Innovative Closed Cavity Façades (CCF) with Inner Shading and Advanced Coatings for Enhancing Thermal Performance in the Tropics

In its simplest terms, a closed-cavity façade (CCF) is a sealed, unventilated enclosure equipped with motorized shading devices, internal double or triple glazing, and external single glazing. This technology effectively controls solar energy and daylight entry into buildings. This research aims to enhance the thermal efficiency of CCFs in tropical climates using Venetian blinds (VB) and advanced glass coatings. EnergyPlus and DesignBuilder were employed to assess various CCF designs and compare them to a single glazing unit (SGU) with grey coatings. This was inspired by a residential case study on Penang Island, Malaysia. The findings indicate that CCFs surpass SGUs in thermal performance and occupant comfort, particularly in Malaysia’s humid tropical climate. CCFs reduced operating temperatures by a monthly percentage ranging from 33.5% to 68.75% in all operations. On an annual basis, temperature reductions ranged from 27.5% to 80.25%, with maximum decreases between 2 °C and 4 °C and minimum decreases between 0.5 °C and 1 °C compared to SGU units. The results show that CCFs outperform SGUs in thermal performance and comfort, reducing operating temperatures by 33.5% to 68.75% monthly and 27.5% to 80.25% annually. Temperature reductions ranged between 2 °C and 4 °C at maximum and 0.5 °C and 1 °C at minimum compared to SGU. Notably, Venetian blinds with nano-coatings (83/58) and low-E coatings (83/23) (Tvis/Tsol) were the most effective. This study highlights the importance of selecting appropriate coatings for CCFs, and demonstrates their potential in enhancing interior temperatures and comfort in Malaysia’s climate. The findings emphasize the significant impact of innovative glazing technologies on improving operational temperatures and occupant comfort using closed-cavity façades in the tropics

Coating Readily Available Yet Thermally Resistant Surfaces with 3D Silver Nanowire Scaffolds: A Step toward Efficient Heater Fabrication

In this study, we synthesized and characterized a 3D network of silver nanowires (AgNWs), employing the polyol approach in ethylene glycol (EG) as the reductant and polyvinylpyrrolidone (PVP) as the structure-directing agent for the growth of AgNWs to design inexpensive, timely responsive AgNWs-based heaters with different substrates. Data obtained from a field emission scanning electron microscope (FESEM) revealed that the average diameter of the synthesized AgNWs was 22 nm, and the average length was 28 µm. UV-visible absorption spectroscopy showed that AgNWs developed in a very pure phase. We investigated the impact of substrate type on the heating dissipation performance by depositing AgNW thin film over three chosen substrates made from readily available materials. The findings indicated that the AgNW-based heater with the wood substrate had the lowest response time of 21 s, the highest thermal resistance of 352.59 °C·cm2/W, and a steady temperature of 135 °C at a low bias voltage of 5 V compared to cement (95 s, 297.77 °C·cm2/W, and 120 °C) and glass (120 s, 270.25 °C·cm2/W, and 110 °C)

Synthesis and Deposition of Silver Nanowires on Porous Silicon as an Ultraviolet Light Photodetector

The applications of silver nanowires (AgNWs) are clearly relevant to their purity and morphology. Therefore, the synthesis parameters should be precisely adjusted in order to obtain AgNWs with a high aspect ratio. Consequently, controlling the reaction time versus the reaction temperature of the AgNWs is crucial to synthesize AgNWs with a high crystallinity and is important in fabricating optoelectronic devices. In this work, we tracked the morphological alterations of AgNWs during the growth process in order to determine the optimal reaction time and temperature. Thus, here, the UV–Vis absorption spectra were used to investigate how the reaction time varies with the temperature. The reaction was conducted at five different temperatures, 140–180 °C. As a result, an equation was developed to describe the relationship between them and to calculate the reaction time at any given reaction temperature. It was observed that the average diameter of the NWs was temperature-dependent and had a minimum value of 23 nm at a reaction temperature of 150 °C. A significant purification technique was conducted for the final product at a reaction temperature of 150 °C with two different speeds in the centrifuge to remove the heavy and light by-products. Based on these qualities, a AgNWs-based porous Si (AgNWs/P-Si) device was fabricated, and current-time pulsing was achieved using an ultra-violet (UV) irradiation of a 375 nm wavelength at four bias voltages of 1 V, 2 V, 3 V, and 4 V. We obtained a high level of sensitivity and detectivity with the values of 2247.49% and 2.89 × 1012 Jones, respectively. The photocurrent increased from the μA range in the P-Si to the mA range in the AgNWs/P-Si photodetector due to the featured surface plasmon resonance of the AgNWs compared to the other metals

Coating Readily Available Yet Thermally Resistant Surfaces with 3D Silver Nanowire Scaffolds: A Step toward Efficient Heater Fabrication

In this study, we synthesized and characterized a 3D network of silver nanowires (AgNWs), employing the polyol approach in ethylene glycol (EG) as the reductant and polyvinylpyrrolidone (PVP) as the structure-directing agent for the growth of AgNWs to design inexpensive, timely responsive AgNWs-based heaters with different substrates. Data obtained from a field emission scanning electron microscope (FESEM) revealed that the average diameter of the synthesized AgNWs was 22 nm, and the average length was 28 µm. UV-visible absorption spectroscopy showed that AgNWs developed in a very pure phase. We investigated the impact of substrate type on the heating dissipation performance by depositing AgNW thin film over three chosen substrates made from readily available materials. The findings indicated that the AgNW-based heater with the wood substrate had the lowest response time of 21 s, the highest thermal resistance of 352.59 °C·cm2/W, and a steady temperature of 135 °C at a low bias voltage of 5 V compared to cement (95 s, 297.77 °C·cm2/W, and 120 °C) and glass (120 s, 270.25 °C·cm2/W, and 110 °C)