Intelligent soft matter: towards embodied intelligence.

Intelligent soft matter lies at the intersection of materials science, physics, and cognitive science, promising to change how we design and interact with materials. This transformative field aims to create materials with life-like capabilities, such as perception, learning, memory, and adaptive behavior. Unlike traditional materials, which typically perform static or predefined functions, intelligent soft matter can dynamically interact with its environment, integrating multiple sensory inputs, retaining past experiences, and making decisions to optimize its responses.

Advancements in Novel Mechano-Rheological Probes for Studying Glassy Dynamics in Nanoconfined Thin Polymer Films.

The nanoconfinement effects of glassy polymer thin films on their thermal and mechanical properties have been investigated thoroughly, especially with an emphasis on its altered glass transition behavior compared to bulk polymer, which has been known for almost three decades. While research in this direction is still evolving, reaching new heights to unravel the underlying physics of phenomena observed in confined thin polymer films, we have a much clearer picture now. This, in turn, has promoted their application in miniaturized and functional applications.

Assessing Activation Quality through Evaporative Drying Patterns of Zr-MOF (UiO-66) Colloidal Droplets.

We demonstrate a simple droplet diagnostic approach to monitor the UiO-66 MOF (metal-organic framework) synthesis and its quality using the sessile droplet drying phenomenon. Drying a sessile droplet involves evaporation-driven hydrodynamic flow and particle-nature-dependent self-assembled deposition. In general, the MOF synthesis process involves different sizes and physicochemical nature of particles in every synthesis stage.

Enhancement of efficiency in CsSnI based perovskite solar cell by numerical modeling of graphene oxide as HTL and ZnMgO as ETL.

Perovskite photovoltaics have an immense contribution toward the all-round development of the solar cell. Apart from the flexibility, stability, and high efficiency, more stress has been given to using lead-free as well as eco-friendly, inexpensive materials in the fabrication of PSC devices. The utilization of non-volatile material, such as cesium tin iodide (CsSnI), can be proposed for designing the PSC device, which not only makes it eco-friendly but also offers better optoelectronic characteristics due to its smaller bandgap of 1.

Improving the efficiency of a CIGS solar cell to above 31% with SbS as a new BSF: a numerical simulation approach by SCAPS-1D.

The remarkable performance of copper indium gallium selenide (CIGS)-based double heterojunction (DH) photovoltaic cells is presented in this work. To increase all photovoltaic performance parameters, in this investigation, a novel solar cell structure (FTO/SnS/CIGS/SbS/Ni) is explored by utilizing the SCAPS-1D simulation software. Thicknesses of the buffer, absorber and back surface field (BSF) layers, acceptor density, defect density, capacitance-voltage (-), interface defect density, rates of generation and recombination, operating temperature, current density, and quantum efficiency have been investigated for the proposed solar devices with and without BSF.

An entropy generation approach to the molecular recoiling stress relaxation in thin nonequilibrated polymer films.

In polymers, the equilibrium state is achieved when the chains have access to the maximum number of conformational states, which allows them to explore a larger conformational space, leading to an increase in the entropy of the system. Preparation of thin polymer films using the spin-coating technique results in polymer chains being locked in a nonequilibrium state with lower entropy due to possible stretching of chains during the process. Allowing enough time for recovery results in the relaxation of the spin-coating-induced molecular recoiling stress.

A qualitative Design and optimization of CIGS-based Solar Cells with SnS Back Surface Field: A plan for achieving 21.83 % efficiency.

Conventional Copper Indium Gallium Di Selenide (CIGS)-based solar cells are more efficient than second-generation technology based on hydrogenated amorphous silicon (a-Si: H) or cadmium telluride (CdTe). So, herein the photovoltaic (PV) performance of CIGS-based solar cells has been investigated numerically using SCAPS-1D solar simulator with different buffer layer and less expensive tin sulfide (SnS) back-surface field (BSF). At first, three buffer layer such as cadmium sulfide (CdS), zinc selenide (ZnSe) and indium-doped zinc sulfide ZnS:In have been simulated with CIGS absorber without BSF due to optimized and non-toxic buffer.

Lead-free novel perovskite BaAsI: First-principles insights into its electrical, optical, and mechanical properties.

Lead-free halide perovskites are a crucial family of materials in the fabrication of solar cells. At present, Solar cells are facing several challenges such as mechanical and thermodynamic instability, toxicity, unsuitable optical parameters, bandgap, and absorption coefficient. BaAsI is a halide perovskite which has demonstrated good efficiency and tremendous promise for usage in solar cell applications, and it offers a possible solution to these issues.

Roles of aqueous nonsolvents influencing the dynamic stability of poly-(-butyl methacrylate) thin films at biologically relevant temperatures.

Poly-(-butyl methacrylate) (PnBMA) is an important polymer in biomedical applications. Here we study the stability of PnBMA thin films prepared on top of slippery silicon substrates and exposed to nonsolvent aqueous incubation media like water and phosphate-buffered saline (PBS) at temperatures relevant to biological applications (37 °C, 25 °C and 4 °C). Dewetting hole growth experiments allowed us to probe the instability in PnBMA films upon incubation followed by thermal annealing.

Engineering linker defects in functionalized UiO-66 MOF nanoparticles for oil-in-water Pickering emulsion stabilization.

Designing metal-organic framework (MOF)-based solid nanoparticles to stabilize Pickering emulsions by fine-tuning their hydrophobicity and lipophobicity is vital for essential applications and fundamental understanding. We demonstrate grafting of palmitic acid in UiO-66 MOF through its linker defects. Our designed and activated nanoparticles (denoted as UP') stabilized the Pickering emulsions of -heptane-in-water.

Decoupling of Glassy Dynamics from Viscosity in Thin Supported Poly(-butyl methacrylate) Films.

We utilized fast scanning calorimetry to characterize the glass transition temperature ( ) and intrinsic molecular mobility of low-molecular-weight poly(-butyl methacrylate) thin films of varying thicknesses. We found that the and intrinsic molecular mobility were coupled, showing no film thickness-dependent variation. We further employed a unique noncontact capillary nanoshearing technique to directly probe layer-resolved gradients in the rheological response of these films.

Scaling mechanical instabilities in drying micellar droplets.

Drying-induced mechanical instabilities in aqueous solution droplets occur primarily because, during evaporation, the central liquid minimizes the surface tension by pulling the packed gel-like region, leading to a stretching effect of the liquid region at the receding wet front. Under an appropriate scenario, it finally perturbs the gel-like zone at the droplet periphery, generating cracks, wrinkles, folds, cavities, buckles, Here we report unique wrinkling patterns from evaporating sessile micellar aqueous droplets on rigid and soft substrates kept at temperatures well above the ambient. The wrinkling patterns remarkably vary depending on the material's elastic modulus and substrate, the concentration of the micellar solution (), and the substrate temperature ().

Cationic surfactant-directed structural control of NaCl crystals from evaporating sessile droplets.

We report morphological regulation of NaCl (sodium chloride) crystals through the evaporative crystallisation process of microdroplets containing a cationic surfactant CTAB (cetyltrimethylammonium bromide). Various fascinating evaporative salt morphologies are observed using different combinations of salt () and surfactant () concentrations. Each observed morphology is carefully explained by the interplaying physical phenomena, such as crystallisation, micellisation, evaporative dewetting, and surface adsorption of anionic couneterions.

Tunable Properties of MAPLE-Deposited Thin Films in the Presence of Suppressed Segmental Dynamics.

Processing polymer thin films by physical vapor deposition has been a major challenge due to material degradation. This challenge has limited our understanding of morphological control by top-down approaches that can be crucial for many applications. Recently, matrix-assisted pulsed laser evaporation (MAPLE) has emerged as an alternative route to fabricate polymer thin films from near-gas phase growth conditions.

Stratification and two glass-like thermal transitions in aged polymer films.

Using X-ray reflectivity, spectroscopic ellipsometry and Raman spectroscopy, we have studied the stratified structure and the two glass-like thermal transitions in sufficiently aged glassy polystyrene films. We find that favorable interaction between the solid substrate and the polymer film induces stratification within the film resulting in different densities across the film thickness. Existence of two glass-like thermal transitions (one at 70 °C and the other at 95 °C) is independently confirmed by temperature dependent spectroscopic ellipsometry and Raman spectroscopy measurements.

Tuning crystalline ordering by annealing and additives to study its effect on exciton diffusion in a polyalkylthiophene copolymer.

The influence of various processing conditions on the singlet exciton diffusion is explored in films of a conjugated random copolymer poly-(3-hexylthiophene-co-3-dodecylthiophene) (P3HT-co-P3DDT) and correlated with the degree of crystallinity probed by grazing incidence X-ray scattering and with exciton bandwidth determined from absorption spectra. The exciton diffusion coefficient is deduced from exciton-exciton annihilation measurements and is found to increase by more than a factor of three when thin films are annealed using CS solvent vapour. A doubling of exciton diffusion coefficient is observed upon melt annealing at 200 °C and the corresponding films show about 50% enhancement in the degree of crystallinity.

Effect of Annealing on Exciton Diffusion in a High Performance Small Molecule Organic Photovoltaic Material.

Singlet exciton diffusion was studied in the efficient organic photovoltaic electron donor material DTS(FBTTh). Three complementary time-resolved fluorescence measurements were performed: quenching in planar heterojunctions with an electron acceptor, exciton-exciton annihilation, and fluorescence depolarization. The average exciton diffusivity increases upon annealing from 1.

Spatially Distributed Rheological Properties in Confined Polymers by Noncontact Shear.

When geometrically confined to the nanometer length scale, a condition in which a large portion of the material is in the nanoscale vicinity of interfaces, polymers can show astonishing changes in physical properties. In this investigation, we employ a unique noncontact capillary nanoshearing method to directly probe nanoresolved gradients in the rheological response of ultrathin polymer films as a function of temperature and stress. Results show that ultrathin polymer films, in response to an applied shear stress, exhibit a gradient in molecular mobility and viscosity that originates at the interfaces.

Solution-Processable Silicon Phthalocyanines in Electroluminescent and Photovoltaic Devices.

Phthalocyanines and their main group and metal complexes are important classes of organic semiconductor materials but are usually highly insoluble and so frequently need to be processed by vacuum deposition in devices. We report two highly soluble silicon phthalocyanine (SiPc) diester compounds and demonstrate their potential as organic semiconductor materials. Near-infrared (λ(EL) = 698-709 nm) solution-processed organic light-emitting diodes (OLEDs) were fabricated and exhibited external quantum efficiencies (EQEs) of up to 1.

Segmental relaxations have macroscopic consequences in glassy polymer films.

We have investigated the consequences of physical aging in thin spin-coated glassy polystyrene films through detailed dewetting studies. A simultaneous and equally fast exponential decay of dewetting velocity, width, and height of the rim with aging time was observed, which is related to a reduction of residual stresses within such films. The temperature dependence of these decay times followed an Arrhenius behavior, yielding an activation energy of 70±6 kJ/mol, on the same order of magnitude as values for the β-relaxation of polystyrene and for relaxations of surface topographical features.

Aging of thin polymer films cast from a near-theta solvent.

We have examined the aging behavior of spin-cast thin polymer films as a function of their processing history. Films prepared from solutions close to the Θ temperature were aged for varying times at room temperature, followed by a dewetting experiment above the glass transition temperature of the polymer. The characteristic aging time varied strongly with the quality of the solvent, which is attributed to distorted chain conformations in the as-cast films.