bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Polymer Membranes for the Recovery of Copper, Zinc and Nickel from Model Solutions and Jewellery Waste
Authors: Radzymińska-Lenarcik Elżbieta , Pyszka Ilona , Urbaniak Włodzimierz
Published: February 2023

A polymeric inclusion membrane (PIM) consisting of matrix CTA (cellulose triacetate), ONPPE (o-nitrophenyl pentyl ether) and phosphonium salts (Cyphos 101, Cyphos 104) was used for separation of Cu(II), Zn(II) and Ni(II) ions. Optimum conditions for metal separation were determined, i.e., the optimal concentration of phosphonium salts in the membrane, as well as the optimal concentration of chloride ions in the feeding phase. On the basis of analytical determinations, the values of parameters characterizing transport were calculated. The tested membranes most effectively transported Cu(II) and Zn(II) ions. The highest recovery coefficients (RF) were found for PIMs with Cyphos IL 101. For Cu(II) and Zn(II), they are 92% and 51%, respectively. Ni(II) ions practically remain in the feed phase because they do not form anionic complexes with chloride ions. The obtained results suggest that there is a possibility of using these membranes for separation of Cu(II) over Zn(II) and Ni(II) from acidic chloride solutions. The PIM with Cyphos IL 101 can be used to recover copper and zinc from jewellery waste. The PIMs were characterized by AFM and SEM microscopy. The calculated values of the diffusion coefficient indicate that the boundary stage of the process is the diffusion of the complex salt of the metal ion with the carrier through the membrane.
Fabrication of Fibrin/Polyvinyl Alcohol Scaffolds for Skin Tissue Engineering via Emulsion Templating
Authors: Zhou Guoying , Zhu Jiayan , Inverarity Catriona , Fang Yifeng , Zhang Zhao , Ye Hua , Cui Zhanfeng , Nguyen Linh , Wan Haitong , Dye Julian F.
Published: February 2023

In the search for a novel and scalable skin scaffold for wound healing and tissue regeneration, we fabricated a class of fibrin/polyvinyl alcohol (PVA) scaffolds using an emulsion templating method. The fibrin/PVA scaffolds were formed by enzymatic coagulation of fibrinogen with thrombin in the presence of PVA as a bulking agent and an emulsion phase as the porogen, with glutaraldehyde as the cross-linking agent. After freeze drying, the scaffolds were characterized and evaluated for biocompatibility and efficacy of dermal reconstruction. SEM analysis showed that the formed scaffolds had interconnected porous structures (average pore size e was around 330 µm) and preserved the nano-scale fibrous architecture of the fibrin. Mechanical testing showed that the scaffolds’ ultimate tensile strength was around 0.12 MPa with an elongation of around 50%. The proteolytic degradation of scaffolds could be controlled over a wide range by varying the type or degree of cross-linking and by fibrin/PVA composition. Assessment of cytocompatibility by human mesenchymal stem cell (MSC) proliferation assays shows that MSC can attach, penetrate, and proliferate into the fibrin/PVA scaffolds with an elongated and stretched morphology. The efficacy of scaffolds for tissue reconstruction was evaluated in a murine full-thickness skin excision defect model. The scaffolds were integrated and resorbed without inflammatory infiltration and, compared to control wounds, promoted deeper neodermal formation, greater collagen fiber deposition, facilitated angiogenesis, and significantly accelerated wound healing and epithelial closure. The experimental data showed that the fabricated fibrin/PVA scaffolds are promising for skin repair and skin tissue engineering.
Solid-State Surface Patterning on Polymer Using the Microcellular Foaming Process
Authors: Kim Jaehoo , Kim Shin Won , Kweon Byung Chul , Kim Kwan Hoon , Cha Sung Woon
Published: February 2023

This study proposes a novel process that integrates the molding and patterning of solid-state polymers with the force generated from the volume expansion of the microcellular-foaming process (MCP) and the softening of solid-state polymers due to gas adsorption. The batch-foaming process, which is one of the MCPs, is a useful process that can cause thermal, acoustic, and electrical characteristic changes in polymer materials. However, its development is limited due to low productivity. A pattern was imprinted on the surface using a polymer gas mixture with a 3D-printed polymer mold. The process was controlled with changing weight gain by controlling saturation time. A scanning electron microscope (SEM) and confocal laser scanning microscopy were used to obtain the results. The maximum depth could be formed in the same manner as the mold geometry (sample depth: 208.7 μm; mold depth: 200 μm). Furthermore, the same pattern could be imprinted as a layer thickness of 3D printing (sample pattern gap and mold layer gap: 0.4 mm), and surface roughness was increased according to increase in the foaming ratio. This process can be used as a novel method to expand the limited applications of the batch-foaming process considering that MCPs can impart various high-value-added characteristics to polymers.
Development of Benzobisoxazole-Based Novel Conjugated Polymers for Organic Thin-Film Transistors
Authors: Jeong WonJo , Lee Kyumin , Jang Jaeyoung , Jung In Hwan
Published: February 2023

Benzo[1,2-d:4,5-d′]bis(oxazole) (BBO) is a heterocyclic aromatic ring composed of one benzene ring and two oxazole rings, which has unique advantages on the facile synthesis without any column chromatography purification, high solubility on the common organic solvents and planar fused aromatic ring structure. However, BBO conjugated building block has rarely been used to develop conjugated polymers for organic thin film transistors (OTFTs). Three BBO-based monomers, BBO without π-spacer, BBO with non-alkylated thiophene π-spacer and BBO with alkylated thiophene π-spacer, were newly synthesized and they were copolymerized with a strong electron-donating cyclopentadithiophene conjugated building block to give three p-type BBO-based polymers. The polymer containing non-alkylated thiophene π-spacer showed the highest hole mobility of 2.2 × 10−2 cm2 V−1 s−1, which was 100 times higher than the other polymers. From the 2D grazing incidence X-ray diffraction data and simulated polymeric structures, we found that the intercalation of alkyl side chains on the polymer backbones was crucial to determine the intermolecular ordering in the film states, and the introduction of non-alkylated thiophene π-spacer to polymer backbone was the most effective to promote the intercalation of alkyl side chains in the film states and hole mobility in the devices.
Particleboard Production from Paulownia tomentosa (Thunb.) Steud. Grown in Portugal
Authors: Esteves Bruno , Aires Pedro , Sen Umut , Gomes Maria da Glória , Guiné Raquel P. F. , Domingos Idalina , Ferreira José , Viana Hélder , Cruz-Lopes Luísa P.
Published: February 2023

Paulownia wood has raised high attention due to its rapid growth and fire resistance. The number of plantations in Portugal has been growing, and new exploitation methods are needed. This study intends to determine the properties of particleboards made with very young Paulownia trees from Portuguese plantations. Single layer particleboards were produced with 3-year-old Paulownia trees using different processing parameters and different board composition in order to determine the best properties for use in dry environments. The standard particleboard was produced at 180 °C and a 36.3 kg/cm2 pressure for 6 min using 40 g of raw material with 10% urea-formaldehyde resin. Higher particle size lead to lower-density particleboards, while higher resin contents lead to higher density of the boards. Density has a major effect on board properties with higher densities improving mechanical properties such as bending strength, modulus of elasticity (MOE) and internal bond, lower water absorption but higher thickness swelling and thermal conductivity. Particleboards meeting the requirements for dry environment according to NP EN 312 standard, could be produced with young Paulownia wood with acceptable mechanical and thermal conductivity properties with density around 0.65 g/cm3 and a thermal conductivity of 0.115 W/mK.
Multifunctional Self-Assembled Peptide Hydrogels for Biomedical Applications
Authors: Sedighi Mahsa , Shrestha Neha , Mahmoudi Zahra , Khademi Zahra , Ghasempour Alireza , Dehghan Hamideh , Talebi Seyedeh Fahimeh , Toolabi Maryam , Préat Véronique , Chen Bozhi , Guo Xindong , Shahbazi Mohammad-Ali
Published: February 2023

Self-assembly is a growth mechanism in nature to apply local interactions forming a minimum energy structure. Currently, self-assembled materials are considered for biomedical applications due to their pleasant features, including scalability, versatility, simplicity, and inexpensiveness. Self-assembled peptides can be applied to design and fabricate different structures, such as micelles, hydrogels, and vesicles, by diverse physical interactions between specific building blocks. Among them, bioactivity, biocompatibility, and biodegradability of peptide hydrogels have introduced them as versatile platforms in biomedical applications, such as drug delivery, tissue engineering, biosensing, and treating different diseases. Moreover, peptides are capable of mimicking the microenvironment of natural tissues and responding to internal and external stimuli for triggered drug release. In the current review, the unique characteristics of peptide hydrogels and recent advances in their design, fabrication, as well as chemical, physical, and biological properties are presented. Additionally, recent developments of these biomaterials are discussed with a particular focus on their biomedical applications in targeted drug delivery and gene delivery, stem cell therapy, cancer therapy and immune regulation, bioimaging, and regenerative medicine.
Prediction of Ultimate Capacity of Concrete Columns Reinforced with FRP Bars
Authors: Korentz Jacek , Czarnecki Witold
Published: February 2023

FRP bars are used in concrete structures as an alternative to steel bars as they have many advantages such as high tensile strength, high strength-to-weight ratio, electromagnetic neutrality, lightweight and no corrosion. There is a perceived lack of standard regulations for the design of concrete columns with FRP reinforcement, e.g., in Eurocode 2. This paper describes a procedure for predicting the bearing capacity of concrete columns with FRP reinforcement based on the interaction of axial force and bending moment, which was developed on the basis of existing design recommendations and standards. It was shown that the bearing capacity of eccentrically loaded RC sections depends on two parameters, which are the mechanical reinforcement ratio ω and the location of the reinforcement in the cross-section expressed by the β factor. The analyses carried out showed the existence of a singularity in the n–m interaction curve indicating the fact that in a certain loaded range, the curve is concave, and more it was shown that the balance failure point for sections with FRP reinforcement takes place for eccentric tension. A simple procedure for calculating the required reinforcement from any FRP bars in concrete columns was also proposed. Nomograms developed from n–m interaction curves provide for the accurate and rational design of FRP reinforcement in columns.
Hybrid Carbon Nanocomposites Made of Aerospace-Grade Epoxy Showing Synergistic Effects in Electrical Properties and High Processability
Authors: Zaccardi Federica , Toto Elisa , Marra Fabrizio , Santonicola Maria Gabriella , Laurenzi Susanna
Published: February 2023

In this work, we investigate the processability and the volumetric electrical properties of nanocomposites made of aerospace-grade RTM6, loaded with different carbon nanoparticles. Nanocomposites with graphene nanoplatelets (GNP), single-walled carbon nanotubes (SWCNT) and hybrid GNP/SWCNT in the ratio 2:8 (GNP2SWCNT8), 5:5 (GNP5SWCNT5) and 8:2 (GNP8SWCNT2) were manufactured and analyzed. The hybrid nanofillers are observed to have synergistic properties as epoxy/hybrid mixtures showed better processability than epoxy/SWCNT, while maintaining high values of electrical conductivity. On the other hand, epoxy/SWCNT nanocomposites present the highest electrical conductivities with the formation of a percolating conductive network at lower filler content, but very large viscosity values and filler dispersion issues, which significantly affect the final quality of the samples. Hybrid nanofiller allows us to overcome the manufacturing issues typically associated with the use of SWCNTs. The combination of low viscosity and high electrical conductivity makes the hybrid nanofiller a good candidate for the fabrication of aerospace-grade nanocomposites with multifunctional properties.
Experimental and Numerical Investigation of the Mechanical Properties of 3D-Printed Hybrid and Non-Hybrid Composites
Authors: Heitkamp Tim , Girnth Simon , Kuschmitz Sebastian , Waldt Nils , Klawitter Günter , Vietor Thomas
Published: February 2023

Recent research efforts have highlighted the potential of hybrid composites in the context of additive manufacturing. The use of hybrid composites can lead to an enhanced adaptability of the mechanical properties to the specific loading case. Furthermore, the hybridization of multiple fiber materials can result in positive hybrid effects such as increased stiffness or strength. In contrast to the literature, where only the interply and intrayarn approach has been experimentally validated, this study presents a new intraply approach, which is experimentally and numerically investigated. Three different types of tensile specimens were tested. The non-hybrid tensile specimens were reinforced with contour-based fiber strands of carbon and glass. In addition, hybrid tensile specimens were manufactured using an intraply approach with alternating carbon and glass fiber strands in a layer plane. In addition to experimental testing, a finite element model was developed to better understand the failure modes of the hybrid and non-hybrid specimens. The failure was estimated using the Hashin and Tsai–Wu failure criteria. The specimens showed similar strengths but greatly different stiffnesses based on the experimental results. The hybrid specimens demonstrated a significant positive hybrid effect in terms of stiffness. Using FEA, the failure load and fracture locations of the specimens were determined with good accuracy. Microstructural investigations of the fracture surfaces showed notable evidence of delamination between the different fiber strands of the hybrid specimens. In addition to delamination, strong debonding was particularly evident in all specimen types.
Improving the Integrated Fabrication of Insulation Systems in Electric Drives by Injection Molding of Thermosets Due to Processing Conditions and Slot Design
Authors: Rösel Uta , Kneidl Maximilian , Franke Jörg , Drummer Dietmar
Published: February 2023

The expanding demand for electro mobility in general and specifically for electrified vehicles requires the expansion of electro mobility technology with respect to variations in the requirements of the process and the application. Within the stator, the electrical insulation system has a high impact on the application properties. So far, limitations, such as the identification of suitable materials for the stator insulation or high costs in the processes, have hindered the implementation of new applications. Therefore, a new technology that allows integrated fabrication via the injection molding of thermosets is founded in order to expand the applications of stators. The possibility of the integrated fabrication of insulation systems to meet the demands of the application can be improved by the processing conditions and the slot design. Within this paper, two epoxy (EP) types with different fillers are investigated to show the impact of the fabrication process in terms of different parameters; these include the holding pressure or the temperature setup, as well as the slot design and with that the flow conditions. To evaluate the improvement in the insulation system of electric drives, a single slot sample, consisting of two parallel copper wires, was used. Then, the two parameters of the average partial discharge (PD) and the partial discharge extinction voltage (PDEV), as well as the full encapsulation detected by microscopy images, were analyzed. It was shown that both characteristics (electric properties—PD and PDEV; full encapsulation) could be improved in terms of an increase in the holding pressure (up to 600 bar) or a reduction in the heating time (around 40 s), as well as the injection speed (down to 15 mm/s). Further, an improvement in the properties can be reached by increasing the space between the wires, as well as the wire and the stack, due to a higher slot depth or by implementing flow-improving grooves that have a positive effect on the flow conditions. With that, the optimization of the integrated fabrication of insulation systems in electric drives via the injection molding of thermosets was enabled with respect to the process conditions and the slot design.
Starch Nanoparticles: Preparation, Properties and Applications
Authors: Marta Herlina , Rizki Dina Intan , Mardawati Efri , Djali Mohamad , Mohammad Masita , Cahyana Yana
Published: February 2023

Starch as a natural polymer is abundant and widely used in various industries around the world. In general, the preparation methods for starch nanoparticles (SNPs) can be classified into ‘top-down’ and ‘bottom-up’ methods. SNPs can be produced in smaller sizes and used to improve the functional properties of starch. Thus, they are considered for the various opportunities to improve the quality of product development with starch. This literature study presents information and reviews regarding SNPs, their general preparation methods, characteristics of the resulting SNPs and their applications, especially in food systems, such as Pickering emulsion, bioplastic filler, antimicrobial agent, fat replacer and encapsulating agent. The aspects related to the properties of SNPs and information on the extent of their utilisation are reviewed in this study. The findings can be utilised and encouraged by other researchers to develop and expand the applications of SNPs.
Ultra-High Molecular Weight Polyethylene Modifications Produced by Carbon Nanotubes and Fe2O3 Nanoparticles
Authors: Torrisi Alfio , Torrisi Lorenzo , Cutroneo Mariapompea , Michalcova Alena , D’Angelo Milena , Silipigni Letteria
Published: February 2023

Thin sheets of ultra-high molecular weight polyethylene (UHMWPE), both in pristine form and containing carbon nanotubes (CNTs) or Fe2O3 nanoparticles (NPs) at different concentrations, were prepared. The CNT and Fe2O3 NP weight percentages used ranged from 0.01% to 1%. The presence of CNTs and Fe2O3 NPs in UHMWPE was confirmed by transmission and scanning electron microscopy and by energy dispersive X-ray spectroscopy analysis (EDS). The effects of the embedded nanostructures on the UHMWPE samples were studied using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and UV–Vis absorption spectroscopy. The ATR-FTIR spectra show the characteristic features of the UHMWPE, CNTs, and Fe2O3. Concerning the optical properties, regardless of the type of embedded nanostructures, an increase in the optical absorption was observed. The allowed direct optical energy gap value was determined from the optical absorption spectra: in both cases, it decreases with increasing CNT or Fe2O3 NP concentrations. The obtained results will be presented and discussed.
Effect of Fiber Fraction on Ballistic Impact Behavior of 3D Woven Composites
Authors: Shi Xiaoping , Sun Ying , Xu Jing , Chen Li , Zhang Ce , Zhang Guoli
Published: February 2023

This paper studies the ballistic impact performance of 3D woven composites (3DWCs) with hexagonal binding patterns. Para-aramid/polyurethane (PU) 3DWCs with three kinds of fiber volume fraction (Vf) were prepared by compression resin transfer molding (CRTM). The effect of Vf on the ballistic impact behavior of the 3DWCs was analyzed by characterizing the ballistic limit velocity (V50), the specific energy absorption (SEA), the energy absorption per thickness (Eh), the damage morphology and the damage area. 1.1 g fragment-simulating projectiles (FSPs) were used in the V50 tests. Based on the results, when the Vf increases from 63.4% to 76.2%, the V50, the SEA and the Eh increase by 3.5%, 18.5% and 28.8%, respectively. There are significant differences in damage morphology and damage area between partial penetration (PP) cases and complete penetration (CP) cases. In the PP cases, the back-face resin damage areas of the sample III composites were significantly increased to 213.4% of the sample I counterparts. The findings provide valuable information for the design of ballistic protection 3DWCs.
Electrospun Nanomaterials Based on Cellulose and Its Derivatives for Cell Cultures: Recent Developments and Challenges
Authors: Peranidze Kristina , Safronova Tatiana V. , Kildeeva Nataliya R.
Published: February 2023

The development of electrospun nanofibers based on cellulose and its derivatives is an inalienable task of modern materials science branches related to biomedical engineering. The considerable compatibility with multiple cell lines and capability to form unaligned nanofibrous frameworks help reproduce the properties of natural extracellular matrix and ensure scaffold applications as cell carriers promoting substantial cell adhesion, growth, and proliferation. In this paper, we are focusing on the structural features of cellulose itself and electrospun cellulosic fibers, including fiber diameter, spacing, and alignment responsible for facilitated cell capture. The study emphasizes the role of the most frequently discussed cellulose derivatives (cellulose acetate, carboxymethylcellulose, hydroxypropyl cellulose, etc.) and composites in scaffolding and cell culturing. The key issues of the electrospinning technique in scaffold design and insufficient micromechanics assessment are discussed. Based on recent studies aiming at the fabrication of artificial 2D and 3D nanofiber matrices, the current research provides the applicability assessment of the scaffolds toward osteoblasts (hFOB line), fibroblastic (NIH/3T3, HDF, HFF-1, L929 lines), endothelial (HUVEC line), and several other cell types. Furthermore, a critical aspect of cell adhesion through the adsorption of proteins on the surfaces is touched upon.
Effect of Denture Disinfectants on the Mechanical Performance of 3D-Printed Denture Base Materials
Authors: Alkaltham Nora S. , Aldhafiri Reem A. , Al-Thobity Ahmad M. , Alramadan Hassan , Aljubran Hussain , Ateeq Ijlal Shahrukh , Khan Soban Q. , Akhtar Sultan , Gad Mohammed M.
Published: February 2023

Denture care and maintenance are necessary for both denture longevity and underlying tissue health. However, the effects of disinfectants on the strength of 3D-printed denture base resins are unclear. Herein, distilled water (DW), effervescent tablet, and sodium hypochlorite (NaOCl) immersion solutions were used to investigate the flexural properties and hardness of two 3D-printed resins (NextDent and FormLabs) compared with a heat-polymerized resin. The flexural strength and elastic modulus were investigated using the three-point bending test and Vickers hardness test before (baseline) immersion and 180 days after immersion. The data were analyzed using ANOVA and Tukey’s post hoc test (α = 0.05), and further verified by using electron microscopy and infrared spectroscopy. The flexural strength of all the materials decreased after solution immersion (p < 0.001). The effervescent tablet and NaOCl immersion reduced the flexural strength (p < 0.001), with the lowest values recorded with the NaOCl immersion. The elastic modulus did not significantly differ between the baseline and after the DW immersion (p > 0.05), but significantly decreased after the effervescent tablet and NaOCl immersion (p < 0.001). The hardness significantly decreased after immersion in all the solutions (p < 0.001). The immersion of the heat-polymerized and 3D-printed resins in the DW and disinfectant solutions decreased the flexural properties and hardness.
Natural Rubber Composites Using Hydrothermally Carbonized Hardwood Waste Biomass as a Partial Reinforcing Filler- Part I: Structure, Morphology, and Rheological Effects during Vulcanization
Authors: Lubura Jelena , Kobera Libor , Abbrent Sabina , Pavlova Ewa , Strachota Beata , Bera Oskar , Pavličević Jelena , Ikonić Bojana , Kojić Predrag , Strachota Adam
Published: February 2023

A new generation biomass-based filler for natural rubber, ‘hydrochar’ (HC), was obtained by hydrothermal carbonization of hardwood waste (sawdust). It was intended as a potential partial replacement for the traditional carbon black (CB) filler. The HC particles were found (TEM) to be much larger (and less regular) than CB: 0.5–3 µm vs. 30–60 nm, but the specific surface areas were relatively close to each other (HC: 21.4 m2/g vs. CB: 77.8 m2/g), indicating a considerable porosity of HC. The carbon content of HC was 71%, up from 46% in sawdust feed. FTIR and 13C-NMR analyses indicated that HC preserved its organic character, but it strongly differs from both lignin and cellulose. Experimental rubber nanocomposites were prepared, in which the content of the combined fillers was set at 50 phr (31 wt.%), while the HC/CB ratios were varied between 40/10 and 0/50. Morphology investigations proved a fairly even distribution of HC and CB, as well as the disappearance of bubbles after vulcanization. Vulcanization rheology tests demonstrated that the HC filler does not hinder the process, but it significantly influences vulcanization chemistry, canceling scorch time on one hand and slowing down the reaction on the other. Generally, the results suggest that rubber composites in which 10–20 phr of CB are replaced by HC might be promising materials. The use of HC in the rubber industry would represent a high-tonnage application for hardwood waste.
Progress in Biomaterials for Cardiac Tissue Engineering and Regeneration
Authors: Scafa Udriște Alexandru , Niculescu Adelina-Gabriela , Iliuță Luminița , Bajeu Teodor , Georgescu Adriana , Grumezescu Alexandru Mihai , Bădilă Elisabeta
Published: February 2023

Cardiovascular diseases are one of the leading global causes of morbidity and mortality, posing considerable health and economic burden on patients and medical systems worldwide. This phenomenon is attributed to two main motives: poor regeneration capacity of adult cardiac tissues and insufficient therapeutic options. Thus, the context calls for upgrading treatments to deliver better outcomes. In this respect, recent research has approached the topic from an interdisciplinary perspective. Combining the advances encountered in chemistry, biology, material science, medicine, and nanotechnology, performant biomaterial-based structures have been created to carry different cells and bioactive molecules for repairing and restoring heart tissues. In this regard, this paper aims to present the advantages of biomaterial-based approaches for cardiac tissue engineering and regeneration, focusing on four main strategies: cardiac patches, injectable hydrogels, extracellular vesicles, and scaffolds and reviewing the most recent developments in these fields.
Impact Performance of 3D Printed Spatially Varying Elastomeric Lattices
Authors: Dwyer Charles M. , Carrillo Jose G. , De la Peña Jose Angel Diosdado , Santiago Carolyn Carradero , MacDonald Eric , Rhinehart Jerry , Williams Reed M. , Burhop Mark , Yelamanchi Bharat , Cortes Pedro
Published: February 2023

Additive manufacturing is catalyzing a new class of volumetrically varying lattice structures in which the dynamic mechanical response can be tailored for a specific application. Simultaneously, a diversity of materials is now available as feedstock including elastomers, which provide high viscoelasticity and increased durability. The combined benefits of complex lattices coupled with elastomers is particularly appealing for anatomy-specific wearable applications such as in athletic or safety equipment. In this study, Siemens’ DARPA TRADES-funded design and geometry-generation software, Mithril, was leveraged to design vertically-graded and uniform lattices, the configurations of which offer varying degrees of stiffness. The designed lattices were fabricated in two elastomers using different additive manufacturing processes: (a) vat photopolymerization (with compliant SIL30 elastomer from Carbon) and (b) thermoplastic material extrusion (with Ultimaker™ TPU filament providing increased stiffness). Both materials provided unique benefits with the SIL30 material offering compliance suitable for lower energy impacts and the Ultimaker™ TPU offering improved protection against higher impact energies. Moreover, a hybrid lattice combination of both materials was evaluated and demonstrated the simultaneous benefits of each, with good performance across a wider range of impact energies. This study explores the design, material, and process space for manufacturing a new class of comfortable, energy-absorbing protective equipment to protect athletes, consumers, soldiers, first responders, and packaged goods.
Poly(ε-caprolactone)-poly(ethylene glycol) Tri-Block Copolymer as Quercetin Delivery System for Human Colorectal Carcinoma Cells: Synthesis, Characterization and In Vitro Study
Authors: Ferrentino Nancy , Romano Maria Preziosa , Zappavigna Silvia , Abate Marianna , Del Vecchio Vitale , Romano Dario , Germinario Chiara , Grifa Celestino , Filosa Rosanna , Pappalardo Daniela
Published: February 2023

Quercetin is a hydrophobic molecule with short blood circulation times and instability. The development of a nano-delivery system formulation of quercetin may increase its bioavailability, resulting in greater tumor suppressing effects. Triblock ABA type polycaprolactone-polyethylenglycol- polycaprolactone (PCL-PEG-PCL) copolymers have been synthetized using ring-opening polymerization of caprolactone from PEG diol. The copolymers were characterized by nuclear magnetic resonance (NMR), diffusion-ordered NMR spectroscopy (DOSY), and gel permeation chromatography (GPC). The triblock copolymers self-assembled in water forming micelles consisting of a core of biodegradable polycaprolactone (PCL) and a corona of polyethylenglycol (PEG). The core-shell PCL-PEG-PCL nanoparticles were able to incorporate quercetin into the core. They were characterized by dynamic light scattering (DLS) and NMR. The cellular uptake efficiency of human colorectal carcinoma cells was quantitatively determined by flow cytometry using nanoparticles loaded with Nile Red as hydrophobic model drug. The cytotoxic effect of quercetin-loaded nanoparticles was evaluated on HCT 116 cells, showing promising results.
Fabrication of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Fibers Using Centrifugal Fiber Spinning: Structure, Properties and Application Potential
Authors: Vanheusden Chris , Vanminsel Jan , Reddy Naveen , Samyn Pieter , D’Haen Jan , Peeters Roos , Ethirajan Anitha , Buntinx Mieke
Published: February 2023

Biobased and biodegradable polyhydroxyalkanoates (PHAs) are currently gaining momentum. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) polymer has a useful processing window for extrusion and injection molding of packaging, agricultural and fishery applications with required flexibility. Processing PHBHHx into fibers using electrospinning or centrifugal fiber spinning (CFS) can further broaden the application area, although CFS remains rather unexplored. In this study, PHBHHx fibers are centrifugally spun from 4–12 wt.% polymer/chloroform solutions. Beads and beads-on-a-string (BOAS) fibrous structures with an average diameter (ϕav) between 0.5 and 1.6 µm form at 4–8 wt.% polymer concentrations, while more continuous fibers (ϕav = 3.6–4.6 µm) with few beads form at 10–12 wt.% polymer concentrations. This change is correlated with increased solution viscosity and enhanced mechanical properties of the fiber mats (strength, stiffness and elongation values range between 1.2–9.4 MPa, 11–93 MPa, and 102–188%, respectively), though the crystallinity degree of the fibers remains constant (33.0–34.3%). In addition, PHBHHx fibers are shown to anneal at 160 °C in a hot press into 10–20 µm compact top-layers on PHBHHx film substrates. We conclude that CFS is a promising novel processing technique for the production of PHBHHx fibers with tunable morphology and properties. Subsequent thermal post-processing as a barrier or active substrate top-layer offers new application potential.
Approaches in Sustainable, Biobased Multilayer Packaging Solutions
Authors: Eissenberger Kristina , Ballesteros Arantxa , De Bisschop Robbe , Bugnicourt Elodie , Cinelli Patrizia , Defoin Marc , Demeyer Elke , Fürtauer Siegfried , Gioia Claudio , Gómez Lola , Hornberger Ramona , Ißbrücker Constance , Mennella Mara , von Pogrell Hasso , Rodriguez-Turienzo Laura , Romano Angela , Rosato Antonella , Saile Nadja , Schulz Christian , Schwede Katrin , Sisti Laura , Spinelli Daniele , Sturm Max , Uyttendaele Willem , Verstichel Steven , Schmid Markus
Published: February 2023

The depletion of fossil resources and the growing demand for plastic waste reduction has put industries and academic researchers under pressure to develop increasingly sustainable packaging solutions that are both functional and circularly designed. In this review, we provide an overview of the fundamentals and recent advances in biobased packaging materials, including new materials and techniques for their modification as well as their end-of-life scenarios. We also discuss the composition and modification of biobased films and multilayer structures, with particular attention to readily available drop-in solutions, as well as coating techniques. Moreover, we discuss end-of-life factors, including sorting systems, detection methods, composting options, and recycling and upcycling possibilities. Finally, regulatory aspects are pointed out for each application scenario and end-of-life option. Moreover, we discuss the human factor in terms of consumer perception and acceptance of upcycling.
Ion-Imprinted Polymer Structurally Preorganized Using a Phenanthroline-Divinylbenzoate Complex with the Cu(II) Ion as Template and Some Adsorption Results
Authors: Bivián-Castro Egla Yareth , Zepeda-Navarro Abraham , Guzmán-Mar Jorge Luis , Flores-Alamo Marcos , Mata-Ortega Brenda
Published: February 2023

The novel [Cuphen(VBA)2H2O] complex (phen: phenanthroline, VBA: vinylbenzoate) was prepared and used as a functional monomer to preorganize a new ion-imprinted polymer (IIP). By leaching the Cu(II) from the molecular imprinted polymer (MIP), [Cuphen(VBA)2H2O-co-EGDMA]n (EGDMA: ethylene glycol dimethacrylate), the IIP was obtained. A non-ion-imprinted polymer (NIIP) was also prepared. The crystal structure of the complex and some physicochemical, spectrophotometric techniques were also used for the MIP, IIP, and NIIP characterization. The results showed that the materials are nonsoluble in water and polar solvents, which are the main features of polymers. The surface area of the IIP is higher than the NIIP demonstrated by the blue methylene method. The SEM images show monoliths and particles smoothly packed together on spherical and prismatic-spherical surfaces in the morphology of MIP and IIP, respectively. Moreover, the MIP and IIP could be considered as mesoporous and microporous materials, shown by the size of the pores determined by the BET and BJH methods. Furthermore, the adsorption performance of the IIP was studied using copper(II) as a contaminant heavy metal. The maximum adsorption capacity of IIP was 287.45 mg/g at 1600 mg/L Cu2+ ions with 0.1 g of IIP at room temperature. The Freundlich model was found to best describe the equilibrium isotherm of the adsorption process. The competitive results indicate that the stability of the Cu-IIP complex is higher than the Ni-IIP complex with a selectivity coefficient of 1.61.
Enhancement in Mechanical Properties of Glass/Epoxy Composites by a Hybrid Combination of Multi-Walled Carbon Nanotubes and Graphene Nanoparticles
Authors: Turaka Seshaiah , Bandaru Aswani Kumar
Published: February 2023

In this work, an attempt was made to improve the mechanical performance of glass fibre-reinforced polymer composites by adding multi-walled carbon nanotubes (MWCNT) and graphene nanoparticles (GNP) and their hybrid combination at different weight fractions (0.1 to 0.3%). Composite laminates with three different configurations (unidirectional [0°]12, cross-ply [0°/90°]3s, and angle-ply [±45°]3s) were manufactured using the compression moulding method. Characterisation tests such as quasistatic compression, flexural, and interlaminar shear strength properties were carried out per ASTM standards. Failure analysis was carried out through optical and scanning electron microscopy (SEM). The experimental results showed a substantial enhancement with the 0.2% hybrid combination of MWCNTs, and GNPs showed 80% and 74% in the compressive strength and compressive modulus, respectively. Similarly, flexural strength, modulus, and interlaminar shear strength (ILSS) increased by 62%, 205%, and 298%, respectively, compared to neat glass/epoxy resin composite. Beyond the 0.2% of fillers, the properties started to degrade due to the agglomeration of MWCNTs/GNPs. The order of layups per mechanical performance was UD, followed by CP and AP.
Transfer Length vs. Slip of Prestressed Fiber-Reinforced Polymer Reinforcement
Authors: Jokūbaitis Aidas , Valivonis Juozas
Published: February 2023

A comprehensive analysis of the relationship between transfer length and slip of different types of prestressed fiber reinforced polymer (FRP) reinforcement is provided. The results of the transfer length and slip together with the main influencing parameters of approximately 170 specimens prestressed with different FRP reinforcement were collected. After the analysis of a larger database of transfer length versus slip, new bond shape factors were proposed for carbon fiber composite cable (CFCC) strands (α = 3.5) and carbon fiber reinforced polymer (CFRP) bars (α = 2.5). It was also determined that the type of prestressed reinforcement has an influence on the transfer length of the aramid fiber reinforced polymer (AFRP) bars. Therefore, α = 4.0 and α = 2.1 were proposed for AFRP Arapree bars and AFRP FiBRA and Technora bars, respectively. Moreover, the main theoretical models are discussed together with the comparison of theoretical and experimental transfer length results based on the slip of reinforcement. Additionally, the analysis of the relationship between transfer length and slip and the proposed new values of the bond shape factor α have the potential to be introduced in the production and quality control processes of precast prestressed concrete members and to stimulate additional research that increases the understanding of the transfer length of FRP reinforcement.
Methods and Characteristics of Drug Extraction from Ion-Exchange-Resin-Mediated Preparations: Influences, Thermodynamics, and Kinetics
Authors: Yuan Junlin , Li Conghui , Wang Shanshan , Zhang Hui , Wang Zengming , Zheng Aiping , Gao Xiuli
Published: February 2023

Since the discovery of ion-exchange resins, they have been used in many fields, including pharmacy. Ion-exchange resin-mediated preparations can realize a series of functions, such as taste masking and regulating release. However, it is very difficult to extract the drug completely from the drug–resin complex because of the specific combination of the drug and resin. In this study, methylphenidate hydrochloride extended-release chewable tablets compounded by methylphenidate hydrochloride and ion-exchange resin were selected for a drug extraction study. The efficiency of drug extraction by dissociating with the addition of counterions was found to be higher than other physical extraction methods. Then, the factors affecting the dissociation process were studied to completely extract the drug from the methylphenidate hydrochloride extended-release chewable tablets. Furthermore, the thermodynamic and kinetic study of the dissociation process showed that the dissociation process obeys the second-order kinetic process, and it is nonspontaneous, entropy-decreasing, and endothermic. Meanwhile, the reaction rate was confirmed by the Boyd model, and the film diffusion and matrix diffusion were both shown to be rate-limiting steps. In conclusion, this study aims to provide technological and theoretical support for establishing a quality assessment and control system of ion-exchange resin-mediated preparations, promoting the applications of ion-exchange resins in the field of drug preparation.
Cytotoxicity Analysis for the Hydroxyl Functionalized MWCNT Reinforced PMMA Nanocomposites in Oral Squamous Carcinoma (KB) Cells
Authors: Patel Vijay , Joshi Unnati , Joshi Anand , Upadhyay Tarun Kumar , Al-Keridis Lamya Ahmed , Saeed Mohd
Published: February 2023

In this particular research study, a unique three-dimensional mixing technique was used to incorporate multi-walled carbon nanotubes (MWCNTs) into polymethyl methacrylate (PMMA), and the KB cell line was used in the analysis of cytotoxicity, apoptosis detection, and cell viability using the MTT assay protocol. At low concentrations (0.001 to 0.1 g/mL), these results showed that the CNT did not seem to cause cell death or apoptosis directly. It increased lymphocyte-mediated cytotoxicity against KB cell lines. This was demonstrated by the fact that the CNT increased the time it took for KB cell lines to die. In the end, the unique three-dimensional mixing method solves problems such as clumping and uneven mixing that have been written about in the relevant literature. Phagocytic uptake of MWCNT-reinforced PMMA nanocomposite by KB cells leads to oxidative stress and apoptosis induction in a dose-dependent manner. The cytotoxicity of the generated composite and the ROS (reactive oxygen species) it produces may be controlled by adjusting the MWCNT loading. The conclusion that can be drawn from the studies to date is that it could be possible to treat some types of cancer using PMMA that has MWCNTs incorporated into it.
Candidatus Scalindua, a Biological Solution to Treat Saline Recirculating Aquaculture System Wastewater
Authors: Micolucci Federico , Roques Jonathan A. C. , Ziccardi Geoffrey S. , Fujii Naoki , Sundell Kristina , Kindaichi Tomonori
Published: February 2023

Recirculating aquaculture systems (RAS) are promising candidates for the sustainable development of the aquaculture industry. A current limitation of RAS is the production and potential accumulation of nitrogenous wastes, ammonium (NH4+), nitrite (NO2−) and nitrate (NO3−), which could affect fish health and welfare. In a previous experiment, we have demonstrated that the marine anammox bacteria Candidatus Scalindua was a promising candidate to treat the wastewater (WW) of marine, cold-water RAS. However, the activity of the bacteria was negatively impacted after a direct exposure to RAS WW. In the current study, we have further investigated the potential of Ca. Scalindua to treat marine RAS WW in a three-phase experiment. In the first phase (control, 83 days), Ca. Scalindua was fed a synthetic feed, enriched in NH4+, NO2− and trace element (TE) mix. Removal rates of 98.9% and 99.6% for NH4+ and NO2−, respectively, were achieved. In the second phase (116 days), we gradually increased the exposure of Ca. Scalindua to nitrogen-enriched RAS WW over a period of about 80 days. In the last phase (79 days), we investigated the needs of TE supplementation for the Ca. Scalindua after they were fully acclimated to 100% RAS WW. Our results show that the gradual exposure of Ca. Scalindua resulted in a successful acclimation to 100% RAS WW, with maintained high removal rates of both NH4+ and NO2− throughout the experiment. Despite a slight decrease in relative abundance (from 21.4% to 16.7%), Ca. Scalindua remained the dominant species in the granules throughout the whole experiment. We conclude that Ca. Scalindua can be successfully used to treat marine RAS WW, without the addition of TE, once given enough time to acclimate to its new substrate. Future studies need to determine the specific needs for optimal RAS WW treatment by Ca. Scalindua at pilot scale.
Evaluation of Technical Feasibility of Solar Heat Integration in Agri-Food Industries
Authors: Guillen-Angel Julio , Julian Ignacio
Published: February 2023

This work assesses the use of different solar heating integration configurations and heating storage solutions for three different agri-food industries located in southern Europe. TRNSYS is employed to model different Solar Heat for Industrial Process (SHIP) integration options and to quantify the solar thermal share with respect to the overall thermal demand, as well as to estimate the avoided consumption of fuels and CO2 emissions in the existing boiler units as a result of the solar system integration. The SHIP integration is complemented with the evaluation of selected phase-change materials (PCM) to promote latent heat storage under the specific conditions of the considered agri-food demo sites and solar irradiation characteristics. The arrangement of flat-plate solar collectors coupled with latent heat storage was found to enhance the yearly averaged solar share of the SHIP solutions, reaching 13% of the overall thermal demand for an average Spanish winery demo site. Furthermore, the estimation of the gross solar heat production for a mid-size Italian spirits distillery yielded 400 MWh/y, leading to annual fossil fuel savings of 32 tons and yearly avoided CO2 emissions of up to 100 tons. Similarly, the SHIP integration model for an average French charcuterie predicted a 55% solar share of the thermal demand required for plant cleaning purposes, resulting in roughly 50 tons of CO2 emissions avoided per year. The estimated payback period (PBP) for the Italian spirits demo case under the current economic scenario is below 9 years, whereas the PBP for the other demos does not exceed the expected lifetime of the solar plants (25 years).
Digital-Rock Construction of Shale Oil Reservoir and Microscopic Flow Behavior Characterization
Authors: Wei Jianguang , Li Jiangtao , Yang Ying , Zhang Ao , Wang Anlun , Zhou Xiaofeng , Zeng Quanshu , Shang Demiao
Published: February 2023

In shale oil reservoirs, nano-scale pores and micro-scale fractures serve as the primary fluid storage and migration space, while the associated flow mechanism remains vague and is hard to understand. In this research, a three-dimensional (3D) reconstruction of the shale core and micro-pore structure description technique is established; digital core technology for shale reservoirs was developed using X-ray computed tomography (X-CT), scanning electron microscope (SEM) and a focused ion beam scanning electron microscope (FIB-SEM). Microscopic oil–water two-phase flow is mimicked using the lattice Boltzmann method (LBM), a well-acknowledged approach to exploring nanoconfined fluid dynamics. In addition, coupled with digital cores, the flow characteristics of shale reservoirs are characterized. The total porosities of bedding fractures in shale and lamellar shale are 2.042% and 1.085%, respectively. The single-phase oil flow inside bedding fractures follows Darcy’s linear flow principle. This work can deepen the understanding of the microscopic flow characteristics of continental shale reservoirs and provide a reference for similar problems that may be encountered.