Fragile fruits, which are prone to mechanical damage and microbial infection, necessitate protective materials that possess both cushioning and antimicrobial properties. In this study, we present a novel genipin-crosslinked chitosan/gelatin aerogel (CS/GEL/GNP) synthesized through direct mixing and free-drying techniques. The mechanical properties and cushioning capacities of the CS/GEL/GNP aerogel were thoroughly characterized, alongside an evaluation of its antimicrobial efficacy. The composite aerogel demonstrated remarkable compressibility and shape recovery characteristics. In a transportation simulation test, the aerogel effectively protected strawberries from mechanical damage. Furthermore, the composite aerogel exhibited enhanced antimicrobial activities against Escherichia coli, Staphylococcus aureus and Botrytis cinerea in vitro. The quality of strawberries was successfully maintained at ambient temperature when packaged with the CS/GEL/GNP. Notably, the aerogel could be completely degraded in the soil within 21 days and is nontoxic to cells. Consequently, the dual-functional CS/GEL/GNP aerogel presents a promising option for packaging materials aimed at protecting delicate fruits.
This study explores the effectiveness of soft viscoelastic biopolymer inclusions in mitigating cyclic liquefaction in loosely packed sands. This examination employs cyclic direct simple shear testing (CDSS) on loose sand treated with gelatin while varying the gelatin concentration and the cyclic stress ratio (CSR). The test results reveal that the inclusion of soft, viscoelastic gelatin significantly reduces shear strain and excess pore pressure during cyclic shear. Liquefaction potential, defined as the number of cycles to liquefaction (NL) at an excess pore pressure ratio (ru = Delta u/sigma ' vo) of 0.7, is substantially improved in gelatin-treated sands compared to gelatin-free sands. This improvement in liquefaction resistance is more pronounced as the inclusion stiffness increases. Furthermore, the viscoelastic pore-filling inclusion helps maintain skeletal stiffness during cyclic shearing, resulting in a higher shear modulus in gelatin-treated sand in both small and large-strain regimes. At a grain scale, pore-filling viscoelastic biopolymers provide structural support to the skeletal frame of a loosely packed sand. This pore filler mitigates volume contraction and helps maintain the effective stress of the soil structure, thereby reducing liquefaction potential under cyclic shearing. These findings underscore the potential of viscoelastic biopolymers as bio-grout agents to reduce liquefaction risk in loose sands.
Magnaporthe oryzae causes a fungal disease that poses a serious risk to global food security. Nanoagrochemicals are perceived as sustainable, economical, and environmentally friendly alternatives to traditional pesticides. Plant immune activators can be applied as the active ingredients of nanopesticides to control diseases in agriculture, but their use is limited and corresponding research is lacking. In this study, a nanodelivery system (PBZ@CaCO3@SG) for the on-demand release of a plant immune activator (probenazole; PBZ) was prepared using nano-CaCO3 after coating with sodium alginate-gelatin (SG). In vitro, at 48 h, the release rate reached 97.9% and 88.4% at pH 4.5 and 6.0, respectively, which greatly exceeded that under neutral conditions (pH 7.4), with acid-responsive release characteristics. Moreover, it responded quickly to the acidic microenvironment generated during M. oryzae infestation and rationally released PBZ, effectively improving plant resistance to M. oryzae and minimizing disease. Notably, M. oryzae infection was markedly reduced, by 60.6%, after PBZ@CaCO3@SG treatment. Mechanistically, PBZ@CaCO3@SG enhanced both physical barrier formation and systemic acquired resistance in rice, enhancing resistance to M. oryzae. It also showed good biosafety for both microbial communities and earthworms in the soil. This comprehensive study revealed multiple mechanisms by which PBZ@CaCO3@SG interacts with plants and pathogens, inhibits damage, and maintains nontarget biosafety, emphasizing its great potential for plant disease management.
Water scarcity is a critical problem around the world, and superabsorbent hydrogels has attracted growing attention in water management for handling water deficiency during agricultural and forestry practices. Herein, intending to apply gelatin hydrogel as soil conditioner, humic substances (HS) extracted from Chinese medicine residue compost were used to modify gelatin hydrogel through either physical mixing or chemical cross-linking. The results demonstrated that low level of HS could improve the hardness and rheological properties of the hydrogels, however, the gel strength significantly decreased when the concentration of HS rose up to 16 g/L. As revealed by TEM and XRD, chemical cross-linking reaction promoted the development of denser network structures, thereby improving the hardness and rheological properties of the hydrogels. Subsequently, applying HS at a concentration of 3 g/L was found to be preferable for enhancing the swelling ratio of the gelatin hydrogels, and lightweight substrates amended with the resultant hydrogels displayed superior water retention ratio (17.23 +/- 0.79 % for GelHS3 and 17.74 +/- 1.31 % for GelHS3-EDC). Furthermore, it was proved that HSincorporated hydrogels can effectively keep moisture for the growth of Melaleuca alternifolia (Maiden & Betche) Cheel saplings under drought stress. These findings suggest that humic substances can be utilized to modify hydrogels for use as soil conditioners.
Currently, the primary composition of fibrous filter materials predominantly relies on synthetic polymers derived from petroleum. The utilization of these polymers, as well as their production process, has a negative impact on the environment. Consequently, the adoption of air filter media fabricated from natural fibers would yield significant environmental benefits. Nowadays not only particle and odour capture performance but also ensuring a high energy efficiency and flame retardant properties in air filters is of utmost importance for automotive and HVAC filters. In this study, for the production of biodegradable and flame retardant air filters with a high quality factor, free standing gelatin/sodium alginate blend fibers were successfully produced via centrifugal spinning. The water-soluble mats were stabilized by physical methods using both thermal and ionic crosslinking. The CGCA (Crosslinked-Gelatin/Calcium Alginate) mat exhibited exceptional filtration performance for PM0.3 particles, achieving a 94.2 % efficiency rating at a pressure drop of 135 Pa. Moreover, blending of biopolymers and subsequent calcination provided V0 level flame retardancy according to UL94 standard. The preliminary biodegradation studies showed that proposed nanofibrous filters were completely degraded in soil in 7 days.
Extensively used plastic mulch film causes tremendous environmental pollution. Developing biodegradable mulch film represents an emerging demand for future agriculture. Bone gelatin (BG) has emerged as promising candidates in the field of biodegradable agricultural mulch film due to its eco-friendly and biodegradable attributes, yet the terrible mechanical properties and hydrophobicity are great challenges. Here, aminodimethylsiloxane/POSS polymer/bone gelatin (PDMS-NH2/PAH/BG) mulch film was prepared by incorporated POSS-allyl glycidyl ether hydroxyethyl acrylate polymer (PAH polymer) and aminodimethylsiloxane (PDMSNH2) into the BG. The effect of PDMS-NH2 dosages on performances of PDMS-NH2/PAH/BG mulch film was explored. When the PDMS-NH2 dosage was 4 %, the mulch film had a water contact angle (WCA) of 128 +/- 1 degrees, tensile strength (TS) of 5.93 +/- 0.81 MPa, and elongation at break (EAB) of 361.38 +/- 25.04 %. After being buried in the soil for 60 days, the degradation rate of mulch film reached 78 %. Additionally, it also had favourable light transmission, water vapor barrier and moisture retention and insulation performance. Pot experiment showed that the wheat seeds germination rate covered mulch film was 98 % and it could promote the growth of seedlings. The results indicated that PDMS-NH2/PAH/BG mulch film could serve as a biodegradable mulch film to boost crop yields, inspiring advancements in green ecological agriculture.
Dispersive soil is highly susceptible to water erosion, leading to significant engineering challenges, such as slope instability and canal damage. Common modifiers such as lime are effective but cause environmental pollution. Therefore, it is important to explore eco-friendly modifiers. This study investigates the effects of sticky rice and calcium chloride (SRC) on dispersive soil. Dispersivity tests identified an optimal ratio of sticky rice to calcium chloride of 3:1. To analyze the effects of different SRC contents and curing times on the soil properties, tests of dispersivity, hydraulic, mechanical, chemical, and microscopic mechanisms were conducted based on this optimal ratio. The results indicated that 1.5% SRC effectively eliminated soil dispersivity even without curing, and its effectiveness improved with an extended curing time. After 28 days of curing, the water stability increased significantly, permeability decreased by an order of magnitude, and cohesion improved by approximately 85.97%. SRC reduced soil dispersivity through three primary mechanisms: lowering the pH, promoting ion exchange between Ca2+ and Na+, and the cementing effect of the sticky rice paste. Additionally, Ca2+ acted as a bridge between organic colloids and clay particles, further strengthening the structural stability of microaggregates. Overall, SRC proved to be an effective eco-friendly modifier for improving physicochemically dispersive soil.
Most biopolymers used as additives for the improvement of expansive subgrade soils are ecofriendly but highly uneconomical and unsustainable. Even the traditional additives such as cement, lime, and fly ash that are used widely for most soil improvement schemes are highly notorious for their carbon footprint. This necessitated the motivation in the present study to utilize an economical, ecofriendly and highly sustainable biopolymer, known as pregelatinized corn starch (PGCS), to improve the strength properties of an expansive subgrade soil. The PGCS was admixed with quarry dust (QD), an industrial waste additive, before blending with the expansive subgrade soil in different mix ratios generated with a 32 full factorial design experiment. The California bearing ratio (CBR) samples were subjected to 7 day curing while that of the unconfined compressive strength (UCS) were subjected to 1, 7, and 28 day curing. Shortly after the improvement of the expansive subgrade soil, the PGCS and QD were used as predictors in the development of two regression models for the two strength parameters (CBR and UCS) of the expansive subgrade soil considered in the study. Next, multiobjective salp swarm optimization algorithm (MOSSA), a bioinspired algorithm, was employed to optimize the additives in order to obtain optimal values of the strength properties of the expansive subgrade soil blended with the additives. The developed models were set as fitness functions in the slightly modified MOSSA technique. Thereafter, nondominated solutions were determined after the implementation of the optimization analysis. The results obtained from laboratory experiments and the optimization process showed that there was significant improvement in the UCS and CBR of the expansive subgrade soil. Optimal improvement in the UCS (1,326.241 kN/m2) and CBR (36.8%) were observed when an optimum mix ratio of the additives, 0.3117% PGCS and 10% QD, was blended with the expansive subgrade soil.
To improve the formability and bonding strength of 3D printing soil, a temperature-stimulating responsive intelligent soil-hydrogel 3D printing formula was innovatively developed by combining soil and gelatin. Varied soil-gelatin composites, featuring different gelatin content by weight of soil (0 %, 0.5 %, 1 %, and 1.5 %), were prepared and cured at 5 degrees C to facilitate the crosslinking of gelatin. An array of tests, including rheological assessments, compressive tests, and scanning electron microscopy analysis. Were conducted to thoroughly characterize the performance of gelatin-soil composites for 3D printing. Our findings unveiled that, following the cross-linking of gelatin at 5 degrees C, the gelatin-soil composites exhibited superior formability and bond strength compared to the reference. Furthermore, the soil-gelatin composites demonstrated not only comparable compressive strength to the reference but also enhanced interlayer bond strength. This innovative soil-hydrogel 3D printing formula, combining the versatility of soil and the responsive characteristics of gelatin, presents a promising avenue for advancing the capabilities of 3D printed soil.
The alarming issue of food waste, coupled with the potential risks posed by petroleum-based plastic preservation materials to both the environment and human health necessitate innovative solutions. In this study, we prepared nanoemulsions (NEs) of chitosan (CS) and ginger essential oil (GEO) and systematically evaluated the effects of varying NEs concentrations (0, 10 %, 30 %, 50 %) on the physicochemical properties and biological activities of gelatin films. These films were subsequently applied to blueberry preservation. The scanning electron microscopy confirmed that the NEs were well-integrated with the Gel matrix, significantly enhancing the performance of the Gel films, including improvements of mechanical properties (tensile strength from 7.71 to 19.92 MPa; elongation at break from 38.55 to 113.65 %), thermal, and barrier properties (water vapor permeability from 1.52 x 10(-9)to 6.54 x 10(-10) g & sdot;m/Pa & sdot;s & sdot;m(2)). The films exhibited notable antibacterial and antioxidant activities due to the gradual release of GEO, thereby extending the storage life of blueberries. Moreover, the prepared composite films demonstrated excellent biodegradability and environmental friendliness, with the majority of the material decomposing within 30 days under soil microbial action. In conclusion, the active films loaded with NEs exhibit superior performance and hold significant potential for developing biodegradable materials for food preservation.