Self-assembly Of Molecules Research Articles

Enhancing Virus Filter Performance Through Pretreatment by Membrane Adsorbers

Virus filtration is used to ensure the high level of virus clearance required in the manufacture of biopharmaceutical products such as monoclonal antibodies. Flux decline during virus filtration can occur due to the formation of reversible aggregates consisting of self-assembled monomeric monoclonal antibody molecules, particularly at high antibody concentrations. While size exclusion chromatography is generally unable to detect these reversible aggregates, dynamic light scattering may be used to determine their presence. Flux decline during virus filtration may be minimized by pretreating the feed using a membrane adsorber in order to disrupt the reversible aggregates that are present. The formation of reversible aggregates is highly dependent on the monoclonal antibody and the feed conditions. For the pH values investigated here, pretreatment of the feed using a hydrophobic interaction membrane adsorber was the most effective in minimizing flux decline during virus filtration. Ion exchange membranes may also be effective if the monoclonal antibody and membrane are oppositely charged. Consequently, the effectiveness of ion exchange membrane adsorbers is much more dependent on solution pH when compared to hydrophobic interaction membrane adsorbers. Size based prefiltration was found to be ineffective at disrupting these reversible aggregates. These results can help guide the development of more effective virus filtration processes for monoclonal antibody production.

Improved Device Performance and Stability of Less Toxic Solvent-Processed Perovskite Solar Cells with Self-Assembled Molecules

Improved Device Performance and Stability of Less Toxic Solvent-Processed Perovskite Solar Cells with Self-Assembled Molecules

An Energy Level Alignment Study of 2PACz Molecule on Perovskite Device‐Related Interfaces by Vacuum Deposition

Self‐assembling molecules (SAM) have been widely used in inverted perovskite solar cells (PSC) as a hole transfer layer due to nearly lossless charge transfer giving excellent device performance. However, the energy level alignment between SAM‐ and PSC‐related interfaces has not been systematically studied. Herein, the 2PACz, a typical SAM with the largest dipole moment, is chosen as the model system and is studied by vacuum deposition. It is found that the energy level alignment is determined by the orientation of 2PACz molecules on a different substrate. The molecules are lying down on highly oriented pyrolytic graphite and giving nearly zero interface dipole. On solvent‐cleaned and plasma‐treated indium tin oxide (ITO) substrates, the SAM is vertically assembled with 0.22 and 0.13 eV work function increases, respectively. However, on sputtered ITO, SAM is assembled with upside down orientation, with 0.51 eV work function decrease. The change of orientation is due to strong interaction between oxygen vacancies in ITO substrate and carbazole head group of 2PACz. On perovskite film, SAM also shows a slightly upward orientation with additional passivation of free MA+ ions. Herein, it is confirmed that the energy level alignment of SAM plays an important role in hole extraction.

Predicting the Mechanical Properties of Supramolecular Gels.

The prediction of gelation is an important target, yet current models do not predict any post-gel properties. Gels can be formed through the self-assembly of many molecules, but close analogs often do not form gels. There has been success using a number of computational approaches to understand and predict gelation from molecular structures. However, these approaches focus on whether or not a gel will form, not on the properties of the resulting gels. Critically, it is the properties of the gels that are important for a specific application, not simply whether a gel will be formed. Supramolecular gels are often kinetically trapped, meaning that predicting gel properties is inherently a difficult challenge. Here, the first successful a priori prediction of gel properties for such self-assembled, supramolecular systems is reported.

Living Cell-Mediated Self-Assembly: From Monomer Design and Morphology Regulation to Biomedical Applications.

The self-assembly of molecules into highly ordered architectures is a ubiquitous and natural process, wherein molecules spontaneously organize into large structures to perform diverse functions. Drawing inspiration from the formation of natural nanostructures, cell-mediated self-assembly has been developed to create functional assemblies both inside and outside living cells. These techniques have been employed to regulate the cellular world by leveraging the dynamic intracellular and extracellular microenvironment. This review highlights the recent advances and future trends in living cell-mediated self-assembly, ranging from their cytocompatible monomer designs, synthetic strategies, and morphological control to functional applications. The assembly behaviors are also discussed based on the dimensionality of the self-assembled morphologies from zero to three dimensions. Finally, this review explores its promising potential for biomedical applications, clarifying the relationship between initial morphological regulation and the therapeutic effects of subsequent artificial assemblies. Through rationally designing molecular structures and precisely controlling assembly morphologies, living cell mediated self-assembly would provide an innovative platform for executing biological functions.

Research progress on self-assembly of polyphilic liquid crystal molecules

Research progress on self-assembly of polyphilic liquid crystal molecules

Mechanism and strategy of self-assembly of quaternary ammonium surfactant molecules to regulate pesticide droplet impact and wetting of hydrophobic surfaces.

Surfactants regulate the interaction between pesticide droplets and the surfaces of plants on which they are sprayed. The influence of the key structural functional groups of surfactants on the interaction between pesticide droplets and hydrophobic pear leaves has not been explored. The behavior of Imidacloprid (Imid) droplets regulated by cationic quaternary ammonium surfactants with different structures on hydrophobic pear leaves and their bouncing dynamics were studied. The properties of pesticide droplets regulated by rosin-based bicationic quaternary ammonium salt and ethylene (dodecyl polyoxyethylene/tetradecyl polyoxyethylene) chloride/ammonium bromide were well matched with those of pear leaves with a waxy layer. This structure was closely related to the double-chain structure corresponding to that of double N-head groups in quaternary ammonium surfactants. Quaternary ammonium surfactants regulate the wetting of droplets by forming semi-micellar structures near the three-phase contact line, which drives the droplets to wet and spread on the leaf. The quaternary ammonium surfactant containing the double N-head structure enabled strong wetting and adhesion of pesticide droplets on the hydrophobic surface. The key structural functional groups of different quaternary ammonium surfactants directionally modified the impact kinetics of Imid droplets on the leaf surfaces and their changing trend. The double N-head structure played a key role in the molecular structure of quaternary ammonium surfactants, and the hyperbranched ethylene oxide (EO)chain played a small role in the molecular structure. These results clearly indicate how the structure of key functional groups of quaternary ammonium surfactants regulated the interface adhesion of pesticide droplets on the leaf surfaces and explain the microscopic mechanism of their interaction. © 2024 Society of Chemical Industry.

Highly Oriented and Ordered Co-Assembly Monolayers for Inverted Perovskite Solar Cells.

Perovskite solar cells with inverted architecture have remarkable power conversion efficiency (PCE) and operating stability based on self-assembled molecules (SAMs) hole transport layer. Homogeneous distribution and covalent binding mode of SAM monolayers are critical to improving interfacial property and reducing interfacial losses, which can be achieved through molecular design and co-assembly strategy. Here, we propose co-assembly strategy with SAM by employing a novel 2D π-conjugated structure graphdiyne derivative (PAG) with phosphoric acid groups. Through the π-π interaction and hydrogen bonding between PAG and SAM, the enhanced tridentate anchoring and highly ordered molecular orientation perpendicular to the substrate are successfully achieved. The improvement of interfacial characteristics further optimizes the crystalline quality and buried interface properties of perovskite films, allowing us to achieve a remarkable PCE of 26.10 % under standard illumination.

Amino Acid Conjugated Self Assembled Molecules Modified Titanium Surfaces For Investigating Osteoblast Behavior

In this study, human fetal osteoblasts behavior was investigated on titanium surfaces that has been modified with amino acid conjugated self-assembled molecules. For this purpose, 3-aminopropyltriethoxysilane (APTES) was conjugated by histidine and leucine and these newly synthesized molecules were used in different combinations to modify titanium surfaces via creating amino acid conjugated self-assembled monolayers (SAM) on titanium surfaces. The modification of the surfaces to introduce hydrophilic and hydrophobic regions on the surface was achieved with varying concentrations (v/v,100:0 20:80, 50:50, 80:20, 0:100). X-ray photoelectron spectroscopy (XPS) analysis and water contact angle measurements were performed for characterizing all of the modified surfaces in order to verify presence of amino acid specific bonds and wettability behavior to find suitable concentrations to support initial cell adhesion. In order to confirm that the surface modification supported cell adhesion and proliferation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed. Our results have shown that, amino acid SAM modification can be used to fine tune surface wettability and adherent cells were able to proliferate at different rates using different mixture concentrations. This presented approach can prove useful for expanding fine tuning surface chemistry methods for more specific applications and research.

Multistage Regulation Strategy via Fluorine-Rich Small Molecules for Realizing High-Performance Perovskite Solar Cells.

Perovskite solar cells (PSCs) are an ideal candidate for next-generation photovoltaic applications but face many challenges for their wider application, including uncontrolled fast crystallization, trap-assisted nonradiative recombination, and inefficient charge transport. Herein, a multistage regulation (MSR) strategy for addressing these challenges is proposed via the introduction of fluorine-rich small molecules with multiple active points (i.e., 1-[Bis(trifluoromethanesulfonyl)methyl]- 2,3,4,5,6-pentafluorobenzene (TFSP)) into the precursor solution of the perovskite film. The addition of TFSP effectively delays and regulates the crystallization and growth process of the perovskite film for larger grains and fewer defects, and it effectively improves the coverage of self-assembled molecules for efficient charge transport. The multiple active points of TFSP induce a strong binding affinity with uncoordinated defects in the perovskite film. Moreover, the high fluorine content of TFSP induces strong electronegativity to establish a high binding strength between the perovskite film and electron transport layer. Finally, PSCs prepared by the MSR strategy demonstrated an optimal power conversion efficiency (PCE) of 25.46% and maintained 91.16% of the initial PCE under nonpackaged air conditions and at a relative humidity of 45% after 3000h.

“Life” as a Dynamic Supramolecular System Created Through Constructive Approach

Abstract Life can properly respond to external stimuli. This is because life is constructed by individual components (molecules and macromolecules) and responds to the external environment autonomously as a system, through interactions between components, converting energy, and information. This response contrasts with matter, which responds directly to external fields (heat, electric or magnetic fields, light, etc.). Life self-reproduces by converting ingested essential nutrients for self-reproduction and moves to safe and nourished areas. Life also possesses information molecules and propagates the information to its offspring. In this repeatable process, individuals possessing traits adaptable to their environment become the dominant species through natural selection, leading to evolution. We believe that even such a sophisticated life can be constructed as a dynamic supramolecular system by assembling characteristic molecules and macromolecules. This review shows how giant vesicles, self-assemblies of amphiphilic molecules, self-reproduce as primitive model protocells, expressing life-like features by incorporating new components, and eventually evolve into the ultimate artificial cell model.

Low temperature processing of hole transport layer-free CsPbI2Br solar cells assisted by SAM co-deposition

The development of inverted all-inorganic perovskite solar cells (PSCs) is limited by the high processing temperature and poor film coverage of self-assembled molecule (SAM) hole transport layer (HTL). In this work, the hot-air-assisted annealing method was utilized to prepare CsPbI2Br films at low temperature in an ambient environment. The SAM called 2–(3,6-dimethoxycarbazol-9-yl) ethyl phosphonic acid (MeO-2PACz) is added into the CsPbI2Br precursor to spontaneously form MeO-2PACz dipole layer and perovskite light absorber. The MeO-2PACz with abundant phosphate groups modulated the uncoordinated lead at the perovskite's grain boundaries via forming –P–O–Pb and –P=O–Pb bonds, which improves the crystallinity and reduces trap density of perovskite film. Furthermore, the spontaneously formed MeO-2PACz dipole layer on the ITO substrate during the perovskite film processing enhanced hole transport efficiency and reduced non-radiative recombination loss at the ITO/CsPbI2Br interface. As a result, the p-i-n HTL-free inorganic CsPbI2Br PSCs with MeO-2PACz additive achieved a power conversion efficiency of 12.92%, which is significantly higher than the reference PSCs (6.55%). This work provides an easy and efficient way to prepare efficient HTL-free all-inorganic PSCs at low temperature in an ambient environment with MeO-2PACz SAM additive.

Disulfide-Containing Nitrosoarenes: Synthesis and Insights into Their Self-Polymerization on a Gold Surface.

Disulfide-containing nitrosoarenes with [bis(4-nitrosobenzyl) disulfide, NOBnDS (1)] or without [4-nitrosophenyl disulfide, NOPDS (2), and 1,2-bis(4'-nitroso-[1,1'-biphenyl]-4-yl)disulfane, NOBPDS (3)] an alkyl spacer between the sulfur headgroup and the aromatic moiety (phenyl in NOPDS (2) or biphenyl in NOBPDS (3)) were synthesized and used as precursors to form azodioxy thiolate films on Au(111) substrates. Due to the incorporated disulfide functionalities, these specifically designed nitrosoarenes are enabled to self-polymerize through azodioxy bonds on a gold surface. Thin films of NOBnDS (1), NOPDS (2), and NOBPDS (3) were prepared at different adsorption times via the solution-phase self-assembly of molecules onto the Au(111) surface and characterized by Raman spectroscopy, ellipsometry, water contact angle measurements, atomic force microscopy (AFM), and scanning tunneling microscopy (STM). For comparison, films of structurally analogous disulfide-containing nitro derivatives on Au(111), which can form only monolayer films, thus serving as a reference, were also fabricated and characterized. Raman spectra of NOBnDS (1), NOPDS (2), and NOBPDS (3) films on the Au(111) substrates revealed the presence of a N═N stretching band of the E-azodioxy group. Ellipsometry showed that nitrosoarenes form thicker films compared with their nitro counterparts, indicating the formation of azodioxy oligomer films. AFM revealed an island-like morphology of the nitrosoarene films, in contrast to the rather homogeneous one observed for the monolayer films of nitro derivatives. STM images of nitrosoarene films indicated the formation of poorly organized surface structures in which oligomer chains are possibly interdigitated and substantially tilted relative to the surface normal, which agrees with the relatively low values of the ellipsometry-derived thicknesses. The obtained results emphasized the influence of the substituent electronic effects on the on-surface formation of azodioxides and could be used for the future design of azodioxy thiolate films on gold surfaces.

Nanolabels Prepared by the Entrapment or Self-Assembly of Signaling Molecules for Colorimetric and Fluorescent Immunoassays.

Nanomaterials have attracted significant attention as signal reporters for immunoassays. They can directly generate detectable signals or release a large number of signaling elements for readout. Among various nanolabels, nanomaterials composed of multiple signaling molecules have shown great potential in immunoassays. Generally, signaling molecules can be entrapped in nanocontainers or self-assemble into nanostructures for signal amplification. In this review, we summarize the advances of signaling molecules-entrapped or assembled nanomaterials for colorimetric and fluorescence immunoassays. The nanocontainers cover liposomes, polymers, mesoporous silica, metal-organic frameworks (MOFs), various nanosheets, nanoflowers or nanocages, etc. Signaling molecules mainly refer to visible and/or fluorescent organic dyes. The design and application of immunoassays are emphasized from the perspective of nanocontainers, analytes, and analytical performances. In addition, the future challenges and research trends for the preparation of signaling molecules-entrapped or assembled nanolabels are briefly discussed.

Revealing the Effect of Crystalline Self-Assembled Monolayer in Biomimetic Photosynapse with Ultraviolet Light Protection Capability.

The research on photonic synapses holds immense promise for various applications, such as robotics and artificial intelligence. Pursuing lightweight, miniaturized, and low-energy consumption designs is crucial for enhancing efficiency and adaptability in evolving technological environments. To achieve this goal, this work designs a series of conjugated self-assembled molecules with photoactive pyrene, benzo-naphthol-thiophene (BNT), perylene, and benzothieno-benzothiophene cores to develop ultrathin (<3 nm) charge-trapping self-assembled monolayers (SAMs). The highly crystalline BNT forms an orderly arrangement with the semiconducting channel, further exhibiting distinguished current contrast stability (∼108) and synaptic features, including paired-pulse facilitation (153%), ultralow energy consumption (28.9 aJ), and short/long-term plasticity. The device successfully demonstrates the emulation of human learning behavior and the self-protection mechanism against ultraviolet radiation utilizing crystalline and conjugated SAMs with different charge traps. Additionally, the capability of background denoising is evidenced by the high recognition accuracy (∼90%) for the preprocessed images. This study not only strengthens the diverse functionality of SAMs in optoelectronic devices but also highlights the significant potential of device miniaturization for biomimetic applications, making it a crucial contribution to the field.

A Multi-Functional Molecule for Highly Durable, Bending-Resistant, Low-Voltage Driving PSLC Films toward Smart Windows With Radiative Cooling.

Polymer-stabilized liquid crystals (PSLCs) are widely used in smart windows, light modulators, and dimmed glass. However, their low mechanical strength, unsatisfactory electro-optical properties, and poor durability limit their large-scale application. In this study, a PSLC film with outstanding performance is prepared by incorporating a multifunctional molecule into a fine-sculptured liquid crystal/polymer composite. The multifunctional molecule is designed to form a vertically oriented layer with a silane coupling agent through a two-step self-assembly process and improve the mechanical strength of PSLCs by connecting the polymer networks through covalent bonds. In addition, it endowed the film with good thermal stability through the reversible change from hydrogen bonds at low temperatures to C═N bonds at high temperatures. A PSLC film with ultralow saturation voltage (Vsat <25V), wide operating temperature and viewing angle performance, high mechanical strength (60-100% improvement), and high stability (15000 cycles) is prepared through the self-assembly of the multifunctional molecule followed by photomask-assisted photopolymerization. Finally, a bending-resistant, flexible PSLC film with passive radiative cooling capacity is tested and achieved excellent temperature management. This composite film demonstrated superior performance in every aspect, promoting the application of PSLCs in smart windows for cars and buildings.

Structural and electrical characterization of self-assembled Sb4 molecules on metal surfaces.

Antimonene is a promising two-dimensional material that is calculated to have a significant fundamental bandgap usable for advanced applications such as field-effect transistors, photoelectric devices, and the quantum-spin Hall state. Herein, we conducted a comprehensive investigation of self-assembled Sb4 islands on Au and Ag surfaces by scanning tunneling microscopy. The Sb4 molecules form α-phase and β-phase structures on Au and Ag surfaces, respectively, each exhibiting distinct island patterns. We simulated these structures using density functional theory calculations. Finally, we demonstrated the metallic band structure of Sb4 islands and observed the spatial and energy-dependent contributions of Sb4 molecules to the electronic states. This research enhances the understanding of the synthesis process of antimonene on metal surfaces and provides valuable insights for the industrial production of antimonene.

Impact of Self-Assembled Monolayer Structural Design on Perovskite Phase Regulation, Hole-Selective Contact, and Energy Loss in Inverted Perovskite Solar Cells

Recent studies have shown that self-assembled molecule (SAM)-based hole-selective contacts (HSCs) offer a promising solution to the challenges faced by perovskite solar cells (PVSCs), including minimal material consumption, scalable production, high interface stability, and the use of environmentally friendly solvents. In this study, the efficacy of two designs of SAMs (Cz and PA) as HSCs in inverted PVSCs was investigated by comparing them with the conventional MeO-2PACz (MeO) SAM. Surface analyses showed that the surface of PA is smoother than that of Cz, which helps to reduce interfacial defects. Subsequent perovskite deposition exhibited a reduced formation of the PbI2 phase, incidiating that its phase modulation ability is superior to that of MeO. Further analyses demonstrate the superior charge extraction ability of PA as a result of reduced interfacial defects and non-radiative recombination at the HSC/perovskite interface. By further coupling with phenethylammonium iodide (PEAI) surface passivation, both interfaces of the perovskite film were optimized and the inverted ((FAPbI3)0.85(MAPbBr3)0.15)0.95(CsPbI3)0.05 (bandgap = 1.62eV) PVSC achieves a high power conversion efficiency (PCE) of 23.3% and a very high open-circuit voltage of 1.227V due to the largely reduced energy loss. In addition, the PA PVSC exhibits enhanced long-term thermal stability at 85°C in a nitrogen atmosphere.

Construction of myofibrillar protein-based Pickering emulsion for grass carp (Ctenopharyngodon idellus) based on interfacial self-assembly of spice aldehyde molecules: Mechanism and application of imine reaction-stabilized emulsion.

The purpose of this research is to investigate multiple structural spice aldehydes (cinnamaldehyde (CA), citronellal (CN), and melonal (MA)) interact with myofibrillar protein in grass carp (GCMP) and the effects of interfacial interactions on stability properties of Pickering emulsion. It was demonstrated that the functional characteristics of interfacial protein might be greatly improved by the complexation of spice aldehydes with protein particles at the water-oil interface. The fluorescence quenching and molecular docking results revealed that the binding mode of spice aldehyde is primarily dominated by hydrophobic interactions, yet there are hydrogen bonding interactions exist in special structure. When comparing multiple structure aldehyde, CA has a greater binding affinity than CN and MA, as well as the most binding sites at different temperatures. Among them, the interaction of CA and GCMP is enhanced by forming hydrogen bonds through π-bonds owing to its special aromatic ring structure. The O/W structure was further stabilized by the formation of conjugated and unconjugated imines of interfacial protein with spice aldehydes. This work provides a theoretical basis for the interaction and development of protein particles with spice aldehyde in Pickering emulsion stabilization and novel ideas for the application of low value aquatic protein for high quality.

Judicious inhibition of interfacial non-radiative recombination via chlorine-isomerized self-assembled molecules for efficient and durable organic solar cells

Judicious inhibition of interfacial non-radiative recombination via chlorine-isomerized self-assembled molecules for efficient and durable organic solar cells