Search Results (60)

As urbanization and extreme weather conditions intensify, the comprehensive performance requirements for building waterproofing systems are becoming more demanding. Single-layer waterproof membranes often struggle to meet usage requirements in complex environments, leading to the gradual rise of composite waterproof systems. This paper selects three different types of waterproof membranes, ultra-thin reinforced self-adhesive polymer-modified bitumen waterproof membrane, polymer self-adhesive waterproof membrane, and polymer-modified bitumen root penetration-resistant waterproof membrane, and conducts a systematic study on their compatibility and durability. Through tensile performance, low-temperature flexibility, and peel compatibility tests, combined with thermal oxidative aging experiments at different aging times, the mechanical behavior, low-temperature adaptability, and interfacial bonding characteristics of the membranes were analyzed. The results show that the three membranes differ significantly in tensile performance. The root penetration-resistant membrane has the highest strength but is more brittle, the polymer self-adhesive membrane has lower strength but better stability, and the ultra-thin reinforced membrane performs better initially but lacks durability. In terms of low-temperature flexibility, the root penetration-resistant membrane demonstrates superior crack resistance and aging resistance. These divergent aging responses are closely related to differences in reinforcement structure, polymer modification, and the thermal–oxidative sensitivity of the bituminous adhesive layers. Peel compatibility tests show that the peel strength of the composite membranes of the ultra-thin reinforced and polymer self-adhesive membranes is significantly improved, indicating a good synergistic effect and compatibility. Overall, different waterproof membranes exhibit distinct compatibility mechanisms and aging patterns in composite applications, providing a scientific basis for the design and optimization of composite waterproof systems. Full article

Waterproofing systems frequently experience performance degradation during long-term service due to material aging and structural deformation, thereby necessitating localized repair interventions. The bonding interface between newly applied and existing membrane materials is a critical determinant of repair effectiveness. In this study, the aging-dependent repair performance of three representative waterproof membrane systems was systematically investigated using peel strength testing, low-temperature flexibility assessment, and interfacial morphology analysis under thermal–oxidative aging for 2, 5, 14, and 28 days. The results demonstrate that the homogeneous repair system based on ultra-thin reinforced self-adhesive polymer-modified bituminous membranes exhibits superior overall performance, maintaining the highest peel strength with only minor degradation even after 28 days of accelerated aging. In contrast, the polymeric butyl self-adhesive membrane subjected to homogeneous repair exhibited rapid adhesion degradation after 14 days, whereas the heterogeneous repair system showed improved stability during intermediate aging stages. Low-temperature flexibility testing further revealed that root-resistant bituminous membranes exhibited a slower aging rate, with a cracking temperature increase of 7 °C after 28 days, compared to a 10 °C increase observed for ultra-thin self-adhesive membranes. These quantitative findings provide clear guidance for the selection of appropriate repair membrane systems under varying aging conditions in waterproofing engineering, particularly for maintenance and rehabilitation applications. Full article

This study is based on in situ structural test sections and systematically explains the construction processes and key control points of different waterproofing methods by optimizing the self-waterproofing of structural concrete, controlling the installation process of external waterproofing membranes, and managing quality throughout the construction process. For various materials such as polymer-coated waterstops, steel-edged rubber waterstops, and composite grouting pipes with water-swelling strips, the waterproofing performance under the corresponding processes was analyzed through a combination of experiments and numerical simulations. The research focuses on investigating the influence of material selection and construction techniques on waterproofing effectiveness, clarifying the applicable conditions and performance differences among various materials and techniques. The results indicate that polymer-coated waterstops perform significantly better than other materials; self-compacting concrete causes minimal disturbance to waterstops, which is beneficial for waterproofing, but it exhibits deficiencies in early-age crack resistance; refined control of construction techniques plays a decisive role in the overall performance of the waterproofing system. Consequently, detailed construction quality control specifications for the main structure and its components were developed. Full article

Background: Effective prevention of jellyfish stings is crucial for human safety during marine activities. Traditional protective methods are often limited in terms of coverage area and duration of protection; Methods: This study designed and tested a novel jellyfish-repellent textile by coating waterproof polyester fabric with copper ion-loaded multicompartmental nanoparticles, which repel jellyfish by disrupting their cellular membranes and physiological functions. The nanoparticles were synthesized to enable spatial separation of components, enhance stability, and allow controlled copper ion release. They were applied to the fabric in one step via high-voltage electrostatic spray technology, followed by characterization using SEM and FT-IR. The copper sulfate release profile and nanoparticle adhesion were analyzed. Jellyfish-repellent efficacy was evaluated, along with biocompatibility tests including skin sensitization (Magnusson and Kligman method), skin irritation (Draize test), and cytotoxicity (MTT assay on L929 cells and human dermal fibroblasts). Results: SEM confirmed the formation of uniform multicompartmental nanoparticles with sizes ranging from 2.28 to 3.15 μm. FT-IR verified successful anchoring of Cu²⁺ ions to fabric fibers through coordination with hydroxyl groups. Drug release tests demonstrated water-triggered controlled release of copper ions lasting over 168 h, with nanoparticle retention rates exceeding 70% on all fabrics. The textile showed significant effectiveness in repelling jellyfish. Moreover, no apparent sensitization, irritation, or cytotoxicity was observed. Conclusions: A novel jellyfish-repellent textile was successfully developed using copper ion-loaded multicompartmental nanoparticles. This textile provides a promising solution for preventing jellyfish stings and contributes to the advancement of protective gear for marine activities. Full article

Outdoor sportswear increasingly demands multifunctional performance, including waterproofness, breathability, and intelligent thermal regulation. Nanofiber membranes, especially those prepared via electrospinning, offer a promising platform due to their tunable pore structures, high specific surface area, and ease of functionalization. This review outlines progress from fabrication to multifunctional integration, highlighting key quantitative advances: electrospun membranes achieve water vapor transmission rates >10,000 g·m⁻²·day⁻¹ with hydrostatic pressure resistance of 80–150 kPa, and thermal conductivity as low as 0.033–0.040 W·m⁻¹·K⁻¹. We analyze how structural designs enable tailored functionalities for diverse outdoor scenarios. The review’s key contributions include establishing a clear “process-structure-function” framework, critically comparing nanofiber membranes with conventional materials, and identifying industrialization challenges—scalability, durability, cost—while pointing toward smart, sustainable, and customizable future directions. Full article

Underwater acoustics is the optimal method for long-distance information transmission in aquatic environments. Hydrophones, as the core component of sonar systems, have found widespread application across multiple fields. However, existing types of hydrophones exhibit limited detection capabilities under low-signal conditions. To enhance low-frequency long-range detection performance, the development of new hydrophones featuring low power consumption, low frequency, high sensitivity, and miniaturization has become a research priority, with breakthroughs sought in the principle of electroacoustic conversion. Therefore, this study designed a frustum-cone triboelectric hydrophone (FCTH) based on friction layer materials, utilizing an indium-tin oxide (ITO) flexible conductive film on a polyethylene terephthalate (PET) substrate and a Polytetrafluoroethylene (PTFE) film. The sensor consists of a waterproof, sound-transparent polyurethane flow guide, silicone oil, and a frustum-cone triboelectric sensing unit based on a coupled membrane–cavity structure. The frustum-cone triboelectric sensing unit, based on a thin-film-perforated-tube resonance structure, enables omnidirectional detection of low-frequency hydroacoustic signals. The miniaturized design significantly reduces the volume of the FCTH. The acoustic–electric conversion relationship of the FCTH was derived using acoustic theory, thin-film vibration theory, and Maxwell’s displacement current theory. Furthermore, the low-frequency response characteristics of the frustum-cone triboelectric sensing unit were analyzed. The FCTH achieves a wide-frequency response ranging from 50 Hz to 12,000 Hz, with omnidirectional sensitivity and a maximum sensitivity of −174.6 dB. The FCTH achieves a wide-frequency response capability of 50 Hz to 12,000 Hz, with omnidirectional sensitivity and a maximum sensitivity of −174.6 dB. Additionally, through acoustic signal acquisition experiments in air, indoor, and outdoor water environments, the FCTH has been validated to possess excellent underwater acoustic detection performance and application potential across multiple scenarios. Full article

Between 51% and 72% of a bituminous roofing membrane used for structural waterproofing consists of organic material, predominantly bitumen—a derivative of crude oil refining—highlighting the strong dependence of this product on fossil resources. Considering that several tonnes of these membranes must be replaced every 30 to 50 years, substantial potential exists for emission reduction through the establishment of circular material systems. This study investigates this potential by analysing 26 Environmental Product Declarations (EPDs) and life cycle datasets from across Europe covering the period from 2007 to 2023. To ensure comparability, all data were normalised to a declared unit of 1 kg of roofing membrane. The reinforcement layers were categorised into glass and polyester & glass composites, and their differences were examined using Welch’s t-tests. Correlative analyses and linear as well as multiple regression models were then applied to explore relationships between environmental indicators and the shares of organic and mineral mass fractions. The findings reveal that renewable energy sources, although currently representing only a small share of total production energy, provide a major lever for reducing nearly all environmental impact categories. The type of reinforcement layer was also found to influence the demand for fossil resources, both materially and energetically. For most environmental indicators, only multiple regression models can explain at least 30% of the variance based on the proportions of organic and mineral inputs. Overall, the study underscores the crucial importance of high-quality, transparently documented product data for accurately assessing the sustainability of building products. It further demonstrates that substituting fossil energy carriers with renewable sources and optimising material efficiency can substantially reduce environmental burdens, provided that methodological consistency and clarity of indicator definitions are maintained. Full article

Conventional thermoplastic polyurethane (TPU) films are commonly used in the field of waterproof and moisture-permeable textiles because of their excellent mechanical properties and flexibility. However, the high water absorption of TPU films limits their application in sophisticated waterproof and moisture-permeable products, particularly in extremely humid environments, where it may compromise the waterproof performance of textiles and negatively affect the wearing comfort. Therefore, to enhance the durability of these films, TPU was hydrophobically modified with end-hydroxy polydimethylsiloxane (PDMS). Because of its unique low-surface-energy properties and excellent hydrophobicity, PDMS substantially reduces the surface energy of the films and provides them with excellent water repellency, effectively addressing the excessive water absorption issue of TPU films. On this basis, a microporous film featuring waterproof and moisture-permeable properties is produced using phase conversion technology. Compared with that of the unmodified sample, the surface energy of silicone-modified TPU (Si-TPU) decreased by 10.56 mJ/m². Furthermore, the water contact angle increased from 83° to 105°, whereas the water absorption rate considerably reduced after the modification. Moreover, Si-TPU was employed for the fabrication of a microporous membrane, which displayed exceptional moisture permeability (8651.34 g/(m²⸱24 h)). Full article

In this study, multifunctional nanocomposite membranes were fabricated using biopolymeric polylactic acid (PLA) and cellulose acetate (CA) composites via electrospinning. The hydrophobic nanocomposite membranes were reinforced with varying concentrations of silicon dioxide (silica/SiO₂) nanoparticles. The developed PLA–CA–SiO₂ nanofibrous membranes are characterized using field emission scanning electron microscopy (FE- energy-dispersive SEM), energy-dispersive X-ray (EDX), elemental mapping, X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT–IR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. Various physical and mechanical properties of the bio-nanocomposite membrane, such as tensile testing, infrared thermal imaging, ultraviolet–visible spectroscopy (UV–Vis), water contact angle, hydrostatic pressure resistance, and breathability are also investigated. The analysis revealed that a small concentration of silica nanoparticles improves the morphological, mechanical, and thermal characteristics of nanocomposite membranes. The addition of silica nanoparticles improves the UV (A & B), visible and infrared blocking efficiency while also enhancing the waterproofness of protective textiles. The PLA–CA–SiO₂ biopolymer nanocomposite membrane has a fibrous microstructure and demonstrated the tensile strength of 11.2 MPa, a Young’s modulus of 329 MPa, an elongation at break of 98.5%, a hydrostatic pressure resistance of 27 kPa, and a water contact angle of 143.7°. The developed electrospun composite membranes with improved properties provide strong potential to replace petroleum-based membranes with biopolymer-based alternatives, promising improved and wider usage for bio-related applications. Full article

High-performance waterproof and breathable nanofiber membranes (WBNMs) are in great demand for various advanced applications. However, the fabrication of such membranes often relies on fluorinated materials or involves complex preparation processes, limiting their practical use. In this study, we present an innovative approach by utilizing silicon-containing polyurethane (SiPU) as a single-component, fluorine-free raw material to prepare high-performance WBNMs via a simple one-step electrospinning process. The electrospinning technique enables the formation of SiPU nanofibrous membranes with a small maximum pore size (d_max) and high porosity, while the intrinsic hydrophobicity of SiPU imparts excellent water-repellent characteristics to the membranes. As a result, the single-component SiPU WBNM exhibits superior waterproofness and breathability, with a hydrostatic pressure of 52 kPa and a water vapor transmission rate (WVTR) of 5798 g m⁻² d⁻¹. Moreover, the optimized SiPU-14 WBNM demonstrates outstanding mechanical properties, including a tensile strength of 6.15 MPa and an elongation at break of 98.80%. These findings indicate that the single-component SiPU-14 WBNMs not only achieve excellent waterproof and breathable performance but also possess robust mechanical strength, thereby enhancing the comfort and expanding the potential applications of protective textiles, such as outdoor apparel and car seats. Full article

Taking the TPO waterproofing membrane as an example, this paper studies the influence of temperature, speed and welding pressure on the welding quality of a TPO waterproofing membrane lap area through a peel test and a water impermeability test, determines the optimal construction process, and observes and compares the permeable path through laser confocal microscope. Finally, it is applied to the actual effect test in the project. The results show that the welding pressure test tool for the lap area of the waterproofing membrane is designed to meet the welding work test requirements of various lap areas of the waterproofing membrane. The peel strength increases first and then decreases with the increase in welding temperature, and the optimal construction temperature is 400 °C. The optimal construction speed is 4 m/min; at 400 °C welding temperature, the peel strength increases first and then decreases slightly with the increase in welding pressure. The optimal construction pressure is 14.97 N; under the condition of 0.2 MPa, 30 min to 0.6 MPa, 120 min, the water impermeability test of the overlapping area was qualified. In this paper, the optimal construction technology of a TPO waterproofing membrane is determined, which provides guidance for its application and promotion in engineering. Full article

The circular economy (i.e., reuse and recycling of waste materials) is gaining attention for the goal of achieving net-zero waste. In this regard, the use of waterproofing membrane waste in bituminous materials can be a valid option, as every year, a lot of bituminous membrane wastes are generated both as production scraps or end-of-life wastes. Given this background, the recycling feasibility of end-of-life bituminous membrane waste (MW) in asphalt mixtures was assessed in this research study. To this aim, MW shreds (≤20 mm) were added to dense-graded bituminous mixtures using the dry-mixing method. The shreds were dosed at 0.5% by the mix weight (mix coded as SH−) or at 2% by mix weight (mix coded as SH+). A corresponding reference mix without MW was also tested for comparison purposes. The mixtures’ workability, strength and stiffness as well as permanent deformation, moisture and fatigue resistance were evaluated. Overall, the laboratory experimental findings showed that MW-modified bituminous mixtures with a higher dosage of membrane waste (SH+) have relatively higher moisture resistance, fatigue resistance, stiffness and high-temperature performance with respect to the corresponding reference mix. Moreover, both the reference and MW-modified mixtures showed similar workability regardless of the MW content. Full article

A survey and assessment of the technical condition of basement and semi-basement structures in public buildings aged 60 to 130 years were conducted to evaluate their suitability for use as basic shelters. Based on the survey results, the most adverse impacts were identified, including changes in groundwater levels, improper building operation, and the characteristic damages to underground structural elements. Structural solutions were proposed to eliminate the consequences of these damages. The reviewed cases indicate that the vertical and horizontal waterproofing systems used during construction cannot perform their function throughout the building’s entire life cycle. When designing new buildings, waterproof materials should be used for the enclosing structures of underground premises. While this may have a higher initial cost than membrane or coating waterproofing, considering life-cycle costs, it can provide a positive economic effect and improve the quality and comfort of the indoor environment. Full article

Bio-based polyurethane (BPU) offers excellent biocompatibility and outstanding elasticity, providing vast potential for the development of next-generation waterproof and breathable materials. However, achieving stable and uniform electrospinning of BPU remains a significant challenge. Herein, BPU with superior electrospinning performance was synthesized using poly(butylene sebacate), poly(trimethylene ether glycol), ethylene glycol, and methylene diphenyl diisocyanate (MDI) as raw materials. BPU nanofibrous membranes were successfully fabricated using solutions of varying concentrations (12 wt%, 16 wt%, 20 wt%, and 24 wt%), and their morphology, mechanical properties, hydrophobicity, and breathability were systematically analyzed. The nanofibrous membrane prepared with 20 wt% BPU solution exhibited optimal fiber morphology and mechanical properties, with a tensile strength of 15.6 MPa and an elongation at break of 440.8%. In contrast, lower concentrations (12 wt% and 16 wt%) resulted in insufficient fiber formation, leading to poorer performance, while higher concentrations (24 wt%) significantly reduced fiber uniformity, negatively impacting the overall performance. Additionally, the nanofibrous membrane produced from the 20 wt% BPU solution demonstrated significant hydrophobicity and breathability, with a water contact angle of 133.2°, hydrostatic pressure of 48.2 kPa, and breathability of 12.6 kg·m²·d⁻¹. These findings suggest that BPU nanofibrous membranes produced via electrospinning hold great potential for application in functional textiles. Full article

Functional membranes with waterproof, breathable, and thermal regulation capabilities are increasingly sought after across various industries. However, developing such functional membranes commonly involves complex multi-step preparation processes. Herein, we introduced perfluorodecyltriethoxysilane (FAS) into the poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) solution for one-step electrospinning, successfully fabricating membranes that combine these properties. The hydrophobicity of the PVDF-HFP/FAS membrane was greatly improved with the water contact angle increased from 120.6° to 142.9° and the solar reflectance rising from 72% to 92% due to the presence of fluorocarbon segments. The synergistic effect of enhanced hydrophobicity, small pore size, and elevated solar reflectivity resulted in robust water resistance (62 kPa), excellent water vapor transmission rate (12.4 kg m⁻² d⁻¹), and superior cooling performance (6.4 °C lower than commercial cotton fabrics). These findings suggest that the proposed PVDF-HFP/FAS membranes, characterized by desired multifunction characteristics and scalable production, hold great potential for application in diverse strategic fields. Full article