Total Synthesis of Surfactant-Mimetic Nanocolloids via Regioselective Silica Deposition on Bottlebrush Polymers

Abstract

Molecular-mimetic nanocolloids (MMNCs) are promising for advanced materials, yet self-assembly fabrication faces challenges in purity and programmability. We report a total synthesis strategy for surfactant-mimetic nanocolloids (SMNCs), an amphiphilic MMNC subclass. SMNCs consist of a ~5 nm silica nanoparticle head and a bottlebrush polymer tail. Regioselective silica deposition on linear-block-brush polymers via the modified sol–gel method enables precise control. This strategy is versatile and can be adapted to synthesize other MMNCs with different components. It offers a more controlled alternative to self-assembly methods, advancing MMNC synthesis and enabling their broader use in emerging technologies.

1. Introduction

Molecular-mimetic colloids (MMCs) have garnered substantial attention over the past few decades [1,2,3,4,5], encompassing a diverse range of entities, such as colloidal molecules [6,7,8,9,10], colloidal polymers [11,12,13], colloidal liquid crystals [14,15,16], giant molecules/giant surfactants [17,18], etc. The major driving forces come from two aspects: (1) The observable dynamics within MMC systems offer novel perspectives and fundamental insights into the behavior of conventional, often invisible molecular systems [19,20]. (2) Established principles in conventional molecular systems serve as a guiding framework to decipher MMCs with varying length scales and compositions [21]. This reciprocal relationship has propelled the development of assembly frameworks utilizing MMCs as functional building blocks [11,22], and it has also facilitated the exploration of colloid-based materials [23,24], including nano-/micromotors [25,26], interfacial stabilizers [27], nanomedicines [28], superlattices [29], and metamaterials [30], among others.

This remarkable progress has spurred efforts to devise new strategies for the design and synthesis of MMCs with near-molecular-level precision, considering both molecular configuration and surface chemistry. The continuously expanding repertoire of programmable MMCs is a significant catalyst for the advancement of future colloid-based materials [31,32]. Among these, molecular-mimetic nanocolloids (MMNCs), particularly those with sizes ranging from 10 nm to 100 nm, hold the most promise due to their programmable functionality. To date, the majority of MMNCs have been synthesized through self-assembly strategies, such as the polymer–ligand regulation approach (including bio-polymer DNA [33,34,35] and synthetic block polymers [8,13]), nanoconfined assembly utilizing DNA origami templates [7] or other substrates [36], surface patterning on nanoparticle surfaces [37,38], etc. Nevertheless, the utilization of these MMNCs as building blocks for bulk materials is hampered by challenges associated with relatively low yield and purity.

To address the challenges of relatively low yield and purity [22,38] in self-assembly strategies for synthesizing molecular-mimetic nanocolloids (MMNCs), the MMNC total synthesis strategy—inspired by conventional molecular fabrication processes (molecular design and synthesis)—holds the potential to surmount the hurdles encountered in self-assembly-based preparation methods and accelerate the investigation and development of MMNC-based materials [18,39].

Here, we report a novel strategy for the total synthesis of surfactant-mimetic nanocolloids (SMNCs) via the regioselective deposition of silica on bottlebrush polymers (BBPs) (Figure 1). SMNCs exhibit typical amphiphilic characteristics. Moreover, the well-established principles governing amphiphile (surfactant-like) self-assembly can be applied to evaluate the performance of SMNCs. Therefore, the surfactant-mimetic system was selected as a model to illustrate our strategy in this work. Our strategy offers several distinct molecular engineering advantages: (i) The programmable bottlebrush polymers serve as the tail-like component of the final SMNCs. The diverse programmable structural parameters of the BBP tails, such as sidechain length (N_sc, denoted as n in Figure 1), backbone length (N_bb, denoted as b in Figure 1), and the chemical composition of sidechains, can significantly expand the SMNC library. BBPs are size-compatible with nanoparticles (NPs) (here, silica NP lobes) and also possess colloidal properties in addition to their polymeric features [40]. (ii) The regioselective deposition of silica is achieved through a modified Stöber method that we reported previously [41]. The key lies in using a single polymer chain containing carboxyl moieties as the nucleating center for the hydrolysis and subsequent polycondensation of silanes into silica nanoparticles. The size of the silica NP lobes can be tuned by adjusting the relative molar ratio of the added silanes to the carboxyl moieties of the nucleating chains. Furthermore, if necessary, the surfaces of silica lobes can be readily chemically modified by adding other silanes with functional moieties, such as cross-linkable vinyl, fluorine-containing, and fluorescent groups, among others. (iii) Leveraging the nanoscale steric hindrance generated by densely grafted sidechains, the nucleation site can be accurately positioned and confined at the end of the BBPs. These structural features can be exploited for the further design of other silica nanoparticle-based colloidal molecules.

2. Methods

2.1. Materials

All chemicals were used as received unless otherwise noted, including cis-5-norbornene-exo-2,3-dicarboxylic anhydride (NB) (Adamas, Shanghai, China, 97%+), ethanolamine (Adamas, Shanghai, China, 99%+), 4-dimethylaminopyridine (DMAP) (Adamas, Shanghai, China, 99%), α-bromoisobutyryl bromide (BIB) (Adamas, Shanghai, China, 98%), styrene (St) (Adamas, Shanghai, China, 99%), cuprous bromide (CuBr) (Sigma-Aldrich, St. Louis, MO, USA, 99.999%), N,N,N′,N″,N″-Pentamethyldiethylenetriamine (PMDETA) (Adamas, Shanghai, China, 98%), 5-norbornene-2-carboxylic tert-butyl ester (tBNB) (Adamas, Shanghai, China, 97%+), [1,3-Bis (2,4,6-trimethylphenyl)-2-imidazolidinylidene]bis (2-bromopyridine)dichloro (phenylmethylene) ruthenium (G3) (Adamas, Shanghai, China, 95%), ethyl vinyl ether (EVE) (Adamas, Shanghai, China, 98%+), N-methyl-2-pyrrolidone (NMP) (Adamas, Shanghai, China, 99.5%), tetramethyl orthosilicate (TMOS) (Adamas, Shanghai, China, 99%), tetrahydrofuran (THF) (KESHI, Chengdu, Sichuan, China, 99.5%), ammonia water (NH₃·H₂O) (Greagent, Shanghai, China, AR ~25%), calcium hydride (CaH₂) (Greagent, Shanghai, China, AR), hydrochloric acid (HCl) (Chron, Chengdu, Sichuan, China, AR 36–38%), sodium bicarbonate (NaHCO₃) (Greagent, Shanghai, China, 98%+), magnesium sulfate (MgSO₄) (Greagent, Shanghai, China, 98%+), ethyl alcohol (EtOH) (Adamas, Shanghai, China, 99%), n-Hexane (Hex) (Greagent, Shanghai, China, >97%), toluene (Greagent, Shanghai, China, >99.5%), dichloromethane (DCM) (Adamas, Shanghai, China, 99.9%), and deuterated chloroform (CDCl₃) (Adamas, Shanghai, China, 99%). Styrene was distilled under vacuum prior to use and stored in a freezer at −20 °C. DCM for the ROMP reaction was distilled and stored in a freezer at 4 °C.

2.2. Synthesis

2.2.1. Synthesis of Macromonomer Norbornenyl-Terminated Polystyrene (NB-PSt) [42] (Figure S1a)

NB-OH: To a 500 mL flask, cis-5-norbornene-exo-2,3-dicarboxylic anhydride (16.41 g, 164.15 g/mol, 0.1 mol), ethanolamine (6.01 mL, 61.08 g/mol, 0.1 mol), DMAP (12.21 g, 122.17 g/mol, 0.1 mol), and 100 mL toluene were added. A Dean–Stark trap was attached to the flask, and the reaction mixture was heated at reflux (150 °C) for 10 h. Then the toluene was concentrated and removed to yield a faint yellow solid. The crude product was recrystallized three times in an appropriate amount of toluene at 135 °C. Finally, it was dried in a 40 °C vacuum oven to yield 19.68 g of white solid (yield: 95%). The product was used for the following step without further purification. The chemical compositions of NB-OH were confirmed by ¹H NMR (CDCl₃) (Figure S2a).

NB-Br: The protocol for the synthesis of NB-Br is similar to that reported in another study with some modifications [43]. NB-OH (19.68 g, 207.23 g/mol, 0.095 mol) was added to a 200 mL Schlenk flask and protected by N₂. Then, 150 mL of anhydrous N-methyl-2-pyrrolidione (NMP) was added to the above-mentioned Schlenk flask via a syringe to completely dissolve it, and it was cooled to 0 °C. α-bromoisobutyryl bromide (14.83 mL, 229.91 g/mol, 0.12 mol, 1.2-fold compared to the hydroxyl groups) was then added dropwise to the mixture solution under stirring and protection by N₂. The reaction temperature was maintained at 0 °C for 2 h and then slowly increased to ambient temperature, after which the reaction was allowed to continue for 24 h. The mixture was then incubated in an oil bath at 40 °C for 12 h. The brown solution was poured into saturated NaHCO₃ aqueous solution under stirring. The separated oil mixture at the bottom of the beaker was collected and dissolved in 200 mL of DCM. The organic yellow solution obtained was washed three times with 0.1 N HCl aqueous solution (200 mL), 0.1 M Na₂CO₃ aqueous solution (200 mL), and ultrapure water (200 mL) and dried over MgSO₄. The solvent was evaporated and recrystallized three times in EtOH to yield 30.68 g of white solid (yield: 86%). The chemical compositions of NB-Br were confirmed by ¹H NMR (CDCl₃) (Figure S2b).

NB-PSt: St (34.8 mL, 104.15 g/mol, 0.3 mol), CuBr (42.0 mg, 143.45 g/mol, 0.30 mmol), and NB-Br (0.34 g, 1.0 mmol) were added to a 100 mL Schlenk flask. Then, the mixture was purged with N₂ for 30 min under stirring, followed by the addition of PMDETA (63.4 µL, 173.3 g/mol, 0.30 mmol) via a syringe for another 15 min purging of N₂. The mixture was stirred at 65 °C for the desired time, and then the reaction was terminated by cooling it quickly down to room temperature using liquid nitrogen. The product was passed through a short silica column to remove the catalyst and precipitated into MeOH three times. The obtained white powder weighed around 2.38 g. The chemical compositions of NB-PSt were confirmed by ¹H NMR (CDCl₃), as shown in Figure S2c. The conversion determined by ¹H NMR was ca. 8.3%. GPC (DMF): M_n = 2.4 Kg/mol and Ɖ = 1.21.

Other NB-PSt_n polymers with varying lengths were synthesized by increasing the ATRP time, with the structural parameters listed in Table S1.

2.2.2. Synthesis of Bottlebrush Polymers (BBPs) via Sequential ROMP (Figure S1b)

PtBNB-b-P (NB-PSt): The BBPs were prepared via sequential ROMP in a glovebox. tBNB (50 mg, 194.27 g/mol, 0.25 mmol) was dissolved in anhydrous DCM (150 µL) in a 4 mL vial equipped with a stir bar. The G3 catalyst was dissolved in anhydrous DCM at a concentration of 0.011 mol/L. Until reaching a target polymerization degree, a certain volume of G3 solution was quickly added under rapid stirring at room temperature. After 20 min, the solution of MM NB-PSt₈₀ (644 mg, 10.0 Kg/mol, 0.064 mmol) was added and allowed to react for another 2 h. And then, 50 µL of ethyl vinyl ether (EVE) was added into the vial to terminate the reaction. The as-synthesized BBPs were measured by GPC to check the MM conversions. And then the mixture was diluted with DCM and passed through a silica gel column to remove G3. The mixture was purified via fracture precipitation three times to remove residual MMs and then dried in a vacuum oven at 40 °C overnight. The obtained white powder weighed around 0.61 g (yield: 92%). The chemical compositions of PtBNB-b-P (NB-PSt) were confirmed by GPC and ¹H NMR (CDCl₃).

Note that, to characterize the degree of polymerization, a, of the first block PtBNB_a, a parallel sample reaction was terminated through the addition of EVE before adding NB-PSt. The GPC measurement was taken as shown in Figure S4b, while the ¹H NMR measurement was taken after the sample had been dried completely in a vacuum oven and then redissolved in CDCl₃.

PCNB-b-P (NB-PSt): The obtained BBP PtBNB-b-P (NB-PSt) (~0.5 g) was dissolved in DCM (30 mL), and then TFA (10 mL) was dropped into it. The reaction mixture was stirred at room temperature for 24 h. After the reaction was completed, the mixture was concentrated and washed with petroleum ether precipitation three times. Finally, it was dried in a vacuum oven at 40 °C overnight and the obtained white powder weighed around 0.43 g (yield: 86%). The chemical compositions of PCNB-b-P (NB-PSt) were confirmed by ¹H NMR (CDCl₃).

2.2.3. Regioselective Deposition of Silica on BBPs

To a 4 mL glass vial, the bottlebrush polymer PCNB₈₇-b-P (NB-PSt₈₀)₁₉ (~10 mg, MW ≈ 177.3 Kg/mol, n_-COOH ≈ 4.85 µmol) and THF (10 mL) were added. After being fully dissolved, NH₃·H₂O (0.42 mL) was added and shaken for 10 min. Then, TMOS (7.2 µL, 152.22 g/mol, 48.5 µmol) (n_TMOS:n_-COOH = 10:1) was added under sonication for ~ 30 s and incubated for 24 h to complete the reaction.

2.3. Characterizations

GPC: Gel permeation chromatography measurements were conducted on an SSI 1510 HPLC (Scientific Systems, Inc. Burbank, California, USA) equipped with a shodex RI-201H differential refractometer and two series PL1117-6830 and PL1117-6800 300 × 7.5 mm columns (Agilent Technologies Inc., Santa Clara, California, USA). The system was equilibrated at 50 °C in DMF with 1.6 mg/mL LiBr, which served as the polymer solvent and eluent, with a flow rate of 1.0 mL/min. Polymer solutions were prepared at a known concentration (ca. 5 mg/mL), and an injection volume of 20 µL was used. The system was calibrated using polymethyl methacrylate (PMMA) as a standard.

¹H NMR: ¹H NMR spectra were recorded on a Bruker AVIII400 HD (Bruker Corporation, Billerica, Massachusetts, USA) 400 MHz spectrometer with solvent proton resonance as the reference. The spectra were obtained at room temperature with 32 scans. All the synthetic polymers in this work were dissolved in CDCl₃.

DLS: The size measurements were performed using a Malvern ZEN3690 (Malvern Panalytical, Almelo, Netherlands). The size range of particles measured was 0.3–5000 nm, and the electrical conductivity range was 0–200 mS/cm. Samples were dissolved and diluted in good solvent, and measurements were taken at an angle of 90 degrees. Data were analyzed using Zetasizer (8. 01. 4906) software for size distribution.

TGA: Thermogravimetric analysis was performed on SMNCs using a DTG-60H (Shimadzu Corporation, Kyoto, Japan) instrument to determine the silica-to-polymer ratio. Samples were heated from room temperature to 800 °C at a heating rate of 10 °C/min under a nitrogen atmosphere.

SEM: The morphologies of SMNCs were imaged using a JSM 7610F Scanning Electron Microscope (JEOL Ltd., Tokyo, Japan). Samples for SEM were prepared by casting 1.0 µL of solution onto silicon wafers and immediately evaporating solvents (THF) under strong dry air blowing within ~1 s, with casting repeated twice.

TEM: The morphologies of SMNCs were imaged using a JEM-F200 Transmission Electron Microscope (JEOL Ltd., Tokyo, Japan). TEM samples were prepared by casting 5~10 µL of NP solution on 300-mesh copper grids covered with carbon film and then dried at room temperature.

3. Results and Discussion

3.1. Synthesis of Bottlebursh Polymer

First, we synthesized a linear-block-brush bottlebrush polymer, PCNB-b-P (NB-PSt), via sequential ring-opening metathesis polymerization (ROMP) initiated with Grubbs catalyst G3. The synthesis employed the monomer tert-butyl 5-norbornene-2-carboxylate (a mixture of endo-/exo-isomers with a molar ratio of 8:2, tBNB) and the macromonomer norbornene-terminated polystyrene (NB-PSt) [44,45], followed by hydrolysis with trifluoroacetic acid (TFA) in dichloromethane (DCM) (Figure 1 and Figure S1). This hydrolysis step cleaves the tert-butyl groups from the linear PtBNB block, liberating carboxyl groups and forming the PCNB block, which serves as a distinctive sidechain for the final bottlebrush polymer PCNB_a-b-P (NB-PSt_n)_b. Here, a and b denote the degree of polymerization (DP) of the PCNB and P (NB-PSt) brush blocks, respectively, while n represents the DP of the macromonomer NB-PSt. The macromonomer NB-PSt was synthesized via atom transfer radical polymerization (ATRP) using norbornene-functional bromide (NB-Br) as the ATRP initiator; details of the synthesis and characterization are provided in Figures S1–S3. The structural parameters of NB-PSt, including a polymerization degree (n) ranging from 25 to 80 and a molecular weight polydispersity (Ð) of less than 1.25 (Table S1), attest to the good quality of the prepared macromonomers.

The relative length ratio of the linear PCNB block to the neighboring densely grafted PSt sidechains, a/n, is a crucial parameter in our strategy as a heterogeneous sidechain. Generally, the sidechains at the two ends of the wormlike bottlebrush polymer have a relatively larger void space compared to those at the side positions [46]. This “end effect”-induced regioselectivity significantly enhances the performance of a single PCNB chain located at the end of the bottlebrush polymer when it acts as a nucleating agent for silica deposition. Furthermore, as a special single sidechain, if a is much smaller than n, the screening effect of the relatively longer neighboring densely grafted PSt sidechains on the buried single PCNB chain will significantly retard further silica deposition. Conversely, if a is far larger than n, the long and flexible PCNB chain may coil around the brush part due to conformational changes, causing the diffusion of nucleating sites for silica deposition. Therefore, we set a/n > 1 and close degrees of polymerization (DP) for both the PCNB and PSt sidechains. Notably, a/n > 1 should be the boundary condition for using such a single PCNB heterogeneous sidechain as a nucleating agent for silica deposition.

The structural parameters of the linear-block-brush polymers were confirmed by a combination of ¹H NMR and gel permeation chromatography (GPC) techniques. The first PtBNB block was synthesized via ring-opening metathesis polymerization (ROMP) with nearly 100% monomer conversion of tBNB, as evidenced by the complete disappearance of peaks 1 and 2 in Figure 2a and the appearance of signals 1′ and 2′ in Figure 2b. Notably, to reduce costs, we employed an endo- and exo-mixture of tBNB, which resulted in the splitting of signals from protons 1 and 2, as highlighted by the red box in Figure 2a. After the second ROMP with NB-PSt, the signal ranging from 5.1 to 5.8 ppm diverged into two peaks, which could be attributed to the overlap of protons 4′ and 5′ on the backbone of the P (NB-PSt) block and protons 1′′ and 2′′ (Figure 2d). Following hydrolysis with TFA, the insoluble PCNB chain generated in CDCl₃ led to a significant decrease in the signals from protons 1′′′ and 2′′′ (Figure 2e), as well as the disappearance of the sharp peak 3′′+7′ (Figure 2d). Such distinct changes in the signals from protons 1′′ and 2′′ in the PtBNB block (Figure 2d) also confirmed the end effect of the BBPs. The changes in molecular weight during the sequential ROMP and hydrolysis processes were correspondingly verified by GPC (Figure S4). The structural parameters of BBPs are listed in Table S2.

3.2. Synthesis of SNP-b-P (NB-PSt) SMNCs

Subsequently, we carried out the regioselective deposition of silica under mild conditions. The PCNB₈₇-b-P (NB-PSt₈₀)₁₉ BBPs were dissolved in tetrahydrofuran (THF), a good solvent for the PSt component, to prepare a 1 mg/mL solution. Aqueous ammonia (25%) was then slowly added to the BBP solution until the volume content reached 4 vol%. At this point, the volume content of water was approximately 3 vol%. It is important to note that both water and methanol, the byproduct of silane hydrolysis, are poor solvents for PSt sidechains. A high volume content of poor solvents (water and methanol) can induce phase separation and even severe aggregation of the BBPs. The critical volume fraction of water for the collapse of PSt chains in a THF/water mixed solvent is typically 5–8 vol% [47]. However, only the monodisperse state of BBPs facilitates high-quality silica deposition. Therefore, in contrast to the conventional Stöber method, we had to deposit silica NPs under relatively mild conditions. Tetramethyl orthosilicate (TMOS), which exhibits a higher reactivity than ethyl orthosilicate, was selected as the model precursor for this condition. Upon the addition of NH₃·H₂O, the ionization of carboxyl groups from PCNB led to chain collapse due to reduced solubility in THF. The a/n > 1 boundary condition ensured that ionized PCNB chains partially protruded from the crowdy sidechains, forming nucleating sites. These nucleating agents attracted silica oligomers generated during the hydrolysis and polycondensation of TMOS and promoted their further condensation into silica nanoparticles. Each reaction was conducted for 24 h at 40 °C to ensure the complete consumption of TMOS.

The feeding molar ratio of TMOS to the carboxyl groups from BBPs, defined as n_TMOS:n_-COOH, determines the final size of silica lobes. Figure 3 clearly shows the structure of SMNCs synthesized using PCNB₈₇-b-P (NB-PSt₈₀)₁₉ BBPs at a molar ratio of n_TMOS:n_-COOH = 10:1. The size of the SMNCs was ~14.0 ± 3.0 nm (Figure 3c, orange column), with a silica NP lobe of ~5 nm, as shown in the magnified SEM (Figure 3a inset) and TEM images (Figure 3b). The BBP backbones of SMNCs exhibit various topologies—for example, the globular (#1) and rod-like (#2) structures in Figure 3a’s inset. It is likely that the flexible conformation of BBP tails leads to uneven spherical shapes during the drying process for SEM/TEM sample preparation. TGA was performed on the synthesized SMNCs to determine the mass ratio between the silica lobes and the polymer tails. As shown in Figure S5, the bottlebrush polymer exhibited weight loss initiating at 350 °C, with complete decomposition achieved by 450 °C. In contrast, the SMNCs retained 22.2% of their mass at 800 °C, yielding a silica-to-polymer mass ratio of 1:2.69, which is close to the theoretical value (1:2.33). Combined with TEM verification of the single-lobe morphology of the SMNCs, these results confirm the one-to-one correspondence between the silica nanoparticles and the bottlebrush polymer tails.

3.3. Self-Assembly of SMNCs in Selective Solvent

Finally, we induced the self-assembly of these SMNCs in a selective solvent, namely methanol. Methanol is a good solvent for silica lobes due to the inherent hydroxyl groups on the NP surface but a poor solvent for PSt brushes. We added methanol to the THF solution of SNP-5 nm-b-P (NB-PSt₈₀)₁₉ SMNCs to trigger self-assembly, followed by evaporation of THF to enhance solvent selectivity for SMNCs. This process yielded SMNC micelles with an average size of ~213.7 ± 37.8 nm (Figure 4a), significantly larger than the individual SMNCs. The micelles resembled spherical strawberries with a solid core (non-hollow structure) (Figure 4c). Calculated from the volume ratio of dried micelles (d = ~213.7 nm) to SMNCs (d = ~14.0 nm), the average aggregation number per micelle was approximately 14900, indicating a typical compound micelle structure. Additionally, a schematic was drawn to illustrate the orientation of SMNCs on the micelle surface (Figure 4d): SMNCs were packed together randomly to form compound micelles, with silica lobes preferentially oriented outward and BBP tails inward. This compound micelle structure confirms the amphiphilic properties of our SMNCs.

4. Conclusions

In summary, we report a total synthesis strategy for surfactant-mimetic nanocolloids (SMNCs) via regioselective silica deposition on engineered linear-block-brush bottlebrush polymers (PCNB-b-P (NB-PSt)). The resulting SMNCs feature a well-defined silica nanoparticle head (~5 nm) and a programmable bottlebrush polymer tail, as confirmed by SEM and TEM. Furthermore, these SMNCs exhibit typical amphiphilic characteristics and self-assemble into compound micelles (~214 nm) in methanol. This synthesis strategy is versatile, enabling the fabrication of other molecular-mimetic nanocolloids (MMNCs) (e.g., dumbbell-shaped structures using linear-block-brush-block-linear bottlebrush polymers), and adaptable to MMNCs with different nanoparticle lobes, such as metal oxides (e.g., Fe₃O₄) [48]. The structural precision of SMNCs holds potential for applications including emulsion stabilization, targeted drug delivery, and hierarchical assembly structures. For instance, amphiphilic SMNCs can serve as efficient Pickering stabilizers, outperforming molecular surfactants under harsh conditions (e.g., extreme pH) [49]. The ultrasmall silica lobes enable drug loading [50], while the brush tails provide enhanced functionality and reactive sites. Asymmetric single-molecule nanocolloids can potentially direct the assembly of superlattices through oriented interactions between the silica lobes and polymer tails [51]. Our strategy paves the way for a new class of MMNCs and MMNC-based materials.