Water-absorbing Material Research Articles

Capillary container array structures for efficient, energy-saving, and sustainable evaporative cooling and humidification

Evaporative cooling is a widely employed method for air conditioning and heat dissipation, utilizing the phase transition of water to achieve simultaneous cooling and humidification. It relies on high-surface-area solid materials to enhance air-liquid contact upon wetting. However, these water-absorbing materials have drawbacks such as increased air resistance, degradation of water quality, and limited water retention capabilities. This study introduces a novel structure called the capillary container array (CCA) for effective humidification and cooling. The CCA structure overcomes the limitations of traditional methods by incorporating interconnected capillary containers with adjustable spacing and utilizing capillary forces to capture liquid droplets while minimizing the solid component. Compared to commercial paper-based wet curtains, the CCA structure offers significant advantages including strong water retention capabilities, high humidification performance, low air resistance and high pollution resistance. It increases water capacity by 6 times, humidification capacity by 8 %, and temperature drop by 2.2 °C. Moreover, it exhibits a 5-fold longer in water retention duration, a 30 % reduction in air pressure drop and a 3-fold increase in the performance coefficient, and maintains excellent water quality (<1 NTU) over prolonged operation. These advancements make the CCA structure highly promising for various applications in agriculture, industry and environmental conservation.

A Comprehensive Approach for Designing Low Carbon Wood Bio-Concretes.

This paper presents a method for designing low carbon bio-based building materials, also named bio-concretes, produced with wood wastes in shavings form (WS) and cementitious pastes. As the aggregates phase of bio-concretes is composed of plant-based particles, known as porous and high water-absorbing materials, the bio-concretes cannot be designed by using the traditional design rules used for conventional mortar or concrete. Then, the method used in the current paper is an adaptation of a previous one that has been developed in a recent paper where bio-concretes were produced with a cement matrix, three types of bio-aggregates, and a proposal of a design abacus. However, when that abacus is used for designing WBC with low cement content in the matrix, the target compressive strength is not reached. In the present paper, the method is extended to low cement content matrix (up to 70% of cement substitution) and also considering the greenhouse gas (GHG) emission of the WBC. To obtain data for proposing a new design abacus, an experimental program was carried out by producing nine workable WBCs, varying wood volumetric fractions (40-45-50%), and water-to-binder ratios. The bio-concretes produced presented adequate consistency, lightness (density between 715 and 1207 kg/m3), and compressive strength ranging from 0.64 to 12.27 MPa. In addition, the GHG emissions of the WBC were analysed through the Life Cycle Assessment methodology. From the relationships obtained between density, compressive strength, water-to-binder ratio, cement consumption, and GHG emissions of the WBC, calibration constants were proposed for developing the updated and more complete abacus regarding an integrated mix design methodology.

Laboratory exploration of a novel method to protect silicate relics against salt efflorescence by directional induction of water

Salt efflorescence is one of the critical problems for the preservation of immovable silicate relics. Salt efflorescence mainly comes from continuous cycles of crystallization/dissolution or hydration/dehydration of salts in confined pores in silicate relics. Many protocols have been developed in attempts to alleviate possible salt damages with minor success because of endless water and salt feed from underground. In this study, we propose and design a novel technique for salt damage prevention and protection of immovable relics. Materials with higher water-absorbing ability than matrix are applied to control the water and salt migration direction in simulated sand samples. The distribution of moisture content on the surface of sand is followed by hyperspectral imaging. It appears that water and salt molecules will preferentially transport towards positions containing higher water-absorbing material. Both organic and inorganic high water-absorbing materials show effective in controlling the water and salt migration direction, which provides a new approach for the prevention and protection of salt efflorescence in silicate cultural relics.

Improving solar still efficiency through integration of cellulose-based water absorbers and Peltier condensation unit

This study involves a series of experiments aimed at assessing the impact of incorporating water-absorbent materials on the productivity of solar stills. It is worth mentioning that the performed experiments examine the effects of both materials and their location inside solar still unit. The solar still used for the experiments comprised a black-painted metal case and a glass layer positioned at a 30° angle relative to the horizontal. To enhance evaporation performance, a Peltier cooling module was integrated into the system. Furthermore, to prevent thermal losses and improve efficiency, the solar still case was insulated using Styrofoam material. From a scientific standpoint, the variations in this context can be ascribed to three primary variables as, integration Peltier condensation unit, use of water absorber materials like hemp and high-absorbent papers, and the incorporation of absorber dark colors. Throughout the experiments, constant test conditions were established using an artificial light source. In the reference setup, a total of 25 g of clean purified water was obtained, whereas in Case 5 (utilizing black high-absorbent papers on a triangle metal frame) and Case 6 (employing high-absorbent papers in the form of upright columns), which yielded the most efficient results, the amounts of purified water obtained were approximately 34 and 40 g, respectively. The results indicated a remarkable enhancement in thermal efficiency for Case 5 and Case 6, with approximately 29% and 45% increases, respectively, compared to the reference setup. Furthermore, a cost assessment has been conducted, demonstrating that the productivity gained through the use of internal materials contributes to improvements in cost efficiency. In comparison to the reference case, Case 6 exhibits a cost reduction for cost per liter exceeding 35%.

Development of A Potentiometric Portable Extractor for Phosphate using Water Absorbent Materials and Cobalt Wire Electrodes

Soil phosphorus is an essential nutrient in the soil and is very necessary for plants, so measuring the content of elements or their derivatives in the soil is very necessary. This study aimed to develop a portable measuring instrument for phosphate based on the potentiometric principle using cobalt electrodes. The choice of absorbent material to support portable measuring instruments is based on water absorption and the potential response of the cobalt electrode when used with an absorbent. The phosphate electrode was made from cobalt wire and Ag/AgCl as a reference electrode. A comparison of analysis results was carried out between portable extraction potentiometric and conventional potentiometric methods. The results showed that polyvinyl alcohol (PVA) was the best absorbent. Using potentiometric measurements in a portable extractor prototype with PVA as an absorbent material offers promising prospects. The comparison of measurement results between the portable extractor and conventional potentiometric had 0.8039 as the correlation coefficient. Phosphate in conventional potentiometric was measured 1.2809 times higher than portable extraction potentiometric. The potentiometric slopes were -23.69 mv/decade and -26.63 mv/decade for the portable extractor potentiometric and the traditional potentiometric methods, respectively.

Optimising the Production Process of Bacterial Nanocellulose: Impact on Growth and Bioactive Compounds.

Research into bacterial cellulose production has been growing rapidly in recent years, as it has a potential use in various applications, such as in the medical and food industries. Previous studies have focused on optimising the production process through various methods, such as using different carbon sources and manipulating environmental conditions. However, further research is still needed to optimise the production process and understand the underlying mechanisms of bacterial cellulose synthesis. We used Plackett-Burman and Box-Behnken experimental designs to analyse the effect of different factors on bacterial cellulose production. The fermentation kinetics of the optimised medium was analysed, and the produced cellulose was characterised. This approach was used because it allows the identification of significant factors influencing bacterial cellulose growth, the optimisation of the culture medium and the characterisation of the produced cellulose. The results showed that higher sucrose concentrations, higher kombucha volume fractions and a smaller size of the symbiotic culture of bacteria and yeast were the most important factors for the improvement of bacterial cellulose production, while the other factors had no relevant influence. The optimised medium showed an increase in the concentrations of total phenolic compounds and total flavonoids as well as significant antioxidant activity. The produced pure bacterial cellulose had a high water absorption capacity as well as high crystallinity and thermal stability. The study makes an important scientific contribution by optimising the culture medium to produce bacterial cellulose more productively and efficiently. The optimised medium can be used for the production of a kombucha-like beverage with a high content of bioactive compounds and for the production of bacterial cellulose with high crystallinity and thermal stability. Additionally, the study highlights the potential of bacterial cellulose as a highly water-absorbent material with applications in areas such as packaging and biomedical engineering.

Sugarcane-based superhydrophilic and underwater superoleophobic membrane for efficient oil-in-water emulsions separation

The development of ecological, low cost, easy preparation, especially high performance materials for emulsions separation is of great importance due to the rise in pollution of oil-water emulsions from industrial production and domestic waste. Straws as agricultural wastes, including plenty of hydrophilic groups and multi-level pore structures, can be prepared as biomass membranes for oil-water emulsion separation. Herein, a novel super-hydrophilic sugarcane-based (SHS) membrane was prepared using a facile and eco-friendly method including chemical treatment and freeze-drying. The as-prepared SHS membrane has unique wettabilities due to the hydrophilic property of the internal cellulose and the micro-nano pores, including superhydrophilicity (water contact angle of 0°) and underwater superoleophobicity (underwater oil contact angles of over 150°). The SHS membrane has good durability and stability against ultraviolet (UV) irradiation, corrosion by acids and alkalis, mechanical abrasion and especially mould adhesion. Importantly, the SHS membrane can be used for separation of various oil-in-water emulsions, and exhibits excellent separation performances such as high separation efficiency (> 99 %) and good separation flux (above 891 L m−2 h−1 bar−1). The SHS membrane also exhibits excellent recyclability over 10 continuous separation cycles. Furthermore, the SHS membrane can be utilized to selectively absorb water from oils as a water absorbent material. Hence, SHS membrane is a promising and practical material for applications in treatment of wastewater containing oil-water emulsions.

Thermally Degradable Split-Ring Resonator Made on a Gelatin Substrate with Enhanced Dielectric and Conductive Properties

Ingestible electronics, taken orally for monitoring organs, bacteria, and cells, are innovative wireless diagnostic and therapeutic technologies. Whereas residual in-body devices may require surgical removal, food-based sensors are seen as a way of ensuring safety. This study reports a split-ring resonator (SRR) whose resonance can be observed wirelessly. It is fabricated on a thermoresponsive gelatin substrate with a collaged edible metal leaf. Gelatin is a highly water-absorbing material, which may affect the resonator performance. According to high-frequency structural simulations, this resonator requires a low dielectric loss, <0.05, and high conductivity, >106 S/m. We found that these targets were achieved by completely drying the gelatin film and transferring multiple stacked metal leaves onto the film. Thin metal sheets were glued using an oleogel made of beeswax and olive oil, and the use of a hydrophobic material also aided in the transfer. Thus, we gained insights into the criteria for fabricating transient resonators with thermodegradability. SRRs made with edible materials are a technology that works in harmony with people and the environment and could lead to wireless devices or micromachines for the healthcare, agriculture, and livestock industries.

Improvement effects of treating with calcined oyster shell and carbonized cow dung compost on clay with high water content

Effective waste treatment as a new binder apply to improve soft clay is an economical and environmental solution for stabilizing soft clay. In this context, this study proposes a high-water content clay improvement case using calcined waste oyster shells (COS) and carbonized cow dung compost (CC) as substitutes for cement to stabilize clay with high-water content. In this study, the solidifying agent/water ratio, C/(w/100), was introduced as an important parameter to evaluate the improvement effect of COS stabilized clay. Compared with ordinary Portland cement (OPC), the mixed amount of COS required for effective improvement is significantly reduced (≈43–46 %). In addition, the incorporation of more environmentally friendly carbonation materials improves the improvement effect of COS stabilized clay. A comparison with commercial wood charcoal proved that CC with better adsorption capacity significantly improved high-water-content clay. The test results of energy-dispersive X-ray spectrometry (EDS) and scanning electron microscope (SEM) show that with an increase in COS content, the reaction product hydrated calcium silicate is formed, and the improvement effect of stabilized clay is enhanced. In addition, the incorporation of water-absorbent materials reduced the void space in the clay structure, which is conducive to stabilizing the internal cementation of clay. SEM evidenced the change of microstructure of the stabilized clay owing to the gel materials.

Water Harvesting Strategies through Solar Steam Generator Systems.

Solar steam generator (SSG) systems have attracted increasing attention, owing to its simple manufacturing, material abundance, cost-effectiveness, and environmentally friendly freshwater production. This system relies on photothermic materials and water absorbing substrates for a clean continuous distillation process. To optimize this process, there are factors that are needed to be considered such as selection of solar absorber and water absorbent materials, followed by micro/macro-structural system design for efficient water evaporation, floating, and filtration capability. In this contribution, we highlight the general interfacial SSG concept, review and compare recent progresses of different SSG systems, as well as discuss important factors on performance optimization. Furthermore, unaddressed challenges such as SSG's cost to performance ratio, filtration of untreatable micropollutants/microorganisms, and the need of standardization testing will be discussed to further advance future SSG studies.

Thermal performance analysis of a mixed-flow indirect evaporative cooler

This study experimentally investigates the performance of an indirect evaporative cooler based on the Maisotsenko cycle. It consists of a heat and mass exchanger (HMX) with a novel mixed-flow configuration. The de-sized cellulose rich cotton fabric is used as water-absorbing material, and aluminum sheets are used to fabricate the heat mass exchanger unit. The cooling performance indices of the system, namely dew point effectiveness (DPE), wet bulb effectiveness (WBE), and the coefficient of performance (COP), are evaluated at different inlet air temperatures (24 to 35 °C), volumetric flow rates (600 to 1050 m 3 /h), relative humidity (35 to 65%) and the extraction ratio (0.1 to 0.6). The results of the experimental study show that at a relative humidity of 35%, and inlet air temperature of 35 °C, the magnitude of the wet bulb and dew point effectiveness are highest and higher dew point and wet bulb effectiveness are observed at lower mass flow rates. The best cooling capacity and COP were obtained at an extraction ratio of 0.3 and are found to be highest at DBT of 35 °C. The maximum magnitude of CC was 2 kW with a COP of 16. Additionally, the convective heat transfer coefficient is calculated theoretically and compared with the experimental value. Further, a comparison of the obtained results for the mixed flow configuration considered in this study with those for other configurations reported in the literature reveals that the indirect evaporative cooler with mixed-flow configuration yields comparably good effectiveness. • Performance of indirect mixed flow evaporative cooler evaluated experimentally. • Effect of temperature, flow rate, relative humidity and extraction ratio are studied. • The optimum extraction ratio is observed to be 0.30. • Better performance is at higher inlet air temperature with lower humidity. • The maximum COP of 16 was observed at 35 °C with 35% relative humidity.

Water Holding Performance of Natural Fiber–filled Biodegradable Absorbing Materials

ABSTRACT Biodegradable absorbing materials (BAMs) with and without the presence of pineapple leaf fiber (PF) were prepared from the reaction of chitosan, urea and citric acid using a simple hot-mixing process. The effects of constituent ratios and PF loadings on water-absorbing performance were investigated. FTIR results of BAMs indicated the successful synthesis of the crosslinked materials, whereas the intensity of XRD patterns showed very broad peaks due to a combination of amorphous and crystalline regions. Thermogravimetric results showed that more rapid degradation was observed for the prepared materials compared to the commercial water-absorbing material. Variations of constituent ratios slightly affected the water-absorbing performance of BAMs. The presence of PF in BAM clearly improved the water uptake and its water-absorbing performance (>220 g/g) was found nearly the same level as that of a commercial diaper. BAM with the presence of PF has a potential application for slowing down the water evaporation rate from soil and hence reducing the watering cycles.

Bench scale percolation tests on radioactive Cs-contaminated soil in Fukushima and soil modified with water-absorbing polymer agent

The reuse of removed soil generated from decontamination projects in Fukushima as a recycled material for the construction of embankments has been under consideration for the sake of reducing the volume of this soil for its final disposal. Agents containing water-absorbing polymers are used in Fukushima to modify the removed soil in order to increase the separation efficiency of foreign materials and to improve the easiness of handling. As the reuse of modified soil containing organic water-absorbing materials, such as a superabsorbent polymer, is rather rare in the geotechnical field, it necessitates an investigation into the impact of the modifying agent on the leachate quality to ensure the environmental safety of the recycling project. In this study, therefore, bench scale percolation tests were conducted to examine the changes in the leachate quality of the removed soil with and without modification by an agent containing a superabsorbent polymer. The tests lasted for more than 950 days (liquid/solid ratio of over 10). The peak 137Cs concentration in the leachate from the removed soil was 8.6 Bq/L and the accumulated leaching ratio was 0.243 %. The leaching of 137Cs from the modified soil decreased by 60 % after mixing the removed soil with a 3 % water-absorbing polymer agent. The leaching of K+ and ammonia nitrogen (NH4+-N) was 40 % and 60 % lower, respectively, after the soil modification, while the accumulated amount of leaching of the dissolved organic carbon in the initial stage was 60 % higher. The total leachate amount collected from the modified soil was 4 % lower than that collected from the removed soil.

Alkali-Resistant and pH-Sensitive Water Absorbent Self-Healing Materials Suitable for Oil Well Cement

Oil well cement microcracks cause formation fluid channeling, compromising oil and gas extraction safety. Superabsorbent polymer (SAP) can absorb water and swell to prevent fluid channeling. In this study, an alkali-resistant and pH-sensitive SAP was prepared based on the properties of oil well cement slurry. The preparation of the SAP was optimized, including monomer ratio, cross-linking agent dosage, and monomer concentration. The pH sensitivity and alkali resistance of the SAP were evaluated. The results revealed that the SAP exhibited good pH sensitivity, with the absorption rate in water being 2.18 times that of cement slurry filtrate (CSF) at 95 °C. Furthermore, the FTIR spectrum showed that the SAP had a stable molecular structure. The secondary absorption rate in water of the SAP after soaking in CSF was not different from the original absorption rate. Styrene–butadiene latex (SBL) can be used to adjust the SAP’s absorption rate. The SAP’s absorption rate had a good exponential functional relationship with SBL dosage. The SBL dosage can be determined by the functional relationships to prepare a SAP with the required properties.

The role of coarse aggregates in hydrophobized hydraulic concrete

Concrete materials with decreased water-absorption characteristics are optimum for some construction applications. Hydrophobicity accompanied by decreased water absorption in a concrete material can be achieved through its formulation with hydrophobic silica particles. Despite this effect of hydrophobic additions to concrete, the water absorption and hydrophobicity of the final concrete materials can be affected by the water affinity of the coarse aggregates used in their preparation. The role of these coarse aggregates was studied in concrete with added hydrophobic silica particles and prepared with three coarse aggregates with marked differences in their water absorption: quartz rocks (low), igneous andesitic rocks (medium) and igneous basaltic rocks (high). The hydrophobicity and water-absorption characteristics of the concrete materials depended on the coarse aggregates used in their preparations. The materials prepared with quartz as coarse aggregates produced less water-absorbing materials. In contrast, the use of igneous basaltic rocks produced materials with greater absorption. A pretreatment involving impregnation of the igneous basaltic rocks with hydrophobic particles before their use in the preparation of concrete material caused significantly decreased water absorption.

Recent progress in PNIPAM-based multi-responsive actuators: A mini-review

• The preparation methods of PNIPAM-based hydrogel actuators are summarized. • Different response types of PNIPAM-based hydrogel are reviewed. • A broad range of engineering applications are presented. • It is expected to prepare hydrogel actuators with more advanced properties. Hydrogels are water-absorbing materials with three-dimensional network structures. Hydrogel actuators have heterogeneous structures and can respond to specific environmental stimuli. As a typical temperature-responsive polymer, Poly(N-isopropylacrylamide) (PNIPAM) can be combined with other environmental responsive materials to design and manufacture actuators responsive to multiple environmental stimuli. As an emerging material, PNIPAM-based multi-responsive soft actuators could be used in soft robotics, tissue engineering, bionics, and other fields. This review comprehensively introduces the construction methods of the PNIPAM-based hydrogel actuators. Based on the types of environmental response, the designs and applications of the environmental stimuli-responsive hydrogel actuators based on PNIPAM are discussed. In addition, conclusions and perspectives are presented to indicate some issues and expectations for the future studies.

Cotton Cellulose-Derived Hydrogel and Electrospun Fiber as Alternative Material for Wound Dressing Application.

Cotton has been recognized as a useful biomaterial over decades, and it has been widely applied in the textile industry. However, a large amount of cotton waste is generated during the manufacturing processes, but it has been considered as a low-value product. With high content of cellulose remaining in cotton waste, our study focuses on transforming cotton cellulose into a valuable product. Cellulose was extracted from cotton waste and modified into two main materials for wound dressing application: hydrogel-based water absorbent materials and electrospun composite nanofibers. In order to enhance the water absorption, carboxymethyl cellulose (CMC), the modified cellulose with functional group prone to interact with water molecules, has been developed in this study. The hydrogel-based CMC was created by using the chemical cross-linking reaction of epichlorohydrin (ECH). The hydrogel demonstrated the swelling and reswelling ability by 1718 ± 137% and 97.95 ± 9.76%, respectively. Meanwhile, cellulose/PEG in trifluoroacetic acid (TFA) was successfully fabricated as nonwoven composite by a conventional electrospinning technique. The fabrics provided highly appropriated properties as wound dressing, including the following: water absorption was up to 1300 times and water vapor permeability controlled in the range of 2163–2285 g·m−2·day−1. This showed the preliminary information for recovering cotton waste into valuable products.

Hydrogel application improved growth and yield in Senna (Cassia angustifolia Vahl.)

Water availability is one of the most important factors determining plant growth. In moisture-stressed situations, water-absorbing materials are an effective way to increase water retention capacity. In 2016–17, the CSIR-CIMAP Research Centre at Boduppal, Hyderabad, conducted field research on red sandy soil in the semi-arid environment of south India to see what effect different doses of hydrogel had on the growth, yield, and economics of senna, one of India's most export-oriented and economically important crops. The results show that applying 3000 g of hydrogel per hectare resulted in a significant increase in leaf and pod yield (2324.7 kg ha−1 and 675.7 kg ha−1, respectively) compared with the other treatment. It was comparable with the use of 2500 g of hydrogel (2216.8 kg ha−1and 643.4 kg ha−1, respectively). The control had a remarkably lower yield of leaf and pod (1611.6 kg ha−1 and 433.5 kg ha−1), respectively) then the 250 g hydrogel treatment (1730.8 kg ha−1 and 494.8 kg ha−1, respectively). When 3000 g of hydrogel is applied, water use efficiency and soil water holding capacity improves significantly (5.55 kg/ha mm, 50.12%, and 20.28%, respectively). A similar pattern was observed in terms of the growth parameter. Similarly, when comparing the rest of the treatments, the use of the hydrogel at 3000 g per hectare gave a much higher gross return (US$ 2289.7 ha−1), which was comparable to the application of hydrogel to senna crop at 2500 g per hectare (US$ 2183.1 ha−1). A similar pattern was observed in terms of net return (US$ 1669.0 ha−1). The benefit to cost ratio (B: C) was also much higher (2.69) when 3000 g of hydrogel was applied, and it was comparable to the application of 2500 g of hydrogel per hectare (2.52).

Recycling Lithium from Waste Lithium Bromide to Produce Lithium Hydroxide.

Lithium resources face risks of shortages owing to the rapid development of the lithium industry. This makes the efficient production and recycling of lithium an issue that should be addressed immediately. Lithium bromide is widely used as a water-absorbent material, a humidity regulator, and an absorption refrigerant in the industry. However, there are few studies on the recovery of lithium from lithium bromide after disposal. In this paper, a bipolar membrane electrodialysis (BMED) process is proposed to convert waste lithium bromide into lithium hydroxide, with the generation of valuable hydrobromic acid as a by-product. The effects of the current density, the feed salt concentration, and the initial salt chamber volume on the performance of the BMED process were studied. When the reaction conditions were optimized, it was concluded that an initial salt chamber volume of 200 mL and a salt concentration of 0.3 mol/L provided the maximum benefit. A high current density leads to high energy consumption but with high current efficiency; therefore, the optimum current density was identified as 30 mA/cm2. Under the optimized conditions, the total economic cost of the BMED process was calculated as 2.243 USD·kg−1LiOH. As well as solving the problem of recycling waste lithium bromide, the process also represents a novel production methodology for lithium hydroxide. Given the prices of lithium hydroxide and hydrobromic acid, the process is both environmentally friendly and economical.

Lipase-Immobilized Cellulosic Capsules with Water Absorbency for Enhanced Pickering Interfacial Biocatalysis.

Lipase-immobilized cellulosic capsules consisting of hydrophobic ethyl cellulose (EC) and hydrophilic carboxymethyl cellulose (CMC) were developed with a promising interfacial activity and water absorbency for the enhanced Pickering interfacial biocatalysis. Lipase was physically immobilized with water-absorbent materials (CMC) via hydrogen bonding and electrostatic interactions and acted as the interior catalytic core of the capsule. The interfacially active EC worked as the exterior shell, enabling capsules to stabilize the oil-in-water Pickering emulsion for the subsequent Pickering interfacial catalysis. The capsules with CMC created interior water-rich conditions to improve the conformational and enzymatic activity of the immobilized lipase. Compared with capsules without water-absorbent materials, the capsules with CMC enhanced the efficiency of the Pickering interfacial catalysis for the esterification of oleic acid and 1-octanol by 12%. Immobilized with a small amount of lipase (0.0625 g/g), the cellulosic capsules with water absorbency could convert 50.8% of the reactants after 10 h under room temperature, significantly higher than that by the same amount of free lipase in the biphasic system (15%) and a Pickering emulsion (24.1%) stabilized by empty capsules (without lipase). Moreover, the cellulosic capsules could be recycled by simple centrifugation while retaining their high relative catalytic activity for at least eight cycles, demonstrating their sustainable catalytic performance.