This study investigates the durability of silicone-based membranes in contact with hempcrete under combined moisture and temperature exposure. Membrane specimens were aged in contact with non-treated and treated hempcrete under dry and wet conditions at temperatures up to 90 °C. The evolution of chemical, thermal, and microstructural properties was characterized using FTIR, TGA, DSC, optical microscopy, and SEM-EDS analyses. Results show that dry exposure does not induce measurable changes in membrane structure or performance, confirming that temperature alone is not a critical degradation factor. In contrast, wet exposure leads to significant chemical, thermal, and microstructural changes in the membrane, including degradation of the siloxane network, reduced polymer chain mobility, and the formation of calcium-rich mineral deposits at the interface. These results indicate that membrane degradation is governed by a coupled moisture-ion mechanism involving ion transport, mineral deposition, and hydrolysis of the polymer network. Fiber treatment slightly reduces the aggressiveness of the leachate but does not prevent degradation under wet conditions. Overall, moisture availability and leachate chemistry are identified as key factors controlling the durability of silicone membranes in contact with bio-based materials.

Water-resistive barriers (WRBs) are the type of building membranes that play a critical role in protecting structures from environmental loads, such as wind-driven rain, and thereby prevent moisture-related issues that may affect a building’s performance. As such, understanding the hygric behavior of these membranes is crucial to ensuring the long-term performance of the building envelope. Water pressure resistance is an important material characteristic for WRBs to resist certain environmental loads. This property is assessed and compared by hydrophobicity and tensile stiffness, which probe surface and structural characteristics, respectively. Hydrophobicity refers to the repulsion of water from the material’s surface, while tensile stiffness influences its water permeability resistance by maintaining structural integrity against expansion or contraction. Resistance to water permeability demonstrates the material’s resistance to water penetration under pressure. Consequently, three types of WRBs were assessed in this study: a spun-bonded polyolefin film, a rubberized asphalt compound laminated olefin film, and an asphalt-saturated heavy kraft paper. The data on water pressure resistance and hydrophobicity were obtained using two experimental tools, respectively: a hydrostatic head tester and a contact angle goniometer. Whereas, the tensile stiffness data were sourced from the literature. Additionally, high-resolution image microscopy was utilized to capture the surface topography of the membranes. The findings reveal that tensile stiffness alone cannot confer resistance to water permeability when the hydrophobicity of the membrane is lower than that of its counterparts. In this condition, hydrophobicity can act as a controlling factor in determining the resistance to water permeability of membranes.

Long-term performance of silicone-based, fluid-applied membranes used as moisture barriers on conventional concrete and the emerging bio-based building material, hempcrete, was evaluated under a controlled accelerated aging program for up to one year. A combination of thermal - Thermogravimetric Analysis and Differential Scanning Calorimetry; chemical - Fourier Transform Infrared Spectroscopy; and microstructural - Scanning Electron Microscopy coupled with Dispersive X-ray Spectroscopy - analyses was employed to examine the influence of temperature, moisture, and substrate chemistry on membrane degradation. Under dry conditions, the membranes showed no substantial thermal, chemical, or microstructural degradation on either substrate, indicating that temperature alone, up to 90 degrees C, was insufficient to compromise membrane structure. Under wet conditions, however, degradation strongly depended on chemistry generated by the adjacent substrate. In contact with wet concrete, the membrane showed pronounced degradation at elevated temperatures, particularly at 70 and 90 degrees C, where high alkalinity and enhanced leaching of alkaline, calcium-bearing, and other cementitious species led to reduced thermal stability, loss of polymer integrity, and chemically heterogeneous mineralrich surface deposits. In contrast, under wet hempcrete exposure, the membrane showed comparatively stable thermal and chemical behavior at 70 and 90 degrees C. Localized Ca-O-C-rich deposits and surface discoloration were observed, but the primary silicone-related thermal and chemical signatures remained largely unchanged. Longterm assessment at room temperature and 50 degrees C was not feasible because mould growth caused early termination of these conditions. An Arrhenius-based thermal degradation analysis indicated temperature and pH coupling as the primary factor governing degradation. In wet concrete, increasing temperature increased alkalinity and accelerated degradation, whereas in wet hempcrete, increasing temperature reduced alkalinity, likely due to enhanced release of hemp-derived soluble organic compounds. These results highlight the distinct substrate-membrane interactions in hempcrete versus conventional systems and emphasize the need to consider coupled thermal-chemical effects when designing durable moisture barriers for sustainable building envelopes.

Wood is susceptible to various degradation mechanisms when exposed to dynamic environmental conditions, including hydrolysis caused by the infiltration of water into the wood cell structure. This study aims to examine the differences between the effects of two types of accelerated aging on the long-term performance of white spruce wood samples to have a better understanding of the performance of spruce wood in real-world applications. Two separate sets of samples were employed in this experimental study. One set was placed in a hydrolytic aging chamber at 90 °C and 80

Building membranes, specifically those designed as water-resistive barriers (WRBs), play a pivotal role in construction, serving as protective barriers against moisture infiltration from environmental stresses like wind-driven rain, thereby influencing the durability of buildings. As these materials age, changes in their structure can significantly affect their performance in resisting water ingress, with potential implications for the durability of building structures. Therefore, this research investigates the transformative effects of hygrothermal aging on the water-resistance performance, hydrophobicity, chemical integrity, and thermal resistance of the WRBs with a specific focus on non-woven polyethylene, self-adhesive polyethylene, and asphalt-saturated kraft paper, which represent a diverse array of materials commonly used in the construction industry. Two distinct combinations of hygrothermal conditions were designed to age the sample which are 90% RH at 70°C and 40% RH at 40°C, over different time spans of up to eight months. Water pressure resistance was evaluated using a hydrostatic head tester to assess the membranes' ability to withstand water pressure under various aging conditions. Hydrophobicity, a critical characteristic influencing moisture management, was determined through contact angle measurements. Additionally, Fourier Transform Infrared Spectroscopy (FT-IR) was used to detect chemical changes in membrane composition. The thermal stability of the WRBs was also analyzed by thermal gravimetry analysis (TGA). The study shows that aging leads to a slight reduction in the average of water pressure resistance, indicating slight decreases in barrier effectiveness. For contact angle, no significant change is observed in the hydrophobicity of building paper but a very slight decrease in Spun-bonded Poly Olefin film (SPBO) and self-adhesive film. FTIR analysis reveals subtle oxidation changes in building paper, while TGA indicates only minor thermal stability degradation on this membrane and no significant alternation in the chemical integrity of SBPO and self-adhesive film.

Organic solar cells (OSCs) can be highly affected by environmental stresses like heat, moisture, and sunlight during their service life if they are not encapsulated or if the encapsulation leaks. A deep understanding of how each individual organic layer changes/reacts to various environmental factors is a crucial aspect in designing an effective OSC architecture to ensure the longevity and stability of the materials toward the device's performance. While there are numerous examples of encapsulated OSCs operating outdoors for extended periods of time, there is an insufficiency of information available about the individual stability of the materials involved. The focus of this study is to provide a quantitative assessment of the individual unencapsulated OSC layers when they are exposed to combinations of heat, humidity, and light. Ideally, a similar process can be applied to different organic nanolayers in the future, and the results can be used as a reference. Throughout the accelerated aging process, the most impactful environmental stressor was the presence of strong light. Via UV-vis and fluorescence data acquisition, the chloro-boron subphthalocyanine (Cl-BsubPc) layer was observed to be altered by some combination of hydrolysis and nanostructural change, from the strong incident light, which was not observed if aged in the dark. We also observed significant nanolayer film crystallization for other materials when exposed to humid heat and an increase in film hydrophilicity during the aging process. The nanolayer film crystallization could have also contributed to the loss of pi-conjugation/color, which may not have undergone complete photobleaching. Though there were property changes throughout the accelerated aging process, we feel that the relatively long time scale of most changes highlights a characteristic material stability that would translate strongly to standard operating conditions in encapsulated devices. Adopting these methodologies can also be useful to guide further material development broadly in particularly susceptible materials in the future.

Ground tire rubber (GTR)-filled bituminous crack sealants are widely used to repair the cracks generated over the service life of asphalt pavements stemming from long-term exposure to the natural environment and cyclic stresses from traffic loads. GTR content plays a crucial role in the field performance of GTR-filled bituminous crack sealants. Thus, the accurate measurement of GTR content is of paramount importance to predict the performance of the sealant, including pouring viscosity, adhesion to asphalt concrete, and flow ability into micro-voids within the crack. Here, a visual technique was proposed to evaluate non-destructively the GTR content of bituminous crack sealants. The method was applied to several commercial bituminous crack sealants of unknown composition. The results of the optical non-destructive method were also compared to those from the traditional destructive method, which consisted of the combination of solvent extraction and pyrolysis of the residual solid. An acceptable level of linear correlation between the two methods, 0.80, verifies the capability and reliability of the proposed non-destructive visual method of quantifying GTR content in bituminous crack sealants having a uniform background in optical microscope images.

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to "Assessing Individual Material Degradation toward Organic Solar Cells Using Accelerated Nanolayer Lifetime Protocols: Implications for Solar Cell Longevity"Adam R. TetreaultAdam R. TetreaultDepartment of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto M5S 3E5, Ontario, CanadaMore by Adam R. Tetreaulthttps://orcid.org/0000-0002-0870-5772, Itzel Lopez-CarreonItzel Lopez-CarreonConstruction Research Center, National Research Council Canada, 1200 Montreal Rd., Ottawa K1A 0R6, Ontario, CanadaMore by Itzel Lopez-Carreon, Marzieh RiahinezhadMarzieh RiahinezhadConstruction Research Center, National Research Council Canada, 1200 Montreal Rd., Ottawa K1A 0R6, Ontario, CanadaMore by Marzieh Riahinezhad, Elnaz EsmizadehElnaz EsmizadehConstruction Research Center, National Research Council Canada, 1200 Montreal Rd., Ottawa K1A 0R6, Ontario, CanadaMore by Elnaz Esmizadeh, Peter CollinsPeter CollinsConstruction Research Center, National Research Council Canada, 1200 Montreal Rd., Ottawa K1A 0R6, Ontario, CanadaMore by Peter Collins, Kamran Alasvand ZarasvandKamran Alasvand ZarasvandDepartment of Mechanical & Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Ontario, CanadaMore by Kamran Alasvand Zarasvand, Naren VivekanandanNaren VivekanandanDepartment of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto M5S 3E5, Ontario, CanadaMore by Naren Vivekanandan, Ajinkya MandlikAjinkya MandlikDepartment of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto M5S 3E5, Ontario, CanadaMore by Ajinkya Mandlik, Michelle FernandesMichelle FernandesDepartment of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto M5S 3E5, Ontario, CanadaMore by Michelle Fernandes, Kevin GolovinKevin GolovinDepartment of Mechanical & Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Ontario, CanadaDepartment of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto M5S 3E4, Ontario, CanadaMore by Kevin Golovinhttps://orcid.org/0000-0001-8309-7458, and Timothy P. Bender*Timothy P. BenderDepartment of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto M5S 3E5, Ontario, CanadaDepartment of Mechanical & Industrial Engineering, University of Toronto, 5 King's College Road, Toronto M5S 3G8, Ontario, CanadaDepartment of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto M5S 3E4, Ontario, CanadaDepartment of Chemistry, University of Toronto, 80 St. George Street, Toronto M5S 3H6, Ontario, Canada*Email: [email protected]More by Timothy P. Benderhttps://orcid.org/0000-0002-6086-7445Cite this: ACS Appl. Nano Mater. 2024, 7, 9, 11021Publication Date (Web):May 2, 2024Publication History Received17 April 2024Published online2 May 2024Published inissue 10 May 2024https://pubs.acs.org/doi/10.1021/acsanm.4c01679https://doi.org/10.1021/acsanm.4c01679correctionACS PublicationsCopyright © 2024 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views73Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (1008 KB) Get e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Understanding the degradation behaviour of organic photovoltaic (OPV) devices is an essential part to improve their stability prior to massive production. Accelerated aging can help to assess their stability and study the underlying degradation mechanisms of OPVs. Most studies focus on individual layers or a full device, and little is known about the role a pre-aged layer stack plays in the performance of a device. Herein, we report the investigation of the effects of pre-aging of multiple layers on the performance of OPVs. Instead of aging a single layer or an entire stack (sequential layers: ITO/PEDOT:PSS/MoOx/F-BsubPc/C60/BCP/Ag), our process involved aging the intermediate layer stack for 24 h after depositing a specific layer before continuing with the subsequent depositions to fully fabricate/manufacture OPVs. Aging was conducted under four controlled conditions considering parameters including moisture, gas type, and temperature in the absence of light according to the International Summit on Organic Photovoltaic Stability (ISOS) protocols. Short of PEDOT:PSS we found that multiple layers, being subjected to the parameters, resulted in a decline in OPV device performance after being fully manufactured. Device performance is evaluated based on short-circuit current density (Jsc), power conversion efficiency (PCE), and open-circuit voltage (Voc). Our analysis provides insight into the degradation mechanisms of layered/planar OPV structures and offers strategic guidance for optimizing fabrication processes, particularly during the layer deposition transitions. We recommend that during OPV vacuum deposited fabrication, intermediate layers should be protected from moisture, O2, high temperature, and even inert gases, preferably in a low-vacuum environment. Illustration of fabrication process of F-BsubPc/C60 device with pre-aged intermediate layer stack. image

Three room-temperature fluid-applied silicone membranes intended for application in building envelopes were studied in this work. The membranes were subjected to accelerated UV and moisture aging for 5000 h to evaluate their resistance to long-term aging. The properties of the membranes were studied to understand the degradation mechanisms that might occur during accelerated aging. The weight loss, wetting propensity, cracking and oxidation resistance, and storage modulus were measured at different intervals during 5000 h of aging. Based on the material characterization results, the silicone membranes proved to be resilient under aggressive accelerated UV radiation and moisture aging, conditions that can be expected as a result of climate change.

This research investigates the aging resistance of a silicone product exposed to highly alkaline conditions. A silicone membrane was immersed in a pH 13.5 solution and aged up to 30 days at four temperatures between 40 C and 70 C. The effects of alkaline aging on morphology, mechanical properties, thermal properties and surface chemistry of the alkaline-exposed silicone membranes were scrutinized by various techniques. On alkaline solution aging, both surface and bulk morphology and chemical structure were found to evolve as the silicone membrane experienced toughness deterioration. After failure criteria were established based on practical considerations, the service life of the silicone product was estimated using the Dakin-Arrhenius model, which provided for a cross-linking activation energy of 60 kJ/mol. The calculated service life of over one year for silicone membranes revealed alkaline immersion provides significant aging acceleration, although prediction of silicone performance in contact with concrete in field situations requires further investigation.

Roofing membranes produced with ketone-ethylene-ester (KEE) and polyvinyl chloride (PVC) are defined within the standard specification for KEE-based sheet roofing, ASTM D6754, Standard Specification for Ketone Ethylene Ester Based Sheet Roofing, in which it is specified that such membranes must contain at least 50% (wt.) KEE. Until the recent release of ASTM D8154, Standard Test Methods for 1H-NMR Determination of Ketone-Ethylene-Ester and Polyvinyl Chloride Contents in KEE-PVC Roofing Fabrics, in which the determination of KEE content is based on nuclear magnetic resonance (NMR) spectroscopy, no method was sufficiently precise or accurate to measure the KEE content within 1% or better. In this paper, a description is provided of the development and the basic process behind the use of 1H-NMR to establish KEE content in KEE/PVC membranes as described in ASTM D8154. To develop a quantitative method to assess KEE concentration in roofing membranes, several NMR approaches were used, including both solid-state and liquid-state NMR. Approaches using solid-state NMR, including carbon-13 and proton spectroscopy, proved inadequate for the quantification of KEE because of insufficient spectral resolution. Liquid-state NMR proved to be a better approach, but accurate results are achieved only after the KEE-PVC blend is extracted from the roofing membrane through a multistep process. The liquid-state NMR work led to two methods to quantitatively measure the KEE content in blends with PVC. Method A is the simplest, and its accuracy is better than 2.3%. Method B is more protracted, but its accuracy is better than 0.6%.

Structural insulated panels (SIPs) with skins of oriented strand boards (OSB) are increasingly used to build energy efficient dwellings. SIPs are sandwich-like construction products where stress-bearing facer panels are located on both sides of a core of rigid insulation. The lack of knowledge of SIPs amongst home builders and the lack of public data on engineering properties and durability of OSB-SIPs currently limit their use. This is particularly the case in Canada, where the National Building Code of Canada requires that new construction products demonstrate similar service lives to traditional materials. The National Research Council of Canada, in collaboration with suppliers of SIPs and SIP components and Alberta Innovates, have recently addressed issues related to the performance and durability of SIPs for the Canadian construction market. The goal of the work was to develop a basic laboratory programme for the accelerated aging of SIP and help to establish a test protocol to evaluate SIPs for durability. In this chapter, details are provided on elements to assess SIP durability when subjected to conditions that simulate key parameters of the Canadian climate as may occur in-service over their expected life. In service, SIPs are exposed to physical and chemical aging. The physical processes include cyclic weathering conditions, whereas the chemical processes include oxidation and hydrolysis. The results of testing indicate that all SIP components are subject to aging deterioration under a simulated 20–50-year service life, and that aging deterioration can begin relatively early during service. Six failure modes were obtained from the tensile testing of aged SIP coupons, and these modes serve to diagnose the durability of individual SIP components. The results from this test program were used to develop guidelines to assess SIP durability.

Temperature and relative humidity (RH) data within the building envelope of a single-family home at the National Research Council of Canada’s Canadian Centre for Housing Technology were collected over five years. We report on the distribution, rate of change, and the limits of temperature and moisture variations for south-easting wall and south-facing wall and roof systems to better understand the in-situ environmental conditions to which building materials and components typical of homes in North America may be subjected. Over an average year, wall temperature varied from −25 °C to +45 °C, and temperature followed a bimodal distribution, with maxima at 0 °C to 5 °C and 15 °C to 20 °C. Each maximum represented about 1100 h of field exposure. Roof temperatures, which spanned a temperature range from −35 °C to 75 °C, did not show a Gaussian distribution but were characterized as being multi-modal. From values of temperature and RH, absolute moisture contents within the building envelope were found to range between 1 and 55 g/m3, with the most common values being 6–8 g/m3. The application of this information is discussed and related to the development of realistic accelerated aging conditions to obtain a more accurate durability assessment of building envelope materials used in Canadian dwellings.

Bituminous sealants used in the maintenance of roadways are installed hot and heated to 150–200°C during installation. High temperatures can degrade polymers in sealants, but there is no standard method to account for this possible degradation. In an attempt to find such a method, the aging of two sealants in large kettles during field applications was compared to that obtained in the laboratory by heating in a small kettle. The results indicate that 4 h of small kettle aging at the highest suggested sealant application temperature (HiSAT), or about 2 h at HiSAT + 10°C, provided as much copolymer aging as that found in sealants sampled midway through installation. Keywords: agingasphaltbitumenpolymerdegradationsealants Acknowledgements This work was supported by the Canada–USA Crack Sealant Consortium, also known in the USA as the Federal Highway Administration Pool-Fund TPF5(045). Its members are listed in Collins et al. (2008 Collins, P. 2008. Deformation and tracking of bituminous sealants in summer temperatures: pseudo-field behaviour. International Journal of Pavement Engineering, 9(1): 1–8. [Taylor & Francis Online] , [Google Scholar]).