Compact Adsorption Research Articles

Effect of dynamic high-pressure microfluidization on the structural, emulsifying properties, in vitro digestion and antioxidant activity of whey protein isolate.

The effects of dynamic high-pressure microfluidization (DHPM) on the structural, emulsifying properties, in vitro digestion and antioxidant activity of whey protein isolate (WPI) were investigated. The results demonstrated that WPI treated with 100MPa DHPM exhibited superior emulsification performance. This can be attributed to the conformational changes induced by 100MPa DHPM in WPI, leading to a transformation from disordered structures to ordered structures and an increased exposure of fluorophore such as tryptophan residues and hydrophobic groups, reduced aggregation state and particle size of WPI. These factors facilitated the migration of WPI towards the oil-water interface, resulting in the formation of a robust and compact adsorption layer which reduces interfacial tension and enhances emulsification stability. Furthermore, it was observed that while DHPM did not significantly affect the digestibility of WPI, it did enhance exposure to antioxidant amino acids in the digestive products thereby enhanced their antioxidant properties. In summary, structural modification induced by DHPM treatment enhanced both emulsification and antioxidant properties of WPI. These findings highlight the significant potential of DHPM treatment for enhancing the quality of meat products with an emulsion-type structure.

High-power-density adsorption chiller driven by data center waste heat using encapsulated composite as adsorbent

Achieving energy savings in the cooling system, the second-largest energy user, is crucial for reducing power usage effectiveness (PUE) in data centers (DCs). A promising energy conservation strategy for DCs with hybrid cooling systems involves repurposing waste heat from liquid-cooled circuits to drive adsorption chillers, which in turn cool air-cooled components. However, the application requires adsorption chillers capable of operating at ultra-low heat source temperature while possessing high cooling power density. In this paper, we develop a compact adsorption chiller using encapsulated LiCl-embedded silica gel (SG)-water as the working pair, free from corrosion and capacity degradation issues. The chiller is experimentally investigated under typical DC waste heat driven cooling conditions. It features an annular finned tube as the adsorber module to enhance mass transfer area, and a waterproof but breathable membrane encapsulated outside the adsorber to prevent solution leakage from the composite adsorbent. The developed chiller demonstrates a specific cooling power (SCP) of 102.35 W/kg and a volumetric cooling power (VCP) of 7.47 kW/m3 with hot/cooling/chilled water inlet temperatures of 50 °C/30 °C/23 °C, twice the performance of SG-water chillers. This work could advance heat recovery and energy savings in DCs and inspire more research interest into developing low-temperature-driven compact adsorption chillers.

Corrosion behaviour of 110SS steel in hydrochloric acid and blended acid system at 200°C

The influence of organic acids (formic acid, acetic acid) on the corrosion behaviour of 110SS steel, a hydrogen sulphide corrosion resistant alloy steel, in hydrochloric (HCl) acid environments was studied. The corrosion rates of 110SS steels in HCl acid and blended acid were measured using the high-temperature and high-pressure corrosion tester. Scanning electron microscopy was utilised to observe the morphology of corrosion products on steel samples corroded by different acid systems, and the energy dispersive X-ray spectrometer was used to analyse the elemental composition of the corrosion products. The corrosion morphology was observed using a 3D laser scanner. The results indicated that the corrosion rate of 110SS steel in HCl acid at 200 °C was an exponential function of HCl concentration. Reducing the HCl concentration significantly decreased the corrosion rate of 110SS steel. Organic acids and corrosion inhibitors synergistically reduced the corrosion of 110SS steel in HCl acid. Adding 3 wt.% organic acid to the 15 wt.% HCl acid system further reduced the corrosion rate, with a more pronounced effect observed in the HCl–formic acid system compared to the HCl–acetic acid system. Organic acids chemically adsorbed onto the steel surface and decomposed to produce CO, which hindered the attack of hydrogen ions on the metal. The added corrosion inhibitor and intensifier Sb2O3 resulted in the formation of a compact adsorption film on the steel surface, further inhibiting corrosion. The optimal mass ratio of HCl acid to organic acid was found to be 15% to 3%.

Synergism of alkylbenzene sulfonate and cetyltrimethylammonium bromide on corrosion inhibition of carbon steel in CO2 -saturated solutions

The synergistic effect of mixed surfactants, linear alkylbenzene sulfonate (LAS) and cetyltrimethylammonium bromide (CTAB), in inhibiting corrosion of CO2 on carbon steel was studied by weight loss and electrochemical measurement. The surface properties of LAS, CTAB, and their mixture in solution were also studied by surface tension and phase behavior. The surface of corrosion specimens was characterized by infrared spectroscopy, scanning electron microscopy, contact angle, and atomic force microscopy. The results show that LAS, CTAB, and their mixture are inhibitors mainly inhibiting anode reactions. The adsorption of LAS and CTAB molecules on the surface of steel belongs to chemical adsorption and follows Temkin adsorption. LAS or CTAB alone aggregated form spherical micelles or rod-like micelles, which results in the defective film layer and localized corrosion on surface of the steel. Mixed surfactants form closely packed lamellar microstructure in the solution which is correlated to compact adsorption film on the metal surface and better corrosion inhibition. The inhibition efficiency is the highest when the mixed ratio of LAS and CTAB is 2:1.

A study on activated carbon and carbon nanotube based consolidated composite adsorbents for cooling applications

MWCNT based composites enhance the thermal conductivity of the parent activated carbon, and they exhibit a higher volumetric cooling effect than other promising composites. • Synthesis of Activated carbon (AC)-multiwalled carbon nanotube (MWCNT) composites. • AC-MWCNT composites possess higher packing density than parent AC. • AC-MWCNT composites reveal improved thermal conductivity over parent AC. • MWCNT contributes to the CO 2 adsorption capacity of composite adsorbents. • AC-MWCNT composites exhibit improved SCE and COP over other AC-based composites. Activated carbon (AC)/CO 2 pair is very promising for developing an efficient adsorption cooling system (ACS). However, the low packing density and poor heat transfer properties of activated carbon-based ACS prevent their widespread adoption. Addressing these issues, this study focuses on the synthesis and characterization of AC-based consolidated composites comprising Maxsorb III (one type of AC) as adsorbent, multi-walled carbon nanotube (MWCNT) as thermal conductivity enhancer (TCE), and polyvinyl alcohol (PVA) as the binder. The influence of MWCNT on the porous properties, thermal diffusivity, thermal conductivity, and CO 2 adsorption capacity of composite adsorbents has been experimentally investigated. Besides, performance parameters, including the specific cooling effect (SCE) and coefficient of performance (COP), have been theoretically determined under different working conditions. Porous properties results show that developed composites are microporous like AC and exhibit high surface area and pore volume compared to other AC-based composite adsorbents developed so far. The incorporation of MWCNT into AC results in enhancing packing density, thermal diffusivity, and conductivity. One of the developed composites exhibits 2.47 and 3.5 times higher packing density and thermal conductivity than that of parent AC. Besides, the CO 2 adsorption study concludes regarding the contribution of MWCNT in the CO 2 adsorption capacity of composite adsorbents, which in turn results in the improved CO 2 uptake, SCE, and COP over other AC composites found in the literature. This study's findings will greatly stimulate the development of an efficient and compact adsorption cooling system.

Pickering emulsions co-stabilised by cellulose nanofibres and nicotinamide mononucleotide

Emulsified solid particles adsorbed at the oil–water interface can stabilise Pickering emulsions by acting as a physical barrier to the coalescence of oil droplets. Cellulose nanofibres (CNFs) have been used in food-grade Pickering emulsions because of their excellent performance as a low cost and sustainable material. Nicotinamide mononucleotide (NMN) is a small-molecule zwitterion with polar functionality capable of interacting with the CNFs. The ability of cationic CNFs and NMN to co-stabilise sunflower oil Pickering emulsions was investigated under various conditions using methods such as contact angle measurement, creaming stability, rheology, microscopy, thermal stability, and water-holding capacity. Emulsions with ultra-high stability, good gelation, and high plasticity were obtained using single-step shear dispersion with 0.25 wt% CNFs, 0.05–0.3 wt% NMN, and near-neutral pH. NMN stabilised the oil–water interface through electrostatic interactions and hydrogen bonding with CNFs. NMN transferred into the aqueous phase and interacted with CNFs to form a complex with a three-dimensional network structure, which improved the bulk viscosity and steric hindrance of the emulsion and created more compact adsorption of CNFs at the oil–water interfaces. Overall, the synergistic effects of various factors allow NMN to effectively co-stabilise Pickering emulsions with CNFs, making it an exciting method that can be used to encapsulate oil-soluble substances.

High internal phase emulsions stabilized solely by carboxymethyl chitosan

The ability of carboxymethyl chitosan (CMCS) to stabilize high internal phase emulsions (HIPEs) was investigated under various conditions. Emulsions with optimal properties (ultra-high stability, good gelation, and high plasticity) were obtained using single-step shear dispersion at a CMCS content of 0.3 wt% and near-neutral pH. CMCS functioned as a “structuring agent” to form three layers of jammed networks that immobilized the oil droplets enmeshed therein, through molecular rearrangement and characteristics such as flexible molecular entanglement chains and film-forming properties. Specifically, the hierarchical structures from the innermost layer (closest to the droplets) to the outermost layer were interfacial film, branching linear/membrane structures, and outer non-interfacial membranes, respectively. The outer layers of reticular membranes (without adhering onto the droplets) improved the emulsion's bulk viscosity and steric hindrance and further pushed the first layer closer to the dispersed droplets to create more compact adsorption, stabilize a large interfacial area, and improve the protective coating. The branched structure of CMCS also enabled bridging and, hence, the tight interconnection of oil droplets. Overall, the synergistic effects of various factors allowed CMCS to effectively stabilize HIPEs. The adopted strategy is expected to facilitate the development of other emulsifiers for HIPEs.

Bis-Mannich bases as effective corrosion inhibitors for N80 steel in 15% HCl medium

Three novel bis-Mannich bases (named as M-n-M) have been synthesized by condensation reaction of acetophenone and formaldehyde with different aliphatic diamines (n represents the number of carbon atoms in the diamines). Their corrosion inhibition behaviors for N80 steel in 15% HCl solution were evaluated through weight loss measurements, electrochemical tests, scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The results showed that the inhibition efficiency was increased with concentration as well as the alkyl chain length of the inhibitor, with the best inhibitor efficiency obtained as 98.20% for 0.3 % M-8-M in 15% HCl at 90 °C. The electrochemical tests revealed these inhibitors are mixed control type. SEM, AFM, XPS and contact angle measurement results revealed that the inhibitors form a compact adsorption layer on N80 steel surface. Adsorption mechanism of the inhibitors obeys the Langmuir isotherm, and physical adsorption and chemical adsorption exist simultaneously. M-8-M was compared with two commercial inhibitors at elevated temperature and gave a satisfactory corrosion rate of 15.13 mm·y−1 on N80 steel in 15% HCl at 120 °C.

Investigations on the synergistic effect of combined NaOl/SPA collector in ilmenite flotation

Combined collector of different reagents is widely used in mineral flotation, while the synergistic effect mechanism remains in dispute. In this study, two anionic collectors of sodium oleate (NaOl) and styrene phosphonic acid (SPA) were applied in ilmenite flotation. Microflotation experiments showed that NaOl had a stronger collection ability than the SPA, and the mixed collector of NaOl and SPA at a molar ratio of 3:1 exhibited the best performance in ilmenite flotation. Zeta potential measurement revealed that both NaOl and SPA could adsorb onto the ilmenite surface. The practical zeta potentials of the ilmenite using a combined NaOl/SPA collector were different from the calculated value, suggesting the possible interaction between these two agents and the ilmenite surface. X-ray photoelectron spectroscopy (XPS) analysis revealed the chemical adsorption of NaOl at the Fe sites of the ilmenite surface while SPA could interact with both Fe and Ti sites at the ilmenite surface. Molecular dynamics simulation (MDS) showed that the adsorption energy improvement using a NaOl/SPA mixture could be attributed to the mutual complement of NaOl and SPA, in which NaOl were easier to generate compact adsorption structure and SPA had the ability to interact with more metal sites.

Influence of ecofriendly protic ionic liquids on the corrosion and lubricating properties of water-glycol

Three ecofriendly protic ionic liquids (PILs) from sebacic acid, caprylic acid and ricinoleic acid were investigated their anticorrosion and lubrication performances in water-glycol. Based on the analyses of wear scar and QCM-D, the adsorption capacities of the PILs are positively related to their lubrication abilities. Compared with other two PILs, RPR with the stronger adsorption affinity can promote the more significant improvement in the lubricity of water-glycol owing to compact adsorption layer and carbon film. In addition, the results of OCM-D and electrochemical corrosion test are not completely consistent. DSD with weaker adsorption capacity show higher corrosion inhibition property contrasted with CPC, although RPR still outperform DSD and CPC. The abnormal phenomenon is properly explained by quantum chemical calculation.

Soft κ-carrageenan microgels stabilized pickering emulsion gels: Compact interfacial layer construction and particle-dominated emulsion gelation

HypothesisThe well-known gelling ability of κ-carrageenan can make aqueous solutions into soft materials, which are crisp and can be mechanically treated into the nano-sized microgel particle (MP) as the building block for constructing the Pickering emulsion gel (PEG). MPs are expected to adhere and further create the network structure in PEGs due to their viscoelastic texture. Herein, properties of PEGs should be possibly altered by using MPs with different pH and ionic strength. ExperimentsMPs were prepared by shearing and gelling κ-carrageenan solutions simultaneously. Effects of pH and ionic strength on MPs were formulated, and physical properties of PEGs prepared from corresponding MPs were investigated. The interaction between κ-carrageenan molecules was analyzed by FTIR, and the formation process of the interfacial layer was traced by the interfacial rheological technique. FindingsThe moderate K+ could increase the flocculation and hardness of MPs to improve the viscoelasticity of PEGs. Prepared MPs were more favorable for forming PEGs when pH was 8 and 9. The oil fraction impacted physical properties of PEGs slightly. MPs constantly moved to the interface from the continuous phase, forming the compact adsorption layer due to the extrusion of MPs.

Potassium-doped PC71BM for hydrogen storage: Photoelectron spectroscopy and first-principles studies

We consider the fullerene C70 derivative PC71BM as a potential onboard hydrogen storage material. As the cases of many sorbents, metal-decoration is needed to increase the adsorption energy of H2. We study the metal-decoration by intercalating K atoms into a PC71BM film and performing photoelectron spectroscopy measurements. The results reveal that the maximum stoichiometry is K9–10PC71BM. Then we study the hydrogen storage property of an isolated K9PC71BM molecule with density functional theory calculations. A K9PC71BM molecule can compactly adsorb 45H2 (6.22 wt%); the compact adsorption structure does not require large interstitial space in solid phase and thus should be able to be realized in experiments. Considering the poor crystallinity of solid PC71BM (with many large interstitial spaces), a gravimetric capacity >7 wt% can be anticipated. The adsorption energy meets the DOE target of onboard operating temperatures, and van der Waals interaction contributes more than 40% of the adsorption energy.

Zeolite-graphene composite adsorbents for next generation adsorption heat pumps

In this study, consolidated composite adsorbents comprising highly porous zeolite of type AQSOA-Z02 and two types of graphene nanoplatelets (GNPs), namely H25-GNPs and M25-GNPs, are developed to enhance the performance of a thermally powered adsorption heat pump. The thermophysical properties such as specific heat capacity, packing density, thermal conductivity, and porosity of the synthesized composite adsorbents are rigorously investigated. The addition of GNPs into zeolite improves the packing density as well as the thermal conductivity significantly. The highest thermal conductivity is observed for 50 wt% H25-GNPs contained composite, which is almost 127 times higher than the parent zeolite. Porous property investigation reveals that the fabricated composites are microporous, like the parent zeolite. Besides, the equilibrium adsorption uptake of water onto the composite adsorbents is measured gravimetrically at three different temperatures, 30, 50, and 70 °C. The experimental uptake data are correlated with the modified Langmuir, Sun and Chakraborty, and Universal models to describe the adsorption process mathematically. It was found that 20 wt% H25-GNPs contained composite provides almost 43% improvement of effective volumetric uptake over the parent zeolite. All the presented findings would carry significant importance for the development of an efficient and compact adsorption heat pump system. Besides, the obtained results would be very supportive for designing zeolite composite based gas separation and storage, desalination, and thermal energy storage systems.

Effects of fatty acyl chains on the interfacial rheological behaviors of amino acid surfactants

Amino acid surfactants derived from vegetable oils have attracted significant interest in the scientific community due to their excellent biocompatibility and low environmental impact. Because of the wide variety of vegetable oils, derived N-acyl amino acid surfactants may feature various fatty acyl groups and therefore offer diverse properties. According to the composition of commonly used vegetable oils, three main characteristics of fatty acyl structures, namely fatty acyl chain length, the number of CC bonds, and hydroxyl substituent, were summarized in this paper and a series of N-fatty acyl glycinate surfactants were synthesized. The specific effects of these three structural factors on the surface tension and interfacial rheological properties were systematically studied. In doing so, we found that an increase of fatty acyl chain length enhanced the interfacial activity and intermolecular interactions of N-fatty acyl glycinate surfactants. Thus, glycinate surfactants with longer fatty acyls could generate more compact adsorption films with a higher dilational modulus. The cis CC bonds in oleoyl and linoleoyl chains were found to bend the long hydrophobic tails, which might affect the compact arrangement of surfactant molecules and increased the viscoelasticity of interfacial films. In addition, the hydroxyl group on ricinoleoyl was found to inhibit the close packing of the hydrophobic tails and reduced intermolecular interactions. As a result, more viscoelastic films were formed by sodium N-ricinoleoylglycinate. The obtained results gained insights into the relationships between fatty acyl structural characteristics and the interfacial arrangements of N-acyl amino acid surfactants, which present a theoretical foundation for surfactant design and further application.

First-principles study of potassium-doped PC61BM for hydrogen storage

It is known that metal-doped C60 molecule has suitable adsorption energy for H2 adsorption/release around room temperature. However, the gravimetric storage capacity achieved on solid samples is too low (<1 wt%). In this work we study the hydrogen storage property of a metal-doped C60 derivative, K7PC61BM, with density functional theory calculations. The complex of K7PC61BM is selected because it has been observed experimentally. The calculations are performed for an isolated K7PC61BM molecule, but the limited size of interstitial space for solid phase is taken into consideration in finding the adsorption structure. It is found that K7PC61BM can at least adsorb 31H2 molecules (5.07 wt%) due to a compact adsorption structure. The averaged adsorption energy is 0.119 eV/H2, indicating a desorption temperature near room temperature.

Self-Assembled Egg Yolk Peptide Micellar Nanoparticles as a Versatile Emulsifier for Food-Grade Oil-in-Water Pickering Nanoemulsions.

Pickering emulsions stabilized by food-grade particles have garnered increasing interest in recent years due to their promising applications in biorelated fields such as foods, cosmetics, and drug delivery. However, it remains a big challenge to formulate nanoscale Pickering emulsions from these edible particles. Herein we show that a new Pickering nanoemulsion that is stable, monodisperse, and controllable can be produced by employing the spherical micellar nanoparticles (EYPNs), self-assembled from the food-derived, amphiphilic egg yolk peptides, as an edible particulate emulsifier. As natural peptide-based nanoparticles, the EYPNs have a small particle size, intermediate wettability, high surface activity, and deformability at the interface, which enable the formation of stable Pickering nanodroplets with a mean dynamic light scattering diameter below 200 nm and a polydispersity index below 0.2. This nanoparticle system is versatile for different oil phases with various polarities and demonstrates the easy control of nanodroplet size through tuning the microfluidization conditions or the ratio of EYPNs to oil phase. These food-grade Pickering nanoemulsions, obtained when the internal phase is an edible vegetable oil, have superior stability during long-term storage and spray-drying based on the irreversible and compact adsorption of intact EYPNs at the nanodroplet surface. This is the first finding of a natural edible nano-Pickering emulsifier that can be used solely to make stable food Pickering nanoemulsions with the qualities of simplicity, versatility, low cost, and the possibility of controllable and mass production, which make them viable for many sustainable applications.

Structure of Dense Adsorption Layers of Escin at the Air-Water Interface Studied by Molecular Dynamics Simulations.

Saponins are natural surfactants with high surface activity and unique surface properties. Escin is a triterpenoid saponin which has unusually high surface viscoelasticity [Golemanov et al. Soft Matter 2013, 9, 5738] and low permittivity to molecular gas diffusion of its adsorption layers. In our previous study [Tsibranska et al. Langmuir 2017, 33, 8330], we investigated the molecular origin of this unconventional behavior and found that escin molecules rapidly assemble in a compact and stable surface cluster. This behavior was explained with long-range attraction between the hydrophobic aglycones combined with intermediate dipole-dipole attraction and strong short-range hydrogen bonds between the sugar residues in the adsorbed escin molecules. In this study, we performed atomistic molecular simulations of escin molecules in dense adsorption layers with two different areas per molecule. The results show that the surfactant molecules in these systems are much less submerged in water and adopt a more upright position compared to the dilute layers studied previously. A significant number of trapped water molecules are located around the hydrophilic groups placed above the water equimolecular surface to solvate them in the dense layer. To maintain the preferred orientation of the escin molecules with respect to the interface, the most compact adsorption layer acquires a significant spontaneous curvature. The substantial elasticity of the neutral escin layers, as in our previous study, is explained with the presence of a specific interaction, which is intermediate between hydrogen bonding and dipole-dipole attraction (populated lengths in the range 0.16 to >0.35 nm), supplemented by substantial flexibility of the surfactant heads, optimal curvature of the interface, and significant normal displacement of the molecules to allow their tight surface packing. The simulations reveal long-range order within the layers, which signifies the role of the collective behavior of the saponin molecules in such dense adsorption layers.

Design and experimental study of a small scale adsorption desalinator

Adsorption desalinators produce potable water from seawater using low-grade heat at 50–90 °C. The technology has been proven using several experimental systems, but their sizes are too large to allow efficient further development by testing novel adsorption materials and components. In this study, we introduce the world’s most compact adsorption desalinator with a bed size of 0.2 kg silica gel. The system achieves a Specific Daily Water Production of 7.7 kgwater per kgsilica-gel and day. The performance is comparable to the best performing system to date proving that the downscaling is not detrimental. Moreover, the tests demonstrate the benefits of simple heat integration between the adsorber beds, which reduces energy consumption by 25% and increases the Performance Ratio to 0.6. The importance of heat integration is further highlighted in an unprecedented thermal response experiment, which evaluates the partition of energy input in terms of sensible heat and heat of desorption.

Theoretical insights on the comparison of champion dyes SM315 and C275 used for DSSCs reaching over 12% efficiency and the further optimization of C275.

Theoretical insights on the comparison between the champion dyes SM315 and C275 used for high-performance dye-sensitized solar cells (DSSCs) reaching over 12% efficiency with different electron donors only (porphyrin for SM315 and indenoperylene for C275) were explored for the first time. The intrinsic reasons for the significantly improved monochromatic photon-to-electric current conversion efficiency (IPCE) and open circuit voltage (Voc) of C275-based DSSCs over those of SM315 were revealed. According to our results, we find that the larger IPCE of C275 is attributed to its larger electronic coupling, smaller reorganization energy, reduced exciton binding energy and enhanced charge transfer character, all of which when combined lead to a larger electron injection efficiency. In addition, the larger Voc of C275 is due to a greater number of injected electrons, a smaller molecular volume and a smaller projected area, which lead to a more compact adsorption layer with a hindered charge recombination process. Thus, C275 is expected to have more potential to further optimize high-performance DSSCs. In view of the primary shortcoming of C275, which is its relatively narrow absorption spectrum, further optimization was made through structural modification using a series of heterocyclic anchoring groups. Using the same evaluation criteria, the theoretical screening of these dyes based on C275 is carried out. We find that indenoperylene dye with a barbituric acid (BA) anchoring group is a promising candidate for the experimental synthesis of high-performance DSSCs with improved Jsc, Voc and adsorption stability.

CO2 adsorption onto activated carbon–graphene composite for cooling applications

Adsorption cooling system using composite adsorbent and high energy density adsorbate (CO2) provides a significant advantage to reduce the system geometry. This study presents the adsorption characteristics of CO2 onto synthesized composites employing graphene nanoplatelets (GNPs) and activated carbon (AC). The influence of GNPs in the composite is investigated in terms of porous properties, thermal conductivity, and CO2 adsorption capacity. The composite 3 (50 wt% AC and 40 wt% H-25) achieves the highest thermal conductivity enhancement which is 23.5 times higher than parent AC powder. The CO2 adsorption uptakes onto different composites are measured gravimetrically at adsorption temperatures 20–70 °C. The measured data are fitted with modified D-A and Tóth models. The specific cooling effect (SCE) and coefficient of performance (COP) are estimated for various driving heat source temperatures and two evaporation temperatures of 5 and 10 °C with a fixed adsorption/condenser temperature of 30 °C. AC-GNPs based composites are found suitable for developing compact adsorption cooling systems.