Environmental Friendly Materials Research Articles

Functionalization of Emulsion Interfaces: Surface Chemistry made Liquid.

Disperse systems, and emulsions in particular, are currently massively used in fields as varied as food industry, cosmetics, health care and environmentally-friendly materials. To meet increasingly precise needs or targeted applications, these systems need to be endowed with new functionalities at their interfaces, in addition to their composition and structural properties. However, due to the fragility of drops and the low reactivity of their surface, conventional solid surface chemistry cannot be used for such a purpose. Several specific emulsion interface functionalization techniques have thus been developed for targeted systems and applications, but a general framework has yet to be drawn. In this review, we attempt to present these methods in a unified way through the prism of what we may call "liquid surface chemistry". We propose to categorize existing methods into drop-coating strategies, including layer-by-layer techniques and polymer coating, and emulsifier-carrier approaches involving particles and/or amphiphilic molecules. They are discussed in a transversal way, highlighting the underlying physico-chemical principles and providing a comparative analysis of their advantages, current limitations and potential for improvement. We also propose future directions and opportunities, involving for instance DNA-based programmability or artificial intelligence, which could make liquid surface chemistry more versatile and controlled.

A sustainable approach to enhance biodegradability of recycled LDPE with starch biofillers derived from potato peels and rice husk ash*

ABSTRACT This study investigates the potential of using starch derived from potato peels and rice husks as biofiller for the production of biodegradable plastics. Starch was extracted from potato peels and modified using phthalic anhydride, formamide and potassium acetate to ensure its homogeneous dispersion into the low-density polyethylene (LDPE) matrix. The modified potato peel starch and rice husk ash were characterised using various techniques such as SEM, TEM, FTIR, XRD and were blended with recycled LDPE to enhance its biodegradability for making it an applicable environmental friendly packaging material. The quantity of the biofiller was varied from 4 to 12 g while rice husk ash content was kept constant (0.6 g). The addition of the biofiller reduced the tensile strength, tear strength and transparency of the film with an increase in haze %, weight loss both in garden soil and vegetable waste environment indicating the enhancement in biodegradability of the produced blend. Considering the applicability constrain biodegradable blend containing 20% starch was considered as the best one having tensile strength of approximately 10.42 MPa, tear strength 69.4 N, weight loss percentage of 13.29% in garden soil and 11.34% in vegetable waste when studied for a period of 360 days. Modification of starch has however increased both the mechanical (tensile strength – 12.628 MPa, tear strength – 80.47 N) and biodegradability (weight loss percentage of 15.19% in garden soil and 14.45% in vegetable waste) of the films when studied under the same conditions for the sample containing 30% starch in the matrix.

Smart Dental Materials: Unravelling the Exciting Future of Dentistry

Dental materials have changed significantly over the years, with new materials being developed and introduced at a rapid pace. Smart materials are used in dentistry because of their excellent biocompatibility and ability to respond to physiological changes and local environmental stimuli to protect the teeth and promote oral health. Smart dental materials change one or more of their characteristics in response to inputs. They actively contribute to the functionality of the structure or apparatus. Smart materials are an answer to the requirement of environment-friendly and responsive materials. Smart materials are a new generation of materials which hold a good promise for the future in the field of bio‑smart dentistry. They offer significant possibilities, but considerable research is required in this field of material science. It is the need of the hour that all dentists should be aware of these innovative materials to enable their use and utilize their optimal properties in day-to-day practice to provide quality and effective holistic treatment. The objective of this article is to shed light and improve understanding on the various bioactive and smart materials being used in dentistry today and to provide a perspective on the exciting future of these smart dental biomaterials.

A biomacromolecular additive based on pullulan polysaccharide to enhance the life of lead-acid battery packs in DC systems

Abstract With the rapid growth in demand for mobile power, lead-acid batteries still occupy a large market share due to their excellence in energy storage. However, their lifespan is affected by various factors, which limits the application efficiency and environmental friendliness. In this regard, this paper proposes a method to enhance the service life of lead-acid battery packs by applying biomacromolecule additives. A lead-acid battery pack modification method is investigated by introducing chitosan, a natural macromolecule with excellent electrical conductivity and biodegradation properties, into lead-acid batteries. So that the chitosan-modified material forms a stable and protective film on the surface of the battery electrode plate, thereby reducing the analysis of sulphate crystals on the electrode surface. The method of modification of lead-acid battery packs has been studied. Comparative analysis of the experimental data shows that the modified battery pack exhibits lower charge transfer impedance and better electrochemical stability than the traditional lead-acid battery during the cyclic charge/discharge test. Through the cycle charge/discharge test, the energy loss of the battery with biomolecules is 30% lower than that of the unmodified battery, and the number of charge/discharge cycles increases by 60%, which effectively prolongs the service life of the lead-acid battery. The progress of this paper not only has guiding significance for the performance improvement of traditional lead-acid batteries but also provides a significant theoretical and experimental basis for the development and application of environmental friendly battery materials.

Efficient enhancement of piezo-catalytic activity of BaTiO3-based piezoelectric ceramics via phase boundary engineering

Piezoelectric catalysis stemmed from lead-free piezoelectric ceramics is an emerging catalytic technology applied extensively in degradation of organic pollutants due to its low energy consumption and non-pollution. However, the dissatisfied catalytic efficiency of lead-free piezoelectric ceramics has constrained their further development and application. Herein, we employ ion doping to modulate the phase boundary construction of BaTiO3-based piezoelectric ceramics (BaTi(1-x)(Zr1/3Sn1/3Hf1/3)xO3, BTZSH-x), and the degradation performances of organic dyes are explored to illuminate the piezo-catalytic mechanism. The ion doping alters the phase boundary of BaTiO3 ceramics and a two-phase coexistence of rhombohedral-orthorhombic is achieved at room temperature in BTZSH-0.04 ceramic. Consequently, the BTZSH-0.04 ceramic exhibits an excellent degradation efficiency of rhodamine B with 97.27% in 60min and a high reaction rate constant of 0.056 min−1 under ultrasonication which is 7.4 times more than that of pristine BaTiO3. This work provides an advisable policy for constructing environmental-friendly piezoelectric materials with glorious piezo-catalytic activity.

Integrating Data Imputation and Augmentation with Interpretable Machine Learning for Efficient Strength Prediction of Fly Ash-Based Alkali-Activated Concretes

Fly ash-based alkali-activated concrete (AAC) is renowned for its superior mechanical performance and sustainability, presenting an attractive alternative to traditional Portland cement concrete. Despite these advantages, the broad compositional range of AACs presents challenges in precisely tailoring material properties. In this context, machine learning (ML) offers promising prospects to streamline and fast-track the development of advanced materials design strategies by predicting mechanical properties from compositional variations. Effective ML model development, however, hinges on the availability of a comprehensive, high-quality dataset. Previous studies often relied on literature-derived datasets, which typically include outliers, noise, and missing values, potentially leading to biased predictions. Moreover, limited dataset sizes could undermine the robustness of the models. Traditional ML methods applied to AACs also tend to lack interpretability. To address these issues, this paper utilizes several data imputation methods and Generative Adversarial Networks (GANs) for data augmentation, effectively doubling the dataset size. Following this, ML algorithms such as Random Forest (RF), Extreme Gradient Boosting (XGBoost), and Neural Networks (NNs) are leveraged to predict compressive strength. The NN model, especially when enhanced by k-nearest neighbors (kNN) imputation (k = 5), demonstrated superior predictive accuracy compared to RF and XGBoost models. Further, SHAP (SHapley Additive exPlanations) analysis reveals key determinants of compressive strength, such as water content, SiO2, and curing conditions. Visualizations such as SHAP violin and river flow plots further elucidated feature contributions and property distributions. Overall, this study provides a robust framework for exploring composition-strength relationships in AACs, advancing the design of these environment-friendly materials.

The Effect of Employing Green Materials on the Business Performance of the Sustainable Retail Sector

There has been an increasing demand in the retail sector to become more environmentally sustainable in its operations. One crucial aspect of sustainable retail operations is green materials, which can lead to better business performance among firms in sustainable retailing. The quantitative approach was adopted in this study, whereby a structured questionnaire was administered to the respondents, who, in this case, were retailers in a specific sustainable retail environment. The population of this study comprises 200 retailers based in the sustainable retail sector who are using green materials for their supply chain packaging and manufacturing processes, such as Post Industry Recycled, biodegradable and organically oriented materials. This study will help develop strategies to incorporate green materials in business operations to benefit companies in a sustainable retailing business. The research shows that adopting environment friendly materials such as biodegradable and recyclable ones can make a company more profitable, prefered by customers, loyal to the customers and respond to their needs and promote their image to previse customers who are green conscious. It entails that sustainable actors in the retail sector who incorporate green materials in their product designing and manufacturing processes are likely to snatch the sustainable market efficiently.

Excellent facile fabrication of PVA and lignin nanoparticles from wheat straw after novel DES-THF pretreatment

The utilization of environmental friendly and renewable materials has received increasing attention recently. Lignin nanospheres (LNPs) prepared from recovered lignin and residual lignin after DESs and DESs-THF pretreatment were obtained by self-assembly in the present research. Then, films were prepared by incorporating them into polyvinyl alcohol (PVA) solution. The properties of various films were characterized and compared. Results showed that as the LNPs content increased, the UV blocking capacity of the films was gradually enhanced than PVA film. The DES-THF films showed better antioxidant properties up to 69 % due to higher phenolic hydroxyl content. The hydrophobicity of films incorporated with DESs-THF pretreated lignin was consistently better than that of DES pretreated. DES-THF-M films showed a higher Tmax than that of DES-M films, resulting in better thermal stability. Moreover, DES-THF-L films are lighter in color due to a lower degree of condensation, which is favorable to subsequent applications. The incorporation of LNPs improved mechanical and antioxidant properties, thermal stability, and UV shielding ability of PVA films, especially lignin after DES-THF pretreatment. In conclusion, the prepared PVA/LNPs composite films possessed good functional properties that make them potential for packaging materials.

Cellulose nanofiber aerogels: effect of the composition and the drying method

Highly porous and lightweight aerogels of cellulose nanofibers (CNFs) have emerged as a promising class of material. This study delves into the impact of the composition (lignocellulose nanofibers–LCNFs and CNFs) and the drying methods (supercritical drying and freeze-drying) on the morphology and the properties of nanocellulose-based aerogels. The investigation evaluates the concentrations of nanofibers and the influence of lignin, a constituent of LCNFs recognized for enhancing the rigidity of plant cell walls, on the aerogel’s properties. The shrinkage rates, density, pore structure, and mechanical properties of the obtained aerogels are comprehensively compared. Supercritical drying proves advantageous for aerogel formation, resulting in materials with lower density and higher surface area than their freeze-dried counterparts at each concentration level. The use of acetone for supercritical drying contributes to reduce the shrinkage rates compared to ethanol. This decrease is attributed to the formation of a more rigid hydrogel during solvent exchange. Freeze-drying exhibits the lowest shrinkage rates and relatively higher porosity. The presence of lignin in the nanofibers influences the microstructure, yielding smoother and thicker pore walls. This study contributes to the comprehensive understanding of the intricate factors shaping nanocellulose aerogel properties, paving the way for the development of innovative and environmentally-friendly materials.

Water-soluble polysaccharides extracted from Enteromorpha prolifera/PVA composite film functionalized as ε-polylysine with improved mechanical and antibacterial properties

The issue of environmental protection has received sustained and widespread attention. In order to reduce environmental pollution related to traditional plastics, it is an incessant demand to design novel environment-friendly food packaging materials with excellent performance. Sulfated polysaccharide extracted from the “green tide” marine pollution Enteromorpha prolifera (SPE) has been innovatively transformed into a film-forming material for better utilization. The insufficient mechanical properties and limited functionalities, however, hinder its wide application. In this study, polyvinyl alcohol (PVA) was blended to enhance its mechanical properties and ε-polylysine (ε-PL) was incorporated to endow it with antimicrobial performance. A novel and biodegradable film composed of SPE, PVA, and ε-PL was fabricated by casting method. We further determined the physicochemical properties of composited films. Mechanical performance test revealed the tensile strength of SPE-PVA-PL films increased from 5.56 MPa to 6.65 MPa and the E% increased from 128.8 % to 246.9 % compared with that of SPE-PVA films. Antimicrobial tests showed the excellent antibacterial activity of SPE-PVA-PL films against representative microbial species, Staphylococcus aureus and Escherichia coli. The results of this study suggested that the SPE-based composite film has the potential to be used as a potential food packaging and wound dressing materials.

Mesoporous La0.8Sr0.2CoO3/H-COK-12 catalyst synthesized by template method: Highly active for the complete oxidation of CO

Using cheap sodium silicate as a silica source and surfactant P123 as a soft template, an environment-friendly mesoporous material, COK-12, was prepared in a near-neutral environment. COK-12 was modified with n-hexane to obtain an H-COK-12 template with a compact and ordered pore structure. In this study, the modified mesoporous material H-COK-12 was used as the template for the first time, and the mesoporous La0.8Sr0.2CoO3 (LSC) catalyst was prepared by nano-casting method combined with sol–gel method. The results showed that the LSC-650 catalyst synthesized at 650 °C for 2 h possessed a large specific surface area (103.46 m2/g) and the highest surface Co4+/Co3+ and Oads/Olat molar ratio. In addition, the CO conversion with the LSC-T (T = 550, 600, 650, 700 °C) samples indicated that the LSC-650 sample had the best catalytic activity (T50 = 145 °C, T90 = 149 °C) and stability.

Chitosan/CNDs coated Cu electrode surface has an electrical potential for electrical energy application

Polymers and nanomaterials had been widely applied at electrochemical chemosensor and biosensor. Developing technical energy is still much needed, especially using natural environmental friendly material. Both chitosan of biopolymer and carbon nanodots (CNDs) of nanomaterials are highly studied due to their extraordinary properties. The research focus on chitosan and chitosan/CNDs nanocomposite surface that was applied for electrical energy. Nanocomposite was coated on Cu electrode surface by using electroplating method. The coated electrode was dipped into oil samples. The dipped nanocomposite then was characterized by FTIR, XRD, SEM, and Chemosensor. Nanocomposite structure is still maintain its chemical compound, confirmed by FTIR and XRD, which still maintain amine group; hydroxyl group; and crystalinity of chitosan after CNDs intercoporation. Nanocomposite surface morphology show magnetite particle distribution that spreaded on the surface of electrode for both chitosan and CNDs nanocomposite, which is confirmed by SEM. The free dipping method is based on the sensitive material chitosan/CNDs as a chemosensor; the pressure process on the surface of the chitosan/CNDs sensitive material causes the interaction of metal ions and acid compounds, which involves an iontophoresis process where oil atoms that have been excited in the evaporation process will experience atomic vibrations due to electron transport which then the active groups on the Chemosensor directly absorb and bind metals and acids in oil use a chemisorption process which leads to the transfer of charge from the adsorption particles to the chemosensor surface to fill the holes so that a potential difference occurs in the form of electrical pulses which will then be captured by the Arduino system which will be converted into digital data. This process makes technological energy production in the form of electrical energy faster.

Waste-to-energy: Repurposing flexible polyurethane waste for triboelectric nanogenerator applications

Triboelectric Nanogenerators (TENG) is a promising approach for clean energy harvesting. Light weight, flexible, cheap and environmentally-friendly materials are being explored as potential components in the TENG device in order to increase its efficiency. This paper reports the first effort to successfully utilize rebonded flexible polyurethane (RFPU) waste as a tribopositive material in a TENG device. A batch moulding technique was used to create two different densities (60 and 70 kg/m3) of flexible polyurethane (FPU) scraps, including customer waste and slabstock foam production waste. The current study investigates the effect of density on the compression strengths of the RFPU materials, as well as the impact on the output voltage of the TENG. Additionally, the effect of various RFPU sheet thicknesses (2, 4, 6, and 8 mm) as well as the effect of different applied forces and frequencies on the TENG's output voltage were investigated. The findings showed that the compressive strength increases with higher RFPU density. The output voltage values of the TENG device were recorded both with and without pre-charging. The results, without pre-charging, revealed that the highest output voltage of the TENG was obtained using an RFPU sheet with a density of 60 kg/m3. Furthermore, output voltage was shown to decrease with increasing RFPU sheet thickness and to increase with applied frequency. Pre-charging showed a similar trend, but yielded better results compared to the RFPU samples that were not pre-charged. The power density peaked at 0.085 mW/cm2, at a load resistance of 5 MΩ and a force of 4.7 N. The RFPU-based TENG successfully powered four white LEDs connected in series. Analysis of the embodied energy associated with using PU foam waste instead of virgin PU foam was conducted and demonstrated that utilizing PU foam waste provides environmental benefits due to the significant contribution of raw materials to the overall embodied energy in PU foam that is saved when reusing foam waste. Additionally, assessing the embodied energy of the components of the TENG device was also conducted and shows that the generated energy can partially offset the embodied energy of the TENG device. As a result, the prepared RFPU material not only helps to safeguard the environment but also shows great promise for use in developing more efficient and affordable TENGs in the future.

Rice husk ash blended self-consolidating concrete for application in rigid pavements: transforming agro-industrial waste into environment-friendly and sustainable material

Rice husk ash blended self-consolidating concrete for application in rigid pavements: transforming agro-industrial waste into environment-friendly and sustainable material

Production and technical performance of scrimber composite manufactured from industrial low-value wood for structural applications

Development of scrimber composites and other engineered wood products from low-value wood and wood waste provides an effective opportunity to preserve natural resources, minimize waste, and innovate the production of higher-performance, environment-friendly construction materials. In this study, peeler cores, which are the center of poplar logs remaining after the peeling process in the veneer production, were utilized to develop scrimber composites. This study investigated the effects of different resins, including phenol-formaldehyde (PF) and urea formaldehyde (UF), as well as hydrothermal treatments at various temperatures (60 °C and 130 °C), on the physical and mechanical properties of the scrimber composites. Chemical changes in wood components and morphological changes in wood cell walls resulting from hydrothermal treatment were analyzed using Fourier transform infrared spectroscopy and scanning electron microscopy. To clarify how resin type and hydrothermal treatment affect structural performance, several physical and mechanical properties of scrimber composites, including thickness swelling, water absorption, internal bond strength, bending modulus of elasticity, and modulus of rupture, were measured. The test results revealed that hydrothermally treated wood scrims at 130 °C, when bonded with PF resin, produced scrimber composites with superior structural performance.

Improvement of the negative-temperature properties of calcium sulphoaluminate cement by three multifunctional chemical admixtures

The construction of concrete in cold climates is associated with a significant energy consumption and an extensive carbon footprint. This is attributed to the production of raw materials and the necessity for additional measures to prevent frost damage. Finding suitable and environmental-friendly cementitious materials and admixtures for cold weather is a relatively straightforward and cost-effective solution. In this study, calcium sulphoaluminate cement (CSA) was selected, and low doses of three admixtures (lithium carbonate (Li2CO3), calcium mitrite (Ca(NO2)2), and calcium chloride (CaCl2)) were used at low dosages to modify the properties of CSA at sub-zero temperatures. The results showed that: The addition of Li2CO3 to CSA can significantly increase the early hydration of CSA, improve the early mechanical properties, shorten the curing time, and significantly reduce the content of frozen water in the pores. Ca(NO2)2 ensured the sustained late-stage development of CSA strength, which reached 90.5 MPa at −7+28 d; CaCl2 significantly lowered the freezing point of the cement paste and also improved the mid and late-stage strength.

Preparation and arc erosion mechanism of Ni skeleton reinforced Ag-based contact materials with CuO-coated SnO2

The Ag-SnO2 contact material is widely regarded as the most promising environmental friendly electrical contact material. However, during the make and break operations, SnO2 particles rising to the surface can cause increased contact resistance and temperature rise, which affects the service life of the contact material. In this study, a three-dimensional (3D) Ni skeleton reinforced Ag-based contact material with CuO-coated SnO2 are successfully fabricated via powder metallurgy technology. The basic physical properties of the novel contact material were tested and the microstructures and arc erosion morphologies were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The research demonstrated that the hardness and electrical conductivity of the novel contact material are 128.9 HV and 46 %IACS, respectively. It can be observed that the SnO2-rich phase is uniformly distributed in the Ag matrix without significant upward after arc erosion, which indicates that the SnO2@CuO core-shell structure effectively enhances the wettability between Ag and SnO2. Meanwhile, the study revealed that the Ni phase uniformly distributed at the interface of the Ag phase during the arc erosion process, indicating that the 3D Ni skeleton structure effectively impedes the expansion of the Ag molten pool and improves the anti-arc erosion performance.

Research Progress in Starch-based Dye Adsorbents

Abstract: Starch is a typical environment-friendly biomass material and there are considerable quantities of reactive hydroxyl groups in the starch molecule chain. Modifications could introduce a large number of functional groups, which can bind some dyeing contaminants, thereby removing the dyes. According to the different modification methods, starch-based adsorbents can be divided into three categories that are aminated-modified starch, ionic-modified starch, and composite-modified starch. The preparation method, structure properties, and adsorption capacity of modified starch dye adsorbents have been reviewed in this article. It can be concluded that the adsorption property of adsorbents depends on different adsorption conditions and modification methods. The adsorption properties of the adsorbents have been found to be influenced by temperature, initial concentration of dyes, and pH value of solution. Amination modification can introduce amino or amine groups into the starch skeleton to enhance the chelation or electrostatic effect of the adsorbents on dyes. Ion modification can improve the ion exchange and electrostatic interaction between the adsorbents and the dye. Composite modification can improve specific surface area, pore size, adsorption site, and structural stability of the adsorbents. Future studies are required to focus on producing dye adsorbents with high adsorption performance, stable structure, recyclability, and degradability.

Porous Wood Composite as a Green Approach for Enhancing Electrochemical Performance of Gel Polymer Electrolytes for Supercapacitors.

Delignified wood (DW) is a kind of environment-friendly porous material, and its unique hierarchical orous structure and excellent wettability are conducive to the rapid transfer and storage of ions, which can be used as electrolyte matrix of supercapacitors. In order to solve the deficiency of mechanical properties of DW as electrolyte materials, a novel cross-linked polyurethane (CPU) with high water absorption is designed as a reinforced matrix to improve the mechanical properties of electrolytes while maintaining high ionic conductivity. First, DW is immersed in CPU precursor solution, and the DW/CPU composite (W-CPC) is obtained by thermal crosslinking. Finally, W-CPC is soaked in 1 M LiClO4 aqueous electrolyte to obtain the composite gel polymer electrolyte (W-CPC-GPE). Benefiting from the good hydrophilicity of W-CPC, the anisotropic vertical channels inside the DW, and the synergism of hydrogen bond and covalent bond. The highest ionic conductivity and mechanical strength of W-CPC-GPE are 3.5×10-2 S cm-1 and 0.67 MPa, respectively. The W-CPC-5-G based supercapacitor exhibits a high specific capacitance of 146.52 F g-1 and favorable capacitance retention rate of 90.7 % after 5000 cycles. The results show that compounding with DW is an efficient and green way to develop high-performance gel polymer electrolytes for supercapacitors.

A study on preparation of low-cost environment-friendly self-assembled nanocellulose membrane from waste paper

In the context of green development, different types of waste paper were used in this study to prepare environment-friendly nanocellulose membrane by using different pretreatment processes. The results showed that all nanocellulose membranes had a novel microscopic composite morphology: nanocellulose fibers in the middle were tightly arranged and had a certain direction, while nanocellulose fibers at the edge were arranged randomly. Moreover, the type of waste paper affected the formation and property of nanocellulose membranes deeply compared with the pretreatment process. Nanocellulose membrane prepared from office waste paper had a high transmittance (50.8 %) and low oxygen transmission rate (1.548·10−3/cm3mm/(m2·d·KPa)) while that prepared from waste corrugated paper had a high yield (50.63 %), high folding number (81 times), and low water vapor transmission rate (1550.24 g·m−2·day−1). Meanwhile, nanocellulose membrane prepared without any deinking treatment had a significant performance advantage in terms of water vapor barrier and folding resistance. Therefore, in actual application, deinking treatment can be selectivity omitted, which will simplify the preparation process flow and reduce the production cost of nanocellulose membrane. Furthermore, in order to satisfy different application requirements, the appropriate raw materials and treatment processes can be chosen to prepare nanocellulose membranes with different properties. This study provides a simple and low-cost way to prepare high-performance environment-friendly self-assembled nano membrane material, and also achieves the high value utilization of waste paper, which has a certain ecological, economic, and social benefits.