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Written by Xiuyang Xia and Ran Ni Last updated: 13rdMay2022 These are the resources of the parts of theoretical calculation for the following paper: Mismatched ligand density enables ordered assembly of mixed-dimensional, cross-species materials Abstract: The ordered coassembly of mixed-dimensional species-such as zero-dimensional (0D) nanocrystals and 2D microscale nanosheets-is commonly deemed impracticable, as phase separation almost invariably occurs. Here, by manipulating the ligand grafting density, we achieve ordered coassembly of 0D nanocrystals and 2D nanosheets under standard solvent evaporation conditions, resulting in macroscopic, freestanding hybrid-dimensional superlattices with both out-of-plane and in-plane order. The key to suppressing the notorious phase separation lies in hydrophobizing nanosheets with molecular ligands identical to those of nanocrystals, but having substantially lower grafting density. The mismatched ligand density endows the two mixed-dimensional components with a molecular recognition-like capability, driving the spontaneous organization of denselycapped nanocrystals at the interlayers of sparsely-grafted nanosheets. Theoretical calculations reveal that the intercalation of nanocrystals can substantially reduce the short-range repulsions of ligand-grafted nanosheets and is therefore energetically favorable, while subsequent ligand-ligand van der Waals attractions induce the in-plane order and kinetically stabilize the laminate superlattice structure. Instructions Dependencies Python 3.7.3 (Anaconda3 recommended) numpy 1.16.5 matplotlib 3.1.1 Citation

Summary Herein, free-standing supertubes, composed of a single layer of close-packed carbon-coated nanoparticles, are fabricated by a confined-epitaxial-assembly strategy. Benefiting from the tubular geometry, monolayer superlattice structure, and uniform and conformal carbon coating, such free-standing supertubes promise high electrochemical performance while simultaneously serving as a robust platform for reliably elucidating the structure-performance relationship of lithium-ion batteries (LIBs). As a model, Fe3O4 supertubes, when used as LIB anodes, can deliver a capacity of ∼800 mAh g−1 after 500 cycles at 5 A g−1, outperforming most Fe3O4-based materials reported previously. More importantly, the structural evolution of Fe3O4 supertubes is revealed at meso-/nano-/atomic scales simultaneously upon lithiation and delithiation, which correlates well with the battery's capacity reactivation, stabilization, and degradation behaviors during the course of 500 cycles.

SiO is regarded as one of the most promising anode materials for next-generation lithium-ion batteries due to its high energy density and low cost. However, practical applications of SiO are seriously limited by its low initial Coulombic efficiency. Herein, we report an affordable manufacturing method to synthesize carbon-coated C SiO MgSiO3 Si composites with a secondary superparticle structure and an outstanding initial Coulombic efficiency. The in situ evolution of the MgSiO3 phase through the reaction between MgO and SiO2 contributes to the improved initial Coulombic efficiency. The formation of MgSiO3 consumes the deleterious SiO2 phase within SiO, and MgSiO3 acts as an electrochemically inactive phase that can effectively buffer volume variations of active materials. These attributes and the unique mesoporous superparticle structure lead to a markedly improved electrochemical performance. The resultant C SiO MgSiO3 Si anode exhibits an initial Coulombic efficiency of 78.3%, which, to our knowledge, is the highest value ever reported for SiO-based anodes without prelithiation. This work offers a new strategy for addressing the intrinsic low initial Coulombic efficiency of SiO, paving the way toward the mass production of SiO-based anodes for real applications.

The heat dissipation of power amplifier (PA) chips is one of the biggest challenges in the development of miniaturized state of art glass-based high-power RF modules. Glass has excellent electrical properties, but the extremely poor thermal conductivity of it also brings many barriers in the application. Its (quartz glass) thermal conductivity is only 1/93 of that of silicon, so there will be a problem of poor heat dissipation. In recent years, there has been an increasing amount of literature on microfluidic cooling technology and this method was demonstrate as an efficient way in cooling application. In this article, we designed, fabricated, and tested a Si-Glass microchannel heat sink, which took advantage of the high thermal conductivity of silicon to deal with the insufficient thermal conductivity of the glass interposer. Finite element simulation was used to study the thermal property of the Si-Glass heat sink and a multi-parameter optimal method was used to design the geometrical parameters, including the number of flow channels and other geometrical parameters of the heat sink. Then the aforementioned microchannel heat sinks were fabricated using cleanroom fabrication on 4-inch silicon and glass wafers. To complete the thermal test, the Thermal Demonstration Vehicles (TDVs) were fabricated by bonding the sample onto a customized PDMS holder for fluid connections with the flow loop. A programmable power source was used to heat the TDV in a stepwise manner, and a syringe pump was used to supply the liquid to cool the heat sink. Results show that the heat sink can dissipate heat flux greater than 150W/cm2with substrate temperature lower than 100°C.

Layered mesostructured graphene, which combines the intrinsic advantages of planar graphene and mesoporous materials, has become interestingly important for energy storage and conversion applications. Here, an interlayer-confined molecular assembly method is presented for constructing all-graphitic multilaminate membranes (MMG⊂rGO), which are composed of monolayer mesoporous graphene (MMG) sandwiched between reduced graphene oxide (rGO) sheets. Hybrid assembly of iron-oleate complexes and organically modified GO sheets enables the preferential assembly of iron-oleate precursors at the interlayer space of densely stacked GO, driven by the like-pair molecular van der Waals interactions. Confined pyrolysis of iron-oleate complexes at GO interlayers leads to close-packed, carbon-coated Fe3 O4 nanocrystal arrays, which serve as intermediates to template the subsequent formation of MMG⊂rGO membranes. To demonstrate their application potentials, MMG⊂rGO membranes are exploited as dual-functional interlayers to boost the performance of Li-S batteries by concurrently suppressing the shuttle of polysulfides and the growth of Li dendrites. This work showcases the capability of molecular-based hybrid assembly for synthesizing multilayer mesostructured graphene with high packing density and its use in electrochemical energy applications.

In this paper, we design and fabricate a radio frequency (RF) signal transmission structure for a 3D stacked structure. Usually, this structure uses co-planar waveguide (CPW) and Through Silicon Via (TSV) to realize the horizontal and vertical RF signal transmission on the same interposer respectively. With the help of micro-bump, we can transport RF signal in a stacked structure. Furtherly, we design and fabricate a patch antenna with a stacked structure, fed by the structure we proposed. Through the measurement of the antenna, we determine the effectiveness of this transmission structure.

In recent years, radio frequency (RF) systems have been moving towards miniaturization. Traditional wire-bonding technology used in RF systems have significant disadvantages in terms of parametric inductance and package size scaling-down. Therefore, people pay more attention to the high-performance and small-size interconnection schemes of RF systems. In this regard, we designed a series of micro bumps arrays for RF application, including arrays with diameters of 15 μm / 30 μm / 40 μm and a pitch of 30 μm / 60 μm / 80 μm. To study RF property of micro bumps array, Cu / Sn micro bumps arrays jointed double-layer coplanar waveguide (CPW) structures were prepared and tested. By subtracting the insertion loss of CPW line from the test structure's insertion loss, the insertion loss of the micro bumps array can be obtained. Comparing the insertion loss of micro bumps arrays with different diameters, the insertion loss of the micro-bumps array with a diameter of 15 μm is the smallest, and the micro bumps with multiple rows have lower insertion loss than a single micro bump. Among them, the insertion loss of a 3 × 6 micro bumps array with a diameter of 15 μm after bonding is 0.15 dB@40GHz.

In this study, we present a Q-band patch antenna with an underling cavity integrated on the stacked high-resistivity Si interposers. A process is developed and sample is fabricated. Evaluation is done and the measurement results shows that it has an operating frequency of 32.75GHz, a –10dB bandwidth of 1.04GHz, a maximum gain of 3dB. Those results prove the feasibility of integrating high-frequency antennas with TSV interposer preliminary.

Mesoporous FeS2@C superparticles chemically converted from Fe3O4 nanoparticle superlattices were used as anode materials for sodium-ion batteries with superior electrochemical performance. The partial etching of Fe3O4 nanoparticles creates appropriate void space, which is beneficial for confining the growth of ultrasmall FeS2 nanoparticles during sulfidation and for mitigating volume change of active materials during cycling.

Lithium sulfur (Li-S) batteries are regarded as promising candidates for next-generation rechargeable batteries. However, the insulation characteristic of sulfur and severe polysulfide dissolution hindered their development. We presented a facile approach to fabricate Li-S batteries by coating commercial carbon nanotube or graphene slurries on normal sulfur cathode electrode to construct a dual-layer cathode electrode. The conductive CNT or graphene layer could not only improve the conductivity of sulfur cathode, but also suppress the polysulfide diffusion. The CNT@S cathode delivered a high reversible capacity of 740 mAh/g over 300 cycles at 1 C and 870 mAh/g over 100 cycles at 0.2 C. Furthermore, this strategy could be realized on the commercial product line of lithium-ion batteries, which made it possible to large-scale produce Li-S batteries.

The self-assembly of colloidal nanoparticles (NPs) mediated by block copolymers (BCPs) is an efficient way for fabricating nanocomposite superstructures with precise geometric control. Here we report a generalized liquid-air interfacial strategy by exploiting the versatility in tuning the specific affinities between the grafted polymeric ligands and BCPs, enabling the circular assembly of NPs on a liquid surface to afford unique ring-like superstructures. Fe3O4 NPs act as the model system; however, CoFe2O4 and Au NPs are also demonstrated using the proposed assembly method. Functionalizing NPs with a specific polymeric ligand is the key to achieve the circular assembly of NPs, while both the subphase and the solvent annealing temperature have profound influence on the microphase separation behaviors of BCPs and therefore the morphology of the resulting NP assemblies. Moreover, the co-assembly of two types of NPs grafted with distinct polymeric ligands enables unprecendented heterogeneous concentric rings, with each ring consisting of one type of NP.

Mesoporous carbons have been widely utilized as the sulfur host for lithium-sulfur (Li-S) batteries. The ability to engineer the porosity, wall thickness, and graphitization degree of the carbon host is essential for addressing issues that hamper commercialization of Li-S batteries, such as fast capacity decay and poor high-rate performance. In this work, highly ordered, ultrathin mesoporous graphitic-carbon frameworks (MGFs) having unique cage-like mesoporosity, derived from self-assembled Fe3O4 nanoparticle superlattices, are demonstrated to be an excellent host for encapsulating sulfur. The resulting S@MGFs exhibit high specific capacity (1,446 mAh·g–1 at 0.15 C), good rate capability (430 mAh·g–1 at 6 C), and exceptional cycling stability (~0.049% capacity decay per cycle at 1 C) when used as Li-S cathodes. The superior electrochemical performance of the S@MGFs is attributed to the many unique and advantageous structural features of MGFs. In addition to the interconnected, ultrathin graphitic-carbon framework that ensures rapid electron and lithium-ion transport, the microporous openings between adjacent mesopores efficiently suppress the diffusion of polysulfides, leading to improved capacity retention even at high current densities. Open image in new window

Mesoporous FeS2@C superparticles chemically converted from Fe3O4 nanoparticle superlattices were used as anode materials for sodium-ion batteries with superior electrochemical performance. The partial etching of Fe3O4 nanoparticles creates appropriate void space, which is beneficial for confining the growth of ultrasmall FeS2 nanoparticles during sulfidation and for mitigating volume change of active materials during cycling.

Additional file 1. Additional figures and tables.

Self-assembled binary nanocrystal superlattices (BNSLs) represent an important class of solid-state materials with potentially designed properties. In pursuit of widening the range of applications for binary superlattice materials, it is desirable to develop scalable assembly methods that enable high-quality BNSLs with tailored compositions, structures, and morphologies. Here, we report the gram-scale assembly of crystalline binary nanocrystal superparticles with high phase purity through an emulsion-based process. The structure of the resulting BNSL colloids can be tuned in a wide range (AB13, AlB2, MgZn2, NaCl, and CaCu5) by varying the size and/or number ratios of the two nanocrystal components. Access to large-scale, phase-pure BNSL colloids offers vast opportunities for investigating their physiochemical properties, as exemplified by AB13-type CoFe2O4-Fe3O4 binary superparticles. Our results show that CoFe2O4-Fe3O4 binary superparticles not only display enhanced magnetic coupling but also exhibit superior lithium-storage properties. The nonclosed-packed NC packing arrangements of AB13-type binary superparticles are found to play a key role in facilitating lithiation/delithiation kinetics and maintaining structural integrity during repeated cycling. Our work establishes the scalable assembly of high-quality BNSL colloids, which is beneficial for accelerating the exploration of multicomponent nanocrystal superlattices toward various applications.

Covalently linked amphiphilic polymer-paclitaxel (PTX) could self-assemble into micelles to overcome many drawbacks of existing delivery systems of PTX by virtue of tunable compositions, variable sizes, high drug loading content and zero burst release. Moreover, a reduction-responsive system based on glutathione (GSH) can be established by introducing disulfide bonds into the polymeric carriers to improve the selectivity for cancer cells. Herein, we reported a disulfide bond linked polymer-PTX, P(PEGMEA)-co-P(PDPHEMA)-g-PTX with a high PTX loading content of 43.7 wt.%. In vitro cell assay showed that the polymer carrier has almost no cytotoxicity. The half maximal inhibitory concentration (IC50) values of the polymer-PTX conjugate against HEK-293 cells was about 10 times higher than that of HeLa cells after incubation for 72 h. Such a dramatic selectivity for cancer and normal cells provides a promising strategy to improve the therapeutic efficacy and decrease the side effects of PTX in chemotherapy.

Iron-nitrogen-carbon (Fe-N-C) materials featuring Fe-N4 moieties are promising candidates to replace commercial Pt/C catalysts for the oxygen reduction reaction (ORR). Here we report a novel Mn-Fe-N/S@mC catalyst comprising atomically dispersed Fe-N4 sites and a trace amount of Mn-N2S2 sites, which are homogeneously anchored on an ordered mesoporous graphitic carbon framework. This dual-metal catalyst is realized based on the chemical conversion of self-assembled Mn0.43Fe2.57O4 nanocrystal supracrystals, with the dual metal sites and the graphitic framework derived from nanocrystal cores and the associated capping ligands, respectively. When evaluated as electrocatalysts for the ORR, Mn-Fe-N/S@mC exhibits excellent catalytic activity in alkaline media, outperforming conventional Pt/C and most non-precious-metal catalysts reported previously. Notably, the synergistic effect of having Fe and Mn together improves the catalytic activity by a factor of ~ 5. To better understand the high efficiency of Mn doping in enhancing the activity of Fe-N4 sites, density functional theory calculations were carried out, revealing that the synergistic interaction between the dual metal sites reduces the *OH reduction energy barrier during the oxygen reduction pathway.

In digital holography, the reconstructed resolution is generally limited by the size of the numerical aperture. For a lens-free imaging configuration, the high-frequency information is lost due to the finite size of the recorded area. It is challenging to obtain an enhanced-resolution recovery with the finite-recorded hologram. Here, we propose an algorithm to enhance the reconstructed resolution by utilizing sparse prior of the image. We combine the sparse regularization term with the extrapolation of the recorded area based on the inverse problem approach. For regularization, the l0-norm is utilized to promote the sparsity of the solution during the iterative process. An iterative optimization algorithm is developed to solve the nonconvex resolution enhancement problem, which is implemented by substituting the primal–dual saddle-point problem for the primal problem. Our method can circumvent the limitation of the recorded area and produce enhanced-resolution recovery by employing the sparsity of the object distribution. Both the simulation and experiment indicate that the proposed algorithm can achieve the superior enhancement for reconstructed resolution with a single captured hologram in a digital in-line holography.