Raspberry-like Structure Research Articles

Design and fabrication of superamphiphobic coating based on raspberry-like F–SiO2@PSA hybrid nanocomposite particles

Emulsifier-free polymerization was employed to prepare the submicron spherical PSA (the copolymer of styrene and acrylic acid), then SiO2 was grown on the surface of the PSA by sol-gel method to form F–SiO2@PSA particles. It was found that when styrene: acrylic acid = 2.5:1 and tetraethyl orthosilicate: PSA was between 2.17:1 and 6.38:1, a perfect raspberry-like structure could be obtained. The coating based on F–SiO2@PSA particles exhibited contact angles of 167.3 ± 1.4°, 152.1 ± 1.5°,150.3 ± 1.6°, 150.9 ± 1.6°, 142.2 ± 1.7°, 143.7 ± 1.5° and 146.6 ± 1.9° to water, diiodomethane, soybean oil, rapeseed oil, hexadecane, kerosene, and waste engine oil, respectively. The F–SiO2@PSA coating could reduce the adsorption of protein by 90% compared with the control surface. It was observed that bacteria and platelets could hardly adhere to the coating surface after 24 h of E. coli culture and 3 h of platelet-rich plasma immersion. The anti-adhesion to proteins, platelets, and bacteria will give the coating a promising application in the medical field.

Thermal Stability and Melting Dynamics of Bimetallic Au@Pt@Au Core-Shell Nanoparticles

Thermal stability is an important feature of the materials used as components and parts of sensors and other devices of nanoelectronics. Here we report the results of the computational study of the thermal stability of the triple layered Au@Pt@Au core-shell nanoparticles, which are promising materials for H2O2 bi-directional sensing. A distinct feature of the considered sample is the raspberry-like shape, due to the presence of Au nanoprotuberances on its surface. The thermal stability and melting of the samples were studied within classical molecular dynamics simulations. Interatomic forces were computed within the embedded atom method. To investigate the thermal properties of Au@Pt@Au nanoparticles, structural parameters such as Lindemann indexes, radial distribution functions, linear distributions of concentration, and atomistic configurations were calculated. As the performed simulations showed, the raspberry-like structure of the nanoparticle was preserved up to approximately 600 K, while the general core-shell structure was maintained up to approximately 900 K. At higher temperatures, the destruction of the initial fcc crystal structure and core-shell composition was observed for both considered samples. As Au@Pt@Au nanoparticles demonstrated high sensing performance due to their unique structure, the obtained results may be useful for the further design and fabrication of the nanoelectronic devices that are required to work within a certain range of temperatures.

A highly sensitive electrochemical sensor derived from peptide amphiphilic inspired self-assembled, ordered gold nanoparticles for determination of 22 β-lactams

Achieving ordered arrangement of gold nanoparticles (AuNPs) on an electrode can further improve the signal intensity of an electrochemical immunosensor. This ordered AuNPs self-assembly can be inspired by peptide amphiphile (PA). The rational design of hydrophobic chains in PA is a crucial step when the range of hydrophobic alkane chain from 14 to 18 carbons. As arginine (R) can combine specifically with Au surface plane (111), four PAs, i.e., C15H23CO-RR (C16R2), C15H23CO-RRR (C16R3), C15H23CO-RRRR (C16R4), and C15H23CO-RRRRR (C16R5), in this work are designed to investigate the extent of ordered AuNPs self-assembly. The results indicate that C16R4 presented a dominant electron donating ability and can inspire the self-assembly of AuNPs to form a mono-dispersed raspberry-like structure (C16R4-AuNPs) to obtain the largest ΔI (15.4 μA). In the detection system, C16R4-AuNPs firstly capture and immobilize anti-β-lactam receptor monoclonal antibodies (mAb) by electrostatic adsorption, and the anti-β-lactam receptor mAb possess antigen-antibody binding sites away from the active site of the receptors. Then, they capture β-lactam receptors through an antigen-antibody reaction to form a ternary complex (C16R4-AuNPs-mAb-β-lactam receptors). Based on this indirect-labeling process, the receptor active sites have been exposed completely, facilitating ligand recognition, which greatly further improves the sensitivity of the present method. Finally, a highly sensitive electrochemical immunosensor based on the ternary complex is developed to achieve the determination of 22 β-lactam antibiotics, which is more sensitive and applicable than other reported electrochemical sensors.

Raspberry-like micro-size polymer with high spherical shape-retention capability and adhesion as binder for ceramic separators

Surface coating with binders and ceramic particles is one of the most effective strategies to enhance thermal stability and electrolyte wettability of polyolefin separators, yet is still challenged by the issue of hole blocking and contradiction between adhesion and thermostability of binders. Herein, a raspberry-like micro-size polymer (RMP) binder with a soft core inside and hard spheres outside was prepared through seed swelling polymerization. The micron size helps RMP binder to effectively bond separator and electrode, solving the pore blocking problem encountered with traditional liner binders. The raspberry-like structure combines softness and rigidity, ensuring both high spherical shape-retention capability and good binding strength. The ceramic separator with RMP binder shows low thermal shrinkage and high ionic conductivity, achieving high cycling stability and low impedance of the batteries. This work provides new inspiration to construct novel binders for ceramic-coated separators with long-term stability for high-performance lithium-ion batteries.

Surface encapsulating UV filters based on self-assembly of an amphiphilic random copolymer by miniemulsion polymerization

A nanoparticles encapsulating UV filters were prepared by miniemulsion polymerization, in which methyl methacrylate (MMA) as the monomer, and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. Scanning electron microscopy (SEM) and X-ray photoelectron spectrometry (XPS) confirmed that the amphiphilic random copolymers poly (styrene-co-methacrylic acid) P(St-co-MAA) not only acted as the stabilizer but also self-assembled on the surface of the P(MMA-EGDMA) polymers. During the miniemulsion polymerization, most UV filters were encapsulated in the P(St-co-MAA) self-assembly aggregates on the surface of nanoparticles, giving the nanoparticles a raspberry-like structure. As the mass ratio of P(St-co-MAA) to MMA and EGDMA at 1.0, the encapsulation efficiency of UV filters was 69.85%, whereas 70.7% of UV filters were located in the P(St-co-MAA) self-assembly layer. The leakage of UV filters from the raspberry-like nanoparticles was negligible after continuous stirring in isopropyl myristate (IPM) for 24 h. The sun protection factor (SPF) and UVA Protection Factor (UVAPF) value of sunscreen formulation incorporated with the raspberry-like nanoparticles could reach 58.8 and 6.82, respectively. It enhanced UV protection more efficiently than the nanoparticles with a smooth surface.

Synthesis of inorganic/organic raspberry-like composite particles for superhydrophobic and superlipophilic coatings

A facile synthetic route to composite particles with raspberry-like structure was reported, and further led to superhydrophobic and superlipophilic surface by the usage of these composite particles. In this approach, the poly(styrene-co-3-methacryloxypropyl trimethoxysilane) (P(St-MPS)) particles were fabricated by one-step dispersion polymerization. Then, the P(St-MPS)@SiO2 composite particles with raspberry-like structure were obtained by hydrolysis of tetraethoxysilane (TEOS) with (P(St-MPS)) particles under alkaline conditions. The morphology of the (P(St-MPS))@SiO2 composite particles could be controlled by adjusting the ratio of the initial reactants 3-methacryloxypropyl trimethoxysilane (MPS) and styrene (St). A possible mechanism of the morphology changes was also discussed, the reactive siloxane groups of the (P(St-MPS)) particles induce the growth of silica generated by the hydrolysis of tetraethoxysilane (TEOS) on its surface to form raspberry-like structure. In addition, the water contact angle (WCA) of the coating was 152° ± 2°, and the oil contact angle (OCA) of the coating was close to 0°, which demonstrated a superhydrophobic and superlipophilic properties by a rational surface modification of this P(St-MPS)@SiO2 composite particles with raspberry-like structure. Hydrophobic properties could be adjusted by varying the surface morphology of the P(St-MPS)@SiO2 composite particles. The coatings could be used in applications such as self-cleaning and oil-water separation and whole process was carried out under mild conditions and did not involve complex steps.

Au nanoparticles decorated covalent organic framework composite for SERS analyses of malachite green and thiram residues in foods

A three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrate composed of gold nanoparticles (AuNPs) self-assembled covalent organic frameworks (COFs) was fabricated via the electrostatic interaction between positively charged COFs and negatively charged AuNPs, which exhibited excellent SERS performance and were successfully applied for the analyses of malachite green (MG) residue in different seafood products as well as thiram residue in several kinds of fruit juice. The raspberry-like structure SERS substrate has a larger surface area that can provide more adsorption sites in testing and improve the efficiency of sample enrichment. By using this developed SERS substrate, the detection linearity ranges are 1.0 × 10−9 mol·L−1–1.0 × 10−6 mol·L−1 for MG and 5.0 × 10−8 mol·L−1–1.0 × 10−5 mol·L−1 for thiram (R2 ≥ 0.995). The detection limits are 6.2 × 10−10 mol·L−1 for MG and 1.7 × 10−8 mol·L−1 for thiram, respectively. The COF-AuNPs substrate was actually applied for analysis of MG in seafood products and thiram in different fruit juice, with the recoveries in the ranges of 94.67–108.99 % for MG and 95.00–107.58 % for thiram, and both of the relative standard deviation (RSD) are no more than 5.88 %. This work indicates that the developed COF-AuNPs substrate is promising for SERS analyses and detections of residues in foods.

High Figure of Merit SPR Sensor Based on Raspberry-Like Silica

To address the problems that the surface plasmon resonance (SPR) sensor is not sensitive enough to detect biomolecules in the refractive index range (RI=1.33-1.34), and the traditional methods to enhance the sensitivity cause the sensor poor bioaffinity, this paper proposed raspberry-like silica assisted high figure of merit (FOM) fiber-optic SPR sensor. The finite element method results show that when the raspberry-like silica is introduced to the SPR sensor, the resonant electric field intensity on the sensor surface is 2.97 times stronger than that of SPR sensors only. Raspberry-like silica particles composed of different noble metals nanoparticles (AuNPs, PtNPs, and CuNPs) were prepared to compare and analyze the effects of different nanoparticles on the sensing performance. The sensing experiments showed that AuNPs raspberry-like silica had the most excellent performance, enabling the sensor to achieve high sensitivity of 5264.3 nm/RIU, which is 2.65 times higher than the Au film SPR sensor. The fitting calculations showed that the AuNPs raspberry-like silica assisted SPR sensor had a high FOM of 42.9 RIU-1, 1.9 times more than the Au film SPR sensor. In addition, the sensor has good temperature stability, repeatability, and generality after the corresponding test. The proposed raspberry-like structure provides a new approach to obtaining both high sensitivity and high FOM for the SPR sensor, which makes the sensor potential for biosensing.

An Efficient Substrate-Free Method of Producing SiO2-Based Nanoparticles for Superhydrophobic Applications.

We report on the preparation of SiO2-based nanoparticles readily available for superhydrophobic applications. In contrast to usual approaches, our process is substrate-free and based on electrostatic adsorption of small SiO2 particles onto large SiO2 cores with the aid of poly(diallyldimethylammonium chloride) followed by calcination and chemical modification with trichlorododecylsilane. The as-prepared nanoparticles are in powder form and exhibit stable superhydrophobic behavior at room temperature because of the unique combination between the hierarchical raspberry-like structure and low surface energy. If properly stored, the nanoparticles retain their functional properties for several months.

Studies on Hydrophobic Silica/Silicone Rubber Composite Microspheres with Dual-Size Microstructures.

In this study, a series of microsphere composites were prepared by the hydrosilylation of nanospherical SiO2 and silicon rubber microspheres. The influence of different host-guest size ratios on the wettability of the SiO2/silicone rubber composite microspheres was explored. The structures and performance of the composite microspheres were investigated using scanning electron microscopy and contact angle testing. The results showed that the prepared SiO2/silicone rubber composite microspheres had a raspberry-like structure and exhibited a rose petal effect. When the SiO2 content was 30%, the water contact angle of the SiO2/silicone rubber composite microspheres reached a maximum, and 30% was used as the optimal ratio for compounding SiO2 having different particle diameters with silicone rubber microspheres. Wettability calculations and analyses were performed for the surface with the composite microspheres. The results indicated that the structure with dual-size roughness could significantly improve surface hydrophobicity. As the ratio of the host-guest size increased, the contact angle of the water phase also increased. However, the surface structures of the composite microspheres were not uniform because of the surface chemical composition and the uncontrollable distribution of the small spheres on the surface of the large spheres during compounding. As a result, water droplets appeared in the Cassie-impregnated state on the composite microsphere particle coating, resulting in the phenomenon of high hydrophobicity and high adhesion.

Facile preparation of raspberry-like mesoporous poly(styrene-co-divinylbenzene)/Ag composite particles for antibacterial superhydrophobic surfaces and liquid marbles

Due to their unique properties, raspberry-like colloidal particles (RCPs) have been widely used in various fields. However, a facile, scalable and robust approach of producing raspberry-like colloidal particles remains an ongoing challenge. Herein, raspberry-like mesoporous poly(styrene-co-divinylbenzene) (PSD) polymeric particles were fabricated by one-step dispersion polymerization in the solvent mixture of ethanol and toluene. The morphologies of obtained polymeric particles could be easily tuned from spherical to raspberry-like structure by changing the composition of the solvent mixtures. A rational mechanism for the formation of raspberry-like polymeric particles was also proposed according to the morphological evolution under different copolymerization conditions. With the assitance of the immonilized PVP layer, the raspberry-like PSD colloidal particles can be further functionalized by depositing Ag nanoparticles on the particle surface. The antibacterial activity of raspberry-like PSD/Ag composite particles against E. coli was up to 99.99%. In addition, raspberry-like PSD/Ag composites can be further utilized to construct antibacterial superhydrophobic surface and liquid marbles.

Rapid pH-responsive self-disintegrating nanoassemblies balance tumor accumulation and penetration for enhanced anti-breast cancer therapy

The dilemma of tumor accumulation and deep penetration has always been a barrier in antitumor therapy. Stimuli-responsive size changeable drug delivery systems provide possible solutions. Nevertheless, the low size-shrinkage efficiency limited the antitumor effects. In this study, an instant pH-responsive size shrinkable nanoassemblies named self-aggregated DOX@HA-CD (SA-DOX@HA-CD) was formulated using small-sized hyaluronic acid modified carbon dots (HA-CD) as monomers, which could self-aggregate into raspberry-like structure via hydrophobicity force in neutral pH and rapidly disassemble into shotgun-like DOX-loaded CD monomer in simulated tumor microenvironment (pH 6.5), owing to the transformation in electrical charge and hydrophobicity/hydrophilicity of this system. The transmission electron microscopy showed that the clustered SA-DOX@HA-CD had a diameter of ~150 nm, and thoroughly disassembled into ~30 nm nanoparticles in response to acidic environment. The disassemble efficiency was approximately 100%. Attributed to this property, SA-DOX@HA-CD led to enhanced cellular internalization and accumulation in 4T1 cells in simulated tumor microenvironment, as well as deep tumor penetration in 3D tumor spheroid model. Besides, the imine bond between DOX and HA-CD endowed DOX with pH-responsive release profile in the acidic lysosome environment. Furthermore, in the orthotopic 4T1 tumor-bearing mouse model, SA-DOX@HA-CD demonstrated higher tumor accumulation than non-aggregated DOX-HA-CD. Meanwhile, in response to the acid tumor microenvironment, the dissociated DOX-HA achieved deep tumor penetration, which consequently resulted in 2.5-fold higher antitumor efficiency. The formulation of self-aggregated SA-DOX@HA-CD provides a simple and effective alternative to prepare pH-responsive size-shrinkable nanodrug delivery systems. Statement of significanceThe heterogeneity of tumor vasculature and the high tumor interstitial pressure lead to the barriers in tumor accumulation and deep penetration, which calls for opposite properties (e.g. size) of drug delivery systems. To address this dilemma, various size changeable nanoparticles have been developed utilizing special features of tumor microenvironment, such as pH, enzyme and reactive oxygen species. Nevertheless, the current strategies face the problems of incomplete hydrolysis of chemical bonds or insufficient enzyme degradation, which result in only partial size shrinkage, hindering the tumor deep penetration effects. Here we developed a self-assembled nanocluster, which could respond to acidic pH rapidly and thoroughly disassemble into small nanodots due to the alteration of hydrophobicity/hydrophilicity/charge, leading to approximately 100% dissociation. This strategy provides a new concept for design of size changeable drug delivery systems.

Synthesis of raspberry-like structure zinc oxide nanoparticles via glycol-solvothermal, low-temperature solvothermal and coprecipitation methods

Highly crystalline ZnO nanoparticles with a pure phase and raspberry-like structure were synthesized using three different techniques (glycol-solvothermal, low-temperature solvothermal, and coprecipitation methods). Physisorption analysis and field emission scanning electron microscopy confirmed the large specific surface area of the ZnO nanoparticles with a mesoporous–macroporous structure due to the interstices of aggregated and agglomerated secondary and tertiary ZnO particles. The ZnO nanoparticles from the coprecipitation method presented the best performance among the three products, owing to their highest purity and crystalline phase, large Brunauer–Emmett–Teller surface area (23.0 m2·g -1 ) and pore volume, and the finest mesoporous–macroporous structure. ZnO nanoparticles can be used in various applications such as catalysis, biosensing, imaging, drug delivery, and pollution absorption for the purpose of environmental remediation.

Effect of Structural Features on the Superhydrophobicity of SiO2-Based Coatings.

A detailed correlation between topographical features and wettability of chemically modified coatings based on silica nanoparticles (SiO2) was performed. In this study, hierarchical structures were prepared by the layer-by-layer (LbL) technique using two different approaches: random roughened surfaces were obtained by exploring stacking defects spontaneously arisen after 15, 30, and 45 assembly cycles of 22 nm SiO2, and a particular structure, commonly known as raspberry-like, was obtained by depositing 22 nm SiO2 over the first deposited 400 nm SiO2. As an intrinsic attribute of the assembly process, the average slope of random roughened surfaces seems to be constant and virtually independent of the number of deposited layers. Additionally, the local slopes are always lower than a critical value (Φcrit) required to stabilize the solid-liquid-air interface; thus, a fully wetted Wenzel state is invariably observed with water contact angles (WCAs) ∼130°. On the other hand, since the local slopes of the raspberry-like structure follow a nearly spherical curvature, small SiO2 can stabilize the solid-liquid-air interface by increasing the local contact angle and avoid the deep penetration of water into the surface asperities, resulting in a WCA ∼167°. The results also suggest that nanoroughness might also play an important role in the pinning effect of the solid-liquid-air contact line, favoring the maintenance of superhydrophobicity of raspberry-like surfaces.

Effects of colloidal silica on the properties of POSS-containing fluorinated poly(styrene–acrylate)/SiO2 composite materials

Polyhedral oligomeric silsesquioxane (POSS)-containing fluorinated poly(styrene–acrylate)/SiO2 (POSS-FPSA/SiO2) composite materials were prepared by preemulsification and direct blending method. The SiO2 particles were induced aggregated onto the surface of POSS, and sol–gel processes were simultaneously carried out with addition of co-solvent to form raspberry-like structure. 29Si NMR and XRD results confirmed that POSS were successfully grafted to polymer and were evenly dispersed uniformly in polymer matrix. The average diameter of composite latexes increased from 63 to 81 nm with increasing addition of SiO2 content. AFM and WCA images confirmed that sol–gel processes were promoted by increasing addition of SiO2 content, which improved the roughness and hydrophobicity of composite films. XPS spectra displayed that two kinds of Si–O bonds existed on the surface of composite films. One was related to the Si–O groups of SiO2, and the other was attributed to the Si–O–Si groups obtained from the sol–gel processes. The peak area of the former decreased from 56.86% to 38.78%, while the latter increased from 43.14% to 62.22%. TGA curves demonstrated that the composite film exhibited better thermal stability when the SiO2 content was 10.0%. In addition, serious phase separation would decrease the thermal stability of composite films.

Morphology-Tailored Gold Nanoraspberries Based on Seed-Mediated Space-Confined Self-Assembly.

Raspberry-like structure, providing a high degree of symmetry and strong interparticle coupling, has received extensive attention from the community of functional material synthesis. Such structure constructed in the nanoscale using gold nanoparticles has broad applicability due to its tunable collective plasmon resonances, while the synthetic process with precise control of the morphology is critical in realizing its target functions. Here, we demonstrate a synthetic strategy of seed-mediated space-confined self-assembly using the virus-like silica (V-SiO2) nanoparticles as the templates, which can yield gold nanoraspberries (AuNRbs) with uniform size and controllable morphology. The spikes on V-SiO2 templates serve dual functions of providing more growth sites for gold nanoseeds and activating the space-confined effect for gold nanoparticles. AuNRbs with wide-range tunability of plasmon resonances from the visible to near infrared (NIR) region have been successfully synthesized, and how their geometric configurations affect their optical properties is thoroughly discussed. The close-packed AuNRbs have also demonstrated huge potential in Raman sensing due to their abundant “built-in” hotspots. This strategy offers a new route towards synthesizing high-quality AuNRbs with the capability of engineering the morphology to achieve target functions, which is highly desirable for a large number of applications.

Fabrication of hydrophobic composite films by sol-gel process between POSS -containing fluorinated polyacrylate latexes and colloidal silica particles

A novel hydrophobic composite films (POSS-FPA-SiO2) were prepared by directly physically mixing octavinyl polyhedral oligomeric silsesquioxane containing fluorinated polyacrylate latexes (POSS-FPA) with colloidal silica. Sol-gel processes were carried out on the surface of POSS with addition of co-solvent to enhance roughness and hydrophobicity of composite films. TEM photos revealed that colloidal silica particles had enriched and aggregated on the surface of POSS, the sol-gel processes of silica particles occurred to form raspberry-like structure particles. The average diameter data indicated that the aggregation of colloidal silica particles on the surface of POSS had increased the average diameter of the composite latexes. FT-IR spectra confirmed that two kinds of SiO bonds existed in the composite films, which one related to the SiO framework of POSS and the other obtained form the sol-gel processes. SEM and AFM images illustrated that the coarse structure obtained from the sol-gel processes had increased the roughness of the composite surface. The water contact angle (WCA) of composite films were found increasing as the sol-gel processes. TGA curves demonstrated that the composite films exhibited much better thermal stability than that of pure FPA and POSS-FPA films.

Synthesis and characterization of mesoporous CaCO3@PSS microspheres as a depot system for sustained Methylene Blue delivering

Polystyrene sulfonate (PSS)-doped calcium carbonate microparticles (CaCO3@PSS) were synthesized and used for the encapsulation of Methylene Blue (MB). SEM and TEM images suggest the formation of spherical particles with about 2 μm diameters and raspberry-like structure. Brunauer–Emmett–Teller method was used to analyze the specific surface area and the pore size distribution of the CaCO3@PSS microparticles. The sorption of MB from aqueous solution onto CaCO3@PSS microspheres was studied and equilibrium isotherm determined. A physisorption process was indicated by the values of sorption energy (BD) 2.39 × 10−7 mol2/J2, mean free energy (ED) 1.5 kJ/mol and heat of sorption (B) 28.8 J/mol estimated from the Dubinin-Radushkevich and Temkin isotherms. The Langmuir model precisely describes the isotherm and the maximum adsorption capacity was 149.3 mg/g indicating homogeneous nature of adsorption sites and monolayer coverage of MB on the CaCO3@PSS microparticle inner and outer surfaces. The pseudo-second-order model can better describe the adsorption kinetics with a maximum adsorption attained within 5 h. The intra-particle diffusion process was identified as the main mechanism controlling the rate of the dye sorption. The MB release from CaCO3@PSS microspheres was found to be pH-responsive. The presence of negatively charged PSS− groups in pores of CaCO3@PSS microparticles prevents the initial burst release of MB, decreasing the release rate of MB. The experimental results indicate high potential of CaCO3@PSS microspheres as carriers for encapsulation and controlled release of cationic dye molecules, such as photosensitizer MB, used in photodynamic therapy.

Preparation of highly cross-linked raspberry-like nano/microspheres and surface tailoring for controlled immunostimulating peptide adsorption

The surface functionalities of ionic liquid-functionalized nano/microspheres with a highly cross-linked raspberry-like structure could be well controlled by adjusting the functional chains appropriately.

PVP-assisted synthesis of raspberry-like composite particles

Composite particles composed of SiO2 nanoparticles and polystyrene (PS) spheres with a raspberry-like structure were successfully synthesized by a PVP-assistant sol–gel method. The as-prepared products were systemically characterized by FT-IR, TGA, SEM and TEM. The characterization results indicated that the amount of polyvinyl pyrrolidone (PVP) and concentration of ammonia solution played key roles in tailoring the structure of the composite particles, including size and surface density of SiO2 nanoparticles on the surface of PS spheres. During the PVP-assisted sol–gel process, the synthesized nano-sized SiO2 particles were favorably deposited on the surface of PS spheres to form hierarchical composite particles. By adjusting the amount of PVP and pH value of reaction system, the typical raspberry-like particles with controllable coverage of SiO2 nanoparticles on PS spheres were obtained. Subsequently, the composite particles with well controllable morphology were modified with OcTMS and orderly deposited on the substrate. The effect of the composite particles with different morphologies on the wetting property was investigated. Finally, superhydrophobic surface was generated and the water contact angle was up to 154°. PS–SiO2 composite particles with hierarchical structure were successfully prepared by a PVP-assisted sol–gel method, which exhibited a superhydrophobic property after surface modification with OcTMS.