Synthetic design towards targeted chiral anionic surfactant templated chiral mesoporous silica

Jin, Haiying; Qiu, Huibin; Gao, Chuanbo; Che, Shunai

doi:10.1016/j.micromeso.2008.03.035

Cited by 18 publications

(8 citation statements)

References 25 publications

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“…It is consistent with the well-documented facts that the pitch of the internal helical mesostructures decreases when the rod diameter is decreased. [10,[33][34][35] An interesting and apparently more complicated screwlike mesostructure with wavelike edges can also be observed in the one-pot synthesis at PFOA/ C 18 TAB f= 0.05 (Figure 2 d). The screwlike structures can be easily found under TEM observations ( Figure S4 in the Supporting Information).…”

Section: Resultsmentioning

confidence: 80%

“…As discussed before, an internal helical rod with a smaller r value should have tighter internal twisting, [10,[33][34][35] which is not advantageous to form an ordered hexagonal mesostructure. Because the internal helical-to-coiled structure transition can release the internal twisting to maintain a close-packing hexagonal structure, it is expected that an internal helical mesostructured rod with a smaller r value should release more internal twisting (i.e., larger k value) through the formation of the external helix.…”

Section: Discussionmentioning

confidence: 94%

“…When the pitch size of an internal helical structure is decreased, the curvature of the threadlike micelle at a given location increases, which leads to further derivation from a perfect hexagonal symmetry. Relative to S0 and S1, S2 synthesized at a higher f value of PFOA/C 18 TAB has a smaller diameter, and thus its internal helical structure should have an even smaller pitch size, [10,[33][34][35] thus leading to a much tighter internal helical configuration and less-ordered hexagonal mesostructure. By assuming that the hexagonal symmetry is a stable mesostructure at a given synthetic regime in our synthesis, an optimum structure with both minimized derivation from perfect hexagonal packing (considering the mesostructure assembly) and maximized decrease in the surface free energy (considering the helical morphology) should be compromised.…”

Section: Discussionmentioning

confidence: 99%

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Evolution of Helical Mesostructures

Yuan

Zhao

Liu

et al. 2010

Chemistry A European J

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An intriguing evolution from a simple internal helix to a hierarchical helical (HH) mesostructure with both internal and external helices or a complicated screwlike and concentric circular (CC) mesostructure is successfully observed. The complicated helical structures are determined by TEM studies and 3D electron tomography. We demonstrate a topological helix-coil transition between the internal and external helices to reveal the origin of the HH mesostructure and the relationship between the straight helical and HH rods. Moreover, the boundary condition of the helix-coil transition is clarified to explain in detail the formation of complex helical structures, such as the screwlike mesostructure. It is proposed that the final structural characteristics are determined exactly by the balance between the decrease in the surface free energy and the maintenance of the hexagonal packing in one individual rod, which explains the formation of unusual CC, HH, and screwlike morphologies in one pot. Our success has opened new opportunities in the characterization of complex porous architectures, thus paving a way to remarkable advances in the fields of synthesis, understanding, and application of novel porous materials.

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Section: Resultsmentioning

confidence: 80%

Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

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Evolution of Helical Mesostructures

Yuan

Zhao

Liu

et al. 2010

Chemistry A European J

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“…Such significant reduction in the textural properties of MCMSS nanoparticles can be attributed to the disappearance of separate mesoporous silica nanoparticles, which are characterized by superior textural properties. This is reported by Jin et al [34] who had indicated that the generation of separate mesoporous silica demands very rigorous ionization degree (for HCl/C16-L-Ala) of the amphiphilic molecule, which controls the molecular packing to form helical propeller-like micelle. The increase of acid/surfactant molar ratio increased the ionization degree of the anionic amphiphilic molecules and thus increased its electrostatic interaction with the quaternary ammonium group of CSDA.…”

Section: Resultsmentioning

confidence: 78%

“…The increase of acid/surfactant molar ratio increased the ionization degree of the anionic amphiphilic molecules and thus increased its electrostatic interaction with the quaternary ammonium group of CSDA. The strong interaction between the surfactant head group and quaternary ammonium group of CSDA will cause the formation of separate mesoporous silica [34]. …”

Section: Resultsmentioning

confidence: 99%

Optimization of Synthesis Parameters for Mesoporous Shell Formation on Magnetic Nanocores and Their Application as Nanocarriers for Docetaxel Cancer Drug

El‐Toni

Ibrahim

Labis

et al. 2013

IJMS

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In this work, Fe3O4@SiO2 nanoparticles were coated with mesoporous silica shell by S−N+I− pathway by using anionic surfactant (S−) and co-structure directing agent (N+). The role of co-structure directing agent (CSDA) is to assist the electrostatic interaction between negatively charged silica layers and the negatively charged surfactant molecules. Prior to the mesoporous shell formation step, magnetic cores were coated with a dense silica layer to prevent iron oxide cores from leaching into the mother system under any acidic circumstances. However, it was found that both dense and mesoporous coating parameters affect the textural properties of the produced mesoporous silica shell (i.e., surface area, pore volume and shell thickness). The synthesized Fe3O4@SiO2@m-SiO2 (MCMSS) nanoparticles have been characterized by low-angle X-ray diffraction, transmission electron microscopy (TEM), and N2 adsorption-desorption analysis, and magnetic properties. The synthesized particles had dense and mesoporous silica shells of 8–37 nm and 26–50 nm, respectively. Furthermore, MCMSS possessed surface area of ca. 259–621 m2·g−1, and pore volume of ca. 0.216–0.443 cc·g−1. MCMSS showed docetaxcel cancer drug storage capacity of 25–33 w/w% and possessed control release from their mesochannels which suggest them as proper nanocarriers for docetaxcel molecules.

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