Low Adhesion Research Articles

Construction of Iron-Modified Lignin-Based Nanomicrocapsules for Enhancing the Functionality of Natural Product-Based Pesticides.

To address the issue of low pesticide utilization owing to poor dispersibility, low leaf surface adhesion, and poor transport within plants, this study exploits electrostatic interactions between sodium lignosulfonate (SL) and dodecyltrimethylammonium chloride (DTAC) to induce self-assembly, followed by iron ion (Fe3+) chelation and loading with a natural product-based pesticide, rosin-based triazole derivative (RTD), yielding RTD@SL-DTAC-Fe nanomicrocapsules (NMs). It is worth noting that the presence of Fe3+ enhances the dispersibility of the NMs. The water dispersibility and photostability of RTD are significantly improved after encapsulation, and a stimulus response to laccase is achieved. Leaf-washing experiments confirm the enhanced adhesion of RTD@SL-DTAC-Fe NMs to the surface of rice plant leaves compared to that of free RTD. Fluorescently labeled NMs exhibit bidirectional transport within rice plants, and RTD@SL-DTAC-Fe NMs demonstrates better transport performance than RTD. In vitro and in vivo antifungal tests indicate that encapsulation by NMs significantly enhanced pesticide activity. Field trials demonstrate that NMs exhibited prolonged efficacy compared to RTD. Finally, the safety evaluation confirms the environmental friendliness of the NMs. This study provides valuable insight for optimizing and improving the utilization efficiency and biosafety of natural product-based pesticides.

Superhydrophobicity With Self-Adaptive Water Pressure Resistance and Adhesion of Pistia Stratiotes Leaf.

Superhydrophobic surfaces are promising for optimizing amphibious aircraft by minimizing water drag and adhesion. Achieving this involves ensuring these surfaces can resist high liquid pressure caused by deep water and fluid flow. Maximizing the solid-liquid contact area is a common strategy to improve liquid pressure resistance. However, this approach inevitably increases solid-liquid adhesion, making it challenging to guarantee a trade-off between the two wetting characteristics. Here, it is found that the Pistia stratiotes leaf exhibits superhydrophobicity with high water pressure resistance and low adhesion, attributed to its self-adaptive deformable microstructure with unique re-entrant features. Under pressure, these microstructures deform to increase the solid-liquid contact area, thereby enhancing water pressure resistance. The re-entrant features elevate the deformation threshold, enabling higher modulus microstructures to achieve adaptive response. This facilitates the recovery of deformed microstructures, restoring the air layer and maintaining low adhesion. Following these concepts, Pistia stratiotes leaf-inspired surfaces are fabricated, achieving an 183% improvement in water impact resistance and an ≈80% reduction in adhesion after overpressure compared to conventional superhydrophobic surfaces. The design principles inspired by Pistia stratiotes promise significant advancements in amphibious aircraft and other trans-media vehicles.

Mechanochemical Damage Self‐Repairable Photothermal Anti/De‐Icing Superhydrophobic Coating by Dynamic Bonding Phase‐Change Fillers with the Matrix

AbstractThe development of robust superhydrophobic coatings with the capacity for self‐healing against mechanochemical damage is pivotal for their practical deployment. This study develops a physically and chemically self‐healing superhydrophobic coating with exceptional durability for anti‐icing applications using a simple spray coating method. This is achieved by incorporating phase‐change fillers into a dynamic cross‐linked matrix via dynamic imine bonds. Specifically, oleylamine (ODA) is encapsulated within rigid diatomite nanopores and modified with dopamine (DOA), significantly enhancing the grafting efficiency of aminopropyl‐terminated polydimethylsiloxane (NH₂‐PDMS‐NH₂) (N‐DOA). The incorporation of 15% N‐DOA increases the water contact angle (WCA) of the acrylic resin/aminopropyl‐terminated polydimethylsiloxane (AR/NH₂‐PDMS‐NH₂) matrix to 159.7° and reduces the sliding angle (SA) to 2.9°, while also improving the mechanical durability of coating to withstand 600 abrasion cycles. The dynamic imine bonds between NH₂‐PDMS‐NH₂ and trimesic acid (BTC) facilitate the mobility of N‐DOA and NH₂‐PDMS‐NH₂, enabling rapid recovery of superhydrophobic properties and low ice adhesion strength after abrasions, scratches, oxygen plasma etching, and multiple de‐icing cycles due to the synergistic phase‐change effect of ODA. Thus, the self‐healing coating produced via this simple spray method presents a novel approach for superhydrophobic coatings in anti‐icing applications.

Evaluation of Mixing Temperature in the Preparation of Plant-Based Bigels

Understanding gel structures and behavior is a prerequisite for attaining the desired food application characteristics. The mixing temperature is crucial when incorporating thermolabile active compounds into gels. This study evaluated the effect of mixing temperature on the physical and chemical properties of a bigel system prepared using a carnauba wax/canola oil oleogel and Arabic gum hydrogels. The results showed that bigels prepared at lower temperatures (30 and 40 °C) resulted in a solid-like state under crystallization temperature, resulting in matrices with larger hydrogel droplets, softer texture, and lower adhesiveness, spreadability, and solvent binding capacity. In contrast, bigels prepared at higher temperatures (50 and 60 °C), around crystallization temperature but with no solid state, resulted in matrices with smaller hydrogel droplets and higher firmness, adhesiveness, and spreadability. These bigels had a higher apparent viscosity, especially at lower shear rates, and solid-like behavior in the linear viscosity range. During the bigel preparation process, adjusting the mixture temperature had no effect on the samples’ oxidative stability, FTIR spectra, or thermal properties. The results highlighted the importance of hydrogel droplet size on the microstructure of the formed bigels, and smaller droplets could act as effective fillers to reinforce the matrix without making chemical changes.

Nanosecond laser interference ablation of fluorine-free aluminum alloy surfaces for dynamic adhesion and static wettability synergistically modulating water collection

Water collection from mist is a potential solution to water scarcity, which is a critical issue worldwide. In this paper, laser interference ablation assisted with stearic acid immersion has been used to achieve synergistic modulation of dynamic adhesion and static wettability for water collection on fluorine-free aluminum alloy surface. The research demonstrates that there is an optimal balance point between dynamic adhesion and static wettability for water collection. This optimal point shifts toward low dynamic adhesion at the high misting rate due to the flooding on metastable surfaces with high dynamic adhesion. In addition, wetting transition induced by tilting is observed on metastable surfaces. The good stability of the proposed fluorine-free surface has been demonstrated by the long-term water collection and long periods of immersion in water. This work can provide theoretical inspiration and a scalable preparation method for green and stable water collection strategies.

Enhanced Biodegradation of Silk Fibroin Hydrogel for Preventing Postoperative Adhesion.

An absorbable adhesion barrier is a medical device that prevents postoperative adhesion and matches its biodegradation time with the regeneration period of its target tissues, which is important for antiadhesion effects. Physical hydrogels of Bombyx mori silk fibroin (SF) proteins are degradable in vivo. However, their biodegradation time is too long to exert antiadhesion effects. To shorten the biodegradation time of the SF hydrogels, we decreased the molecular weight (MW) of the SF proteins by alkaline treatment and prepared low-MW (LMW) SF hydrogels. The hydrogels contained less β-sheet crystalline and more amorphous structures than conventional, high-MW (HMW) SF hydrogels. Because of the potential loosened SF molecular structures in the hydrogel networks, the LMW SF hydrogels showed enhanced biodegradation (i.e., shorter in vitro enzymatic biodegradation time and faster in vivo biodegradation rate) as well as a lower affinity for plasma proteins and fibroblasts, which are involved in postoperative adhesion formation. An antiadhesion test using a rat abdominal adhesion model demonstrated that the LMW SF hydrogel applied to the abraded cecum was almost completely degraded within two weeks postimplantation, with a significantly lower adhesion severity score than that in the untreated model rat group. Conversely, the HMW SF hydrogel remained between the cecum and abdominal wall, with the same adhesion severity as that of the untreated model rat group. Therefore, we concluded that the antiadhesion effects of SF hydrogels were induced by enhanced biodegradation. The results of this study indicate the potential of LMW SF hydrogels as absorbable adhesion barriers.

Environment-tolerant, inherently conductive and self-adhesive gelatin-based supramolecular eutectogel for flexible sensor

Although hydrogels have attracted increasing attention in the stretchable devices, the low adhesion properties and poor environmental adaptation still seriously restrict their development and application. Herein, we focused on the interaction between polymer networks with disperse media and their resultant influence on gel performance, and constructed self-adhesive and environment-tolerant gelatin/polyacrylamide supramolecular-polymer double-network (Gelatin/PAM SP-DN) eutectogels using multiple supramolecular interactions between natural macromolecule and well-designed deep eutectic solvent (DES). The dual networks of Gelatin/PAM SP-DN eutectogels produced significant supramolecular forces with DES, including hydrogen bonding and electrostatic interaction, contributing to enhance the energy dissipation capacity. Additionally, the Gelatin-PAM SP-DN eutectogels were more prone to generate strong bonding force to various substrates, showcasing both in-situ and ex-situ adhesion performance, and even being used for wet and underwater adhesion. The eutectogels revealed excellent environmental tolerance to maintain excellent mechanical flexibility, conductivity and adhesion at high and low temperatures, ensuring the constructed sensor to sensitively and reliably perceive strain, pressure and human motions over a wide temperature range. Also, the eutectogel demonstrated great potential as a temperature sensor. This work opens up a new horizon in the design of multifunctional and environment-tolerant natural macromolecule-based gel materials for flexible electronics, human-machine interaction and health diagnosis.

A fluorine-free bioinspired multifunctional slippery coating for ultra-long-term anticorrosion of Mg alloy, static/dynamic anti-icing, antibacterial and antifouling

Poor corrosion resistance limits the application of Mg alloy and it is meaningful to explore a surface coating technology for ultra-long-term corrosion protection of Mg alloy. Superhydrophobic surface (SHS) and smooth liquid-injected porous surface (SLIPS) have shown important application value in the field of Mg alloy corrosion protection. However, the unstable special interface of air layer or lubricant cannot act as stable corrosion barrier for the long term. Inspired by frog skin, a bionic fluorine-free multifunctional slippery coating (MSC) is prepared by one-step spraying a mixture of epoxy resin, silicone oil, modified nano TiO2 and modified micron mica powder. MSC exhibits a microstructure similar to frog skin, excellent slippery (sliding angle ∼ 3°) and strong lubricant retention. Different from anticorrosion mechanism of SHS and SLIPS by their special interface, MSC, storing silicone oil on the surface and inside the coating, demonstrates ultra-long-term anticorrosion to Mg alloy (both neutral salt spray and 3.5 wt% NaCl solution immersion for 60 days) due to excellent barrier effect throughout coating, and the scratch defect area of MSC is not significantly eroded after 14 days of salt spray. Moreover, MSC exhibits excellent static/dynamic anti-icing ability and low ice adhesion in a −20℃ environment, outstanding adhesion (level 4B), high hardness (3H), antibacterial (>94 %), antifouling, chemical stability and resistance to boiling water, ice water and UV radiation. All these excellent properties can promote the application of Mg alloy in a wider range of fields.

Functionalized porous 316 L stainless-steel with oil reservoir against ice adhesion

Slippery liquid-infused porous surfaces (SLIPSs) are used in anti-fouling, anti-icing and anti-corrosion, but lack of long-term durability is a challenge due to lubricant depletion. SLIPS with self-lubricating properties can achieve extended durability without reapplying the lubricant. Generally, lubricant is stored close to surface, thus lubricant reservoir is limited. Here bulk of porous material acts as lubricant reservoir in 316L stainless-steel SLIPS with self-lubricating properties for lowering ice adhesion. The reservoir was fabricated by using a space holder technique in metal injection molding (MIM) with lubricant reservoir volume up to 17.3%. Surface was activated with vinyltrimethoxysilane (VTMS) to attract lubricant. Ice adhesion strength was increased up to three times against non-porous reference in ice adhesion testing using porous surface without lubrication. The best performing SLIPS showed 6.7 times lower ice adhesion against counterpart porous surface without lubricant and 1.7 times lower than non-porous reference. This self-lubrication was achieved on mechanically durable structure having an adjustable lubricant storage capacity by temperature-driven phenomenon during de-icing.

A tissue-adhesive, mechanically enhanced, natural Aloe Vera-based injectable hydrogel for wound healing: Macrophage mediation and collagen proliferation

Macromolecule hydrogels made from natural extracts have received much attention because of their favorable biocompatibility and wound healing properties. However, their clinical applications are limited by their insufficient mechanical strength and low adhesion properties. To overcome these limitations, we developed a novel injectable Aloe vera hydrogel (PDMA-GelMA@AV). By integrating gelatin methacrylate (GelMA) and polydopamine methacrylamide (PDMA), we significantly improved the mechanical and adhesion properties of the hydrogel. The PDMA-GelMA@AV hydrogel degraded in a simulated wound environment, which was synchronized with the sustained release of the bioactive components of A. vera. In vitro and in vivo analyses revealed that this hydrogel has good biocompatibility. In vitro studies also revealed that the sustained release of the active ingredients of A. vera promoted fibroblast proliferation and migration and increased the expression of key proteins and mRNAs required for wound healing. In addition, it modulated LPS-stimulated macrophages and decreased the expression of TNF-α, IL-1β and iNOS while increasing the expression of TGF-β and ARG. In vivo experiments further confirmed the efficacy of hydrogels in wound healing applications. These findings offer a novel perspective on the application of natural macromolecules as hydrogel-based delivery vehicles in wound care.

Micro/Nano Hierarchical Dumbbell-like and Micropapillae Structure Improves Light Absorption and Facilitates Anti-icing/Deicing Performance.

The emergence of ice formation and accretion presents significant challenges, catalyzing an urgent need for clean and efficient anti-icing solutions. Solar energy, a powerful and sustainable resource, can be integrated with the micronano-structured superhydrophobic surface to enhance anti-icing and deicing performance through the solar photothermal effect, overcoming the limitations of a traditional superhydrophobic surface. Herein, inspired by bamboo and lotus leaves, a synergetic photothermal anti-icing superhydrophobic surface (PASS) has been developed. This was achieved through nanosecond laser ablation and chemical modification, resulting in a surface with remarkable superhydrophobic low adhesion (water contact angle >167°, rolling angle < 2°). The PASS notably extends the freezing time of water droplets to 1056 s and delays frost formation to 47 min at 60% humidity. Moreover, the surface retains its superhydrophobic properties after enduring several rigorous tests. Additionally, the photothermal conversion efficiency reaches up to 67.31%, and the temperature increases to 95.6 °C under 1.5 sun illumination for 600 s in ambient conditions (Tr = 7 °C). The ice melting time is only 120 s under 1 sun illumination at -15 °C. Consequently, the PASS sample stands as a preeminent strategy for anti-icing and deicing pursuits owing to its exceptional photothermal proficiency, superhydrophobicity, and enduring robustness.

Physically Cross-Linked PVA Hydrogels as Potential Wound Dressings: How Freezing Conditions and Formulation Composition Define Cryogel Structure and Performance

Objectives: Hydrogels produced using the freeze–thaw method have demonstrated significant potential for wound management applications. However, their production requires precise control over critical factors including freezing temperature and the choice of matrix-forming excipients, for which no consensus on the optimal conditions currently exists. This study aimed to address this gap by evaluating the effects of the above-mentioned variables on cryogel performance. Methods: Mechanical properties, absorption capacity, and microstructure were assessed alongside advanced analyses using differential scanning calorimetry (DSC) and low-field nuclear magnetic resonance relaxometry (LF TD NMR). Results: The results demonstrated that fully hydrolyzed polyvinyl alcohol (PVA) with a molecular weight above 61,000 g/mol is essential for producing high-performance cryogels. Among the tested formulations, an 8% (w/w) PVA56–98 solution (Mw~195,000; DH = 98.0–98.8%) with 10% (w/w) propylene glycol (PG) provided the best balance of stretchability, durability, and low adhesion. Notably, while −25 °C is often used for cryogel preparation, freezing the gel precursor at −80 °C yielded superior results, producing materials with more open, interconnected structures and enhanced mechanical strength and elasticity—deviating from conventional practices. Conclusions: The designed cryogel prototypes exhibited functional properties comparable to or even surpassing commercial wound dressings, except for absorption capacity, which remained lower. Despite this, the cryogel prototypes demonstrated potential as wound dressings, particularly for use in dry or minimally exuding wounds. All in all, this study provides a comprehensive analysis of the physicochemical and functional properties of PVA cryogels, establishing a strong foundation for the development of advanced wound dressing systems.

Electroless Copper Patterning on TiO2-Functionalized Mica for Flexible Electronics

The formation of conductive copper patterns on mica holds promise for developing cost-effective flexible electronics and sensing devices, though it is challenging due to the low adhesion of mica’s atomically flat surface. Herein, we present a wet-chemical method for copper patterning on flexible mica substrates via electroless copper deposition (Cu-ELD). The process involves pre-functionalizing 50 µm thick muscovite mica with a titanium dioxide (TiO2) layer, via a sol–gel dip-coating method with a titanium acetylacetonate-based sol. Photolithography is employed to selectively activate the TiO2-coated mica substrates for Cu-ELD, utilizing in situ photodeposited silver (Ag) nanoclusters as a catalyst. Copper is subsequently plated using a formaldehyde-based Cu-ELD bath, with the duration of deposition primarily determining the thickness and electrical properties of the copper layer. Conductive Cu layers with thicknesses in the 70–130 nm range were formed within 1–2 min of deposition, exhibiting an inverse relationship between plating time and sheet resistance, which ranged from 600 to 300 mΩ/sq. The electrochemical thickening of these layers to 1 μm further reduced the sheet resistance to 27 mΩ/sq. Finally, the potential of Cu-ELD patterning on TiO2-functionalized mica for creating functional sensing devices was demonstrated by fabricating a functional resistance temperature detector (RTD) on the titania surface.

Copper Sulfide Nanorod-Embedded Urinary Catheter with Hydrophobicity and Photothermal Sterilization.

The high prevalence of catheter-associated urinary tract infections (CAUTIs) is causing significant concern in healthcare systems. Antibacterial urinary catheters have been developed to prevent CAUTIs in clinical application. In this work, a copper sulfide nanorod (CuS NR)-embedded urinary catheter (CuS/UC) was designed as an antibacterial urinary catheter with photothermal sterilization. The CuS NRs with low cytotoxicity were synthesized via the hydrothermal method. The CuS NRs were embedded into urinary catheters at different weight percentages. The CuS/UC exhibited homogenous surface roughness, low wettability, hydrophobicity, and low adhesiveness, promoting minimal interaction with bacteria and healthy cells. Under near-infrared (NIR) laser irradiation, the 0.8 weight percentage of CuS NRs in the urinary catheter (0.8CuS/UC) reached a temperature of 67.4 °C, demonstrating its photothermal antibacterial activity and suitability for catheter sterilization. Agar plate test verified that CuS/UCs exhibited a superior photothermal antibacterial activity against both Gram-negative Escherichia coli (E. coli) and Gram-positive Streptococcus aureus (S. aureus). Moreover, the 0.8CuS/UC exhibited excellent biocompatibility and anti-cell adhesion properties. The 0.8CuS/UC with photothermal performance, excellent biocompatibility, and anti-cell adhesion properties demonstrated its potential as a photothermal antibacterial catheter for clinical applications.

Mechanism of Wheel-Rail Adhesion Recovery during Large Sliding processes under Water Lubrication condition

The challenge of low adhesion between the wheel and rail constrains the advancement of train braking technologies, resulting in sliding during braking, increased braking distances, and even operational safety incidents. Low adhesion arises from the contamination of the rail surface by a third body, such as water or oil, significantly reducing adhesion. However, experimental studies have found that wheel-rail adhesion coefficient under water lubrication conditions possesses a recovery capability: In scenarios characterized by low adhesion in water lubrication conditions, a secondary rise in adhesion occurs when substantial wheel-rail sliding is present. This paper focuses on numerically modeling the unique phenomenon of adhesion recovery during large-sliding processes under water lubrication conditions. Considering the notable differences in frictional heating during wheel sliding, as opposed to pure rolling conditions, we construct a wheel-rail contact model under mixed lubrication conditions that incorporates the solid-liquid coupled heat transfer effect. This model achieves stable solutions for the wheel-rail contact relationship and the temperature at the wheel-rail interface. The impacts of velocity, axle load, water temperature, and slide ratio on the adhesion recovery phenomenon are discussed, revealing the underlying mechanism of adhesion recovery during large sliding processes. Finally, brake adhesion tests under water lubrication conditions are conducted on a scaled test rig to validate the proposed theoretical model.

A novel multifunctional photocatalytic membrane based on β-FeOOH for oily wastewater purification

In order to deal with the environmental pollution caused by complex oily wastewater, it is necessary to develop filtration membrane materials. However, significant challenges such as poor effect of emulsion separation, limited functionality, and susceptibility to membrane fouling require urgent resolution. Here, we successfully prepared a β-hydroxyl iron oxide/polydopamine-polyethylenimine/polyacrylonitrile (β-FeOOH/PDA-PEI/PAN) nanofiber membrane for treatment of complex wastewater by growing PDA-PEI on a blow-spinning PAN nanofiber membrane and decorating the membrane with β-FeOOH. The porous structure and the large number of hydrophilic groups greatly increase the hydrophilicity of the membrane and give the membrane high permeation fluxes (11531.26 L m−2 h−1) for surfactant-free kerosene-in-water emulsion. The loaded β-FeOOH nanorods increase the roughness of the membrane surface, which enhances the underwater superoleophobic ability of the membrane, and promotes the demulsification of the emulsion and makes it have high separation efficiency of 99.48 % for surfactant-stabilized kerosene-in-water emulsion. In addition, the β-FeOOH/PDA-PEI/PAN also exhibited high organic dye removal efficiency (99.38 %) due to the presence of β-FeOOH. The synergistic effect of low oil adhesion and photocatalysis enhances the antifouling and self-cleaning performances of the material. Significantly, the multifunctional membrane also shows exceptional oil/water separation ability and good stability. The presented synergistic strategy of β-FeOOH/PDA-PEI/PAN membrane materials represents a prospective candidate for the treatment of complex wastewater.

Self-gelling, tunable adhesion, antibacterial and biocompatible quaternized cellulose/tannic acid/polyethylene glycol/montmorillonite composite powder for quick hemostasis

Hemostatic powders are widely used in incompressible or irregularly shaped bleeding wounds, but traditional hemostatic powders exhibit low adhesion, unsatisfactory hemostatic effect, limited infection control, and are not suitable for clinical or emergency situations. This study developed a novel self-gelling hemostatic powder (QTPM) consisting of quaternized cellulose (QC)/ tannic acid (TA)/ polyethylene glycol (PEG)/ montmorillonite (MMT). QTPM could absorb interfacial liquid hydrating to a stable hydrogel which form a switchable adhesion to tissues. Moreover, QTPM exhibits excellent antibacterial property by the synergistic effect of QC and TA. Furthermore, QTPM directly activate intrinsic and extrinsic coagulation hemostatic pathways to enhance hemostasis, and it concentrate coagulation factors. In vivo hemostasis study results show that QTPM significantly accelerated hemostasis and reduced blood loss compared with the blank group (>75 % reduction in hemostatic time, >85 % reduction in blood loss) in liver bleeding model (hemostasis time of 71.67 ± 7.09 s, blood loss of 19.23 ± 2.60 mg) and tail amputation model (hemostasis time of 91.03 ± 12.05 s, blood loss of 15.24 ± 1.77 mg). Therefore, the advantages of QTPM including rapid and effective hemostasis, easy usage, easy storability and adaptability make it a potential biomaterial for rapid hemostasis direction in the clinical setting.

Microcavity-assisted cloning (MAC) of hard-to-clone HepG2 cell lines: cloning made easy

Cloning is a key molecular biology procedure for obtaining a genetically homogenous population of organisms or cell lines. It requires the expansion of new cell populations starting from single genetically modified cells. Despite the technical progress, cloning of many cell lines remains difficult. Cloning often fails either due to the strenuous conditions associated with manipulating cells or because many cells don’t tolerate a single-cell state. Here we describe a new cloning method utilizing low adhesion microcavity plates. This new technique, named microcavity-assisted cloning (MAC) was developed to clone difficult-to-clone HepG2 cells. The clones were produced following CRISPR/Cas9 knockout of the GSTA1 gene by a random distribution of 200, 400, and 800 cells into 550 microcavities of a 24-well low adhesion plate originally designed for the culture of spheroids. The knockout of GSTA1 was verified at the protein level using Western blotting. The advantages of the MAC method are its low cost, ease of the procedure, and the possibility of scaling up the throughput and automatization.

Rice husk-derived self-healing superhydrophobic films using solvent-less approach for drag reduction and oil absorption behaviour

The present work focuses on a sustainable approach to transform rice-husk waste into self-healing superhydrophobic films with potential application for drag-reduction and oil absorption. Rice husk was transformed into amorphous nano silica particles (d50 ∼ 150 nm) exhibiting mesoporosity with a surface area of 400 m2/g. Superhydrophobic films fabricated using a solvent-less approach showed the transition from flattened to nano-globular morphology with increasing silica content in polydimethylsiloxane (PDMS), leading to exceptional superhydrophobicity. The optimized film with a particle fraction of 60 % exhibited high de-wetting (> 150º) and mechanical strength (∼7 MPa). The film showed extremely low water droplet adhesion of ∼19 μN, similar to lotus leaf owing to high negative Laplace pressure. Significantly, the film exhibited persisting de-wettability and endurance under harsh chemical, thermal, and mechanical conditions. The robustness is further fortified with room temperature self-healing and real-time self-regeneration characteristics, persisting even after exposure to strong acids and significant abrasion. The multidimensional aspects of the film embarked with a 70 % drag reduction and effective oil-water separation. The present work not only provides a sustainable pathway for managing agricultural waste but also a practical and easy-to-implement approach to tackle oil spill incidents.

Speed planning and control in complex road conditions based on vehicle driving capability

In order to solve the problem of vehicle speed planning that meets the constraints of safety and efficiency in complex road environments (large curvature and low adhesion), a differential equation planning method based on vehicle dynamics analysis is proposed. First, the structural parameter expression of the limit speed that meets the lateral tire force constraint during steady-state steering is derived. Secondly, the tire force execution space of the front and rear wheels is combined into an FF diagram, and an implicit differential equation that considers load transfer and driving mode factors is obtained. The differential equation is solved to obtain the limit speed along the path, and a limit speed calculation method for discrete path information is given. Finally, a lateral and longitudinal collaborative model predictive controller is designed, and a CarSim and Simulink joint simulation platform is built. Trajectory tracking simulation experiments are carried out on both continuous and discrete information paths with the planned limit speed. The results show that the limit speed planning method proposed in this paper can complete the trajectory tracking task in complex road environments as quickly as possible while controlling the tire force within the range of the stable friction circle.