Superabsorbent Materials Research Articles

Exploring the influence of polymers on soil ecosystems: prospective from agricultural contexts

The utilization of advanced polymeric materials has indeed emerged as a significant trend in sustainable agriculture, offering a range of innovative applications aimed at enhancing productivity, minimizing environmental impact, and promoting resource efficiency. Smart polymeric materials enable the controlled release of pesticides, herbicides, and fertilizers, thereby enhancing their efficacy while reducing the quantities needed. Superabsorbent polymeric materials act as soil conditioners, assisting in alleviating the negative impacts of drought by retaining moisture and enhancing soil structure. This fosters improved plant growth and resilience in water-scarce environments. Polycationic polymers play a role in plant bioengineering, facilitating genetic transformation processes aimed at enhancing crop productivity and disease resistance. Advanced polymeric systems contribute to the arsenal of precision agriculture tools by enabling precise delivery and targeted application of agricultural inputs. This approach enhances resource efficiency, reduces waste, and minimizes environmental impact while optimizing crop yields. In reviewing recent developments in the design and application of advanced polymeric systems for precision agriculture, several key considerations emerge.

Poly(acrylic acid)-Sodium Alginate Superabsorbent Hydrogels Synthesized by Electron-Beam Irradiation-Part II: Swelling Kinetics and Absorption Behavior in Various Swelling Media.

Hybrid hydrogels with superabsorbent properties based on acrylic acid (20%), sodium alginate (0.5%) and poly(ethylene oxide) (0.1%) were obtained by electron-beam irradiation between 5 and 20 kGy, and are characterized by different physical and chemical methods; the first results reported showed gel fractions over 87%, cross-link densities under 9.9 × 103 mol/cm3 and swelling degrees of 400 g/g. Two types of hydrogels (without and with 0.1% initiator potassium persulfate) have been subjected to swelling and deswelling experiments in different swelling media with different pHs, chosen in accordance with the purpose for which these superabsorbent materials were obtained, i.e., water and nutrients carriers for agricultural purposes: 6.05 (distilled water), 7.66 (tap water), 5.40 (synthetic nutrient solution) and 7.45 (organic nutrient solution). Swelling kinetics and swelling dynamics have been also studied in order to investigate the influence of swelling media type and pH on the absorption phenomenon. The swelling and deswelling behaviors were influenced by the hydrogel characteristics and pH of the swelling media. Both the polymeric chain relaxation (non-Fickian diffusion) and macromolecular relaxation (super case II) phenomenon were highlighted as a function of swelling media type.

Heat transfer mechanism of superabsorbent polymers phase change energy storage cold-formed steel wall under fire

The superabsorbent polymer phase change materials (SAP materials) exhibit exceptional water absorption and retention properties, offering substantial potential for fire protection in steel structures, thereby reducing the need for sheathing boards and fire-retardant coatings, while minimizing energy consumption. Understanding the heat-mass exchange theory of SAP materials is crucial for enhancing their application in the building industry. This study develops a comprehensive theoretical model for heat-mass exchange in cold-formed steel (CFS) walls incorporating SAP materials. An equilibrium phase change model and a simplified thermal radiation model were developed to capture the water loss and dynamic heat exchange processes in SAP materials. These models were integrated into a transient fluid-solid-thermal coupling model using Ansys Fluent and User Defined Functions. In the case study, the newly developed numerical models can accurately predict temperature field changes in CFS walls with SAP materials, demonstrating the heat transfer mechanisms of hot and cold flanges at different temperature rise stages. The developed numerical model was used to investigate the effects of factors such as the moisture content of the SAP material, web depth, and flange width on the fire resistance of the CFS wall. Results indicated that increasing the wall stud height improves fire resistance, while increasing flange width has little effect on hot flange temperature. These findings provide a theoretical foundation and practical guidelines for the application of SAP phase change insulation materials in the building industry, promoting energy reduction and supporting sustainable construction practices.

A novel cost-effective kapok fibers and regenerated cellulose-based carbon aerogel for continuous oil/water separation

The development of cost-effective, environmentally friendly, and reusable superabsorbent materials for removing oil spills from water presents significant challenges. Herein, a novel, cost-effective, environmentally friendly, and reusable carbon aerogel (KRxCA) was synthesized by combining kapok fibers (KF) with hardwood pulp regenerated cellulose, dissolving in a mixture of N-methyl morpholine-N-oxide monohydrate (NMMO) and deep eutectic solvent (DES), which is named co-solvent DNS. This carbon aerogel presents remarkable compressibility, elasticity, and fatigue resistance, maintaining maximum stress after 100 cycles at 50 % strain due to its three-dimensional network of carbonized hollow tubular KF fixed by carbonized regenerated cellulose. The water contact angle (144.7°) indicates the excellent hydrophobicity of the KR10CA, demonstrating the potential for efficient oil/water separation. The resulting ultra-light (3.78 mg cm−3) and high porous (98.9 %) KR10CA exhibits exceptional oil sorption capacity (137.5–371.7 g⋅g−1) and retains 89.3 % of its sorption capacity after ten extrusion cycles. Additionally, as a filter membrane, the KR10CA effectively separates n-hexane from water with a high flux rate (21972.7 L m-2h−1). Therefore, the carbon aerogel derived from renewable resources presents itself as a cost-effective and environmentally friendly oil/water separator for practical application.

Swelling Behaviors of Superabsorbent Composites Based on Acrylic Acid/Acrylamide Copolymer and Attapulgite

The swelling behaviors and water retention of superabsorbent sand-fixing materials prepared from acrylic acid/acrylamide copolymer (AA/AM) and acid-modified attapulgite under ultrasonic treatments and different pH conditions were investigated. The results demonstrated that a suitable amount of attapulgite can effectively improve the absorption capacity and saltwater performance. The superabsorbent achieved the highest absorptions of 1257.54 g/g and 209.45 g/g in distilled water and a 0.9 wt% NaCl solution, and a higher water absorbency occurred over a wide pH range of 5~9 when the ultrasonic power was 200 W and the attapulgite content was 10%. The addition of attapulgite could significantly increase the water absorption and retention.

High performance superabsorbent material based on biopolymers as a promising and sustainable framework for enhancing fresh water resources

The fact that current fresh bodies of water are suffering climate changes and man-made pollution resulting in negative effects leading to water scarcity has become a serious issue in several areas worldwide. Therefore, exploring new opportunities to exploit alternative freshwater resources is urgent. Harvesting atmospheric water by superabsorbent materials (SAWH) is standing out from the solutions to exploit an alternative water source. In this study, functional eco-friendly hydrogels based on carboxymethyl cellulose derived from rice husks and chitosan from shrimp shells were synthesized. The hydrogel was also reinforced with nanosilica from rice husk to improve the physicochemical characteristics and water uptake. The hydrogel samples with nanosilica (HS0) or without nanosilica (H0) were obtained by a simple process including a dehydration process with acetone and a vacuum dry process. All hydrogels were investigated for absorption-desorption in water and in relative humidity (RH, 45 % and 90 %) media. The results indicated that the excellent swelling ratio of HS0 and H0 in water was about 921.49 % and 709.76 %, respectively. The high water uptake ratio of HS0 and H0 was approximately 43 % and 63 % at 90 % RH, and was 8.3 % and 9 % at 45 % RH, respectively. The structure and morphology of hydrogels were also characterized by FTIR, TGA, SEM, and BET analysis. The reusability results of HS0 and H0 in water and in RH media demonstrated that their water uptake remained nearly stable. The bio-based hydrogels have the potential to replace traditional synthetic sorbent polymers for sustainable SAWH, showing promising industrial applicability.

An Overview of Polymeric Hydrogel Applications for Sustainable Agriculture

Agriculture, a vital element of human survival, confronts challenges of meeting rising demand due to population growth and product availability in developing nations. Reliance on pesticides and fertilizers strains natural resources, leading to soil degradation and water scarcity. Addressing these issues necessitates enhancing water efficiency in agriculture. Polymeric hydrogels, with their unique water retention and nutrient-release capabilities, offer promising solutions. These superabsorbent materials form three-dimensional networks retaining substantial amounts of water. Their physicochemical properties suit various applications, including agriculture. Production involves methods like bulk, solution, and suspension polymerization, with cross-linking, essential for hydrogels, achieved through physical or chemical means, each with different advantages. Grafting techniques incorporate functional groups into matrices, while radiation synthesis offers purity and reduced toxicity. Hydrogels provide versatile solutions to tackle water scarcity and soil degradation in agriculture. Recent research explores hydrogel formulations for optimal agricultural performance, enhancing soil water retention and plant growth. This review aims to offer a comprehensive overview of hydrogel technologies as adaptable solutions addressing water scarcity and soil degradation challenges in agriculture, with ongoing research refining hydrogel formulations for optimal agricultural use.

Effect of Mixing Ratio of Super Absorbent Materials on the Growth and Yield of Bell Pepper in the Ferric Luvisols of Mogotio, Kenya

Agriculture in arid and semi-arid regions (ASALs) faces challenges due to limited water and problematic soils. This study investigates the potential of superabsorbent materials like Super Absorbent Polymers (SAPs) and pumice to enhance water retention and agricultural productivity in Ngubreti in Mogotio Sub-County, Kenya, representing ASALs. Using a randomized design with different material ratios and a control group, the research analysed soil parameters and plant growth indicators. Incorporating superabsorbent materials increased soil porosity, reduced bulk density, and improved water retention. Bell pepper production notably increased by 53.4%, with the SAP Pumice Double Half (SPDH) treatment showing the highest yield. This research underscores superabsorbent materials' ability to enhance ASAL soil conditions and agricultural output, particularly SPDH treatment. Precise material concentration control and consideration of their impact on soil penetration rates are crucial for optimal results. The study contributes to sustainable agriculture in water-scarce regions, emphasizing soil management's role in crop productivity. Further research and region-specific experiments are needed for broader applicability. Farmers are advised to assess their soil characteristics and consider a recommended median soil-additives mixing ratio of 1:833. Long-term effectiveness warrants additional investigation

Superabsorbent Hydrogels in the Agriculture and Reclamation of Degraded Areas

Superabsorbent materials (SAPs) are crosslinked polymer networks composed of ionic and non-ionic monomers. SAPs can absorb and retain water solutions up to several hundred times their own weight. As a result of swelling, they form a gel that is insoluble in water, considered safe and decomposes over time. This review focuses on the synthesis, degradation and chemical composition of SAP materials, with particular emphasis on chemical substances that are soluble in water and can migrate into the environment. Numerous applications of natural and synthetic hydrogels in agriculture and the reclamation of degraded areas in preventing erosion, retention water, reducing leaching of colloidal soil components and plant protection products, fertilisers and mineral salts into surface waters have been described. The influence of SAPs on the microbial activity of soils is described. New trends in the search for environmentally friendly SAPs made of modified biopolymers and waste materials are presented, which not only increase yields, but also ensure sustainable agro-environmental development.

Synthesis and characterization of poly (acrylamide‐co‐acrylic acid)/chitosan (derived from fish scales) for controlled release of amoxicillin drug

AbstractChitosan (CS) can be extracted from waste fish scales through a series of chemical processes, including demineralization, deproteinization, and deacetylation. The biomaterial poly (acrylamide [AM]‐co‐acrylic acid [AA])/CS is a unique superabsorbent material synthesized through the free radical graft copolymerization method by using AM, AA, and CS powder. During synthesis, ammonium persulfate is used as an initiator, and N, N′‐methylene bisacrylamide is used as a cross‐linker. Scanning electron microscopy and Fourier transform infrared spectroscopy have been studied to know about the morphology and structure of the synthesized superabsorbent materials. The water absorbency of the material continuously increases from day 1 to day 30. The thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) of the superabsorbent material show adequate thermal stability. The X‐ray diffraction (XRD) analysis indicates that the synthesized biomaterial is virtually amorphous in nature. The percentage of biodegradability increases with time. The encapsulation efficiency of amoxicillin drugs is around 70%, which indicates that the biomaterial is highly efficient for drug release applications. The synthesized novel biomaterial is a low‐cost, eco‐friendly, and thermally stable hydrogel that can be effectively used in drug release applications.Highlights Chitosan (CS)‐based hydrogels are highly pH‐sensitive towards drug release. The biodegradability and swelling behavior of the synthesized biomaterial were studied by adopting a suitable methodology. The novel material formed was characterized by using Fourier transform infrared spectroscopy, TGA, and Scanning electron microscopy. The encapsulation efficiency, kinetic study, and controlled drug release behavior of the amoxicillin drug were studied in solutions of simulated gastric fluid and phosphate‐buffered saline. The material developed in this study shows good performance in controlled drug delivery, and is therefore suitable for manufacturing medical devices used in drug delivery.

A Freeze‐Resistant, Highly Stretchable and Biocompatible Organohydrogel for Non‐Delayed Wearable Sensing at Ultralow‐Temperatures

AbstractWearable electronics based on conductive hydrogels (CHs) easily suffer from prolonged response times, reduced wearing comfort, shortened service lives, and impaired signal accuracy in cold environments, because conventional CHs tend to freeze at subzero temperatures and lose their flexibility, adhesion, transparency, and conductivity, which will limit their applications in extreme environments. Inspired by the way psychrotolerant creatures and superabsorbent materials interfere with the hydrogen bonding networks of water, a freeze‐resistant conductive organohydrogel (COH) is facilely fabricated. The synergy effect between charged polar terminal groups and a binary solvent system of water–ethylene glycol weakens the hydrogen bonding between water molecules and endows the COH with remarkable freezing tolerance (−78 °C). Additionally, the obtained COH is ultra‐stretchable (≈6185%), tough (9.2 MJ m−3), highly transparent (≈99%), self‐adhesive (10.2–27.8 kPa), and biocompatible. This versatile COH is assembled into a strain sensor and a well‐designed bracelet electrocardiogram sensor. Benefiting from the exceptional low‐temperature tolerance of the prepared COH, these devices exhibit fast response with delay‐free signals even at −40 °C. Overall, this work proposes a strategy to develop multifunctional COHs for supporting human health in cold environments.

Swelling behaviors of superabsorbent composites based on acrylic acid/acrylamide copolymer and acid-modified attapulgite.

The swelling behaviors and water retention of superabsorbent materials prepared from acrylic acid/acrylamide copolymer and acid-modified attapulgite under ultrasonic treatment and different pH conditions were investigated. The results demonstrated that a suitable amount of attapulgite can effectively improve the absorption capacity. The superabsorbent achieved the highest absorptions of 1257.54 g g-1 and 209.45 g g-1 in distilled water and a 0.9 wt% NaCl solution, and a higher water absorbency occurred over a wide pH range of 5-9 when the ultrasonic power was 200 W, and the attapulgite content was 10%. Addition of attapulgite could significantly increase the water absorption and retention of this kind of material, which can be applied as a sand-fixing material.

Elaboration and characterization of biodegradable poly(aspartic-co-glutamic acid) hydrogels as soil additives with different crosslinkers

This work introduces a promising biodegradable copolymer synthesized through the fusion of D,L-aspartic acid (ASP) and L-glutamic acid (GA) utilizing melt polymerization. Employing infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (1H NMR, 13C NMR), and X-ray diffraction (XRD), the copolymer’s structural characterization highlights its distinctive physicochemical attributes. The synthesis, conducted with a facile and controllable melt polymerization method, yielded a remarkable product yield of up to 81%. The optimization of water absorption properties involved a meticulous exploration of various diamine cross-linking agents—hexamethylene diamine (HMD), lysine (LYS), and a synthesized tartaric acid dihydrazide (TD) derivative. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and scanning electron microscopy (SEM) were employed to confirm the copolymer’s structure, morphology, and cross-linking efficiency. The findings underscore exceptional water retention capabilities, with a peak swelling ratio of 11.874% achieved at a 10% concentration of hexamethylene diamine. Beyond advancing superabsorbent materials, this study contributes to mitigating environmental concerns associated with non-biodegradable alternatives.

Enhanced Water Absorbency and Water Retention Rate for Superabsorbent Polymer via Porous Calcium Carbonate Crosslinking.

To improve the water absorbency and water-retention rate of superabsorbent materials, a porous calcium carbonate composite superabsorbent polymer (PCC/PAA) was prepared by copolymerization of acrylic acid and porous calcium carbonate prepared from ground calcium carbonate. The results showed that the binding energies of C-O and C=O in the O 1s profile of PCC/PAA had 0.2 eV and 0.1-0.7 eV redshifts, respectively, and the bonding of -COO- groups on the surface of the porous calcium carbonate led to an increase in the binding energy of O 1s. Furthermore, the porous calcium carbonate chelates with the -COO- group in acrylic acid through the surface Ca2+ site to form multidirectional crosslinking points, which would increase the flexibility of the crosslinking network and promote the formation of pores inside the PCC/PAA to improve the water storage space. The water absorbency of PCC/PAA with 2 wt% porous calcium carbonate in deionized water and 0.9 wt% NaCl water solution increased from 540 g/g and 60 g/g to 935 g/g and 80 g/g, respectively. In addition, since the chemical crosslinker N,N'-methylene bisacrylamide is used in the polymerization process of PCC/PAA, N,N'-methylene bisacrylamide and porous calcium carbonate enhance the stability of the PCC/PAA crosslinking network by double-crosslinking with a polyacrylic acid chain, resulting in the crosslinking network of PCC/PAA not being destroyed after water absorption saturation. Therefore, PCC/PAA with 2 wt% porous calcium carbonate improved the water-retention rate by 244% after 5 h at 60 °C, and the compressive strength was approximately five-times that of the superabsorbent without porous calcium carbonate.

Biorefinery concept in the meat industry: From slaughterhouse biowastes to superaborbent materials

The expansion of food production has a large environmental impact in many ways. More specifically, 30–40% of total food production is lost as wastes and/or by-products before it reaches the market. In this sense, blood is an inevitable by-product in the meat industry that typically consists of 3–5% of the total weight of the animal. The dry organic matter present in blood is mostly protein, which can be employed more efficiently as raw material in the development of biodegradable materials. In the present manuscript, the blood collected after slaughtering of Iberian pigs was centrifuged and the upper (i.e., plasma) and bottom (i.e., red cells) layers were separated. Three freeze-dried fractions were characterized and evaluated on terms of their potential in the field of bioplastics: whole blood, plasma and bottom layer. Albumin was detected clearly in the plasma fraction, while globulins in red cells. After their characterization samples were mixed thoroughly with glycerol and injection molded at 120 °C. Special applications may be proposed for every fraction (i.e., whole blood, plasma or red cells), as the materials displayed different properties depending on the raw material employed. Thus, plasma resulted in materials with a greater deformability and swelling capacity during immersion, resulting in superabsorbent materials when processed at milder conditions (80 °C).

Innovative hydrogels use in the germination and growth of tree species Paulownia tomentosa and Cupressus sempervirens

Research goal: This article presents the results of a research project aimed at demonstrating the effects and benefits of using an organic ingredient, hydrogel (Hydro Start), to improve the germination and growth of Paulownia tomentosa and Cupressus sempervirens seedlings. Materials and Methods: The experiments started in May 2022 and were conducted in the CREA-OF greenhouses in Pescia (PT) on seeded plants of Paulownia tomentosa and Cupressus sempervirens. The seeds were placed in pots with various hydrogel capsules to determine whether there were any effects on germination and plant growth. Agronomic analyses of the seeds and plants, microbiological analyses and substrate evaluation were also conducted. Results and Discussion: The experiment showed that the use of hydrogel can improve the quality and resistance of sown plants of Paulownia tomentosa and Cupressus sempervirens. In general, the improvement in average germination time and plant growth was proportional to the number of hydrogel capsules inserted into the substrate at the time of sowing; this also influenced the microbial colonisation of the soil. Studies show that the water retained by the hydrogel forms a water reserve in the soil that can increase the water uptake efficiency of plants. Mixing superabsorbent materials (hydrogels) with soils or growing media can significantly increase the water-holding capacity of the soil. Water is available to plants for a longer period of time, making them more resistant, especially during transplanting. Furthermore, the incorporation of hydrogels into the soil or growing media allows for improved germination, plant growth and nutrient and water uptake. Conclusions: Research shows that hydrogels can be used in a variety of ways due to their ability to retain water. These innovations can also ensure and promote plant survival in drought conditions. The results show that new hydrogels need to be evaluated not only for their physical properties, but also for their biological attributes related to the positive and negative aspects that bind microorganisms to plants.

Chitosan Superabsorbent Biopolymers in Sanitary and Hygiene Applications

The consumption of diapers and sanitary products has constantly been rising. Several problems are associated with using chemical-based sanitary products, which are difficult to degrade easily and cause nappy rash and bacterial infections in babies. Therefore, there is an increasing shift towards natural-based sanitary products because of their biodegradability, non-toxicity, and biocompatibility. Several studies are being carried out in which researchers have incorporated natural polymers, such as cellulose, starch, alginate, and xantham gum for producing superabsorbent materials. Chitosan (CS) is one such natural polymer that exhibits anti-microbial activity because of the functional groups present in its structure. Moreover, it is also easily available, biodegradable, and non-toxic. This review mainly focuses on CS’s properties and several approaches to synthesizing natural polymer-based superabsorbent products, such as sanitary pads and diapers. It also briefly discusses the diversified applications of CS as a biopolymer in the cosmetic, medical, food, and textile industries. In addition, this study implies using CS as a superabsorbent biopolymer in the manufacturing and producing sanitary products for women and children. Due to the excellent water retention capacity, swelling ability, and anti-microbial activity exhibited by CS can be considered a potential candidate for producing superabsorbent biopolymers.

Glucose‐derived superabsorbent hydrogel materials based on mechanically‐interlocked slide‐ring and triblock copolymer topologies

AbstractA series of glucose‐based degradable superabsorbent hydrogels with potential to tackle issues associated with sustainability, flooding, and drought has been designed and fabricated. These hydrophilic networks were constructed through integrating glucose as a primary building block –into cyclic oligomers and block polymers, which were combined into mechanically‐interlocked slide‐ring crosslinked materials. Crosslinking of slide ring α‐cyclodextrin/poly(ethylene glycol)‐type polyrotaxanes with acid‐functionalized ABA triblock copolymers comprised of mercaptopropionic acid‐functionalized poly(glucose carbonate (ethyl propargyl carbonate))‐b‐poly(ethylene glycol)‐b‐mercaptopropionic acid‐functionalized poly(glucose carbonate (ethyl propargyl carbonate)), afforded degradable superabsorbent hydrogels through establishment of chemically‐labile ester linkages, in addition to glycosidic and carbonate groups of the polymer precursors. With an emphasis on development of fundamental synthetic design strategies to achieve high‐performance superabsorbent hydrogels that could behave as robust materials, which are derived from natural components and exhibit hydrolytic degradability, effort went into optimization of the composition, structure, and topology leading to water uptake capacities >30× by mass. Investigations of composition‐structure‐topology‐morphology effects on properties as a function of variations of PEG main chain length, degree of α‐cyclodextrin coverage, and concentration of pre‐gel solution, indicated that the slide‐ring polymer and triblock copolymer networks feature high water uptake, tunable mechanical properties, and sustainability with construction from renewable natural products and in‐built degradability.

Development and Characterization of Biobased Superabsorbent Materials for Agricultural Applications: Study in Lettuce (Lactuca sativa L.) under Drought Stress

Development and Characterization of Biobased Superabsorbent Materials for Agricultural Applications: Study in Lettuce (Lactuca sativa L.) under Drought Stress

Effect of fiber length and treatments on the hygroscopic properties of milkweed fibers for superabsorbent applications

This study investigated the influence of pre-treatment methods and size distribution on the hygroscopic properties of milkweed fibers (MW). Pre-treatment methods included hydrothermal treatment and hybrid treatment, which involves the hydrothermal treatment followed by the alkaline treatment. Scanning electron microscope (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) were used to investigate the effect of pre-treatments on morphology, chemical composition, and crystallinity of milkweed fibers, respectively. Brunauer–Emmett–Teller (BET) surface area analysis was also used to measure the surface area of milkweed fibers after each pre-treatment. The results revealed that only after 5 min of stirring, hydrothermal treatment and hybrid treatment enhanced the water absorption capacity of non-treated MW fibers from 18 ± 4 g/g to 54 ± 4 g/g and 50 ± 1 g/g, respectively. The SEM and FTIR confirmed the removal of waxes from the surface of milkweed fibers after applying hydrothermal treatment without causing any changes to the hollow structure of fibers. Hydrothermal treatment improved hydrophilicity and hence better hygroscopic characteristics of MW fibers, as evidenced by increased absorption capacity and better water retention property. The hybrid treatment, on the other hand, caused the hollow structure of MW fibers to collapse completely, and left holes on the surface. As confirmed by FTIR and XRD, this occurred because of the dissolution of lignin and hemicellulose. As a result of these severe morphological alterations, the hybrid treated MW fibers showed inferior water retention properties compared to the hydrothermally treated sample. Further, it was observed that MW fibers with larger size distribution exhibited higher water absorption capacity and better water retention properties compared to the smaller fibers. Therefore, it can be concluded that hydrothermal treatment can improve the hydrophilicity of MW fibers and pave the way for their application as superabsorbent materials in a simple and cost-effective manner. • The effect of treatment methods on hygroscopic properties of MW fibers were studied. • MW fibers offer a promising potential for application as sustainable superabsorbent. • Hydrothermal treatment improves MW fibers hygroscopic properties by removing waxes. • Hybrid treatment diminished water retention property due to morphological defects. • Longer MW fibers showed better water retention only after hydrothermal treatment.