Dielectric properties of dithiol self-assemble monolayers （SAMs） under ac electric field were presented, Using a Hg-SAM/SAM-Ⅱg junction, the ac impedances of dithiol SAMs were measured using a sinusoidal perturbati...Dielectric properties of dithiol self-assemble monolayers （SAMs） under ac electric field were presented, Using a Hg-SAM/SAM-Ⅱg junction, the ac impedances of dithiol SAMs were measured using a sinusoidal perturbation of 30 mV （peak to-peak） with the frequency ranging from 1 Hz to 1 MHz at zero bias. The contributions from dithiol SAMs and solvent interlayers were separated due to their different behaviors at ac impedance. The peak position in the loss spectra （the plot; of tgδ vs. frequency） moves to low frequcney with the incrcase of chain length of dithiols. Using a correlation of peak position with the chain length, the active energies of 23-39 meV for dithiol SAMs of C6-C10 under an ac electric field were derived,展开更多
As a powerful and sensitive tool for the characterization of zeolite building units,UV Raman spectroscopy has been used to monitor interzeolite transformation from FAU to CHA and MFI zeolites.The results show that the...As a powerful and sensitive tool for the characterization of zeolite building units,UV Raman spectroscopy has been used to monitor interzeolite transformation from FAU to CHA and MFI zeolites.The results show that the behavior of double 6-membered rings(D6Rs)in the FAU zeolite framework plays an important role during the formation of the target product in the interzeolite transformation.For the transformation of FAU to CHA,because both zeolites contain the same D6R units,direct transformation occurs,in which the D6Rs were largely unchanged.In contrast,for the transformation of FAU to MFI,the D6Rs can be divided into two single 6-membered rings(S6Rs),which further assembled into the MFI structure.In this crystallization,5-membered rings(5Rs)are only observed in the MFI framework formation,suggesting that the basic building units in the transformation of FAU to MFI are S6Rs rather than 5Rs.These insights will be helpful for further understanding of the interzeolite transformation.展开更多
Hierarchical self-assembly is a fundamental principle in nature, which gives rise to astonishing supramolecular architectures that are an inspiration for the development of innovative materials in nanotechnolog）a Her...Hierarchical self-assembly is a fundamental principle in nature, which gives rise to astonishing supramolecular architectures that are an inspiration for the development of innovative materials in nanotechnolog）a Here, we present the unique structure of a cone-shaped amphiphilic designer peptide. While tracking its concentration-dependent morphologies, we observed elongated bilayered single tapes at the beginning of the assembly process, which further developed into novel double-helix-like superstructures at high concentrations. This architecture is characterized by a tight intertwisting of two individual helices, resulting in a periodic pitch size over their total lengths of several hundred nanometers. Solution X-ray scattering data revealed a marked 2-layered internal organization. All these characteristics remained unaltered for the investigated period of almost three months. In their collective morphology, the assemblies are integrated into a network with hydrogel characteristics. Such a peptide-based structure holds promise as a building block for next-generation nanostructured biomaterials.展开更多
Engineering complex nanocomposites that specifically target the hepatitis B virus （HBV） and overcome the limitations of current therapies such as limited efficacy and serious side effects is very challenging. Here, ...Engineering complex nanocomposites that specifically target the hepatitis B virus （HBV） and overcome the limitations of current therapies such as limited efficacy and serious side effects is very challenging. Here, for the first time, the antiviral effect of engineered plasmonic gold and layered double hydroxide self-assemblies （AuNPs/LDHs） is demonstrated, using HBV as a model virus and hepatoma-derived HepG2.2.215 ceils for viral replication, assembly, and secretion of infectious virions and subviral particles. AuNPs/LDHs were obtained by a simple, cost-effective procedure in which small AuNPs （-3.5 nm） were directly obtained and organized on the surface of larger LDH nanoparticles （-150 nm） by exploiting the capability of MgLDH, ZnLDH, and MgFeLDH to manifest their ＂structural memory＂ in the aqueous solution of Au（O2CCH3）3. The self-assembly approach of AuNPs and LDHs was assessed by transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS）, powder X-ray diffraction （PXRD）, and UV-Vis analysis （UV-Vis）. All AuNPs/LDHs tested reduced the amount of viral and subviral particles released from treated cells by up to 80% and exhibited good cytocompatibility. AuNPs/MgFeLDH showed the highest antiviral HBV response with more than 90% inhibition of HBV secretion for the whole concentration range. Preliminary studies on the mechanism of HBV inhibition reveals that in the presence of AuNPs/LDHs, HBV particles are sequestered within the treated cells. The antiviral and low cytotoxic plasmonic properties of these Au/LDH nanocomposites indicate that they hold significant potential to be tailored as novel efficient therapeutics for the treatment of hepatitis B.展开更多
We present measurements of the in situ, microscopic architecture of a self- assembled bilayer at the interface between a regularly nanopatterned surface and an aqueous sub-phase using neutron reflectometry. The substr...We present measurements of the in situ, microscopic architecture of a self- assembled bilayer at the interface between a regularly nanopatterned surface and an aqueous sub-phase using neutron reflectometry. The substrate is patterned with a rectangular array of nanoscale holes. Because of the high quality of the pattern, using neutron reflectometry, we are able to map the surface-normal density distribution of the patterned silicon, the penetration of water into the pattern, and the distribution of a deposited film inside and outside of the etched holes. In this stud; 1,2-dilauroyl-sn-glycero-3-phosphocholine （DLPC） single bilayers were deposited on the hydrophilic patterned surface. For bilayers deposited either by vesicle fusion （VF） or by the Langmuir-Schaefer （L-S） technique, the most consistent model found to fit the data shows that the lipids form bilayer coatings on top of the substrate as well as the bottoms of the holes in an essentially conformal fashion. However, while there is a single bilayer on the unetched silicon surface, the lipids coating the bottoms of the holes form a complex bimodal structure consistent with a rough surface produced by the etching process. This study provides insight into film transfer both outside and inside regular nanopatterned features.展开更多
文摘Dielectric properties of dithiol self-assemble monolayers （SAMs） under ac electric field were presented, Using a Hg-SAM/SAM-Ⅱg junction, the ac impedances of dithiol SAMs were measured using a sinusoidal perturbation of 30 mV （peak to-peak） with the frequency ranging from 1 Hz to 1 MHz at zero bias. The contributions from dithiol SAMs and solvent interlayers were separated due to their different behaviors at ac impedance. The peak position in the loss spectra （the plot; of tgδ vs. frequency） moves to low frequcney with the incrcase of chain length of dithiols. Using a correlation of peak position with the chain length, the active energies of 23-39 meV for dithiol SAMs of C6-C10 under an ac electric field were derived,
基金supported by the National Key R&D Program of China(2017YFB0702800)the National Natural Science Foundation of China(2152780065,91634201 and 21720102001)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB17000000)~~
文摘As a powerful and sensitive tool for the characterization of zeolite building units,UV Raman spectroscopy has been used to monitor interzeolite transformation from FAU to CHA and MFI zeolites.The results show that the behavior of double 6-membered rings(D6Rs)in the FAU zeolite framework plays an important role during the formation of the target product in the interzeolite transformation.For the transformation of FAU to CHA,because both zeolites contain the same D6R units,direct transformation occurs,in which the D6Rs were largely unchanged.In contrast,for the transformation of FAU to MFI,the D6Rs can be divided into two single 6-membered rings(S6Rs),which further assembled into the MFI structure.In this crystallization,5-membered rings(5Rs)are only observed in the MFI framework formation,suggesting that the basic building units in the transformation of FAU to MFI are S6Rs rather than 5Rs.These insights will be helpful for further understanding of the interzeolite transformation.
文摘Hierarchical self-assembly is a fundamental principle in nature, which gives rise to astonishing supramolecular architectures that are an inspiration for the development of innovative materials in nanotechnolog）a Here, we present the unique structure of a cone-shaped amphiphilic designer peptide. While tracking its concentration-dependent morphologies, we observed elongated bilayered single tapes at the beginning of the assembly process, which further developed into novel double-helix-like superstructures at high concentrations. This architecture is characterized by a tight intertwisting of two individual helices, resulting in a periodic pitch size over their total lengths of several hundred nanometers. Solution X-ray scattering data revealed a marked 2-layered internal organization. All these characteristics remained unaltered for the investigated period of almost three months. In their collective morphology, the assemblies are integrated into a network with hydrogel characteristics. Such a peptide-based structure holds promise as a building block for next-generation nanostructured biomaterials.
文摘Engineering complex nanocomposites that specifically target the hepatitis B virus （HBV） and overcome the limitations of current therapies such as limited efficacy and serious side effects is very challenging. Here, for the first time, the antiviral effect of engineered plasmonic gold and layered double hydroxide self-assemblies （AuNPs/LDHs） is demonstrated, using HBV as a model virus and hepatoma-derived HepG2.2.215 ceils for viral replication, assembly, and secretion of infectious virions and subviral particles. AuNPs/LDHs were obtained by a simple, cost-effective procedure in which small AuNPs （-3.5 nm） were directly obtained and organized on the surface of larger LDH nanoparticles （-150 nm） by exploiting the capability of MgLDH, ZnLDH, and MgFeLDH to manifest their ＂structural memory＂ in the aqueous solution of Au（O2CCH3）3. The self-assembly approach of AuNPs and LDHs was assessed by transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS）, powder X-ray diffraction （PXRD）, and UV-Vis analysis （UV-Vis）. All AuNPs/LDHs tested reduced the amount of viral and subviral particles released from treated cells by up to 80% and exhibited good cytocompatibility. AuNPs/MgFeLDH showed the highest antiviral HBV response with more than 90% inhibition of HBV secretion for the whole concentration range. Preliminary studies on the mechanism of HBV inhibition reveals that in the presence of AuNPs/LDHs, HBV particles are sequestered within the treated cells. The antiviral and low cytotoxic plasmonic properties of these Au/LDH nanocomposites indicate that they hold significant potential to be tailored as novel efficient therapeutics for the treatment of hepatitis B.
文摘We present measurements of the in situ, microscopic architecture of a self- assembled bilayer at the interface between a regularly nanopatterned surface and an aqueous sub-phase using neutron reflectometry. The substrate is patterned with a rectangular array of nanoscale holes. Because of the high quality of the pattern, using neutron reflectometry, we are able to map the surface-normal density distribution of the patterned silicon, the penetration of water into the pattern, and the distribution of a deposited film inside and outside of the etched holes. In this stud; 1,2-dilauroyl-sn-glycero-3-phosphocholine （DLPC） single bilayers were deposited on the hydrophilic patterned surface. For bilayers deposited either by vesicle fusion （VF） or by the Langmuir-Schaefer （L-S） technique, the most consistent model found to fit the data shows that the lipids form bilayer coatings on top of the substrate as well as the bottoms of the holes in an essentially conformal fashion. However, while there is a single bilayer on the unetched silicon surface, the lipids coating the bottoms of the holes form a complex bimodal structure consistent with a rough surface produced by the etching process. This study provides insight into film transfer both outside and inside regular nanopatterned features.
