Functionalized Silica Particles Research Articles

Cu(II) complexes using acylhydrazones or cyclen for biocidal antifouling coatings

Abstract Copper and copper-based compounds have broad spectrum antimicrobial activity, but concerns about leaching into the environment and toxicity on non-target organisms is leading the use of copper-based coatings being restricted. Our objective was to develop coatings that used the biocidal activity of copper, but with low negative impacts by reducing its leaching into the environment. This study reports the synthesis and characterisation of copper coordinating ligands, their formulation into coatings and testing of their antibacterial activity. A polyacylhydrazone and a series of simple acylhydrazones were synthesised and coordinated to Cu(II), but were considered unsuitable due to either their poor water-solubility or high levels of copper leaching. In an alternative approach, copper was successfully chelated to the tetraazamacrocycle, cyclen, and used to synthesise Cu(II)-cyclen functionalised silica particles, which were successfully combined with commercial paint formulations. These functionalised products showed poor antibacterial activity when incorporated into epoxy coatings, probably due to the low copper content of the formulations. However, these ligands may have other applications, such as removal of heavy metals from contaminated effluent steams.

One-step functionalization and polymer grafting potential of green silica derived from rice husk ash

Green silica has been synthesized from rice husk ash which exempts the landfilling of agricultural waste and the requirement of higher temperature for digestion, unlike the conventional mode of silica synthesis making the process of precipitation and functionalization sustainable. An energy-efficient method of functionalization has been optimized for the synthesis of functionalized silica from rice husk ash via co-condensation. The potential for providing better reinforcement leads silica to be used as filler in composite manufacturing. To obtain a better silica-polymer interaction, nitroxide functionalized silica has been synthesized over three different types of silica samples using different processes. The nitroxide functionalities were introduced by thiol-ene reaction between 4-acryloyloxy(2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and mercaptopropyl functionalized silica particles. The mercaptopropyl functionalized silica was synthesized by post-modification as well as co-condensation over commercial precipitated silica, commercial rice husk ash silica, and silica synthesized in the lab from sodium silicate obtained from rice husk ash. By comparing mercaptopropyl and nitroxide grafting density, it has been observed that the nitroxide loading highly depends on the method of functionalization and the co-condensed samples show higher nitroxide loading compared to the post-modified samples. The nitroxide functionalized samples were further subjected to polystyrene grafting, and the efficiency of surface nitroxide radicals in capturing the polymer radicals with respect to nitroxide loading was determined. The grafting density was observed to increase with the increase in conversion and the increase in the initiator-to-monomer ratio. However, the grafting density was observed to be saturated at some point despite having a higher surface area and surface nitroxide radicals. The study can be used to tune the surface nitroxide radical concentration and surface area for optimum polymer grafting for engineering applications.

Mucoadhesive Mesoporous Silica Particles as Versatile Carriers for Doxorubicin Delivery in Cancer Therapy.

Due to their structural, morphological, and behavioral characteristics (e.g., large volume and adjustable pore size, wide functionalization possibilities, excellent biocompatibility, stability, and controlled biodegradation, the ability to protect cargoes against premature release and unwanted degradation), mesoporous silica particles (MSPs) are emerging as a promising diagnostic and delivery platform with a key role in the development of next-generation theranostics, nanovaccines, and formulations. In this study, MSPs with customized characteristics in-lab prepared were fully characterized and used as carriers for doxorubicin (DOX). The drug loading capacity and the release profile were evaluated in media with different pH values, mimicking the body conditions. The release data were fitted to Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin kinetic models to evaluate the release constant and the mechanism. The in vitro behavior of functionalized silica particles showed an enhanced cytotoxicity on human breast cancer (MCF-7) cells. Bio- and mucoadhesion on different substrates (synthetic cellulose membrane and porcine tissue mucosa)) and antimicrobial activity were successfully assessed, proving the ability of the OH- or the organically modified MSPs to act as antimicrobial and mucoadhesive platforms for drug delivery systems with synergistic effects.

Functionalization of mesoporous silica with oligoisoprene brushes: Application as charge for elastomers reinforcement

The interfacial interaction between mesoporous silica nanoparticles (MSN) and natural rubber was successfully improved by surface modification of hydrophilic silica using oligoisoprene brushes. This approach involved grafting 3-aminopropyltriethoxy silane (APTES) onto the silica surface, achieving a grafting efficiency of 13.22 % and generating amine groups. The long polyisoprene chains of natural rubber were selectively cleaved using an optimized oxidative reaction, resulting in the formation of short oligomers with carbonyl chain ends known as Carbonyl Telechelic Natural Rubber (CTNR), having a molecular weight of 4100 g/mol. The CTNR oligomers were subsequently linked to APTES-modified silica via a Schiff's base reaction, imparting hydrophobicity to the silica surface and enhancing its compatibility and dispersion within the natural rubber matrix. Two conditions, MSN@CTNR1 and MSN@CTNR2, were investigated, exhibiting grafting efficiencies of 10.66 % and 4.70 %, respectively. The functionalized silica particles from MSN@CTNR1 were examined and incorporated at varying proportions into rubber latex, leading to the formation of thin films. Surprisingly, films containing 1 part per hundred rubber (phr) functionalized silica had better mechanical and thermal properties than films containing unmodified silica. This study underscores the potential of MSN, whose surfaces are modified by grafting oligoisoprene brushes, to enhance the crosslinking points and serve as innovative additives in the formulation of composite rubber films. Furthermore, these findings highlight the prospects of utilizing modified silica nanoparticles as coating additive materials, enabling the enhancement of properties and performance in rubber-based composites, thereby paving the way for the development of advanced coating applications in diverse industries.

A ‘Turn-On’ Carbamazepine Sensing Using a Luminescent SiO2/-(CH2)3NH2/-C6H5 + Rh6G System

Carbamazepine is a crucial medication used to treat nervous system disorders, and its low level of absorption in the human body suggests that a significant amount of it may be present in sewage water. Consequently, this pioneering research deals with the synthesis and application of a luminescent sensor based on rhodamine 6 G-modified bifunctional silica particles for the determination of carbamazepine. The sensing material was fabricated in one step by the sol–gel technique and the dye was adsorbed onto the surface from an alcohol solution. The composition, morphology and size of functionalized silica particles were determined by physico-chemical methods. The material’s features provide the possibility of its application as a sensing material for carbamazepine determination at a variety of concentrations. The sensor possesses a linear response towards carbamazepine in the concentration range of 0.8–200.0 μM with a limit of detection (LOD) of 17.9 μM and a limit of quantification (LOQ) of 59.7 μM and has demonstrated reliable quantification over a wide range of concentrations, from therapeutic to high fatal concentrations. Additionally, the sensing mechanism has been proposed, which involves the formation of hydrogen bonding between carbamazepine and Rhodamine 6G immobilized bifunctional silica particles.

Iron functionalized silica particles as an ingenious sorbent for removal of fluoride from water

The paucity of safe drinking water remains a global concern. Fluoride is a pollutant prevalent in groundwater that has adverse health effects. To resolve this concern, we devised a silica-based defluoridation sorbent from pumice rock obtained from the Paka volcano in Baringo County, Kenya. The alkaline leaching technique was used to extract silica particles from pumice rock, which were subsequently modified with iron to enhance their affinity for fluoride. To assess its efficacy, selected borehole water samples were used. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared and X-ray fluorescence spectroscopy was used to characterize the sorbent. The extracted silica particles were 96.71% pure and amorphous, whereas the iron-functionalized silica particles contained 93.67% SiO2 and 2.93% Fe2O3. The optimal pH, sorbent dose and contact time for defluoridation of a 20 mg/L initial fluoride solution were 6, 1 g and 45 min, respectively. Defluoridation followed pseudo-second-order kinetics and fitted Freundlich's isotherm. Fluoride levels in borehole water decreased dramatically; Intex 4.57–1.13, Kadokoi 2.46–0.54 and Naudo 5.39–1.2 mg/L, indicating that the silica-based sorbent developed from low-cost, abundant and locally available pumice rock is efficient for defluoridation.

Crystalline silica particle functionalized by PEG for its collision-enhanced detection at ultramicroelectrode

Detecting individual particulate matter is highly significant in many areas, such as mine safety, environment, and human health. The analytical method based on single entity electrochemistry (SEE) has shown great potential in detecting, counting, and measuring individual particles, especially conductive metals or carbon particles, based on their unique charge transfer reactions at an ultramicroelectrode (UME). In this study, we report an innovative SEE method for improving the sensitivity of the detection of electrochemical inert crystalline silica particles by functionalizing silica particles with polyethylene glycol (PEG) molecules. The PEG surface functionalization of the silica was characterized by Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. The morphology of silica particles was characterized by a scanning electron microscope (SEM), and a transmission electron microscope (TEM) was employed to calibrate size distribution and determine the elemental composition of silica particles. The surface charges of silica particles were measured by dynamic light scattering techniques. The collision behaviors of crystalline silica particles with UME were investigated by cyclic voltammetric experiments, which are rarely reported in the literature. The crystalline silica particles were detected based on electrochemically blocking the flux of the redox mediator at the surface of UME, which showed significant signal amplification in the proposed method. Our method was demonstrated for detecting crystalline silica functionalized with or without PEG, acquiring the limit of quantification (LOQ) values of 0.391 μM (23.45 μg/L) and 0.824 μM (49.45 μg/L), respectively, which confirmed that a more than two times improvement in LOQ could be achieved over the PEG functionalized silica particles. We further presented a theoretical model using finite element simulations with COMSOL Multiphysics. We deduced a quantitative relation between the distribution of the current step size and the size distribution of silica particles. Therefore, the reported method here provides a paradigm for SEE-based detection of electrochemically inert crystalline silica particles, which extends the previous report substantially concerning particle detection.

Effects of Vinyl Functionalized Silica Particles on Thermal and Mechanical Properties of Liquid Silicone Rubber Nanocomposites

It is very important to develop a new method of preparing high-performance liquid silicone rubber-reinforcing filler. Herein, the hydrophilic surface of silica (SiO2) particles was modified by a vinyl silazane coupling agent to prepare a new type of hydrophobic reinforcing filler. The structures and properties of modified SiO2 particles were confirmed using Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS), specific surface area and particle size distribution and thermogravimetric analysis (TGA), the results of which demonstrated that the aggregation of hydrophobic particles is greatly reduced. Additionally, the effects of the vinyl-modified SiO2 particle (f-SiO2) content on the dispersibility, rheology, and thermal and mechanical properties of liquid silicone rubber (SR) composites were studied for application toward high-performance SR matrix. The results showed that the f-SiO2/SR composites possessed low viscosity and higher thermal stability, conductivity, and mechanical strength than of SiO2/SR composites. We believe that this study will provide ideas for the preparation of high-performance liquid silicone rubber with low viscosity.

Surface Modification of Silica Particles with Adhesive Functional Groups or Their Coating with Chitosan to Improve the Retention of Toothpastes in the Mouth.

Silica is widely used in the oral care formulations to act as an abrasive and to give the products its distinct physical properties. In this study, silica particles were synthesized using a co-condensation of tetraethyl orthosilicate with a series of functional silane compounds [(3-mercaptopropyl)trimethoxysilane, (3-glycidyloxypropyl)trimethoxysilane, and (3-acryloxypropyl)trimethoxysilane)]. The surface of the particles based on tetraethyl orthosilicate and (3-glycidyloxypropyl)trimethoxysilane was then further modified with 3-aminophenylboronic acid. Commercial Aerosil R972 Pharma silica particles were also coated with chitosan. Additionally, commercially available (3-maleimido)propyl-functionalized silica particles were used in this study. All these functionalized silica particles were incorporated into toothpaste formulations, and their retentive properties were tested on ex vivo sheep tongue mucosa models using fluorescent microscopy-based flow-through techniques. Those surfaces with chitosan, phenylboronic acid, and acryloyl groups were shown to provide a significant improvement in the retention of the oral care formulations during the retention testing. The retention of toothpastes containing silica functionalized with maleimide and thiol groups was also superior compared to that of unmodified silica particles. This study synthesized and tested a range of silica particles and demonstrated that the functionalized silica incorporated into toothpastes can significantly improve the retention of these formulations on oral mucosal surfaces.

Surface Tension and Viscosity Dependence of Slip Length over Irregularly Structured Superhydrophobic Surfaces.

A comprehensive understanding of the slip phenomenon on liquid/solid interfaces is essential for multiple real-world applications of superhydrophobic materials, especially those involving drag reduction. In the current contribution, the so-called “slip-length” on an irregularly structured superhydrophobic surface was systematically evaluated, with respect to varying liquid surface tension and viscosity. The superhydrophobic polymer–nanoparticle composite (SPNC) material used exhibits a dual-scale surface roughness and was fabricated via coating a surface with a mixture of polydimethylsiloxane solution and functionalized silica particles. A cone-and-plate rheometric device was employed to quantify the slip length. To independently study the impact of surface tension and viscosity, three types of aqueous solutions were used: sodium dodecyl sulfate, ethanol, and polyethylene glycol. Our experimental results demonstrate that a decreasing surface tension results in a decreasing slip length when the fluid viscosity is held constant. Meanwhile, the slip length is shown to increase with increasing viscosity when the surface tension of the various liquids is matched to isolate effects. The study reveals a linear relationship between slip length and both capillary length and viscosity providing a reference to potentially predict the degree of achievable drag reduction for differing fluids on SPNC surfaces.

Interaction of functionalised surfaces on silica with dissolved metal cations in aqueous solutions

Abstract The study clearly shows that different metal cations were efficiently removed from water by employing coated silica particles with SO3H-terminated functionalized surfaces. Significant amounts of Fe, Mn, Ca, Mg, Na, and K could be removed from natural water samples with different concentrations varying from 0.075 mg/l for Mn up to 12 000 mg/l for Na by stirring the functionalized silica particles in the water samples for 1 h at room temperature. ICP–MS verify the removal of the elements and ToF-SIMS analyses clearly showed the presence of the elements on the particles after the treatment procedure. The removal of the metal cations is believed to be due to electrostatic attraction of the positively charged presumably hydrolysed metal cations to the negatively charged deprotonated SO3H-groups. However, from the current study it can not be excluded that chemisorption of the cations by the SO3H-group may be possible.

Fluoride removal from aqueous solutions using alginate beads modified with functionalized silica particles

Fluoride in water and wastewater is considered a dangerous contaminant and in drinking water has a profound effect on teeth and bones. In this study, the synthesized controllable morphology silica particles were functionalized with N-(2-aminoethyl)-3-aminopropyl tri‑methoxy silane and used for the fabrication of alginate-silica composites for fluoride removal from aqueous solutions. The characterization of silica particles was performed using SEM, XRD, FTIR, and Zeta-potential analyses. The prepared particles were amorphous with positive surface charge, and had a narrow size distribution (300±5 nm). The results of the mechanical resistance analysis showed that the reinforced silica-alginate bead had remarkable stability, and only less than 10% of silica-alginate beads were damaged after incubation for 48 h. In the adsorption experiment section, the pH value of 4.5 was obtained as the optimum value for fluoride removal. The kinetics investigation showed that all the experiments achieve their adsorption equilibrium within 2 h. The reaction rate of the process was found to follow the second-order equation. The isotherm investigation illustrated that the Langmuir model provided a better prediction of the experimental data. The maximum removal capacities of the composites were found to be 51.02 mg/g for fluoride ions. The adsorbent was regenerated and reused for 6 cycles with proper performance.

Temperature-responsive Pickering emulsions stabilized by poly(ethylene glycol)-functionalized silica particles

A series of PEG-functionalized silica nanoparticles with various molecular weight (MW 200, 400, 550, 2000, 5000 g.mol−1) have been prepared through a one-step synthesis and further used for the elaboration of temperature-responsive Pickering. The physicochemical properties of the nanoparticles were determined by TEM, TGA, DLS, surface tension and zeta potential measurements and the formed emulsions have been characterized by optical microscopy. The ability of SiO2@mPEG 550 to form temperature-responsive emulsions with oils of different nature has been explained by the hydrophilic/hydrophobic balance of the PEG/mPEG chains. The emulsions stabilized with PEG-functionalized SiO2 NPs undergo a clear temperature-triggered destabilization from room temperature to 80 °C due to the modification of the distribution of the PEG/mPEG chain at the oil-water interface.

Synthesis, structural characterization, antifouling and antibacterial properties of polypyridinium salt coated silica nanoparticles

Four bare silica particle carriers with different particle sizes and functional organic-inorganic silica particles (SiO2-2/P4VP-psl) “grafted” by P4VP-psl (polypyridinium salt) were selected to test their antibacterial and antifouling activities. The relationships between particle sizes, grafting degrees of pyridinium salt unit and their antibacterial ability were investigated by using Escherichia coli (E. coli) ATTC25922 as model bacterium and calculated by the colony count method. The results showed that silica particle sizes did not work in its antibacterial and antifouling activities. Functional SiO2-2/P4VP-psl possessed both the good antibacterial, antifouling activities of zwitterionic polymers, and the stability advantage of inorganic particle, which was environmental friendly disinfection materials in purifying water. The antibacterial rate was almost 100%. The stability of SiO2-2/P4VP-psl in bovine serum albumin solutions was very excellent with the unchanged particle size for 60 h. Moreover, the higher the grafting degree of pyridinium salt unit was, the stronger the sterilizing ability of SiO2-2/P4VP-psl was.

Preparation and characterization of poly(3-mercaptopropyl)methylsiloxane functionalized silica particles and their further modification for silver ion chromatography and enantioselective high-performance liquid chromatography

The present work reports on the preparation of polythiol-functionalized silica particles by thermally and photo-initiated radical addition reactions using poly(3-mercaptopropyl)methylsiloxane (PMPMS) as sulfhydryl group-rich surface modification reagent. Prior to surface modification with PMPMS, the silica was vinylized with vinyl trimethoxysilane. Finally, the usefulness of the thiolated silica particles was demonstrated by their further modification for various HPLC applications such as argentation chromatography and chiral separations. Aiming at a sulfhydryl group-rich, thin PMPMS layer on the surface of the silica several factors such as quantity of PMPMS, radical starter and reaction time were investigated by a design of experiment (DoE) approach. In thermally induced polymerization reactions 2,2’-azobis(isobutyronitrile) (AIBN) was used as radical starter, in photo-induced reactions 2,2-dimethoxy-2-phenylacetophenone (DMPA) was used instead. The incorporation of PMPMS was evaluated by elemental analysis and reactive and accessible sulfhydryl groups were determined by performing a thiol-disulfide exchange reaction with 2,2’-dipyridyl disulfide (DPDS). Consequently, thiol-functionalized silica particles (200 Å, 5 µm) with 1.81 ± 0.07 µmol sulfhydryl groups per m2 were prepared and further functionalized for silver ion chromatography and chiral separation chromatography clearly proving its utility as platform for further silica functionalization. The fabricated stationary phase for silver ion chromatography showed promising separation abilities for fatty acid methyl esters (FAME) according to the amount of double bonds within the fatty acid residue and cis- and trans-stilbene as model molecule for cis-trans isomerism. After the successful incorporation of O-tert-butylcarbamoyl quinine (tBuCQN) as chiral selector via thiol-ene click chemistry onto the PMPMS layer, the obtained chiral stationary phases (CSP) showed good separation of derivatized amino acids in polar organic elution mode comparable with a column based on commercially available CHIRALPAK QN-AX silica particles (120 Å, 5 µm).

Probing Ligand-Receptor Interaction in Living Cells Using Force Measurements With Optical Tweezers.

This work probes the binding kinetics of COOH-terminus of Clostridium perfringens enterotoxin (c-CPE) and claudin expressing MCF-7 cells using force spectroscopy with optical tweezers. c-CPE is of high biomedical interest due to its ability to specifically bind to claudin with high affinity as well as reversibly disrupt tight junctions whilst maintaining cell viability. We observed single-step rupture events between silica particles functionalized with c-CPE and MCF-7 cells. Extensive calibration of the optical tweezers’ trap stiffness and displacement of the particle from trap center extracted a probable bond rupture force of ≈ 18 pN. The probability of rupture events with c-CPE functionalized silica particles increased by 50% compared to unfunctionalized particles. Additionally, rupture events were not observed when probing cells not expressing claudin with c-CPE coated particles. Overall, this work demonstrates that optical tweezers are invaluable tools to probe ligand-receptor interactions and their potential to study dynamic molecular events in drug-binding scenarios.

Comparative cytotoxic study of silica materials functionalised with essential oil components in HepG2 cells

This work evaluated the cytotoxic effect of different EOCs-functionalised silica particle types. The in vitro toxicity of eugenol and vanillin-immobilised SAS, MCM-41 microparticles and MCM-41 nanoparticles was evaluated on HepG2 cells, and compared to free EOCs and pristine materials. The results revealed that free essential oil components and bare silica had a mild cytotoxic effect on HepG2 cells. However, the comparative study showed that free eugenol and vanillin had a milder cytotoxic effect than the equivalent concentrations of immobilised components on the different silica particles, while differences in cell viability between the bare and functionalised particles relied on the type of analysed material. The most cytotoxic materials were eugenol and vanillin-functionalised MCM-41 micro with IC50 values of 0.19 and 0.17 mg/mL, respectively, at 48 h exposure. Differences in cytotoxicity between functionalised particles may be attributed to the density of the functional components on their surface as a result of the functionalisation reaction performance for different materials. The study of the physico-chemical properties of particles demonstrated that cationic nature and increased hydrophobicity could be responsible for promoting cell-particle interactions for the eugenol and vanillin functionalised silica particles, enhancing their cytotoxic behaviour.

Glycine-functionalized silica as sorbent for cobalt(II) and nickel(II) recovery

We disclose that glycine functionalized silica particles (SiO2-Gly) are highly effective sorbents for the removal of Co(II) and Ni(II) ions from aqueous solution. SiO2-Gly can be prepared from commercial silica gel in a high yielding two step synthesis, and features a glycine concentration of 0.63 mmol∙g−1 (27 mmol∙cm−2). This material can recover up to 2.81 mmol∙g−1 of Co(II) ions or 3.02 mmol∙g−1 of Ni(II) ions from aqueous solution, a capacity which is tenfold higher than unmodified silica and comparable to the best performing sorbents reported in the literature. These sorption capacities are superstoichiometric in relation to the concentration of glycine on the surface. Sorption of cobalt(II) was improved by addition of ammonia to leaching solutions to give rise to more readily absorbed cobalt amine complexes. Regeneration of sorbent was investigated by desorption of adsorbed metals under mildly acidic solutions, and efficient desorption was noted for both metals. To probe the mechanism of sorption, a thorough characterization campaign involving TGA, FTIR, nitrogen adsorption/desorption, SEM, solid state NMR, solid state UV–Vis-NIR, -COOH titration and pHpzc – pH drift methods was undertaken. Our mechanistic study indicated that adsorption was mediated by electrostatic interaction.

Thermal stability of superhydrophobic and oleophobic silica nanoparticle spray coating

Superhydrophobic surfaces are known to offer high water repellency, however many industries such as the petrochemical and automotive industry need not only water resistant surfaces but also require oil resistant surfaces. Oleophobic coatings repel/reduce adhesion of viscous liquids and oil to the surface. Nano-coatings like silica nanoparticle coatings are known to offer both superhydrophobic and oleophobic properties. In this study, we evaluated both functionalized (FSP) and non-functionalized commercial silica particles (NFSP) and functionalized silica nanoparticles (FSN). Some of the key issues with employing both superhydrophobic and oleophobic coatings are durability and thermal stability. In our studies, we assessed the thermal stability of silica nanoparticle spray coatings, targeting a thermal stability of 500 °C. Our results indicated that the FSN coating exhibited both high water (≥ 150°) and oil (≥140°) contact angle at lower temperatures (100 °C) and was thermally stable up to 400 °C, in which the WCA and OCA only decreased by 10–13 °.

Droplet Rolling and Spinning in V-Shaped Hydrophobic Surfaces for Environmental Dust Mitigation.

The motion of a water droplet in a hydrophobic wedge fixture was examined to assess droplet rolling and spinning for improved dust mitigation from surfaces. A wedge fixture composed of two inclined hydrophobic plates had different wetting states on surfaces. Droplet rolling and spinning velocities were analyzed and findings were compared with the experiments. A wedge fixture was designed and realized using a 3D printing facility and a high speed recording system was adopted to evaluate droplet motion in the wedge fixture. Polycarbonate sheets were used as plates in the fixture, and solution crystallization and functionalized silica particles coating were adopted separately on plate surfaces, which provided different wetting states on each plate surface while generating different droplet pinning forces on each hydrophobic plate surface. This arrangement also gave rise to the spinning of rolling droplets in the wedge fixture. Experiments were extended to include dust mitigation from inclined hydrophobic surfaces while incorporating spinning- and rolling droplet and rolling droplet-only cases. The findings revealed the wedge fixture arrangement resulted in spinning and rolling droplets and spinning velocity became almost 25% of the droplet rolling velocity, which agrees well with both predictions and experiments. Rolling and spinning droplet gave rise to parallel edges droplet paths on dusty hydrophobic surfaces while striations in droplet paths were observed for rolling droplet-only cases. Spinning and rolling droplets mitigated a relatively larger area of dust on inclined hydrophobic surfaces as compared to their counterparts corresponding to rolling droplet-only cases.