Air Pores Research Articles

Modeling of microwave thawing and reheating of multiphase foods: A case study for packed rice

Microwave (MW) thawing and reheating of porous foods such as rice is a common practice, but uniform heating can be difficult to achieve. Computer simulation models were developed using the finite-element method to study MW thawing and reheating of packed rice. A method to obtain an apparent thermal conductivity was proposed, which accounts for heat distribution by water evaporation and condensation through the air pores in the sample. Reheating experiments of mashed compact rice and regular porous rice were carried out on a flatbed MW oven for 90 s. Similarly, thawing experiments were conducted on porous rice for 180 s. Good agreement between simulated and experimental results was obtained when correcting for thermal conductivity of the pores and for the volumetric power absorption between the frozen and thawed fractions This can help in the design of specifically designed porous foods and containers that allow for fast and homogeneous reheating.

Improved Design and Fabrication of a Compression Moulding Machine with Performance Evaluation

This study explores the advancements in the design and performance of an improved compression moulding machine aimed at efficiently recycling various plastic wastes, with an emphasis on Polyethylene Terephthalate (PET). With global plastic waste accumulation posing severe environmental challenges, enhancing recycling technologies is imperative. The re-designed machine was tested at operating temperatures of 200°C, 250°C, and 300°C, highlighting the critical role of temperature and processing duration in determining product quality. Theoretical heating times were found to be shorter than actual times due to real-world inefficiencies such as heat loss and thermal conductivity variations. Weight loss during heating, attributed to the evaporation of volatile components and thermal degradation, was observed. The formation of air pores in samples with extended heating times underscored the necessity for precise process control. The PET melting process initiated effectively at approximately 250°C. The improved machine demonstrated significant potential in enhancing recycling efficiency and versatility.

Optimisation of mechanical properties and pore structure of lightweight geopolymer concrete

Lightweight geopolymer has good physical and mechanical properties, thermal and chemical stability and low carbon dioxide emissions. The development of high-strength lightweight geopolymer concrete (LGC) for load-bearing structures can expand geopolymer applications. The use of ground granulated blast-furnace slag (GGBFS) to improve the mechanical properties and pore structure of LGC was investigated. The ultimate compressive stress of LGC containing GGBFS were analysed, as well as the variation in microscopic pore structure. Specimens of LGCs with different strengths (LC20, LC30 and LC40) were investigated. As the GGBFS content increases, the ultimate compressive stress and specific strength of LGC increases, while the strain corresponding to the peak stress decreases, indicating that the mechanical properties and deformation resistance of LGC are improved. The carbon dioxide emissions of LGC are less than those of cement-based lightweight concrete, indicating that LGC has good sustainability. Moreover, the addition of GGBFS can produce more gel and reduce the volume proportion of capillary pores and air pores, resulting in LGC densification. Recommended GGBFS contents for strength grades LC20, LC30 and LC40 are 0–12.7%, 12.7–24.6% and 24.6–30%, respectively. The LGC is lightweight and has high strength, and has potential for application in civil engineering.

Preparation of three dimensional boron nitride-aluminum oxide dual thermal network resin-based composite materials and their performance study

With the gradual miniaturization and integration of electronic devices, the design and development of new high thermal conductivity polymer-based composite materials are crucial for enhancing the performance of modern electronic devices. In this study, three-dimensional boron nitride (3D-BN) aerogels with vertically aligned structures were prepared using the ice templating method, serving as the primary thermal conductive network. Subsequently, aluminum oxide (Al2O3)/epoxy resin (EP) nanofluids were infiltrated into the aerogel’s air pores using vacuum impregnation. The Al2O3 particles in contact with each other formed the secondary thermal conductive network. Thus, a 3D BN-Al2O3/EP composite material with a dual thermal conductive network structure was successfully fabricated. The composite material exhibited a high thermal conductivity coefficient of 1.077 Wm−1K−1 when loaded with 17.67 wt% BN and 26.23 wt% Al2O3, representing a 496 % increase compared to pure EP and a 211 % increase compared to 3D-BN/EP composite materials. Furthermore, this composite material demonstrated excellent thermal stability and mechanical properties. This work provides a new direction for designing novel polymer-based composite materials with low filler loading and high thermal conductivity performance.

Studying the effect of the ratio of water to binder and sand to aggregate on the hardness of concrete mixtures and compressive strength of roller-compacted concrete by experimental method

In roller-compacted concrete technology, withthe use of low water and cement content, the concrete mixture after kneading has high hardness and compaction equipment must be used to compact and shape the product.Therefore, the content of mixing water, binder, and aggregate are considered decisive factors, greatly affecting the properties of roller compacted concrete in both the fresh state and the hardened state.The paper uses the mathematical method of two-factor rotatable central compositional planning to simulate the effect of volumetric ratios of water-binder (VN/VCKD) and sand-aggregate (VC/VCL) on the objective functions of the test. The selected objective functions are the hardness of the concrete mixture and the compressive strength of the roller-compacted concrete at the age of 28 days.From the obtained objective functions, it is shown that both control variables VN/VCKDand VC/VCLhave a significant influence on the valuesof the experimental model. When the VN/VCKDratio increases, the water content contributes to increasing the plasticityand reducing the hardness of the concrete mixture. At the same time, excess water exists in the concrete mass in the form of air bubbles,pores,and magnetism. That reduces the compressive strength of the product. Furthermore, the VC/VCLratio of the aggregate that is too small or too large tends to cause the compressive strength of the concrete to decrease.

AI-assisted deep learning segmentation and quantitative analysis of X-ray microtomography data from biomass ashes

X-ray microtomography is a non-destructive method that allows for detailed three-dimensional visualisation of the internal microstructure of materials. In the context of using phosphorus-rich residual streams in combustion for further ash recycling, physical properties of ash particles can play a crucial role in ensuring effective nutrient return and sustainable practices. In previous work, parameters such as surface area, porosity, and pore size distribution, were determined for ash particles. However, the image analysis involved binary segmentation followed by time-consuming manual corrections. The current work presents a method to implement deep learning segmentation and an approach for quantitative analysis of morphology, porosity, and internal microstructure. Deep learning segmentation was applied to microtomography data. The model, with U-Net architecture, was trained using manual input and algorithm prediction.•The trained and validated deep learning model could accurately segment material (ash) and air (pores and background) for these heterogeneous particles.•Quantitative analysis was performed for the segmented data on porosity, open pore volume, pore size distribution, sphericity, particle wall thickness and specific surface area.•Material features with similar intensities but different patterns, intensity variations in the background and artefacts could not be separated by manual segmentation – this challenge was resolved using the deep learning approach.

Marchantia polymorpha GOLDEN2-LIKE transcriptional factor; acentral regulator of chloroplast and plant vegetative development.

The GOLDEN2-LIKE (GLK) transcription factors act as a central regulatory node involved in both developmental processes and environmental responses. Marchantia polymorpha, a basal terrestrial plant with strategic evolutionary position, contains a single GLK representative that possesses an additional domain compared to spermatophytes. We analyzed the role of MpGLK in chloroplast biogenesis and development by altering its levels, preforming transcriptomic profiling and conducting chromatin immunoprecipitation. Decreased MpGLK levels impair chloroplast differentiation and disrupt the expression of photosynthesis-associated nuclear genes, while overexpressing MpGLK leads to ectopic chloroplast biogenesis. This demonstrates the MpGLK functions as a bona fide GLK protein, likely representing an ancestral GLK architecture. Altering MpGLK levels directly regulates the expression of genes involved in Chl synthesis and degradation, similar to processes observed in eudicots, and causes various developmental defects in Marchantia, including the formation of dorsal structures such as air pores and gemma cups. MpGLK, also directly activates MpMAX2 gene expression, regulating the timing of gemma cup development. Our study shows that MpGLK functions as a master regulator, potentially coupling chloroplast development with vegetative reproduction. This illustrates the complex regulatory networks governing chloroplast function and plant development communication and highlight the evolutionary conservation of GLK-mediated regulatory processes across plant species.

Design and fabrication of a porous prism film for display backlight applications

This study demonstrates a fabrication method of a porous brightness enhancement film (pBEF) that offers brightness enhancement, light diffusion, color shift reduction, and improved thermal stability. During the ultraviolet imprinting and solvent evaporation processes, the nano/submicron-sized air pores are generated within the polymer prism structure, and micropatterns spontaneously form on the prism surface. The inner pores ranging from 30 to 450 nm can effectively scatter light to mitigate color shift, which is caused by multiple internal reflections within the prism structure. The micropatterns have multiple rings formed one around another with 5–15-µm diameter on the prism surface improve visual quality. Moreover, the obtained functions are achieved in a single film solution, obviating the need for using multiple materials, and the fabrication process is relatively simple and fast as it is conducted under ambient conditions. When the pBEF is integrated into a liquid-crystal display backlight, it provides the brightness enhancement performance and comparable viewing angle distribution of a regular BEF combined with an additional diffuser (two films) and increases brightness by ∼8% compared to a bead prism (particle-based BEF). Additionally, it reduces the redshift (Δxy) from 0.1605 to 0.1415. Furthermore, the pBEF exhibits a lower coefficient of thermal expansion than the regular BEF.

Damage detection on cooling tower shell based on model textures

Ensuring the structural integrity of cooling towers is paramount for safety and efficient operation. This paper presents a novel approach for detecting damage on cooling tower shells, utilising textures derived from laser scanning and close-range photogrammetry. The proposed method delves beyond the limitations of solely relying on colour information by harnessing the rich details embedded in various textures, including diffuse, normal, displacement, and occlusion. The study demonstrates the efficacy of this approach for identifying significant concrete damage. A Convolutional Neural Network (CNN) trained on diffuse textures successfully detects high damage instances with minimal misdetection. However, accurately pinpointing low damage, often manifesting as subtle cracks, and mimicking other patterns like air pores, ribbing, and colour variations, presents a formidable challenge. To tackle this challenge, the authors introduce a novel "composed raster layer" that merges information from multiple textures. This pre-processed layer amplifies the visual cues associated with low damage, facilitating its differentiation from similar patterns. While the current implementation employing multi-resolution segmentation and rule-based classification exhibits promising results, further optimization is acknowledged to refine the accuracy of low damage detection. The successful application of textures commonly used in rendering techniques underscores their remarkable potential for enhancing damage detection in civil engineering applications. While acknowledging limitations such as the analysis of a single cooling tower and the reliance on specific software for damage detection, the study proposes future research directions. This research holds significant implications for the field of civil engineering by offering a promising approach for automated and efficient damage detection on cooling tower shells.

Development of Hydrophilic Oxide/Polymer Composite Membranes for Polymer Electrolyte Fuel Cells Operating at Wide Temperature Range

Toward the wide-spread use of heavy-duty vehicles (HDVs) operated by polymer electrolyte fuel cells (PEFCs) should approach the higher temperature around 120oC besides normal temperature (60-80oC). Commercial perfluorosulfonic acid-based electrolyte (PFSA, e.g. NafionⓇ) shows better proton conductivity with chemical stability in wide temperatures range, though decreases under low back pressure at 100~120 oC. In order to improve the proton conductivity at the higher temperature range, composite membrane of NafionⓇ with a hydrophilic filler of Ta doped TiO2 (Ta-TiO2) was synthesized. The Ta-TiO2 nanoparticles fillers with fused-aggregate network microstructure were synthesized by the flame method, and were crushed by wet mill(Star Burst, :Sugino Machine Limited CO.). The fillers were mixed with NafionⓇsolution (20 wt.%：D2020 Chemours Co.) by use of a rotary ultrasonic dispersing processor (500 rpm, 60 min. PR-1 :Thnky Co.), a planetary ball mill (500 rpm、30 min.：PULVERISETTE 6：FRITSCH Co.), and a defoaming processor (500 rpm、5 min.：HM-400W: Kyouritu Seiki). The dispersion solution was coated in hot air by use of a die coating system (die coater: Taku-Dai Mini-50: Daimon Co., Ltd.), and were hot-pressed (140 ℃ 3 min. TCMD-2.5:TOHO KOGYO co.) to form composite membranes (9 cm×9 cm ×25 µmt).The cross-sectional backscattered electron image BSE) of the composite membrane observed by scanning electron microscope (SEM, acceleration voltage 2 kV, SU9000: Hitachi High-Tech Co.) and transmission electron microscope (TEM, H-9500: Hitachi High-Tech Co.). The proton conductivity of the composite membrane was measured by the AC four-probe method. The current-voltage (IV) polarization curves of Single cells using the prepared composite membrane (membrane thickness: 25 µm) were measured at 80 ℃ 100% RH and 120 ℃ 20% RH, back pressure 50 kPaG.The obtained composite membranes were well flexibility with softness. The BSE images indicated that the high contrast images of Ta-TiO2 parties were uniformly dispersed in composite membrane. The higher magnified of the cross-sectional TEM images also showed that the hydrophilic surface of Ta-TiO2 adhered to the Nafion® without any air pores. The proton conductivity of the composite membrane at 80% RH increased with increasing Ta-TiO2 content and showed maximum value of 0.13 S cm-1at 3 wt%, and then decreased. The maximum proton conductivity was 1.3 times higher than that of Nafion®. The IV performance of the single cell using composite membrane kept same performance to that using Nafion® membrane at 80 oC 100% RH, and then improved at 120 oC 20% RH. The water content at 120 oC 20% RH kept higher value by the effect of hydrophilicity of the Ta-TiO2, which would be one of the reasons to enhance the cell performance at 120 oC 20% RH. Figure 1

Mechanical properties and damage characteristics of concrete under different atmospheric pressures

The aim of this study was to investigate the mechanical properties and damage characteristics of concrete under different atmospheric pressures (50 kPa, 80 kPa, and 101 kPa). The failure modes, compressive strength, dynamic elastic modulus, stress–strain curve, air pore structure, and acoustic emission (AE) parameters of concrete specimens were evaluated under the different atmospheric pressures. The results showed that as the atmospheric pressure decreased, the concrete damage gradually transitioned from tensile damage to shear damage, the compressive strength and dynamic elastic modulus decreased, and the peak strain increased. The pore structure of the hardened concrete changed, the number of air pores and air content decreased, and the average pore size and pore spacing coefficient increased considerably. Additionally, an analysis of the AE parameters showed that the development pattern of the concrete ringing counts and energy were mostly the same under different atmospheric pressures. The decrease in atmospheric pressure was accompanied by a corresponding gradual decrease in the AE rate of change parameters and cumulative AE parameters, indicating that the concrete crack expansion rate slowed down while the total cracking activity decreased. Moreover, the inverted V-shape of the b-value curve was not obvious, and the peak b-value decreased with decreasing atmospheric pressure. Finally, a combination of the Weibull distribution theory, Lognormal distribution theory, and strain equivalent hypothesis was used to establish a concrete uniaxial compression constitutive model considering atmospheric pressure. The model can reflect the evolution law of the mechanical properties of concrete under uniaxial compression under different atmospheric pressures.

Long-term volume stability of ECC containing high-volume steel slag

The utilization of steel slag (SS) in the field of concrete remains limited due to its poor soundness. This work studies the long-term volume stability and strength development (up to 1 year) of engineered cementitious composites (ECC) containing high-volume SS. The result shows that the compressive, splitting-tensile and flexural strength of ECC containing SS begins to decline after 90 d, while the decline in the corresponding matrix is much higher. Especially, the matrix with 60 wt% SS loses its integrity by 360 d. The expansion of SS reduces the fracture toughness of the matrix, leading to an increase in toughness and ductility, while changing the cracking pattern of the ECC. Additionally, the introduction of ground granulated blast furnace slag (GGBFS) results in a decrease in volume expansion and strength loss of ECC caused by expansion of SS. Randomly distributed PVA fibers restrict volume expansion of ECC containing SS, while trapped air pores introduced with PVA fibers act as relievers, dispersing expansive stress. Combined introduction of GGBFS and PVA fibers leads to a 49.8 % reduction in expansive strain and a 126 % increase in compressive strength of ECC compared with the matrix with high-volume SS.

Lightweight thermo- and heat-resistant composite materials based on polyimide foam

A prepolymer foaming composition based on 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride methyl ester and diamines: 4,4'-diaminodiphenylmethane and m-phenylenediamine for the production of high-temperature polyimide foam (PIF) is proposed. The p ossibility o f u sing P IF a s a b inder f or c omposite materials (foam composites) reinforced with carbon or organic fibers with low density (0.4–1.1 g/cm3) a s a result of foaming of the binder during the formation of the foam composite is shown. The density and mechanical properties of the foam composite can vary within a relatively wide range depending on the volume content of the fiber and air pores. The high glass transition temperature of 260°C, combined with the high thermal stability of carbon or polyimide fibers, contributes to the retention of the mechanical properties of such composites at elevated temperatures. The temperature of the start of mass loss of the foam composite must be at least 550°C, and it depends on the type of fibrous material. The combination of the excellent thermal and mechanical properties of lightweight PIF composites, together with the exceptional fire resistance of polyimide materials, may provide new applications in advanced aircraft and shipbuilding technologies.

ПОРЫ ВОЗДУХОВОВЛЕЧЕНИЯ В СТРУКТУРЕ ГАЗОБЕТОНА

Aerated concrete is one of the most popular building materials, which has unique properties such as light weight, high sound and heat insulation characteristics and strength. However, its porous structure may reduce its strength and durability. In this article, the author examines the various types of pores in aerated concrete and their effect on its properties. Gel and capillary pores are the main types of pores that are formed during the production of aerated concrete. Air (gas) pores are formed as a result of a chemical reaction between gas and binder. They also affect the properties of aerated concrete, but to a lesser extent than gel and capillary ones. However, air entrainment pores negatively affect the quality of aerated concrete. This type of pore is formed when pouring an aerated concrete mixture and represents air bubbles that reduce the strength of the material and impair its thermal insulation properties. To improve the quality of aerated concrete and prevent the formation of air entrainment pores, it is necessary to optimize production technologies and control the pouring process. The article also discusses the features of the formation of an air entrainment pore and the transformation of the shape of entrained air in an air entrainment pore with the shape of an inverted drop.

Wearable Capacitive Tactile Sensor Based on Porous Dielectric Composite of Polyurethane and Silver Nanowire.

In recent years, the implementation of wearable and biocompatible tactile sensing elements with sufficient response into healthcare, medical detection, and electronic skin/amputee prosthetics has been an intriguing but challenging quest. Here, we propose a flexible all-polyurethane capacitive tactile sensor that utilizes a salt crystal-templated porous elastomeric framework filling with silver nanowire as the composite dielectric material, sandwiched by a set of polyurethane films covering silver nanowire networks as electrodes. With the aids of these cubic air pores and conducting nanowires, the fabricated capacitive tactile sensor provides pronounced enhancement of both sensor compressibility and effective relative dielectric permittivity across a broad pressure regime (from a few Pa to tens of thousands of Pa). The fabricated silver nanowire-porous polyurethane sensor presents a sensitivity improvement of up to 4-60 times as compared to a flat polyurethane device. An ultrasmall external stimulus as light as 3 mg, equivalent to an applied pressure of ∼0.3 Pa, can also be clearly recognized. Our all-polyurethane capacitive tactile sensor based on a porous dielectric framework hybrid with conducting nanowire reveals versatile potential applications in physiological activity detection, arterial pulse monitoring, and spatial pressure distribution, paving the way for wearable electronics and artificial skin.

A Comparative Account of External Sculpture of the Eggs of Two Tiger-Moths (Erebidae: Arctiinae: Lepidoptera) from India

This study aimed to update the taxonomic data of two tiger moths which were earlier based upon the taxonomic characteristics of adult specimens only like male and female genitalic features. This study is an attempt to prove that the ultrastructural characteristics of the egg chorion of these tiger moth species are also important and they can be used in early taxonomic identifications of these species based on egg characteristics as they are also found to be species-specific. A scanning electron microscope was used to inspect, characterize and depict eggs of two species referable to Spilarctia Butler and Cladarctia Koda of the Erebidae family. The descriptions and comparative morphological analyses of the eggshells of Spilarctia multiguttata (Walker) and Cladarctia quadriramosa (Kollar) were compiled to present the structural complexity of these tiny eggs and depict the distinct patterns of structural features including the central micropylar pit, micropylar rosette, number of micropyles and aeropyles. The SEM analysis revealed their unique architecture which allows for unrestricted exchange of oxygen and carbon dioxide while limiting water loss because of the presence of minute air pores all over the chorion. From the results, it is evident that the ultrastructural egg chorion characters are of great taxonomic value at specific as well as generic levels and these types of investigations must be amplified to improve and escalate the morphological personation of tiger moths.

Experimental performance assessment of a novel insulation plaster as an energy-efficient retrofit solution for external walls: A key building material towards low/zero carbon buildings

Thermal insulation plasters have become the focus of attention in the building sector. Among the most important reasons for this is the high thermal energy losses of the buildings. Since conventional briquettes used in buildings allow high heat transfer, the construction industries are looking for alternative insulation ways with low cost and high thermal efficiency. The use of insulation plasters is becoming popular due to the high cost and installation of insulation materials such as Expanded Polystyrene (EPS), which is among the alternative ways. Therefore, in this study, the novel insulation plaster (NIP) developed in contrast to traditional insulation plasters is tested on conventional briquettes in different thicknesses. On considering the total heat transfer coefficient (U-value), it is understood that whilst the conventional briquette has the highest value with approximately 5.5 W/m2K, the briquette with 2-2 NIP thickness has the lowest value with a value of almost 2.86 W/m2K. As a result of the tests, the total heat transfer coefficient of the briquette with 1-1 NIP thickness is observed to have an improvement of nearly 22.5% compared to conventional briquettes, while a progress of approximately 36.4% is seen in briquettes with 2-1 NIP thickness. In addition, it is revealed that the best mitigation in the overall heat transfer coefficient is about 47.9% in briquettes with 2-2 NIP thickness. It is also figured out that NIP has additional thermal durability thanks to the dead air pores and boron minerals in its internal structure.

RECOVERY OF PHENOL-FORMALDEHYDE SOLID WASTE FROM THE PRODUCTION OF INORGANIC THERMAL INSULATING MATERIALS

The production of inorganic thermal insulation materials with a fibrous structure, consisting of a fibrous skeleton and air pores, generates phenol-formaldehyde solid waste. Formaldehyde resin is used to crosslink, or glue, fibers together, so that most of the phenol and formaldehyde released after evaporation is found in wastewater, while the remaining part is generated as solid waste. The paper characterizes solid waste using the following chemical analyses: UV-VIS spectrophotometry, atomic absorption spectrophotometry, and gas chromatography. This is done with the aim to provide a more detailed consideration of the pollution potential. Based on the conducted research, it can be concluded that the drainage water according to the criteria for underground water contains increased amounts of copper, cadmium, lead, chromium, cobalt, nickel and phenol. At the same time, the concentrations of copper, cadmium, nickel and phenol also exceed the values, which is a condition that requires more detailed investigations. The concentration of phenol is getting close to the threshold value (0.050 mg/dm3), according to which measures are recommended. The paper proposes an eco-technical solution for waste stabilization through supercritical aqueous oxidation of phenol-formaldehyde and metal waste.

Effects of the inhomogeneous microstructures on buffer layer ablation failure in high voltage cables

In recent years, growing attention has been paid to the buffer layer ablation failure in high voltage cables. The buffer layer was always regarded as a homogeneous material in previous studies, while in this paper, the effects of its structural inhomogeneity on failure is found unneglectable. The buffer layer is recognized to be a porous material comprising fibers and air pores through microscopic characterization. Its porosity is measured to be 85% by testing mercury intrusion porosimetry. Especially, some small fiber protrusions are observed on the surface of buffer layer, which are categorized and named as tip protrusions and arched protrusions. Subsequently, the influence of these fiber protrusions is investigated by quantitatively proposing their geometric models. The electric field distortion is observed at the fiber regions after finite element simulation. Under the extreme circumstances when the tip protrusions are vertical and close to the central area of air gap, the maximum electric field at tip site can reach to 28.5 kV/mm, which is 9.5 times of the breakdown threshold of air. And the maximum electric field of arched protrusions region can reach to 5.94 kV/mm, which is more moderate but still higher than the threshold. Therefore, it is demonstrated that the breakdown of air gap inner cables can be induced by the inhomogeneous fiber protrusions.

High solar water droplet evaporation rates from Actinocyclus sp. diatom frustules decorated with silver nanoparticles

Solar vapour generation technology has emerged as a promising approach for reducing the global problem of water shortage issues via the solar water interfacial evaporation technique utilised for water purification. However, achieving superior light absorption and a high evaporation rate in a solar evaporator remains challenging. Here, we show that high solar interfacial water evaporation rates can be achieved using a natural and sustainable biomaterial, diatom frustules, decorated with silver nanoparticles made using a one-pot synthesis method. The species of diatom selected for this study was Actinocyclus sp. that has complex nano- and micro-structured surfaces and air pores that lead to multiple light scattering. The absorptance before and after silver nanoparticle coating was measured after creating a thin frustule layer on a hydrophobically treated quartz substrate. It was found that the cleaned and uncoated frustules had zero absorptance from 400 nm to 1200 nm. However, silver nanoparticles coated frustules showed a large broadband absorptance up to 90 % from 400 nm to 1200 nm, covering most of the solar spectrum, due to localised surface plasma resonance and multiple light scattering in the air pores. The frustules were floated on the surface of a water droplet for solar water interfacial evaporation rate measurements. A high evaporation rate of 5.4 kg m−2 h−1 under 1 sun irradiation was found for silver nanoparticles decorated frustules and for a droplet volume of 10 mm3. This is significantly larger than that found for frustules without silver nanoparticles or bare water where the evaporation rates were 1.7 kg m−2 h−1 and 1.2 kg m−2 h−1, respectively. Moreover, increasing the number of floating frustules per drop resulted in a factor of 1.67 enhancement. Our results show that research into silver nanoparticle decorated frustules can potentially provide a novel route for fabricating a high-performance solar vapour generator.