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Spent coffee grounds (SCGs) are waste residues arising from the process of coffee brewing and are usually sent to landfills, causing environmental concerns. SCGs contain a considerable amount of fatty acids and is therefore a promising green alternative bio-based phase change material (PCMs) compared to conventional organic and inorganic PCMs. In this study, the extraction of coffee oil from SCGs was conducted using three different organic solvents-ethanol, acetone, and hexane. The chemical composition, chemical, and thermophysical properties of these coffee oil extracts were studied to evaluate their feasibility as a bio-based PCM. Gas chromatography-mass spectroscopy (GC-MS) analysis indicated that coffee oil contains about 60-80 % of fatty acids while the phase transition temperature of the coffee oil extracts is approximately 4.5 ± 0.72 °C, with latent heat values of 51.15 ± 1.46 J/g as determined by differential scanning calorimetry (DSC). Fourier Transform Infrared Spectroscopy (FTIR) and DSC results of coffee oil extracts after thermal cycling revealed good thermal and chemical stability. An application study to evaluate coffee oil extract as a potential cold therapy modality showed that it can maintain temperatures below normal body temperature for up to 46 min. In conclusion, this work exemplifies the potential of SCGs as a promising green and sustainable resource for bio-based PCMs for low-temperature thermal energy storage applications such as cold-chain transportation and cold therapy.

Organic Phase Change Materials (oPCMs) are practical and efficient materials in regulating temperature changes, with broad applications including building material, textiles, and food packaging. However, their flammability poses the main challenge to their widespread applications. This review summarizes various approaches to reduce the flammability of oPCMs including incorporation of flame retardants in shape stabilized PCMs and microencapsulated PCMs, chemical transformations and surface coating, paying particular attentions to the flammability parameters such as limiting oxygen index (LOI), total heat released (THR), peak heat release rate (pHRR) as well as the mechanisms of fire retardancy. Flame-retardant oPCM for practical applications such as plasterboards and fabrics will be highlighted. Further strategies to enhance flame retardant properties of oPCM, such as, incorporation of synergistic flame retardants, chemical modification of PCM (e.g. intrinsically flame-retardant oPCM), have been proposed and commented in the conclusion of this paper.

This paper demonstrated that the hues of both neutral and oxidised colours of isoindigo-based donor–acceptor polymers could be tuned subtly by means of variation of the number and type of donor groups.

A series of triazine-based compounds (M1–M7) have been prepared from 1,3,5-triazine, 2,4,6-triamino-1,3,5-triazine, 2,4-dichloro-6-methoxy-1,3,5-triazine and 2-chloro-4,6-dimethoxy-1,3,5-triazine, and their thermal phase change properties.

While nanotechnology has been traditionally applied in the fields of material sciences, medicine and microelectronics, its potential applications in the built environment have been growing. The application of nanomaterials in construction and building materials might be the key to replicating features of natural systems that have been improved to perfection over millions of years. It can also help to achieve pollution control by reducing the carbon footprint of buildings and promoting sustainability in the long term. This chapter reviews current knowledge on the application of nanotechnology in certain building components such as windows, brick, stone and wood. In addition, the short- and long-term effects of nanomaterials on the environment and human health will be addressed. Lastly, this chapter will also identify the future challenges and major obstacles for the application of nanomaterials in the built environment.

This study investigates organic solvent nanofiltration (OSN) using the membranes composed of 2D Zn-TCPP(Fe) nanosheets. A group of organic dyes with different molecular weights, hydrophilic properties and functional groups was selected as probe solutes in ethanol, isopropanol and ethyl acetate, respectively, to examine their OSN characteristics through the Zn-TCPP(Fe) membrane. The intermolecular interactions of organic solvent, dye and Zn-TCPP(Fe) nanosheets profoundly influence the mass transfer in the nano channels of the lamellar membrane. Representatively, the isopropanol solution of Brilliant Blue G dye turns out to have a favorable OSN performance (>90 % rejection with an average permenance of 175 L ∙ m - 2 ∙ h - 1 ∙ b a r - 1 ) over 4 h, whereas replacement of isopropanol by ethanol results in incipient loss of rejection. However, for this ethanol solution feed, incorporating an optimal dose of ZIF-8 nanograins into the nanosheets via co-deposition, a particle-over-lamellae structure formed unveils a significant improvement on OSN. Such boost is attributed to a combinative effect, i.e., alleviating dye-nanosheet complexation so as to reduce disturbing the lamellar structure as well as to assist desolvation of the dye over the feed side. To comprehend how solvent-slolute-nanosheet interactions dominate OSN, besides the experimental characterizations, both visco-molar volume and Stokes-Einstein diameter that describe fluid dynamic properties of solute molecule in a solvent are employed to assist the analysis. Possessing hydrophilic characteristic, Zn-TCPP(Fe) nanosheet engages strong hydrophilic association with hydrophilic dye and solvent, leading to weak OSN performance. Fundamentally, there are mutual interactions among solvent, solute and nanosheets in this membrane system, in which the prevailed pair of them impacts OSN performance.

This work invents a composite membrane constituted by the granular NaY zeolite as the major phase (~ 74 vol%), which is integrated with carbonaceous (~ 23 vol%) and glass-fiber phases. The zeolite particles are intimately bonded by carbonaceous to constitute a dendritic distribution of zeolite-carbonaceous amalgam frames (ZCF) that enclose micron-scaled voids, thus resembling a solid foam. These copious voids act virtually as tiny separation cells so as to favor permeance. The membrane shows high rejection to traces of water-soluble dyes, namely Methylene Blue (MB), Rhodamine-B (RB) and Methyl Orange (MO). Rejection to the probe dye molecules relies on electrostatic-interactions between the molecules and ZCF along carbonaceous pores. The interactions are influenced by the pH of feed since it affects magnitude and sign of charge on both ZCF and the dyes. Sterically, since NaY allows only water to penetrate, the dye molecules could crossover the carbonaceous phase in the filtrate if there are no rejection mechanisms. Typically, the membrane manifests a stable rejection (99%) and permeance (88 L/h m2 bar) for the 10 ppm MB solution. Attaching a stable surfactant thin layer on the pore wall allows the membrane to handle higher MB concentrations.

This study invents a post-pyrolysis modification approach to render the resulting carbon membrane (CM) competent for organic solvent nanofiltration (OSN). A bitumen coating on a porous stainless-steel disk (PSD) serves as the precursor for the intended carbon membrane (CM), which is attained through pyrolysis in Ar. The bitumen coating casts dual-pore networks in the CM because of the dominant asphaltene constituent in bitumen. The subsequent chemical decoration of CM was pursued through the following protocol: dopamine (DA) was deployed in the nanopores of CM via pressurized infiltration and followed by Tris buffer passes through to trigger in situ conversion of DA to polydopamine (PDA), which was affixed over the pore walls to furnish chemical affinity (termed as CMPDA). Additionally, the catechol moiety of PDA was arranged to chelate with the Zn2+ ion, aiming to trim the -OH anchor (termed as CMPDA-Zn) to probe the effect of chelate on separation. The three membranes (CM, CMPDA, and CMPDA-Zn) were thereafter assessed by the separation of ethanol or isopropanol from phenolics [tannic acid (TA)/tetracycline (TC)]. A significantly improved OSN performance [rejection (%) ↔ permeance (L/(m2·h·bar))] of CM vs CMPDA was observed: (i) for TA feed, 13% ↔ 85 L/(m2·h·bar) vs 83% ↔ 12 L/(m2·h·bar); and (ii) for TC feed, 20% ↔ 78 L/(m2·h·bar) vs 78% ↔ 12 L/(m2·h·bar). Compared to CMPDA, CMPDA-Zn further advances the rejection performance (∼89% for TA and ∼80% for TC) over 50 h separation. They are benchmarked by the latest literature results. The performance enhancements can be attributed to the spreading of PDA or PDA-Zn sites in the dual-pore networks, so that they are able to offer H-bonding and steric blocking roles, a chemicomechanical effect, to seize solute molecules over pore walls. It is this interfacial drag effect that sustains the solute rejection.

Microencapsulated phase change materials (MEPCMs) possess great potential as thermal energy storage materials for heating and cooling applications in industries. However, one important disadvantage of many MEPCMs is their low thermal conductivity. To enhance the thermal conductivity of PCMs, additives with high thermal conductivity are usually added into PCMs. However, these additives might not be mixed uniformly with the PCMs. Herein we report the first use of a polyurethane acrylic lacquer and hardener (PALH) as an adhesive to allow the additives to be uniformly coated on the surface of the shell of MEPCMs. A vacuum filtration assisted drop-casting method was employed to coat nano additives such as nano graphite, copper nanowires, titanium carbide and multi-walled carbon nanotubes (MWCNT) on the shell of commercial MEPCM (MPCM 28D) using PALH. MWCNT was found to be the most effective in improving the thermal conductivity of the MEPCM, giving an 87% increase when just 5 wt.% of MWCNT was added. Field Emission Scanning Electron Microscope (FESEM) images confirm the successful uniform coating of MWCNT on the shell of MPCM 28D, while Differential Scanning Calorimeter (DSC) thermograms show that the phase change properties of MPCM 28D remain largely similar to the pre-coated MPCM 28D. Furthermore, thermal cycling tests indicate that MWCNT do not significantly affect the energy storage and release performance of MPCM 28D. These results indicate that coating MEPCMs with MWCNT can be a simple and effective method to improve their overall thermal conductivity without sacrificing its performance.

This study utilizes the elementary grains of fish scale to construct a filtration membrane, which manifests organic solvent nanofiltration (OSN) efficacy relying on a microflow-promoted adsorption percolation mechanism. Specifically, a colloidal suspension of Barramundi fish scales (BFS) in concentrated sulfuric acid was blended with polyvinyl alcohol (PVA) in aqueous medium. The resulting suspension was thereafter coated on two pieces of cellulose filtration paper (CFP), followed by sandwiching the two coating layers together. The resulting stacked sheet was then subjected to partial pyrolysis under slight compression to complete the membrane preparation. The resulting membrane possesses a fibrous matrix in which individual cellulose fiber is wrapped by a selective layer comprising of cubic-shaped grains that aggregate together and leave nano-crevices. The tortuous pores amongst the fibers act as permeation channels where the coating layer chafes with the permeate stream. The membrane offers high retentions (> 90%) for Sudan IV and Rose Bengal in solvent solutions of ethanol and isopropanol respectively. The assessments suggest that the membrane separation proceeds via a hybrid mechanism, by which convective feed flowing through the permeation channels disperses into the nano-crevices of the selective layer, where pore diffusion facilitates adsorption due to the increase in liquid-solid contact. In addition, the fact that liquid streams chafe with the rough selective layer amidst the permeation channels increases residence time. The friction, pore diffusion, adsorption and buildup mutually sustain the solute retention rates.