correlates well with Langmuir isotherm model with a maximum sorption capacity of 993.06 mg g−1 at 298K. U(VI) can be leached from the loaded adsorbent using 0.01 M Na2CO3 as desorbing agent and its sorption capacity remains unaffected even after 4 adsorption-desorption cycles. Hence, the present study reveals that HAp@D-gCN nanocomposite could serve as an environmental friendly material with potential application in environmental remediation.

A biodegradable ZnFe2O4/PLLA electrospun fibers based longitudinal mode piezoelectric membrane for health monitoring

Recently, multifunctional sensors based on piezoelectric active film fabricated with environmental friendly materials is a nascent field which can address the growing concern of electronic waste. Nevertheless, frequently utilized poly(vinylidene fluoride) (PVDF) and poly(L-lactic acid) (PLLA) encounter challenges of limited biocompatibility and weak piezoelectricity with low shear piezoelectric coefficient (d14), respectively. Accordingly, a biodegradable piezoelectric sensor comprising of PLLA nanofiber blended with ZnFe2O4 nanoparticles was developed in this work. The ZnFe2O4 nanoparticles served as heterogeneous nucleation center leading to improved piezoelectric coefficient and output than pure PLLA due to more consistent orientation of CO dipoles. The ZnFe2O4/PLLA film exhibited significant performance improvement featured with 1.7-fold higher longitudinal piezoelectric coefficient (d33 ∼ 6.5 ± 0.3 pm/V), nearly 250 % boosting on the output voltage. The ZnFe2O4/PLLA piezoelectric sensor induced high sensitivity (2–10 N:0.55 V/N; 10–32 N:0.29 V/N) and excellent mechanical stability for 27,000 cycles. The results of the soil burial experiment demonstrate that the film can degrade by over 75 % within 90 days, confirming its excellent biodegradability. Moreover, the ZnFe2O4/PLLA nanofibers based piezoelectric sensor could serve as effective detection evidenced by different output signals of head motion, pulse and artery beating demonstrating its feasible application for health monitoring. Considering the characteristics of straightforward fabrication and readily accessible sustainable materials, the ZnFe2O4/PLLA sensor provides an appealing eco-friendly solution for self-powered flexible personal devices disregarding the need to dispose of electronic waste.

Biodegradable chitosan hydrogel film incorporated with polyvinyl alcohol, chitooligosaccharides, and gallic acid for potential application in food packaging

AbstractThe food and beverage industry worldwide is trying to switch to using environment-friendly and bio-degradable materials in food packaging to avoid environmental concerns of using petroleum-derived plastic (synthetic polymers) materials. In this study, chitosan (CH) hydrogel films were fabricated by using its derivative chitooligosaccharides (COS) as an additive, polyvinyl alcohol as a plasticiser, and bioactive gallic acid as a cross-linker. The physical, mechanical, structural, barrier (e.g., moisture, water vapour permeability (WVP), and UV-barrier property), thermal properties, and biodegradation patterns of fabricated films were investigated. The use of bio–composite in CH films exhibited a synergistic effect. A film with a homogenous/smooth surface and excellent mechanical and thermal properties was obtained. Additionally, incorporating COS and gallic acid reduced the moisture content, WVP, and transparency. Moreover, the films exhibited good colour, strong UV-barrier properties, and good biodegradable capacity in soil. The results suggest that eco-friendly CH hydrogel films have promising potential to be used in food packaging.

Aromatic copolyesters with tunable dielectric and thermal properties enabled by aryl building blocks

Polymer dielectric materials in high-frequency communication applications needs to meet strict requirements, and the future development trend is high performance and environmental friendly materials. Herein, we propose a design strategy for simultaneously adjusting multiple performances by building blocks (naphthyl, diphenyl ether, and phenyl). The synthesized copolyester containing phenylene ether structures exhibits good comprehensive properties, including high thermal stability (the temperature at 5 wt% weight loss, 475–495 °C) and inherent flame retardancy (limiting oxygen index 37.8 %∼40.1 %, UL-94 V-0 level), low water absorption (0.16 %∼0.46 %), low dielectric constant (3.04–3.31 @10 GHz) and low dielectric loss (0.0020–0.0028 @10 GHz). The crankshaft naphthyl and bent diphenyl ether structures together change the free volume or spacing of polymer chains, thereby effectively affecting the density or motility of the polarizable groups. These aromatic structures also possess high charring-ability, thus enabling the polymers with the inherent high flame retardancy. Since only carbon, hydrogen, and oxygen elements are introduced into the copolyesters, it supplies a solving approach to eliminate the potential chemical concern arising from introducing heteroatoms such as halogen or phosphorus into polymers.

Ferroelectric and Relaxor-Ferroelectric Phases Coexisting Boosts Energy Storage Performance in (Bi0.5Na0.5)TiO3-Based Ceramics.

With the intensification of the energy crisis, it is urgent to vigorously develop new environment-friendly energy storage materials. In this work, coexisting ferroelectric and relaxor-ferroelectric phases at a nanoscale were constructed in Sr(Zn1/3Nb2/3)O3 (SZN)-modified (Bi0.5Na0.5)0.94Ba0.06TiO3 (BNBT) ceramics, simultaneously contributing to large polarization and breakdown electric field and giving rise to a superior energy storage performance. Herein, a high recoverable energy density (Wrec) of 5.0 J/cm3 with a conversion efficiency of 82% at 370 kV/cm, a practical discharged energy density (Wd) of 1.74 J/cm3 at 230 kV/cm, a large power density (PD) of 157.84 MW/cm3, and an ultrafast discharge speed (t0.9) of 40 ns were achieved in the 0.85BNBT-0.15SZN ceramics characterized by the coexistence of a rhombohedral-tetragonal phase (ferroelectric state) and a pseudo-cubic phase (relaxor-ferroelectric state). Furthermore, the 0.85BNBT-0.15SZN ceramics also exhibited excellent temperature stability (25-120 °C) and cycling stability (104 cycles) of their energy storage properties. These results demonstrate the great application potential of 0.85BNBT-0.15SZN ceramics in capacitive pulse energy storage devices.

Degradable, self-healing, humidity-driven poly(urethane-urea) film

Humidity-driven materials are widely used in actuators, soft robots, sensors, and other fields. The extensive use of these materials increases the demand for degradable, highly durable, and self-healing materials. However, the preparation of such ideal materials still faces serious challenges. Herein, a novel poly(urethane-urea) film material (PUU-DHA-Cu4) with synergetic quadruple dynamic bonds (acylhydrazone bonds, boron-oxygen bonds, coordination bonds, and hydrogen bonds) is developed. The prepared PUU-DHA-Cu4 film material exhibited a tensile strength of 23.2 MPa, an elongation at break of 1142 %, and a healing efficiency of 90.1 % after 48 h of self-healing at room temperature. Meanwhile, the reversibility of the boron-oxygen bond imparts degradability to the material. Finally, a humidity-driven poly(urethane-urea) material that not only has self-healing ability but can also be degraded easily was successfully developed. This work will make a valuable addition to the field of environment-friendly humidity-driven materials.

Development and characterisation of agar/silver nanoparticles-based film from Gracilaria canaliculata for food packaging

Gracilaria canaliculata was used as a novel source to extract agar, and for the green synthesis of silver nanoparticles. Silver nanoparticles (0.1 - 0.3%) were incorporated into the agar matrix to develop an environment-friendly food packaging material using the solution casting method. The concentration of nanoparticles affected the physical, thermal, and mechanical properties of the films. Films containing higher concentrations of silver nanoparticles exhibited promising properties, and demonstrated strong antimicrobial activity against both Gram-negative and Gram-positive foodborne pathogens. The film formulation exhibited no cytotoxic effect on HepG2 cells, with cell viability exceeding 94%. These findings suggested that the film possessed favourable characteristics for use as a food packaging material, presenting a potential alternative to plastics.

Recent progress in research and development of rare-earth free iron nitride permanent magnet

The high cost of rare earth materials, unstable supply and high demand remain big problems to solve for permanent magnet industries. Thus α″-Fe<sub>16</sub>N<sub>2</sub> has been picked up as one of the most promising rare earth-free magnet candidates because of its use of environmental-friendly raw materials, confirmed giant saturation magnetic flux density (2.9 T), and reasonably high magnetic anisotropy constant (1.8 MJ/m<sup>3</sup>). Also, α”-Fe<sub>16</sub>N<sub>2</sub> metastable with film form exhibits high tetragonality (c/a=1.1) by interstitial introduction of N atoms, leading to a high magnetocrystalline anisotropy constant (K<sub>u</sub> = 1.0 MJ/m<sup>3</sup>). but synthesis of bulk form has lower properties than thin film (<230 nm) because of magnetic interaction, experimentally low anisotropy, and low density. In this paper, we review the synthetic methods of metastable α”-Fe<sub>16</sub>N<sub>2</sub> with powder and bulk form and discuss the approaches to enhance magnetocrystalline anisotropy of α”-Fe<sub>16</sub>N<sub>2</sub>.

Water-born polyurethane dispersions, containing polysaccharide in their structure

A method of obtaining waterborn polyurethane dispersions containing the natural polysaccharide starch, stable over time and when diluted with water, has been developed by introducing an aqueous solution of starch into the reaction system with a combination of the chain elongation stage and the dispersion process, which is manifested in the high aggregative stability of the dispersions and the ability to form monolithic films, in contrast to mechanical mixtures. Materials acquire the ability to degrade in environmental conditions while maintaining the properties inherent in traditional ionomer polyurethanes. The use of the created method opens up opportunities for the creation of environmental-friendly materials with a given set of properties, promising as physiologically active materials for agriculture, in particular antiperspirants, phytoprotective and growth stimulating materials.

Properties of multi-solid waste cementitious materials for highly efficient indoor formaldehyde degradation via response surface method

The environment-friendly cementitious materials with efficient indoor formaldehyde degradation properties (PRCS) were prepared by using slag to supplement the percentage of silica and aluminium in the phosphogypsum (PG)-red mud (RM) system, cement as an activator, and activation through the sulphate component in PG. PG-MnO2, a component of PRCS, was obtained by redox of potassium permanganate with PG as the carrier. The mechanism of formaldehyde degradation on PG-MnO2 was analyzed by catalytic model fitting, the multi-objective optimization of PRCS was achieved using response surface methodology (RSM), and the hydration products and microstructure of PRCS were characterized. The results show that the maximum compressive strength of PRCS can reach 26.02 MPa (7 days) and 35.13 MPa (28 days), respectively. The response surface model can be effectively used to simulate the compressive strength of PRCS since the experimental results of the best fitting ratio are close to the predicted results. PRCS achieves an initial 84 % degradation of formaldehyde through adsorption and surface active sites, and maintains 63 % efficiency after five degradation cycles. Also, there is no risk of heavy metal ion leaching.

Investigation of physical and electrical properties of a suboxide layer at Si/Si-hexafluoride interface

The silicon suboxide SiOx (x < 2.0) offers promising industrial application possibilities ranging from electrodes in lithium-ion batteries, which are used widely in electrical vehicles and portable devices to sensing applications. Therefore, a low cost, environmental friendly and high performance silicon oxide materials are required for an appropriate operation of any electronic gadget. In this work, we report on the physical and electrical properties of a suboxide layer of up to 1 μm, which was grown on silicon during the formation of a dielectric layer, namely the ammonium silicon hexafluoride. It is a stable oxide exhibiting light emission from 400 to 1700 nm offering scalable and cost-effective large area processing capability. The measurement results reveal interesting properties, which are required to be understood clearly before proceeding with any suitable application. The results have been analyzed using state-of-the-art physical and electrical characterization techniques such as ellipsometry, AFM, SEM, FTIR, photoluminescence lifetime and resistive switching measurements to determine structural, optical and electrical properties. At 300 K the carrier lifetime measurements reveal the lifetime values ranging from about few tens of picosecond up to 4500 picoseconds. Scanning probe analysis indicate a surface roughness of about 30 Å. Resistive memory forming was observed also in these layers at relatively low power thresholds. We provide a comprehensive description of the physical and electrical properties in order to clarify the origin of the observed features. The wavelength dependent real ε1(ω)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varepsilon }_{1}(\\omega )$$\\end{document} and the imaginary ε2ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varepsilon }_{2}\\left(\\omega \\right)$$\\end{document} dielectric functions provided useful insights on optical properties. A lookout is given for the possible applications of this special SiOx dielectric oxide layer.

A Study of Optical Properties of Edible Film based Coconut Water for Sustainable and Environmentally Friendly Materials Packaging

A Study of Optical Properties of Edible Film based Coconut Water for Sustainable and Environmentally Friendly Materials Packaging

Enhanced energy-storage performance with optimized thermally stable dielectric property in BNT–BST ceramics modified by KNN doping

Developing environmental-friendly materials with high-density energy storage is of paramount importance to meet the burgeoning demands for energy storage. In this study, we harness the modulation of a multicomponent solid solution by introducing KNN as a third element into the BNT–BST system, thereby achieving a marked enhancement in both energy storage performance and the temperature stability of the dielectric constant. BNBST–4KNN stands out for its exceptional dielectric stability, with a dielectric constant variation rate within 10% across a broad temperature range of [Formula: see text]C to [Formula: see text]C, a feat attributed to the flattening and broadening of the [Formula: see text] peak. BNBT–2KNN exhibits superior energy storage capabilities, with an energy storage density of 1.324 J/cm3 and an energy storage efficiency of 72.3%, a result of the P–E loop becoming more slender. These advancements are pivotal for the sustainable progression of energy storage technologies.

Analysis and Assessment of H2S Sorption Capacity of the Selected Biofiltration Materials

Hydrogen sulfide known as one of the highly toxic chemical compounds existed in the raw biogas and needs to be eliminated before implementation at any industrial sector. Biofilter (a typical bioreactor) is a tool used to separate sulfide/sulfate from hydrogen by biofiltration method, which is known as the green technology. Packing material is the main component inside a laboratory-scale biofilter to undertake the desulfurization process of H2S. This study is dedicated to evaluating number of selected recyclable/waste organic, inorganic, and synthetic packing material’s rate of impact on amplifying purification progress of hydrogen sulfide from biogas, known as biofilters “removal efficiency (RE)”. Variable effective factors such as environmental and equipment conditions, consumed time (day), and inlet H2S concentration will be controlled throughout the measurements for all chosen packing materials. In the end, the best performed environment-friendly biofiltration material in terms of sorption capacity of H2S from the biogas will be announced.

The Effect of Using Environmentally Friendly Materials and Energy Efficiency in the Production Process on Reducing Carbon Emissions in the West Java Automotive Industry

This research quantitatively analyzes the effect of integrating environmentally friendly materials and energy-efficient production processes on reducing carbon emissions in the West Java automotive industry. Through surveys and statistical analysis, the study examines the adoption of sustainable practices among automotive manufacturers and assesses their impact on carbon emissions reduction. Findings indicate that companies actively embracing sustainable practices demonstrate a significant reduction in carbon emissions compared to those with minimal adoption. The results underscore the importance of prioritizing sustainability initiatives within the automotive industry to mitigate environmental impacts and contribute to global efforts to combat climate change.

The GREENART Project: Environmentally Friendly and Low Impact Materials for the Conservation of Cultural Heritage

ABSTRACT While some green solutions and advanced materials have been proposed in recent decades to improve on traditional conservation processes, conservation practice still uses petroleum-based compounds and procedures that lack time- or energy-efficiency, and are not sustainable. Tackling these issues, the GREENART project (GREen ENdeavor in Art ResToration, Horizon Europe, 2022–2025) is developing green and sustainable systems for the remedial and preventive conservation of works of art, following a ‘safe and sustainable by design’ approach where green components are firstly screened and then used to formulate new materials. This contribution reviews traditional and state-of-the-art materials used in protective coatings, foams and packaging materials, consolidants, cleaning systems, and monitoring tools, and introduces the novel solutions the GREENART project is developing for each of these classes. Some of the new products are already being assessed, and the main processes in the formulation of the solutions are outlined. Life cycle assessment will be carried out before the commercial production of the new systems to demonstrate their full sustainability. Finally, perspectives are discussed, highlighting the role of GREENART in promoting a green transition for cultural heritage preservation.

Polybenzoxazines containing borosiloxane structures as high-temperature resistance (T g > 300 °C) and environment-friendly flame-retardant materials

A series of borosiloxane structures-containing polybenzoxazines (PBZs) with intrinsic environment-friendly flame-retardant properties and high-temperature resistance are investigated in this study. Initially, borosiloxane structures-containing benzoxazine macromonomers (BZ-BSiO-X) were synthesized through a condensation reaction between silicon ethoxy groups-containing benzoxazine monomers (P-mdes), boric acid (BA) and diphenyldimethoxysilane (DPDMS) with varying feed ratios. Subsequently, the benzoxazine groups in BZ-BSiO-X underwent ring-opening polymerization at elevated temperatures to produce poly(BZ-BSiO-X). The properties of poly(BZ-BSiO-X) were evaluated using Dynamic Mechanical Analysis, Thermogravimetric Analysis and an Oxygen Index instrument. The results show that the heat resistance of poly(BZ-BSiO-X) is enhanced by the cross-linking structures formed by the P-mdes segment and B-N coordination interaction, leading to their glass transition temperatures (T g, tan δ) exceeding 300 °C. The thermal stability and flame-retardant properties of poly(BZ-BSiO-X) are reinforced via the borosiloxane structures formed through DPDMS and BA, resulting in a 5% weight loss temperatures (T d5) around 400 °C and limiting oxygen index (LOI) values above 30. These polymers, containing environment-friendly flame-retardant boron (B) and silicon (Si) elements, exhibit potential as alternatives to halogen- or phosphorus-containing flame-retardant materials and are expected to be used in various fields as environment-friendly flame-retardant materials.

Green sound-absorbing material prepared by using natural fiber for building acoustics

Natural fibers are recently seen as a replacement for synthetic fibers as core material to produce sound-absorbent materials. These are biodegradable and renewable, and using them as sound-absorbent material brings many environmental benefits as it is much greener compared to existing inorganic and synthetic fibers. Present exploration serves the purpose of investigation and comparison of the acoustic absorption characteristics of individual and mixed natural fibers; jute, coconut coir, and bamboo. Each fiber is reinforced with natural rubber in a certain weight ratio during the fabricating stage. The fibers are then compressed with the help of mould and ram piston in a hydraulic press. The compression is done in the form of cylindrical samples of 40 mm diameter. Each specimen is kept 36 mm thick, according to the given standards. The impedance tube technique is used to evaluate acoustical performances. Multilayered composites made of layers of coir, jute, and bamboo performed better in all the frequency ranges than composites made of individual fibers. Results establish that these fibers are promising and a viable option for light and environment-friendly sound absorption materials.

Chitosan gels in the nutrient controlled release: a review

The use of slow and controlled release fertilizers (S/CRFs) has been beneficial in enhancing fertilizer utilization and crop yields, improving food security. However, the massive use of conventional S/CRFs has also polluted soil, water, and air, which poses a challenge to the sustainability of modern agriculture. To address this, a more efficient and environmentally-friendly material for crop nutrition is needed. Chitosan gels have proven to be an ideal carrier for nutrient transport given their biodegradability and high adsorption characteristics. This paper reviews the cross-linking of chitosan gels, preparation methods, nutrient transport, and performance, and how they contribute to sustainable agriculture. In addition, we detail the contribution of chitosan gels fertilizers to greenhouse gas reduction, soil conditioning, and crop yield improvement. In conclusion, although further research is needed on chitosan gels fertilizers as S/CRFs, it is expected that their use could lead to improved nutrient efficiency and reduced environmental pollution from a long-term development perspective.