Article
Environmental Sciences
Rosendo Mendoza, Carlos Araque-Perez, Bruna Marinho, Javier Rey, Mari Carmen Hidalgo
Summary: This study evaluate the detection ability of ground-penetrating radar (GPR) in detecting structures buried in conductive host materials. By using a 500 MHz shielded GPR antenna and applying predictive deconvolution flow and cover surfaces technique in data processing, the study successfully detected structures that were not visible in the default processing.
Article
Chemistry, Multidisciplinary
Zhi Sun, Na Cheng, Feng Chen, Xin-li Lou, Xia-yan Tong, Jian-wei Zhao, Hong-wen Zhang
Summary: Epoxy resin conductive adhesives with high electrical conductivity have been prepared by adding micron-scale silver-coated copper (Cu@Ag) particles. The properties of the Cu@Ag particles, such as corrosion resistance and oxidation resistance, were found to be improved under high-temperature conditions.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Physical
Na Cheng, Zhi Sun, Xiaohui Yu, Qianzhen Yu, Jianwei Zhao
Summary: In order to improve the conductivity and shear performance of epoxy resin-based adhesives, silver was deposited on the surface of 5 μm flake copper particles as a conductive filler using a simple, environmentally friendly, and stable method. The core-shell metal fillers were prepared by utilizing the autocatalytic properties of Cu without adding any reducing agent during the reaction. The structure of flake plated Cu@Ag particles was characterized, and it was found that a layer of compact and crystalline silver was deposited on the surface of copper particles, which positively affected the performance of silver-plated copper particles. The flake plated Cu@Ag particle-epoxy composite ECAs prepared by this method have excellent properties and significant application value for advanced electronic devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Construction & Building Technology
Dong Lu, Daiyu Wang, Jing Zhong
Summary: Traditionally, conductive fillers are mixed directly with cement matrix before binding with aggregates to develop piezoresistive cement-based sensors. This study proposes a strategy to construct a three-dimensional (3D) conductive network in the mortar with interfacial transition zone (ITZ) directly embedded in it, thus greatly increasing both the conductivity and piezoresistivity without significantly sacrificing mechanical property. Highly conductive graphene-coated fine aggregates (termed conductive G@FAg particles) are prepared and combined with carbon fibers to achieve outstanding electrical conductivity and selfsensing ability.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Materials Science, Multidisciplinary
Yong Wei, Min Wu, Shijie Sun, Jin Liu, Qilin Yue, Yuquan Chen
Summary: In this study, electrically detachable ionic conductive epoxy adhesives (IEPs) with ultra-high initial bonding strength were prepared by introducing poly(ethylene glycol) (PEG) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([BMIM]TFSI) into the epoxy. It was found that the bonding strength could be adjusted by the molecular weight of PEG, and an initial bonding strength of more than 20 MPa could be achieved. The IEPs were able to be completely and automatically detached by applying 60 V DC voltage within 1 min, and the electrically detaching mechanisms of IEPs were studied and linked to the electrodecomposition mechanism of [BMIM]TFSI.
ACS APPLIED POLYMER MATERIALS
(2023)
Review
Construction & Building Technology
Tim Klewe, Christoph Strangfeld, Sabine Kruschwitz
Summary: This article provides an overview of various approaches to moisture measurements with Ground Penetrating Radar (GPR) in civil engineering, emphasizing signal features and discussing their limitations. The study encourages the consideration of approaches that combine different signal features for further developments in the field.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Wengui Li, Wenkui Dong, Yipu Guo, Kejin Wang, Surendra P. Shah
Summary: This paper critically reviews the dispersion and percolation of carbon nanomaterials in smart cementitious composites and their effects on the electrical and piezoresistive performances. The challenges and perspectives for future development of self-sensing stability, data acquisition system, and sensor configuration are proposed.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Materials Science, Multidisciplinary
Matteo Solazzo, Michael G. Monaghan
Summary: PEDOT:PSS is an emerging biomaterial with applications in various biomedical technologies, and researchers are focusing on producing 3D scaffolds from it. The use of PEGDE as a crosslinking reagent improves the performance of PEDOT:PSS, resulting in 3D porous biomaterial sensors with unique mechanical and electrical features.
Article
Polymer Science
Qianyu Zhang, Gaoxiang Xu, Antonio Pizzi, Hong Lei, Xuedong Xi, Guanben Du
Summary: Glyoxal is a promising substitute for formaldehyde in wood bonding. However, the performance of glyoxal-based resin is not satisfactory, particularly in terms of water resistance. This study presents a method to prepare an eco-friendly glyoxal-based adhesive with excellent bonding performance. The adhesive, named CHG resin, is synthesized by reacting citric acid and hexamethylene diamine with glyoxal. The plywood bonded with CHG resin shows superior dry and wet shear strength, surpassing the standard requirements. It also maintains high strength even after immersion in hot water. Consequently, CHG resin has the potential to replace UF and MUF adhesives for wood composites in industrial applications.
Article
Chemistry, Multidisciplinary
Yiwei Gao, Jie Zhao, Zehuan Huang, Tanya K. Ronson, Fen Zhao, Yue Wang, Boyang Li, Chenlu Feng, You Yu, Yongliang Cheng, Dong Yang, Xiao-Juan Yang, Biao Wu
Summary: This study demonstrates the fabrication of functional gels through the self-assembly of anion-coordinated assemblies. The obtained gels exhibit excellent flexibility and selective wettability, making them suitable for conductive adhesion between different surfaces.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Green & Sustainable Science & Technology
Natalia Cardona-Vivas, Mauricio A. Correa, Henry A. Colorado
Summary: This study developed a new composite material made from vinyl-acrylic resin and primary battery waste, showing promising mechanical properties and conductivity for electronic applications. By comparing the performance of different formulations, the optimal composition was identified, and important conclusions were drawn from the tests conducted.
SUSTAINABLE MATERIALS AND TECHNOLOGIES
(2021)
Article
Engineering, Environmental
Yang Liu, Xing Zhang, Bingrui Li, Hongjie Chen, Haofei Li, Junlin Chen, Hua Dong
Summary: Hydrogels have been widely used for flexible wearable strain sensors, but dehydration and low temperature intolerance limit their performance. Eutectogels (EGs) show low temperature tolerance and ionic conductivity, but they are unstable due to water absorption. This study proposes a novel eutecto-/hydro-gel (EHG) concept with super stability, high ionic conductivity and transparency. EHG maintains a dynamic balance between hydration and dehydration, resulting in better long-term sensing performance. Additionally, by integrating photonic crystals, a dual-mode flexible wearable strain sensor is created, improving sensing accuracy.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Energy & Fuels
Ruisheng Wang, Peer Haller
Summary: Wood resources have been widely used throughout human society, and the increasing demand for wood has resulted in the production of large quantities of wood ash waste each year. This paper explores the possibility and potential of using wood ash in civil engineering and discusses research questions and suggestions to improve the commercialization and valorization of wood ash.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Chemistry, Physical
Qi Cao, Yuke Li, Yixin Zhang, Junsong Zhao, Tong Wang, Bowen Yang, Xingyu Pu, Jiabao Yang, Hui Chen, Xingyuan Chen, Xiaoqiang Li, Shahnaz Ghasemi, Hadi Salari, Anders Hagfeldt, Xuanhua Li
Summary: In this study, a wide-bandgap n-type semiconductor B4PyPPM was introduced to modify the perovskite film via an anti-solvent method. This modification reduced trap state densities and inhibited nonradiative recombination, resulting in improved efficiency and stability of the perovskite film.
ADVANCED ENERGY MATERIALS
(2022)
Article
Food Science & Technology
Lei Chen, Jing Li, Zia-ud Din, Chun Hu, Hanguo Xiong
Summary: This study compares the performance of wood adhesives containing different nanoparticles and finds that surface modification can improve dispersion, highlighting the importance of selecting appropriate functional nanoparticles in designing high-performance wood adhesives.
Article
Engineering, Chemical
Elfriede M. Hogger, Hendrikus W. G. Van Herwijnen, Johann Moser, Wolfgang Kantner, Johannes Konnerth
Summary: This study focuses on the performance of wheat flour components, starch and protein, as additives to UF and PF resins in plywood production. The results show that wheat protein has the most promising wet shear strength results for both resins, but its high viscosity limits the addition to 30%. In addition, adding wheat flour and wheat starch to UF resins can provide sufficient wet shear strengths.
JOURNAL OF ADHESION
(2021)
Article
Engineering, Chemical
Elfriede M. Hogger, Hendrikus W. G. van Herwijnen, Johann Moser, Wolfgang Kantner, Johannes Konnerth
Summary: This study found that wheat protein is the most effective additive for both urea formaldehyde and phenol formaldehyde resins. The addition of wheat flour, wheat starch, and wheat protein had an impact on the structure, pH value, and buffer capacity of the resins, but did not affect the curing behavior of the resins.
JOURNAL OF ADHESION
(2021)
Article
Forestry
Maximilian Pramreiter, Alexander Stadlmann, Christian Huber, Johannes Konnerth, Peter Halbauer, Georg Baumann, Ulrich Mueller
Summary: The study investigates the influence of thickness and load angle on the tensile strength and tensile stiffness of peeled veneers compared to thin sawn timber. Results show a size effect for strength parallel to the grain, with significant variations in strength perpendicular to the grain based on thickness. The presence of lathe checks diminishes the strength of veneers compared to solid wood, highlighting the need for further research.
Article
Polymer Science
Catherine Thoma, Pia Solt-Rindler, Wilfried Sailer-Kronlachner, Thomas Rosenau, Antje Potthast, Johannes Konnerth, Alessandro Pellis, Hendrikus W. G. van Herwijnen
Summary: This study analyzed the curing process of carbohydrate-amine adhesives with and without 5-hydroxymethylfurfural (HMF), a key reactant in biomass-derived adhesives. The addition of HMF was found to reduce the activation energy of the curing reaction, thus increasing reactivity. Rheological measurements provided insights into the structure formation of the cured polymer and showed a deviation from homogeneous curing in the viscosity profile.
Article
Forestry
Christoph Winkler, Stefan Haase, Ulrich Schwarz, Markus Jahreis
Summary: Laboratory studies have shown that polymer films filled with electrically conductive filler can be used as piezoresistive material in adhesive applications for wood products, achieving multifunctional bonding and piezoresistive/strain sensing properties. Upscaled test setups were designed for simplified load situations in timber constructions, with a focus on stress-free electrical contact.
WOOD SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Paper & Wood
Claudia Gusenbauer, Karolina Peter, Etienne Cabane, Johannes Konnerth
Summary: Chemical force microscopy allows visualization of chemical nano-properties of materials and analysis of their surface behavior, making it valuable for studying natural substrates like wood. By studying adhesion forces and pK(a) values, this method provides insights into the complex chemical surface properties of materials.
Article
Engineering, Chemical
Elena Averina, Johannes Konnerth, Hendrikus W. G. van Herwijnen
Summary: This study used corn gluten protein, potato protein, and pea protein isolate as natural raw materials for preparing bio-based environmentally friendly adhesives. Glyoxal and polyethyleneimine were used as crosslinking agents. The results showed that crosslinking by glyoxal and polyethyleneimine effectively improved the bonding performance of the protein-based adhesives after water storage.
JOURNAL OF ADHESION
(2023)
Article
Engineering, Chemical
Cedou Kumpenza, Maximilian Pramreiter, Tobias Josef Nenning, Peter Bliem, Rainer Reiterer, Johannes Konnerth, Ulrich Mueller
Summary: This study investigated the tensile modulus of four common polymer-based wood adhesives at different temperatures and found a significant influence of temperature on the tensile modulus. The results showed that the highest tensile moduli were observed at -30 degrees C and decreased significantly with increasing temperature.
JOURNAL OF ADHESION
(2023)
Article
Energy & Fuels
Wilfried Sailer-Kronlachner, Catherine Rosenfeld, Stefan Boehmdorfer, Markus Bacher, Johannes Konnerth, Thomas Rosenau, Antje Potthast, Andreas Geyer, Hendrikus W. G. van Herwijnen
Summary: A batch reaction system with a volume of 1L was developed for the scaled-up production of 5-HMF-based adhesive precursor solutions from industrially available fructose syrup. The stabilizing effect of sodium dithionite addition was demonstrated. The optimized reaction system allows the production of reaction solutions with appropriate 5-HMF concentrations for adhesive synthesis without the need for concentration steps.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Engineering, Chemical
Babureddy Ramachandrareddy, Hendrikus W. G. van Herwijnen, Greeley Beck, Ronny Bredesen, Johannes Konnerth
Summary: According to Eurocode/ European standard, the design of timber structures and wood-based panels for different expected uses is divided into various service classes, taking into account the moisture ranges that may be encountered. It has been observed that the moisture content in the adherend significantly affects the bond lines of wood-adhesive joints. In this study, nanoindentation was used to investigate the influence of moisture on the mechanical properties of commonly used wood adhesive systems. The results showed that different adhesive systems exhibited varying degrees of stability under different relative humidity levels.
INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
(2022)
Article
Polymer Science
Elena Averina, Johannes Konnerth, Hendrikus W. G. van Herwijnen
Summary: The use of proteins obtained from starch production as wood adhesives was investigated. The addition of glyoxal as a crosslinking agent improved the wet strength of protein-based adhesives. The pH level had a significant effect on the wet strength.
Article
Chemistry, Physical
Catherine Rosenfeld, Pia Solt-Rindler, Wilfried Sailer-Kronlachner, Thomas Kuncinger, Johannes Konnerth, Andreas Geyer, Hendrikus W. G. van Herwijnen
Summary: This study evaluates the performance of laboratory-made, single-layered particleboards using fructose-hydroxymethylfurfural-bishexamethylenetriamine (SusB) adhesive as a sustainable alternative. The effects of production parameters on bonding efficiency were investigated, with moisture content having the highest impact on the internal bond strength of SusB-bonded particleboards. By reducing the moisture content, the internal bond strength surpasses the European standard requirements. However, further research is needed to improve the dimensional stabilization of SusB-bonded particleboards.
Article
Engineering, Chemical
Christoph Winkler, Johannes Konnerth, Matthias Finger, Ulrich Schwarz, Benjamin Arminger
Summary: Wood adhesive bond lines are often assumed to be chemically and mechanically homogeneous, but this study finds that there are variations in their mechanical and chemical properties. Different filtration mechanisms of the wood adherend or porous barriers formed by filler particles contribute to differences in filler distribution. These findings suggest that assuming the wood bond line as a homogeneous material in micromechanical modeling of adhesive bonds may not be valid.
JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Chemical
Elena Averina, Johannes Konnerth, Hendrikus W. G. van Herwijnen, Kaichang Li
Summary: Poly (styrene-4-vinylbenzyl chloride) (PSVBC) was synthesized and used in protein adhesives for bonding maple veneers. The effects of various factors on shear strength and water resistance were studied. PSVBC improved the wet shear strength of potato and corn protein adhesives, but not pea protein adhesive.
JOURNAL OF ADHESION
(2023)
Article
Materials Science, Multidisciplinary
Latifeh Nasseri, Catherine Rosenfeld, Pia Solt, Matthias Mihalic, Andreas Kandelbauer, Johannes Konnerth, Hendrikus W. G. van Herwijnen
Summary: This study compares the gel point and crossover point of formaldehyde-based wood adhesives using the isothermal multiwave oscillatory shear test. Rheokinetic analysis shows no significant difference in activation energies between the gel point determined by the multiwave test and the crossover point obtained by the time sweep test.
ACS APPLIED POLYMER MATERIALS
(2023)
