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This study investigates the interface between ice and organic solvents using atomic force microscopy (AFM). Atomically flat ice surfaces were prepared and observed by AFM in 1-octanol, 1-hexanol, and 1-butanol. The results show differences in surface roughness influenced by the interaction of ice and alcohols. Young's modulus of ice was analyzed by force curve measurements, providing valuable insights into the properties of ice in liquid environments. The results showed the characteristics of the ice surface in different solvents, suggesting potential applications in understanding surface and interface phenomena associated with ice under realistic conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] The formation of soft colloidal crystals, which are nonclose-packed ordered arrays of colloidal particles suspended in a solvent, is dictated by a single physical factor that yields a fixed threshold at order–disorder boundaries for different experimental conditions such as ion concentration, solvent type, and particle size. Identifying the determinant factor and its threshold value should enable the prediction of the critical concentrations of colloidal particles to form soft colloidal crystals. Soft colloidal crystals were fabricated using a series of monohydric alcohols as dispersion media and reflectance spectra were measured to locate order–disorder boundaries. The interaction forces acting between particles were also measured by employing atomic force microscopy. The interparticle forces at the order–disorder boundaries exhibited a universal threshold that was independent of the solvent types including alcohols and water. Therefore, the determinant factor for the formation of soft colloidal crystals was determined to be the force acting between the particles. Furthermore, a priori calculation of this critical force and consequently the critical particle concentration in colloidal systems was demonstrated by referring to the pressure at the liquid-to-solid transition in a hard sphere system (Alder transition). [ABSTRACT FROM AUTHOR]

The structural transformation of thin amorphous cellulose films in water and organic solvent vapour has been studied using grazing-incidence X-ray diffraction and atomic force microscopy. Amorphous cellulose films transform to cellulose II upon exposure to water vapour, and cellulose IVII in the dimethyl sulfoxide (DMSO) vapour. The anisotropy in crystalline orientation has developed during the vapour exposure, due both to the surface and confinement effects in thin film geometry. The findings imply a novel route of the vapour treatment of cellulose films to obtain unique structures. [ABSTRACT FROM AUTHOR]

We present a simple method for modification of 2D materials by drop-casting of the organic molecule in solution on the 2D material under ambient conditions. Specifically, we investigated the adsorption of 6-(4,5-Dihydro-1H-imidazol-3-ium-2-yl)-2-(naphthalene-2-yl)benzothiazole methanesulfonate (L63MS) organic molecule on 2D MoS 2 . To better understand the effect of the organic molecule on the 2D material, we also investigated the impact of solvents alone on the materials' properties. The MoS 2 samples were synthesized using ambient pressure chemical vapor deposition. Atomic force microscopy, Raman spectroscopy, photoluminescence spectroscopy and optical microscopy were used to characterize the samples. The measurements were performed after synthesis, after the drop-casting of solvents and after the drop-casting of organic molecule solutions. Our results indicate that the used organic molecule effectively adsorbs on and prompts discernible changes in the (opto)electronic properties of the 2D material. These changes encompass variations in the Raman spectra shape, alterations in the photoluminescence (PL) signal characteristics and modifications in excitonic properties. Such alterations can be linked to various phenomena including doping, bandgap modifications, introduction or healing of defects and that the solvent plays a crucial role in the process. Our study provides insights into the modification of 2D materials under ambient conditions and highlights the importance of solvent selection in the process. [ABSTRACT FROM AUTHOR]

To recover dimethyl sulfoxide, an organic solvent nanofiltration membrane is prepared via the interfacial polymerization method. N-Phenylthiourea (NP)is applied as a water-soluble monomer, reacted with trimesoyl chloride (TMC) on the polyetherimide substrate crosslinked by ethylenediamine. The results of attenuated total reflectance-fourier transform infrared spectroscopy and X-ray electron spectroscopy confirm that N-Phenylthiourea reacts with TMC. The membrane morphology is investigated through atomic force microscopy and scanning electronic microscopy, respectively. The resultant optimized TFC membranes NF-1NP exhibited stable permeance of about 4.3 L m−2 h−1 bar-1 and rejection of 97% for crystal violet (407.98 g mol−1) during a 36 h continuous separation operation. It was also found that the NF-1NP membrane has the highest rejection rate in dimethyl sulfoxide (DMSO), and the rejection rates in methanol, acetone, tetrahydrofuran, ethyl acetate and dimethylacetamide(DMAc) are 51%, 84%, 94%, 96% and 92% respectively. The maximum flux in the methanol system is 11 L m−2 h−1 bar−1, while that in acetone, tetrahydrofuran, ethyl acetate and DMAc is 4.3 L m−2 h−1 bar−1, 6.3 L m−2 h−1 bar−1, 3.2 L m−2 h−1 bar−1, 4.9 L m−2 h−1 bar−1 and 2.1 L m−2 h−1 bar−1, respectively. It was also found that the membrane prepared by N-Phenylthiourea containing aromatic groups has lower mobility and stronger solvent resistance than that of by thiosemicarbazide. [ABSTRACT FROM AUTHOR]

Background: Although X-ray fluorescence microscopy is becoming a widely used technique for single-cell analysis, sample preparation for this microscopy remains one of the main challenges in obtaining optimal conditions for the measurements in the X-ray regime. The information available to researchers on sample treatment is inadequate and unclear, sometimes leading to wasted time and jeopardizing the experiment's success. Many cell fixation methods have been described, but none of them have been systematically tested and declared the most suitable for synchrotron X-ray microscopy. Methods: The HEC-1-A endometrial cells, human spermatozoa, and human embryonic kidney (HEK-293) cells were fixed with organic solvents and cross-linking methods: 70% ethanol, 3.7%, and 2% paraformaldehyde; in addition, HEK-293 cells were subjected to methanol/ C3H6O treatment and cryofixation. Fixation methods were compared by coupling low-energy X-ray fluorescence with scanning transmission X-ray microscopy and atomic force microscopy. Results: Organic solvents lead to greater dehydration of cells, which has the most significant effect on the distribution and depletion of diffusion elements. Paraformaldehyde provides robust and reproducible data. Finally, the cryofixed cells provide the best morphology and element content results. Conclusion: Although cryofixation seems to be the most appropriate method as it allows for keeping cells closer to physiological conditions, it has some technical limitations. Paraformaldehyde, when used at the average concentration of 3.7%, is also an excellent alternative for X-ray microscopy. [ABSTRACT FROM AUTHOR]

Cell-penetrating peptides (CPPs) are highly promising transfection agents that can deliver various compounds into living cells, including nucleic acids (NAs). Positively charged CPPs can form non-covalent complexes with negatively charged NAs, enabling simple and time-efficient nanoparticle preparation. However, as CPPs have substantially different chemical and physical properties, their complexation with the cargo and characteristics of the resulting nanoparticles largely depends on the properties of the surrounding environment, i.e., solution. Here, we show that the solvent used for the initial dissolving of a CPP determines the properties of the resulting CPP particles formed in an aqueous solution, including the activity and toxicity of the CPP–NA complexes. Using different biophysical methods such as dynamic light scattering (DLS), atomic force microscopy (AFM), transmission and scanning electron microscopy (TEM and SEM), we show that PepFect14 (PF14), a cationic amphipathic CPP, forms spherical particles of uniform size when dissolved in organic solvents, such as ethanol and DMSO. Water-dissolved PF14, however, tends to form micelles and non-uniform aggregates. When dissolved in organic solvents, PF14 retains its α-helical conformation and biological activity in cell culture conditions without any increase in cytotoxicity. Altogether, our results indicate that by using a solvent that matches the chemical nature of the CPP, the properties of the peptide–cargo particles can be tuned in the desired way. This can be of critical importance for in vivo applications, where CPP particles that are too large, non-uniform, or prone to aggregation may induce severe consequences. [ABSTRACT FROM AUTHOR]

Partially acetylated cellulose nanofibrils were obtained from the major residual stream associated with tequila production. The morphology and high cellulose content of the bagasse of Agave tequilana greatly facilitated deconstruction of such underutilized biomass. Mild chemical acetylation of the starting material afforded cellulose nanofibrils bearing surface ester groups, making the system less hydrophilic and plasticized. The acetylated nanofiber were characterized for morphology (atomic force microscopy), electrostatic charge (electrophoretic mobility), degree of substitution (DS) (titration) and main chemical features (infrared spectroscopy). Aqueous suspensions of the partially acetylated nanofibers (0.5% concentration) were mixed with a non-polar organic solvent (toluene) to obtain emulsions that were stable for at least 43 days. Cellulose nanofibrils of given DSs (different wettability) formed emulsions with different droplet size, thereby producing emulsion with different properties and stability. The cellulose nanofibrils with smaller sizes and higher contact angle (81°) generated small droplets (10–60 µm) while the cellulose nanofibrils with larger sizes and smaller water contact angle (40°) generated larger droplets (20–80 µm). Agave Bagasse CNF offers a great potential as Pickering emulsion stabilizers, which can be considered in the food, cosmetic and pharmaceutical fields. [ABSTRACT FROM AUTHOR]

The paper presents the synthesis and characterization of poly(trimethylene carbonate) grafted chitosan as a new water soluble biopolymer suitable for in vivo applications. The synthesis was performed via ring-opening polymerization of 1,3-dioxan-2-one (trimethylene carbonate) (TMC) monomer, initiated by the functional groups of chitosan in the presence of toluene as solvent/swelling agent. By varying the molar ratio between the glucosamine units of chitosan and TMC, a series of chitosan derivatives with different content of poly(trimethylene carbonate) chains was synthetized. The structural characterization of the polymers was realized by FTIR and 1H NMR spectroscopy and their solubility was assessed in water and in organic solvents as well. The biocompatibility was investigated by MTS assay on Normal Human Dermal Fibroblasts, and the biodegradability was evaluated in lysozyme buffer solution. Further, the surface properties of the polymer films were analyzed by polarized optical microscopy, atomic force microscopy and water-to-air contact angle measurements. It was established that, by 5% substitution of chitosan with poly(trimethylene carbonate) chains having an average polymerization degree of 7, a water soluble polymer can be attained. Compared to the pristine chitosan, it has improved biocompatibility in solution and moderate wettability and higher biodegradability rate in solid state, pointing its suitability for in vivo applications. [ABSTRACT FROM AUTHOR]

Ion-exchange membranes have been widely used not only in water but also in organic solvents for both scientific exploration and industrial applications. Atomic force microscopy (AFM) is a promising analytical technique to determine membrane functions in both water and organic solvents. Nevertheless, the use of organic solvents frequently causes significant contamination and mechanical drift in AFM imaging investigations. Additionally, the rapid evaporation of organic solvents imposes the limitation of measurement time. Thus, a force curve array measurement requiring a longer time is challenging in organic solvents. Herein, we propose a widely adaptable holder design that facilitates stable AFM measurements in organic solvents for a broad range of AFM systems. Using the designed AFM holder, we investigated silica-membrane interactions in 2-propanol. Our AFM evaluation provides important information on nanoparticle removal with ion-exchange membranes in 2-propanol. The concept of widely adaptable holder design should contribute to the understanding of nanoparticle-membrane interactions and the development of various functional membranes used in organic solvents. [Display omitted] • The proposed holder design facilitates stable AFM measurements in organic solvents. • The design is adaptable to broad AFMs and improves the in-liquid measurements. • The silica nanoparticle-membrane interactions were revealed by the improved AFM. [ABSTRACT FROM AUTHOR]

Lignin‐based nanomaterials fabricated by solution self‐assembly in organic–aqueous solvent mixtures are among the most attractive biomass‐derived products. To accurately control the structure, size, and properties of lignin‐based nanomaterials, it is important to achieve fundamental understanding of its dissolution and aggregation mechanisms. In this work, atomic force microscopy (AFM) and molecular dynamics (MD) simulations are employed to explore the dissolution and aggregation behavior of enzymatic hydrolysis lignin (EHL) in different organic–aqueous solvent mixtures at molecular scale. EHL was found to dissolve well in appropriate organic–aqueous solvent mixtures, such as acetone–water mixture with a volume ratio of 7:3, whereas it aggregated in pure water, ethanol, acetone, and tetrahydrofuran. The interactions between the EHL‐coated AFM probe and the substrate were 1.21±0.18 and 0.75±0.35 mN m−1 in water and acetone, respectively. In comparison, the interaction decreased to 0.15±0.08 mN m−1 in acetone–water mixture (7:3 v/v). MD simulations further indicate that the hydrophobic skeleton and hydrophilic groups of lignin could be solvated by acetone and water molecules, respectively, which significantly promoted its dissolution. Conversely, only the hydrophobic skeleton or the hydrophilic groups were solvated in organic solvent or water, respectively, inducing serious aggregation of lignin. [ABSTRACT FROM AUTHOR]

The ocean harbors a variety of bacteria that contain huge protease resources and offer a great potential for industrial and biotechnological applications. Here, we isolated a protease-secreting bacterium Vibrio pomeroyi strain 12613 from Atlantic seawater and purified a protease VP9 from strain 12613. VP9 was identified as a metalloprotease of the M4 family. VP9 could hydrolyze casein and gelatin but not elastin and collagen. With gelatin as the substrate, VP9 showed the highest activity at 40°C and pH 6.0–8.0. It was stable at temperatures of 50°C and less and in the range of pH 5.0–11.0. VP9 also had good tolerance to NaCl, non-ionic detergents, and organic solvent methanol. Unlike other M4 metalloproteases, VP9 has distinct collagen-swelling ability, and its collagen-swelling effect was concentration dependent. The relative expansion volume of collagen increased by approximately eightfold after treatment with 10 μM VP9 at 37°C for 12 h. The collagen-swelling mechanism of VP9 on bovine-insoluble type I collagen was further studied. Atomic force microscopy observation and biochemical analyses showed that VP9 can degrade proteoglycans in collagen fibers, resulting in the release of collagen fibrils from collagen fibers and the swelling of the latter. In addition, VP9 can degrade glycoproteins, a non-collagenous constituent interacting with collagen in the skin. The characteristics of VP9, such as sufficient specificity toward proteoglycans and glycoproteins but no activity toward collagen, suggest its promising potential in the unhairing and fiber-opening processing in leather industry. [ABSTRACT FROM AUTHOR]

The design of a degradable high-performing thermoset without using organic solvents is critical for the understanding and sustainable development of homogeneous structures with simultaneous reinforcement and toughening functions. Here, we report a novel degradable and recyclable thermoset hyperbranched epoxy resin (EFTH-n) synthesized from bio-based 2,5-furandicarboxylic acid (FDCA). EFTH-n showed excellent performance on common diglycidyl ether of bisphenol-A (DGEBA) with simultaneous improvements in the impact strength, tensile strength, flexural strength, storage modulus and elongation by up to 181.84%, 60.22%, 24.08%, 32% and 58.0%, respectively. The homogeneous microstructure of EFTH-n/DGEBA composites was systematically analyzed using in situ Raman imaging, AFM, SEM, DMA, dynamic light scattering and the positron annihilation lifetime spectroscopy, which enabled us to attribute the improvements to the synergistic effect of the crosslinking density, free volume, intermolecular cavity, hyperbranched topological structure and good compatibility between the components, which was explained by an in situ reinforcing and toughening mechanism. We concluded that EFTH-n could significantly facilitate the degradation of the cured composites under mild conditions without using organic solvents together with a FDCA recycling yield of 56.8 wt%. [ABSTRACT FROM AUTHOR]

In this work we report on the surface characterization of melanin thin films prepared using both water-based and organic solvent-based melanin syntheses. Atomic force microscopy (AFM) analysis of these films suggests that the organic solvent synthesis provides relatively planar basic melanin structures; these basic structures generate surface steps with height in the range of 2–3 nm and small tendency to form larger aggregates. The scaling properties obtained from the AFM data were used to infer the assembling mechanisms of these thin films which depend on the solvent used for melanin synthesis. The behavior observed in organic solvent-based melanin suggests a diffusion-limited aggregation process. Thus films with good adhesion to the substrate and smoother morphologies than water-prepared melanin films are obtained. Electronic structure calculations using a conductorlike screening model were also performed in order to elucidate the microscopic processes of thin film formation. Our results suggest that the agglomerates observed in hydrated samples originate from reaction with water at specific locations on the surface most likely defects on the planar structure. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to present a novel and cost-effective optical biosensor design by simple preparation method for detection of "parathion-methyl," which is a model pesticide pose to public health and the environment. Design/methodology/approach: The optical enzyme biosensor (TCA) for detection of pesticide "parathion-methyl" was developed on the basis of immobilization of tyrosinase enzyme on chitosan film by adsorption technique. The analytic performance of TCA was investigated by measuring its activity with Ultraviolet (UV) visible spectrophotometer. Findings: Uniform porous network structure and protonated groups of chitosan film provided a microenvironment for tyrosinase immobilization evident from Fourier transform infrared (FTIR) spectroscopy and Atomic Force Microscopy analysis. TCA has a wide linear detection range (0-1.03 µM) with high correlation coefficient and it can detect the parathion-methyl concentration as low as 159 nM by noncompetitive inhibition kinetics. Using the TCA sensor both for ten times and at least 45 days without a significant loss in its activity are the indicators of its good operational and storage stability. Moreover, TCA can be applicable to tap water, providing a promising tool for pesticides detection. Originality/value: This is the first time to use the in situ analytical technique that can improve the performance of optical enzyme sensor provided to control the pesticide residue better with respect to traditional techniques. The effect of organic solvents on the performance of optical enzyme biosensor was investigated. Inhibition kinetic of the solvents rarely encountered in literature was also studied besides the pH and temperature tolerance of the optical biosensor. [ABSTRACT FROM AUTHOR]

An axial-substituted silicon phthalocyanine derivative, SiPc(OR)2 (R = C4H9), that is soluble in organic solvent is conveniently synthesized. This silicon phthalocyanine derivative reacts with a hydroxyl group on a substrate and then with another phthalocyanine derivative under mild conditions. The accumulation number of the phthalocyanine molecules on the substrates is easily controlled by the immersion time. On the basis of AFM (atomic force microscopy) images, the surface of the phthalocyanine-modified glass substrate has uneven structures on the nanometer scale. ITO electrodes modified with the composition of the phthalocyanine derivative and PCBM show stable cathodic photocurrent generation upon light irradiation. [ABSTRACT FROM AUTHOR]

Oil spillage has damaged public health noticeably and contributed to significant environmental deterioration. As a result, a significant amount of effort has been spent on investigating and developing the sorbent materials capable of separating oil from water. Thus, the sorbent materials that could be effective particularly in oil spill disposal and resolve such environmental issue remain to be explored. We have proposed luffa cylindrica (LC)-polydimethylsiloxane (PDMS) composite forms to remove the oil and organic components that might be hazardous to aquatic organisms. The scaffolds were fabricated using hand lay-up method with various forms of luffa cylindrica i.e., LC mat, flakes and powder. Various characterizations such as scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), effective porosity, surface wettability, mechanical stability, cytotoxicity and sorption behavior with respect to oil, phosphate buffer saline (PBS) and few organic solvents were performed. The results showed that the scaffold in combination with P-L flakes was highly effective in eradicating oil spills and removing harmful components of crude oil. Scaffolds composed of P-L mat, P-L flakes, P-L powder, and PDMS (P) exhibited oil absorption efficacy around 16.09 ± 4.62 %, 24.49 ± 3.55 %, 15.52 ± 2.67 % and 5.52 ± 1.44 %, respectively. We anticipate that the proposed scaffolds have the tremendous potential to provide a solution to this significant environmental remediation issue and to serve as a cost-effective method for removing oil spills and hazardous crude oil components. Schematic representation of scaffold fabrication using hand lay-up method and the ability of the fabricated scaffolds to absorb oil from the surface of water. [Display omitted] [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) is a class of very good conducting polymers widely used in various optoelectronics and other applications. Though PEDOT:PSS is generally dispersed in an aqueous solvent and displays high acidity and hygroscopic characteristics that weaken the device's performance and stability. In this regard, we report the preparation of poly(3,4-ethylene dioxythiophene) (PEDOT) dispersion in water-free organic solvents with the use of post sulfonated poly (ether sulfone) (P-SPES) as a new polymeric template material. In-situ polymerization of EDOT in P-SPES was carried out using iron(III)p-toluenesulfonate hexahydrate (FePTS) as the oxidant in various non-aqueous solvents resulting in stable dark blue colloidal PEDOT dispersion. The purified PEDOT:P-SPES complex was spin-coated over the glass substrate and checked for conductivity and transmittance. The particle size and roughness of the PEDOT dispersion were analyzed using transmission electron microscopy (TEM) and atomic force microscopy (AFM). The electrical conductivity was observed at ∼0.08 S/cm with a transparency of 94%. The prepared PEDOT dispersion in organic solvent explores a new pathway for the fabrication of organic electronic devices with water-free processing as requirement in optoelectronic applications to improve the device performance. [Display omitted] • For the first time reported sulfonated polyether sulfone as a new polymeric counter ion for PEDOT dispersion in water free organic solvents. • Developed PEDOT dispersion showed stable and narrow particle size of 20–30 nm. • Conductivity value was observed as 0.08 S/cm with transmittance of over the 94%. • The developed PEDOT dispersion in organic solvents will be useful for water free electronics. [ABSTRACT FROM AUTHOR]

Focused on phase separation and morphologies of polymer poly [2-methoxy-5-(2 ’ -ethyl) hexoxy-1,4-phenylenevinylene] (MEH-PPV) and [6,6]-phenylC71-butyric acid methyl ester (PC 70 BM) nanocomposite, we studied the effect of organic solvent on the optical and morphological properties of these blends. The MEH-PPV: PC 70 BM films was prepared using three different solvent; Tetrahydrofuran (THF), Chlorobenzene (CB) and Toluene. On the other hand, the effect of 1–8 octanedithiol additives is also studied with the same different solvents. These blend films are characterized by photoluminescence spectroscopy, UV–Vis absorption spectroscopy and atomic force microscopy (AFM). The photoluminescence results show that the THF solvent provide the better charge transfer. In a morphological view point, the phase segregation was clearly appearing by the addition of the additive on the surface of the blend films. [ABSTRACT FROM AUTHOR]

Carvedilol poly(d,l)-lactide nanoparticles/microparticles were prepared. The size and morphology of the developed particles were optimized to study the carvedilol release profile by studying the effect of organic solvents and polymer amount through atomic force microscopy analysis. Spherical particles were obtained with a minimum size of 125 nm in the case of acetone and a maximum size of 970 nm in the case of dichloromethane affording microparticles formation. The interaction was confirmed by differential scanning calorimeter and Fourier transform infrared. Thein vitrorelease profile of the multicompartment system (pure carvedilol, loaded nanoparticles and microparticles) has shown a sustained release with Korsmeyer–Peppas with T lag model. [ABSTRACT FROM PUBLISHER]

A simplification of the overall method of producing trimethylsilylcellulose solutions in common organic volatile solvents is reported. Microcrystalline cellulose was derivatized aiming its solubilization in tetrahydrofuran and toluene to obtain ultra-thin films of cellulose by spin-coating. The main simplifications are: 1) elimination of a swelling step before dissolution in the binary solvent N,N -dimethylacetamide/LiCl by using microcrystalline cellulose; 2) derivatization of cellulose –OH groups with –Si(CH 3 ) 3 groups was successful with no additional catalyst, like trimethylsilyl chloride, the degree of substitution (DS) being 2.2 ± 0.1. The DS at the extreme surface of the films was computed from the X-ray Photoelectron Spectroscopy data: using solely C 1s fitted component areas and, alternatively, from both C 1s and Si 2p areas. The DS estimated with a technique specific of the surface is close to the bulky one obtained from gravimetric measurements reported in the literature for materials synthesized with catalyst. The topographic uniformity is shown by Atomic Force Microscopy. [ABSTRACT FROM AUTHOR]

Chemical and electrochemical instability of the Li metal interface with organic solvent has been a major impediment to use of Li-metal anodes for next-generation batteries. Here the character of Li surface degradation and the application of atomic layer deposition (ALD) as a protection layer to suppress the degradation are addressed. Using standard Li foil samples in organic solvent with and without in situ deposited ALD Al2O3 protective layers, results from in situ atomic force microscopy, mass spectrometry (including differential electrochemical mass spectrometry), X-ray Photoelectron Spectroscopy (XPS), and ex situ scanning electron microscopy/energy dispersive X-ray spectroscopy are reported. Despite the presence of a thin oxide/hydroxide/carbonate layer on the Li foil surface, degradation readily occurs in organic solvent, particularly at surface features such as ridges. Introduction of the ALD protective layer - deposited directly on this Li foil surface - dramatically suppresses the degradation. [ABSTRACT FROM AUTHOR]

Recent studies have successfully measured surface forces using atomic force microscope (AFM) and modeled surface deformations using the Stokes-Reynolds-Young-Laplace (SRYL) equations for particle-droplet, particle-bubble, droplet-droplet, and bubble-bubble systems in various solutions. The current work focuses on interactions between spherical silica particles and a viscoelastic interface of water droplets in crude oil. The self-assembly of surface active natural polyaromatic molecules (NPAMs) at the oil-water interface has previously been shown to change a viscous dominant oil-water interface to an elastic dominant interface upon aging, due to gradual formation of rigid interfacial networks. AFM was used to measure the interactions between a small silica sphere (D ≈ 8 μm) and a deformable water droplet (D ≈ 70 μm), which exhibits time-dependent interfacial viscoelasticity in NPAM solutions. Unlike the systems studied previously, the measured deformation shown as a repulsive force over the region of constant compliance could not be modeled adequately by the conventional SRYL equations which are applicable only to purely Laplacian interfaces. As the water droplet ages in NPAM solutions, a rigid "skin" forms at the oil-water interface, with the interface exhibiting increased elasticity. Over a short aging period (up to 15 min in NPAM-in-toluene solution), interfacial deformation is well predicted by the SRYL model. However, upon further exposure to the NPAM solution, droplet deformation is overpredicted by the model. Physical properties of this mechanical barrier as a function of interfacial aging were further investigated by measuring interfacial tension, dilatational rheology, and interfacial "crumpling" (non-smooth, non-Laplacian interface) upon droplet volume reduction. By introducing a viscoelasticity parameter to account for interfacial stiffening and using experimentally determined elasticity, we are able to correct this discrepancy and predict droplet deformation under AFM cantilever compression. This parameter appears to be important for modeling non-Laplacian systems of significant viscoelastic contributions, such as biological cell membranes or polymer blends. [ABSTRACT FROM AUTHOR]

The effect of organic solvents on the viability and structural-mechanical (size, surface roughness, and elasticity) properties of actinobacteria of the genus Rhodococcus was studied. The dependence of the survival of Rhodococcus on the hydrophobicity of the solvent, the culture density, and the incubation medium composition was demonstrated. The most resistant strains have been selected. Using combined confocal laser scanning and atomic force microscopy, we established that exposure to solvents resulted in an increase in the relative area and roughness of the surface of living cells and a decrease in their Young's modulus. The involvement of protonand sodium-dependent efflux pumps in the formation of solvent tolerance in Rhodococcus was demonstrated. [ABSTRACT FROM AUTHOR]

Cadmium sulfide (CdS) nanoparticles have been obtained by chemical precipitation onto the surface of single-crystalline silicon from an aqueous solution of ammonia, cadmium chloride (CdCl), and thiourea, as well as from water-DMSO and water-DMF mixtures with the same concentrations of the reagents. According to data of atomic force microscopy, the samples obtained from the aqueous solution consist of individual nanoparticles and agglomerates thereof with sizes of no larger than 1 µm. Materials obtained from the water-organic mixtures are distinguished by the aggregation of CdS nanoparticles into threadlike chains. The length of the formed curved chains and the size of CdS nanoparticles composing them depend on the nature and amount of an organic component of a mixture. Atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy data have shown that the average size of CdS nanoparticles is 2-2.5 nm depending on solvent composition. [ABSTRACT FROM AUTHOR]

Here,we employ n-octanol to elucidate the fundamentalprocesses of hematin crystallization from an organic solvent, identifythe operational mechanisms of growth, and determine the respectivecontrol parameters. The values of the enthalpy, entropy, and freeenergy of the crystal–solution equilibrium suggest that octanolmay structure around the hematin solute molecules and along the crystalinterface. Time-resolved in situ atomic force microscopy demonstratesthat hematin crystal growth strictly follows classical layer growthmechanisms. Steps propagate by the attachment of solute molecules,described by a first-order chemical rate law. The molecules reachthe steps via adsorption on the crystal surface, followed by surfacediffusion, and the kinetic barriers of this pathway offer additionalcrystallization control strategies. Solute incorporation into stepsfrom the adjacent lower and upper terraces is strongly asymmetric,with the lower terrace contributing the major solute amount. Thesefindings provide a foundation for the rational design of hematin crystalsthat may find applications utilizing their high magnetic and opticalanisotropy. [ABSTRACT FROM AUTHOR]

Using the rigid norbornane scaffold, a series of low-molecular-weight organogelators has been synthesised and evaluated. Three separate compounds (16,19and20) were identified as organogelators in three aromatic organic solvents (PhMe, anisole ando-xylene). The formation of fibrillar assemblies at nanometre level was confirmed using atomic force microscopy and transmission electron microscopy. [ABSTRACT FROM PUBLISHER]

Using combined confocal laser scanning and atomic force microscopy (CLSM/AFM), bacterial viability under organic solvent stress was assessed at single cell level. Solvent-exposed bacteria stained with the LIVE/DEAD Bac Light fluoresced green or red, allowing viable and dead cell discrimination. However, with toluene, butanol and acetonitrile, dually fluorescent cells appeared having compromised cell membranes. Changes in size, surface/volume ratio and roughness were revealed as possible resistance mechanisms. [ABSTRACT FROM AUTHOR]

The morphologies and sizes of the self-assemblies formed by the three bola-form peptides in methanol and the underlying formation mechanism were studied in details. [Display omitted] • Substitution of terminal amino acids has great impacts on the morphologies of aggregates formed by bola-form peptides. • The interactions that promoting peptides self-assembling in methanol were significantly different from that in water. • The formation of nanoribbons from Ac-RI 4 R-NH 2 in methanol displayed an obvious kinetics. • Ac-KI 4 K-NH 2 can form a gel phase with superior viscoelasticity in methanol. Peptide molecules can self-assemble to form one-dimensional nanostructures, and the formation of these structures is closely related to the delicate balances of different non-covalent interactions. These non-covalent interactions can be finely tuned by changing the molecular structure and the external conditions. Among them, the introduction of organic solvents to peptide based systems is a simple and effective way for regulating the aggregate structure. In this study, we used three bola-form hexapeptide molecules Ac-KI 4 K-NH 2 , Ac-RI 4 R-NH 2 and Ac-HI 4 H-NH 2 with different hydrophilic amino acids as models to investigate the effect of methanol on the morphology of the self-assemblies. The self-assembly behavior of these peptides in methanol was thoroughly investigated by a combination of transmission electron microscopy (TEM), atomic force microscopy (AFM), circular dichroism spectroscopy (CD), and Fourier transform infrared spectroscopy (FTIR). The results demonstrated that both the solvent methanol and the hydrophilic amino acids in the peptides have a great impact on the morphologies of the self-assemblies. Ac-KI 4 K-NH 2 self-assembled into thin nanofibers in methanol. In contrast, Ac-RI 4 R-NH 2 formed a monolayer helical ribbons with an obvious dynamic process initiating from thin twist nanofibers, then thin helical ribbons, and finally evolved to wide helical ribbons. The dominant nanostructures for Ac-HI 4 H-NH 2 were multi-layer flat ribbons but with a narrower width. These morphologies formed in methanol were significantly different from those formed in water, due to the weakened electrostatic, hydrogen bonding, and hydrophobic interactions between peptides or peptides and methanol. The introduction of methanol creates a completely hydrophobic environment and changes the non-covalent interactions within β-sheets, thus resulting a thin width. A gel phase with superior viscoelasticity was formed by Ac-KI 4 K-NH 2 in methanol and it may have applications in various fields of chemistry, biomedicine, environment and electricity. These results can help us understand the roles of organic solvents in controlling the delicate balance of different non-covalent interactions as well as the final aggregate morphologies and may benefit further research in establishing the relationship among peptide solvent, peptide molecular structure, and the final aggregate morphology. [ABSTRACT FROM AUTHOR]

Gelatin is an important natural biological resource with a wide range of applications in the pharmaceutical, industrial and food industries. We investigated the single-chain behaviors of gelatin by atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS), and found that gelatin exists as long chains by fitting with the M-FJC model. By comparing the single-chain elasticity in a nonpolar organic solvent (nonane) and DI water, it was surprising to find that there was almost no difference in the single-chain elasticity of gelatin in nonane and DI water. Considering the specificity of gelatin solubility and the solvent size effect of nonane molecules, when a single gelatin chain is pulled into loose nonane, dehydration does not occur due to strong binding water interactions. Gelatin chains can only interact with water molecules at high temperatures; therefore, no further interaction of single gelatin chains with water molecules occurred at the experimental temperature. This eventually led to almost no difference in the single-chain F–E curves under the two conditions. It is expected that our study will enable the deep exploration of the interaction between water molecules and gelatin and provide a theoretical basis and experimental foundation for the design of gelatin-based materials with more functionalities. [ABSTRACT FROM AUTHOR]

The use of SU-8-based optofluidic systems (OFS) is validated as an affordable and easy alternative to expensive glass device manufacturing for small-molecule crystallization studies and, in comparison with other polymers, able to withstand most organic solvents. A comparison between two identical OFS (using SU-8 and poly- (dimethylsiloxane), PDMS) against the 36 most commonly used organic solvents for small-molecule crystallization studies have confirmed both the structural and optical stability of the SU-8, whereas PDMS suffered from unsealing or tearing in most cases. In order to test its compatibility, measurements before and after 24 h of continued exposure against solvents have been pursued. Here, three aspects have been considered: in the macroscale, swelling has been determined by analyzing the variations in the optical path in the OFS. For determining compatibility at microscale, fabricated SU-8 micropatterns were solvent-etched and subsequently characterized by scanning electron microscopy (SEM). Roughness of the polymer has also been studied through atomic force microscopy (AFM) measurements at the nanoscale. Experimental measurements of PDMS swelling were in accordance with previously reported observations, while SU-8 displayed a great stability against all the tested solvents. Through this experimental procedure we also show that the OFS are suitable for real-time, on-chip, UV-vis spectroscopy. Micro- and nanoscale observations did not show apparent corrosion on SU-8 surface. Also, two commonly used carrier fluids for microdroplet generation (FC-70 Fluorinert oil and silicone oil) were also tested against the different solvents with the aim of providing useful information for later microbatch experiments. [ABSTRACT FROM AUTHOR]

A novel2,7-carbazole monomer unit was synthesized and used to prepare twopoly(2,7-carbazole)s, both of which were obtained in relatively highmolecular weight and display excellent solubility in common organicsolvents. The polymers were able to effectively disperse carbon nanotubebundles in both THF and toluene using a relatively simple procedureto yield concentrated polymer–carbon nanotube samples thatwere stable for months. The polymer-coated carbon nanotube sampleswere characterized by thermogravimetric analysis, atomic force microscopy,absorption spectroscopy, photoluminescence mapping, and Raman spectroscopy.It was found that the polymers used in this study preferentially interactwith carbon nanotubes having diameters of 1.15 nm or less. Additionally,it was observed that the carbon nanotubes remained effectively debundledby the polymers after removal of solvent, as was demonstrated by Ramanand photoluminescence mapping of solid films of the polymer–carbonnanotube composites. [ABSTRACT FROM AUTHOR]

A photochromic polymer film has been fabricated by the layer-by-layer (LBL) self-assembly through alternating the deposition of poly(acrylic acid) bearing a naphthopyran copolymer and poly(4-vinylpyridine) in an organic solvent. The multilayer assembly process is monitored via UV-vis spectroscopy by measuring the increase in absorbance at 380 nm, and the results reveal that the multilayer films grow in a uniform way in each deposition. Atomic force microscopy (AFM) images prove that the surface of the film was relatively smooth. The photochromic properties of the naphthopyran in the LBL films are investigated and the kinetic results confirm that the colored merocyanine in the LBL films show a significant slow fading speed (critical T1/2 decoloration time increased to 64 min in the 3-bilayer film) and are more stable than those in previous reports. [ABSTRACT FROM AUTHOR]

An understanding of the adhesion of microparticles, particularly microcapsules, containing a functional component to a fabric surface is crucial to an effective application of this com-ponent to the fibre. Fabric surface is very rough; hence, direct measurement of the adhesion of single microparticles to surfaces with a roughness greater than the particle diameter is difficult. In the study reported here, cotton films were generated by dissolving cotton powder in an organic solvent and their properties including surface roughness, thickness, contact angle and purity were characterised. The adhesive forces between single melamine-formaldehyde (MF) resin microparticles and a cotton film under ambient conditions with a relative humidity of above 40% were measured using atomic force microscopy; they are considered to be dominated by capillary forces. It was found that there was little adhesion between a MF microparticle and a cotton film in an aqueous solution of sodium dodecyl-benzene sulphonate as surfactant. Repulsion between them was observed, but it reduced with increase in the surfactant concentration and decrease in the pH of the solution. The repulsion contributions are thought to originate mainly from electrostatic repulsion. It is believed that the studies on the adhesion between single MF microparticles and a cotton film under ambient conditions or dispersed in surfactant solutions, are beneficial to the attempts to enhance the adhesion of microcapsules to fabric surfaces via a modification of their surface composition and morphology. [ABSTRACT FROM AUTHOR]

A novel Y-type polyurethane (polyurethane 3) containing 4-(4-nitrophenylazo)resorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute part of the polymer backbone, was prepared and characterized. Polyurethane 3 is soluble in common organic solvents such as acetone and N, N-dimethylformamide. It shows thermal stability up to 270 °C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of 102 °C. The second harmonic generation (SHG) coefficient ( d33) of the poled polymer film at 1064 nm fundamental wavelength is 2.06 pm V−1. Polymer 3 exhibits thermal stability up to Tg, and no significant SHG decay is observed below 100 °C, which is acceptable for nonlinear optical device applications. Copyright © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

This paper describes the adsorption of sodium dodecyl sulfate (SDS) molecules in a low polar solvent on Ge substrate by using Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy and atomic force microscopy (AFM). The maximum SDS amount adsorbed is (5.0 ± 0.3) × 1014 molecules cm−2 in CHCl3, while with the use of CCl4 as subphase the ability of SDS adsorbed is 48% lower. AFM images show that depositions are highly disordered over the interface, and it was possible to establish that the size of the SDS deposition is around 30-40 nm over the Ge surface. A complete description of the infrared spectroscopic bands for the head and tail groups in the SDS molecule is also provided. [ABSTRACT FROM AUTHOR]

This work reports a facile and rapid method assisted by microwave irradiation for the synthesis of hemin functionalized reduced graphene oxide (hemin–RGO) materials. Our investigation confirmed that the hemin molecules were covalently grafted to the surface of graphene by the amidation reaction of the —NH2 groups on the edges of ethylenediamine functionalized graphene oxide with the —COOH groups of hemin. Hemin–RGO exhibits a homogeneous dispersion in water, dimethylformamide, and acetone after more than one month, indicating that hemin can effectively improve the dispersion and solubility of RGO in the solvent. Hemin–RGO was used as a counter electrode in dye-sensitized solar cells and exhibited preferable electrocatalytic activity for I3− to I− reduction compared with RGO. [ABSTRACT FROM AUTHOR]

Abstract: Modification has been carried out of silicon (100) covered with native oxides with monolayers of octyltrimethoxsilane (C8TMS) and octenyltrimethoxysilane (C8enTMS). Different conditions of adsorption from the organic solvents chloroform, toluene and n-hexane with subsequent exposure to ammonia vapour under ambient atmosphere have been tested for monolayer formation without exclusion of moisture. Thickness of resulting adsorbates has been measured using spectroscopic ellipsometry (SE), water contact angles were measured, and the surface roughness was determined by atomic force microscopy (AFM). If all three results are consistent with the presence of monolayers on the surface, further characterisation has been carried out by angle dependent X-ray photoelectron spectroscopy (XPS). For monolayers, surface roughnesses about <0.3nm were measured, which were mainly determined by the substrate. Thicknesses obtained from SE and XPS agree. Conformational and orientational order of the monolayers determined by attenuated total reflection infrared (ATR-IR) spectroscopy show disordered chains in both cases with nearly isotropic orientation. C8enTMS was found to be partly hydroxylated when treated under alkaline conditions. [Copyright &y& Elsevier]

Abstract: The influences of uniaxial drawing on the different structural scales in thermal-induced polyacrylonitrile (PAN) gel were studied. The results of atomic force microscopy (AFM) and swelling tests indicated that the drawn PAN gels had more compact structure with less solvent contained. Besides, some microphase separations occurred in the highly drawn gel and caused the gel to become more porous, as verified by the results from differential scanning calorimetry (DSC). The wide-angle X-ray diffraction (WAXD) results confirmed that drawing induces chain orientation and partial crystallization in the thermal-induced PAN gels, and higher draw ratio generated greater structural changes in the gels. It was also found from the tensile stress relaxation of the gels that the crosslinks in the gel increased with the draw ratio. In Fourier transform infrared (FTIR) spectra, the blue shift in wave numbers of two absorption peaks (3200–3700cm−1 and around 2244cm−1), and a gradually disappearing peak at 1036cm−1 all indicated the weakening hydrogen bonding between the PAN molecular chains and dimethyl sulfoxide (DMSO) molecules during the drawing process. [Copyright &y& Elsevier]

Abstract: In this work, a column-like nano/micro-scale topography surface has been prepared via trichloro(octyl)silane (TCOS) vapor deposition on the air plasma oxidized polydimethylsiloxane (PDMSOx) surface. TCOS was mixed into n-heptyl alcohol and dimethyl-silicone oil to form a series of mixture. TCOS could anchor to the PDMSOx surface to form column-like nano/micro-scale topography while n-heptyl alcohol and TCOS volatilized to the PDMSOx surface in the subsequent vapor phase process. These surfaces were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared-attenuated total reflection, contact angle measuring system and atomic force microscopy. It was shown that TCOS had been successfully assembled on the polydimethylsiloxane surface. N-heptyl alcohol mixed into alkylsiloxane could regulate the scale and roughness of column-like nano/micro-scale topography. [Copyright &y& Elsevier]

Abstract: The monomolecular organisation of symmetric, chemically modified tetraether lipids caldarchaeol-PO4 was studied using Langmuir film balance, ellipsometry, and atomic force microscopy (AFM). Solid silicon wafer substrates were modified to hydrophobic, hydrophilic, and amino-silanised surfaces; and Langmuir–Blodgett (LB)-films were transferred onto each. LB-caldarchaeol-PO4 films were subjected to further rinsing with organic solvent and additional physical treatments, to compare their resistance and stability on chemisorbed (amino-silanised) and physisorbed (hydrophobic and hydrophilic) surfaces. The resistance and stability of these monolayer films was characterized by ellipsometry and AFM, and film thickness was determined using ellipsometry. AFM was also employed to observe surface morphology. Monolayer films on hydrophobic surfaces were found to be more resistant to rinsing with organic solvent and additional physical treatments than monolayer films on either amino-silanised or hydrophilic surfaces. The hydrophobic effect with hydrophobic surfaces appears to support the formation of stronger caldarchaeol-PO4 films on silicon wafer substrates, with increased resistance and stability. [Copyright &y& Elsevier]

In this paper we report electrochemical investigations of the influence of organic solvents dissolved in aqueous solution on the permeability of nanoporous films derived from a cylinder-forming polystyrene–poly(methyl methacrylate) diblock copolymer (CF-PS-b-PMMA). The nanoporous films (ca. 30 nm in pore diameter) were prepared on planar gold electrodes via UV-based degradation of the cylindrical PMMA domains of annealed CF-PS-b-PMMA films (30–45 nm thick). The permeability of the electrode-supported nanoporous films was assessed using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The faradic current of Fe(CN)63–/4–decreased upon immersion in aqueous solutions saturated with toluene or methylene chloride (5.8 mM and 0.20 M, respectively). EIS data indicated that the decrease in faradic current mainly reflected an increase in the pore resistance (Rpore). In contrast, Rporedid not change in a saturated n-heptane solution, 0.17 M ethanol, or 5.8 mM aqueous solutions of methylene chloride, diethyl ether, methyl ethyl ketone, or ethanol. Atomic force microscopy images of a nanoporous film in aqueous solution with and without 5.8 mM toluene showed a reversible change in the surface morphology, which was consistent with a toluene-induced change in Rpore. The solvent-induced increase in Rporewas attributed to the swelling of the nanoporous films by the organic solvents, which decreased the effective pore diameter. The reversible permeability changes suggest that the surface of CF-PS-b-PMMA-derived nanoporous films can be functionalized in organic environments without destroying the nanoporous structure. In addition, the solvent-induced swelling may provide a simple means for controlling the permeability of such nanoporous films. [ABSTRACT FROM AUTHOR]

Abstract: Wettability alteration of glass substrates due to displacement of the surrounding salt solution by crude oil, and its reversal via salt solution flooding, were investigated as a function of salt concentration and solution pH, and the sample preparation procedure. The resulting wettability states were analyzed by microscopy of the substrate-bound oil residues and contact angle goniometry. Atomic force microscopy of the flooded state under its salt solution showed partial coverage of the substrate by adhering oil nano-blobs. Scanning electron microscopy provides a simpler means to acquire images of residues, but the need to rinse the bulk liquids and dry can introduce preparation artifacts. Three organic solvent rinsing procedures were examined, all showing that oil residue coverage decreases with increasing NaCl concentration and pH, and also decreases after flooding to follow these same trends. However, procedures in which bulk oil was rinsed from the flooded state using the solvents decalin and heptane created extraneous deposition; removal of the salt solution by methanol better preserved the oil residues. After flooding, even the salt solution allowing greatest adsorption/deposition of polar oil components, and strongest oil-substrate adhesion, had reduced coverage to only 20%. Analogous experiments on sandstone rock supported these findings. This suggests that local wettability of reservoirs can fluctuate in response to the oil and water slowly passing through pores during oil recovery by flooding. [Copyright &y& Elsevier]

Abstract: The use of plasma-polymerised fluoropolymer (CFxOy) thin films in the manufacture of microelectromechanical systems (MEMS) devices is well-established, being employed in the passivation step of the deep reactive ion etching (DRIE) process, for example. This paper presents an investigation of the effect of exposure to organic and aqueous liquid media on plasma-polymerised CFxOy thin films. Atomic force microscopy (AFM), scanning electron microscopy (SEM), ellipsometry, X-ray photoelectron spectroscopy (XPS) and dynamic wetting measurements were all employed as characterisation techniques. Highly basic aqueous solutions, including known silicon etchants, were found to cause delamination via degradation of the countersurface below the CFxOy thin film. Films were found to be stable in organic solvents, acidic aqueous solutions and slightly basic aqueous solutions. [Copyright &y& Elsevier]

The frictional properties of poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC) brushes grown from planar silicon surfaces by atom transfer radical polymerization (ATRP) have been characterized using in situfriction force microscopy (FFM). The dry thicknesses of the PMPC brushes ranged from 20 to 421 nm. For brush layers with dry thicknesses greater than ca. 100 nm, the coefficient of friction decreased with increasing film thickness. For shorter brushes, the coefficient of friction varied little with brush thickness. We hypothesize that the amount of bound solvent increases as the brush length increases, causing the osmotic pressure to increase and yielding a reduced tendency for the brush layer to deform under applied load. A comparison of the force−displacement plots acquired for various PMPC brushes under water supports this hypothesis, since a greater repulsive force is measured for thicker brushes. FFM was also used to investigate the well-known co-nonsolvency behavior exhibited by PMPC chains. For a PMPC brush layer of 307 nm dry thickness, the friction force was determined as a function of the volume fraction of alcohol in alcohol/water mixtures. Unlike a previous macroscopic study, a significant increase in the coefficient of friction was observed for ethanol/water mixtures at a volume fraction of 90%. This is attributed to brush collapse due to co-nonsolvency, leading to loss of hydration of the brush chains and hence substantially reduced lubrication. Force measurements normal to the surface indicate much greater hysteresis between approaching and retraction curves under co-nonsolvency conditions. However, no such effect was observed for 2-propanol/water and methanol/water mixtures over a wide range of volume fractions, in agreement with recent ellipsometric studies of PMPC brushes. [ABSTRACT FROM AUTHOR]

Supramolecular assembly and macroscopic properties of a series of bis-(trialkoxybenzamide)-functionalized naphthalene-tetracarboxylicacid-diimide (NDI) chromophores have been studied. The number of methylene units (0, 2, 3, 4; NDI-0, NDI-2, NDI-3, NDI-4, respectively) in between the NDI chromophore and the amide functionalities have been systematically varied to understand the effect of this simple structural variations on the self-assembly. UV−visible spectroscopic studies revealed facile self-assembly in nonpolar medium by synergistic effect of π-stacking, hydrogen-bonding, and hydrophobic interactions. The propensity toward self-assembly was found to follow the order NDI-0≫ NDI-2≈ NDI-3> NDI-4,which could be attributed to the difference in strength of the H-bonding interaction. Atomic force microscopy (AFM) studies revealed unique morphology for the self-assembled structure in each case such as nanostructure with short-range order (NDI-0), elongated nanowires (NDI-2), relatively flat nanoribbons (NDI-3), and discontinuous nanofibers (NDI-4). Effect of such diverse morphologies was found to be highly relevant in correlating the macroscopic properties such as gelation of the individual chromophore. Most strongly aggregating NDI-0did not show gelation in any of the tested solvents but formed lyotropic mesophases (chromonic N and M- phase) which could be related to their crystal like morphology as revealed by AFM images. Contrary to this, NDI-2and NDI-3showed most promising gelation ability in many common organic solvents with very low critical gelation concentrations (in some cases even <0.1 wt %) and NDI-4formed gel only in few solvents which can be attributed to the strength of the self-assembly. The viscoelastic properties of the gels were studied by rheological measurements which revealed remarkable dependence on the morphology of the self-assembled structure. For example, although the self-assembly propensity and gelation ability were almost similar between NDI-2and NDI-3, the yield-stress of the former gel was estimated to be astonishingly high (∼20 times) compared to that of NDI-3gel owing to the large differences in the aspect ratio of the respective 1D-nanostructures. Further the thermodynamic parameters such as ΔHm(enthalpy of melting) of the gel-to-sol transition were determined for various gels and correlated with the molecular structure and self-assembly propensity in solution. [ABSTRACT FROM AUTHOR]