In this review, the authors provide a general review of current research themes where complex surface topography plays a role. Recent innovations and research possibilities have opened up using modern microtopography creation techniques. This review considers a large range of themes in limited depth to provide an introduction and to illustrate how broad the field is and, to those already working in the area, to help gain a broad perspective. Due to the breadth of scope, this review does not go into much depth into any given area. This review aims to provide a comprehensive understanding of and practical guidance on the modern use of micro- and nanotopography to control water; adhesion; wettability; biological adhesion, including implants, cell culture and biofouling; and directional fluid transport. The broad range of functionality is highlighted in the many interfacial interactions. However, the methods allowing economy of scale allowing these surfaces to be used commonly is still in development. To make this review more accessible, the authors have chosen to concentrate on open-access articles to cite.

In this study, poly(vinyl alcohol) (PVA) films were irradiated with hydrogen beams with fluences of 8 × 1017, 16 × 1017 and 24 × 1017 ions/cm2 using a handmade cold beam ion source. The resulting changes in the structural characteristics and functional groups of irradiated PVA films were studied using the X-ray diffraction and Fourier transform infrared spectroscopy methods, respectively. Besides, the optical bandgaps and Urbach energies of untreated and irradiated PVA were calculated using Tauc’s equation. The tail is 1.29 eV for PVA, which improved to 1.59 and 4.17 eV when PVA was exposed to 8 × 1017 and 24 × 1017 ions/cm2 beams, respectively. Furthermore, the parameters of untreated and treated samples, including refractive index, extinction coefficient, conductivities and permittivity, were calculated. Furthermore, the dispersion characteristics of unirradiated and treated films were evaluated. With an increase in hydrogen fluence from 8 × 1017 to 24 × 1017 ions/cm2, the relaxation time was reduced from 2.75 × 10−14 to 0.045 × 10−14 s. Moreover, the optical susceptibility of pure and treated PVA was calculated. The modification induced in the optical characteristics of the irradiated films suggests that these films can be applied in different uses such as in optoelectronic devices.

A titanium metal–organic framework/titanium dioxide (Ti-MOF/TiO2) composed membrane was fabricated by light inductive growth of Ti-MOF ([Ti2-(TpA)2-NDI] n ; TpA = terephthalic acid, NDI = 1,8,4,5-naphthalene-tetracarboxdiimide) on a titanium dioxide film composite optical waveguide (COWG) substrate. The Ti-MOF/TiO2 membrane conforms to a mesoporous structure with a 24 nm pore size and a 108 nm thickness through continuous growth for 40 min under 340 nm ultraviolet light illumination. Under ambient conditions, in terms of COWG sensors, Ti-MOF/TiO2 exhibited the greatest response to ethylenediamine (EDA), followed by nitrogen dioxide (NO2), methylamine and trimethylamine, when exposed to 15 types of benzenes, amines and acidic gases. To improve response selectivity, the Ti-MOF/TiO2 film was modified with 1,3,3-trimethylindolinonaphthospirooxazine (SP), forming an SP@Ti-MOF/TiO2 COWG. This modified COWG showed improved selectivity response by showing robust response to EDA and a negligible response to others. When an EDA gas molecule was adsorbed on the surface of the membrane, charge transfer between them preferentially occurred, leading to a change in the optical parameter. The surface-modified SP@Ti-MOF/TiO2 COWG showed a fast (3 s) and reversible response with a wide detection range (0.1–1000 parts per billion) to EDA gas without the interference of benzene, toluene, xylene, styrene and chlorobenzene; acidic gases; and other amines.

The production of suitable coatings with excellent antibacterial performance has now become a viable technique for enhancing the functional qualities of various biomedical materials. Here, pulsed plasma polymerisation was used to produce an antibacterial coating from the carvone oil of the spearmint plant. The coating films have adjustable chemical and physical properties based on the deposition parameter – that is, duty cycle (DC). The static water contact angle (WCA) values of pulsed wave (PW) plasma-polymerised carvone (ppCar) increase with the increase in DC. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that the molecular structure of carvone is less fragmented, retaining moieties associated with C–O and C=O when the DC is reduced. These C–O and C=O moieties likely reduced the measured static WCA. This surface chemical composition with predominantly C–O and C=O also showed a stronger bactericidal effect, based on the biofilm assay with bacteria (Escherichia coli and Staphylococcus aureus), compared with those coatings with C–C and C–H produced at a higher DC. As shown by the atomic force microscopy images, a lower DC resulted in smoother and more homogeneous coatings than those produced with a higher DC, while field emission scanning electron microscopy images show that when E. coli and S. aureus membranes were attached to PW ppCar, they ruptured and distorted with a pore created and that these distortions and ruptures increased as the DC was reduced.

In this study, fabricated amorphous chalcogenide Ge10Se70Bi20 thin films were irradiated with nitrogen (N+), argon (Ar+), hydrogen (H+) and oxygen (O+) ion beams. The compositions of the pure and irradiated films were investigated using X-ray diffraction, which confirmed the amorphous structures of the pristine and the irradiated Ge10Se70Bi20 thin films. The optical parameters such as optical bandgap, absorption edge, Urbach energy, Tauc parameter and extinction coefficient of the unirradiated and irradiated films were determined using ultraviolet/visible spectroscopy. The energy gap was found to reduce from 1.355 eV for unirradiated Ge10Se70Bi20 to 1.02, 0.73, 0.60 and 0.51 eV after irradiation with nitrogen, argon, hydrogen and oxygen ion beams, respectively. Meanwhile, the band tail of Ge10Se70Bi20, which is 0.12 eV, increased to 0.16, 0.40, 0.45 and 0.48 eV after irradiation with nitrogen, argon, hydrogen and oxygen ion beams, respectively. In particular, the conductivity increased by two orders after the pristine film had been exposed to an oxygen beam. The direct current electrical conductivity of the pristine film increased from 1.5 × 10−7 to 1.4 × 10−5 Ω−1 cm−1 after irradiation with an oxygen ion beam. Furthermore, the activation energy and Mott’s parameters of the original and irradiated Ge10Se70Bi20 films were deduced. The reported modifications of the optical and electrical parameters suggest the use of irradiated Ge10Se70Bi20 thin films in important applications – for example, optical data storage and optoelectronic devices.

Straight and curved hydrophilic microfinned surfaces are prepared in this work by photolithography and sputtering coating techniques using silicon wafers as substrates. The behavioral characteristics of drops on these surfaces are discussed by using image-processing technology. The experimental results show that when a drop is placed on the straight microfinned surface, the front contact line of the drop can move, while the rear contact line remains fixed. On the curved microfinned surface, however, both the front and the rear contact line can move. The drop can be self-propelled directionally from the region with larger roughness to the region with smaller roughness. The characteristics of velocity and acceleration on both surfaces are analyzed. A theoretical model is proposed by analyzing the energy conversion and compared with the experimental results. This study provides a novel microstructured surface for enhancing the heat-transfer performance of condensers.

This paper is devoted to the interfacial aspects of the intraocular behavior, migration and distribution of commonly injected ophthalmic drugs in eyes filled with medical-grade 1300 cSt silicone oil used as a retinal tamponade agent. Novel in vitro and ex vivo models were created for studying the physical properties of the retinal surface and interfacial spreading of the ophthalmic drugs over retinas. In vitro model experiments showed that the droplets of all tested drugs sank rapidly in the silicone oil to contact with the plasma-treated glass and then rapidly spread over the glass surface. In the ex vivo model, the migration phase was followed by contact with and rapid spread/absorption by the retinal interface. The wetting behavior of drugs under contact with the glass substrate and retinas was similar. The characteristic timescales of drug spreading, controlled by the viscous dissipation, were close. All tested drugs migrated to the retinal surface and rapidly spread across the retinal surface. This suggests that intravitreal drugs might be used effectively in eyes filled with silicone oil tamponade, as they rapidly migrate to and spread over the retinal surface.

Copper (Cu)-based materials have been extensively studied for nitrate (NO3 −) removal as an inexpensive and abundant electrocatalyst for water purification through the nitrate reduction reaction (NO3RR). However, it typically suffers from nitrite (NO2 −) accumulation due to high selectivity toward nitrite formation. To address this issue, the authors herein report a strategy of modifying copper nanowires with nickel (Ni) nanoparticles to improve the NO3RR performance. The nickel nanoparticles both facilitate electron transfer from nickel to copper and enhance the conversion of nitrite, thereby improving the overall removal of nitrate with a minimal yield of nitrite. Through a facile liquid-phase deposition process, the loading amount of nickel nanoparticles can be easily tailored by simply changing the concentration of precursors, and the best copper/nickel molar ratio for nitrate removal performance is 20. At this ratio, the material simultaneously delivers a high nitrate removal rate of 92.2% and low nitrite selectivity of only 2.2% at −0.9 V against the reversible hydrogen electrode, accompanied with superior stability for a continuous NO3RR. This study thus offers an efficient, stable and low-cost copper–nickel bimetallic catalyst for NO3RR.

The coalescence characteristics of two vibrated droplets at a certain distance on a microstructured surface with gradient wettability are investigated using a high-speed camera in this work. The results show that the volume ratio of the two droplets has a significant effect on the vibration modes. With the change in the volume ratio, the droplet exhibits different vibration modes, such as the pumping mode (PM), the rocking mode (RM) or the pumping–rocking mixed mode (PRM). In addition, the coalescence time of the two droplets varies with the volume ratio. When the volume ratio is close to 1, the two vibrated droplets are in synchronous PM and the coalescence time is the shortest. When the volume ratio is far from 1, the two droplets may show the RM, the asynchronous PM or the PRM. At this point, the coalescence time is increased, particularly for small volume ratios. Finally, the movement characteristics of three-phase contact lines are discussed, and a theoretical model is proposed to analyze the coalescence process. This work provides a new method to remove droplets rapidly, which is essential to enhance the heat-transfer performance of dropwise condensation.

The production of suitable coating with excellent antibacterial performance has now become a viable technique for enhancing the functional qualities of various biomedical materials. Here, pulsed plasma polymerisation was used to produce an antibacterial coating from carvone oil of spearmint plant. The coating films have adjustable chemical and physical properties based on the deposition parameter, i.e., duty cycles (DC). The static water contact angle (WCA) values of PW ppCar increase with the increase of DC. FTIR and XPS showed that the molecular structure of the carvone is less fragmented, retaining moieties associated with C-O and C=O when the DC is reduced. These C-O and C=O moieties likely reduced the measured static water contact angle. This surface chemical composition with predominantly C-O and C=O also showed a stronger bactericidal effect, based on the biofilm assay with bacteria (E. coli and S. aureus), compared to those coating with C-C and C-H produced at higher DC. According to the AFM images, the lower DC resulted in smoother and more homogeneous coating than those produced with the higher DC, while FE-SEM images show that when E. coli and S. aureus membranes were attached to the PW ppCar, they ruptured and distorted with a pore created, and that these distortions and ruptures increased as the DC was reduced.

Mono-, di- and triethanolamine in combination with methylmorpholinium and hydroxyethylmorpholinium surfactants were investigated for their aggregation and solubilizing properties. A co-operative behavior of the solubilization by mixed surfactant–ethanolamine systems is described. Ethanolamines strongly affect pH and lead to Orange OT phenolic group deprotonation and subsequent increase in aqueous/micellar solubility. The morpholinium surfactant micelles reduce the pK a of the Orange OT phenolic group, enabling its deprotonation at the earlier stages of medium alkalinization. The obtained surfactant–ethanolamine mixtures can solubilize very large amounts of hydrophobic dye, which can then be triggered to precipitate through acidification.

The presence of Escherichia coli in beach sand is directly related to public health outcomes. The physicochemical and wetting properties of sand influence the survival and proliferation of these indicator bacteria. This study is aimed at predicting E. coli concentrations using some of these properties, including the zeta potential, moisture content, Brunauer–Emmett–Teller (BET) surface area, BET pore radius, state of sand, processing temperature and water contact angle of beach sand. For this, the authors developed five machine learning regression models – namely, artificial neural network, support vector machine, gradient boosting machine, random forest and k-nearest neighbors. ANN outperformed other models in predicting E. coli concentrations. In the data-driven analysis, the state of sand, processing temperature and the contact angle representing the wettability of the sand are identified as the most crucial parameters in predicting E. coli concentrations.

In this study, Polyvinyl alcohol (PVA) films were irradiated with hydrogen beam of fluence 8x1017, 16x1017, and 24x1017 ions/cm2 using handmade cold beam ion source. The resulting changes in the structure characteristics and functional groups of irradiated PVA films were studied using XRD and FT-IR methods respectively. In addition, the optical band gaps and Urbach energies of untreated and irradiated PVA were calculated using Tauc’s equation. The tail is 1.29 eV for PVA, improved to 1.59 eV and 4.17 eV when PVA was exposed to 8x1017 and 24x1017 ions/cm2, respectively. Furthermore, the parameters including refractive index, extinction coefficient, conductivities, and permittivity for untreated and treated samples have been calculated. Furthermore, the dispersion characteristics of un-irradiated and treated films are evaluated. With increasing hydrogen fluence of 8x1017 to 24x1017 ions/cm2, the relaxation time is reduced from 2.75x10−14 sec to 0.045x10−14 sec. On the other hand, the optical susceptibility of pure and treated PVA has been calculated. The modification which induced in the optical characteristics of the irradiation films suggests these films to apply in a different uses like optoelectronics devices.

In the absence of additional oxygen, thin films of tungsten (VI) oxide (WO3) were prepared on indium-doped tin oxide conductive glass substrates by radio-frequency (RF) magnetron sputtering. The effects of sputtering power, working air pressure, substrate bias voltage and substrate temperature on the surface morphology, microstructure, optical properties and electrochromic (EC) performance of the films were systematically investigated. The research shows that a sputtering power of 80–100 W can ensure a moderate deposition rate of ∼10−2 nm/s and help obtain non-dense films. Similarly, a working air pressure of 1.0 Pa also leads to the deposition of loose films, which is beneficial for the improvement of the optical transmittance and EC performance of tungsten (VI) oxide thin films. The applied substrate bias has little effect on the optical properties, but it will degrade the coloring and/or bleaching efficiency of tungsten (VI) oxide thin films and greatly reduce their optical modulation. When the substrate temperature rises to 600°C, the film begins to crystallize and exhibits a rod-patterned porous structure, which leads to a small increase in the optical modulation.

Recently, there has been a surge of interest in adopting natural dyes to avoid the environmental difficulties connected with the synthetic coloring compounds. This research focuses on extracting natural dyes from Butea Monosperma plants and on developing sustainable dyeing methods for silk fabric. Natural colorants were extracted using an aqueous and acidic extraction procedure, and the silk fabric was dyed with the extracts using mordanting with a variety of metal and bio mordants. The treatment of fabric and extracts were carried out using microwave irradiation. It was found that after irradiation up to 3 min, the acidic extract shown maximum color strength onto fabric. It was also observed that the acacia and pine-nut hull at 80 °C and before dyeing pomegranate extract at 80 °C and after dyeing of silk fabric at 40 °C using bio-mordants were higher color strength than metallic mordant. For comparative analysis Al salt at 40 °C, Iron salt at 60 °C and tannic acid (T.A.) at 80 °C were provided acceptable results. The color fastness characteristics were also found good to excellent. The bio-mordants not only provide the higher color strength and fastness properties, it was also an environmental friendly approaches. Scanning electron microscopy (SEM) images and Fourier transform infrared spectroscopy (FT-IR) analyses revealed the difference between irradiated and un-irradiated silk fabric. Therefore, it is recommended that MW rays and bio-mordants be used in the natural dyeing of silk fabric because of their deformability and non-toxicity, as well as their high color fastness and color strength properties.

In this study, the self-crimping process of multichain polystyrene into a carbon nanotube was investigated by molecular dynamics simulation. The simulation shows that multichain polystyrene arranged in parallel can self-crimp into a carbon nanotube and form a helix configuration. The formation mechanism illustrates that both the van der Waals potential well and the π–π stacking interaction between polystyrene and the carbon nanotube play a major role in the self-assembly process. Furthermore, some factors such as the chain number of polystyrene, the length of the polymer, the diameter of the carbon nanotube and the simulation temperature are also investigated. Moreover, different replaced polymers are shown, too. This theoretical research can provide valuable support for the design and manufacturing of hybrid structures in the fields of advanced composite materials and functional devices.

Titanium dioxide (TiO2) is widely regarded as one of the most extensively applied photocatalytic semiconductor materials. However, conventional powdered titanium dioxide exhibits certain limitations, including relatively weak light absorption capability, a small surface area and insufficient active sites. This study successfully prepared flexible and porous silicon dioxide (SiO2)–titanium dioxide nanofiber membranes (NFMs) by implementing electrospinning technology and calcination processes. The porous membranes demonstrate remarkable performance in water treatment, featuring a high specific surface area (49 m2/g) and porosity, enabling efficient adsorption and removal of organic pollutants in water. Remarkably, the NFMs-800 variant exhibits outstanding photocatalytic performance, achieving complete removal of adsorbed organic compounds under ultraviolet irradiation. The design and fabrication methods of this porous membrane are simple and scalable, providing a potential solution for practical water-treatment applications. Consequently, the silicon dioxide–titanium dioxide porous membrane holds significant prospects in the field of water treatment, offering a promising contribution to the attainment of efficient and sustainable water resource management.

Quartz fiber fabric is widely used in national defense, military and aerospace industries due to its good high-temperature resistance, chemical stability and excellent thermal shock resistance. However, the tendency of quartz fiber fabric to undergo thermal degradation due to crystallization at high temperature may destroy its high-temperature performance, particularly its high-temperature mechanical properties. In this study, an aluminum oxide (Al2O3) ceramic coating was synthesized on the surface of two-dimensional quartz fiber fabric in aqueous solution near room temperature. The surface morphology and chemical composition were studied to evaluate the quality of the coating by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The annealing behavior at high temperature was evaluated by using an electronic universal testing machine after high-temperature processing. The annealing behavior of the aluminum oxide coating could be improved effectively. The maximum load that the coated fabric can bear was 2.5 times higher than that of the original fabric, proving the superior high-temperature mechanical properties of the coated fabric. The coating on the surface of the fiber could block the damage of high temperature to the quartz fiber, improving the crystallization phenomenon of the quartz fiber at high temperature, followed by improvement in the high-temperature mechanical properties of the fabric.

Johansson gauge blocks (‘Jo blocks’) are made of steel and used for precision length measurement. Their surface is very smooth, and two blocks can adhere to each other; however, strong adhesion occurs only after sliding (wringing). Various hypotheses explaining wringing and adhesion mechanisms in the blocks have been suggested in the literature, including the role of intermolecular forces, oil surface tension and air pressure. The authors study the frictional sliding of two Jo blocks against each other to obtain insights into the mechanisms of wringing. The results show an increase in the friction force with the sliding distance, which is consistent with the removal of the oxide film from the steel surface by wringing. This is likely the dominant mechanism of Jo block adhesion.

Antimicrobial fabrics have become essential in organizing and managing infestation and reducing odor formation by microbes. Various green sources add antimicrobial properties to fabrics, particularly cotton. However, the major problem with microbial fabrics is the reduction in antimicrobial activity after each wash. Cupressaceae pods have shown natural potential as an antimicrobial agent in herbal medicine. This study utilizes Cupressaceae for incorporating antimicrobial properties in cotton fabrics. After methanolic extraction of the Cupressaceae extract, it was applied to cotton fabrics. The application of the extract to cotton fabrics was performed by optimizing concentration, temperature and pH parameters. The extract-modified cotton showed the best performance at a 15 wt.% concentration, 140°C and pH 7.5. The treated fabrics were tested in the presence and absence of a binder using the standard washing method ISO 105-C10:2006. The mordant-treated fabric retained 16.4% more activity after 20 washes. Finally, the antimicrobial activity of the greenly developed antimicrobial cotton fabrics was checked against Staphylococcus, Escherichia coli, Bacillus and Candida albicans by using the AATCC 100-2004 test method. The study indicated that the prepared cotton fabric showed better antimicrobial activity against the earlier mentioned strains, except for C. albicans. The prepared antimicrobial fabric showed a wide range of antimicrobial activities and a lower fungal activity. Thus, the prepared fabric can be used for wound dressings, hospital staff gown material and athlete’s sportswear to prevent microbial infection.