In this paper, we formulate the first law of global thermodynamics for stationary states of the binary ideal gas mixture subjected to heat flow. We map the non-uniform system onto the uniform one and show that the internal energy 𝑈(𝑆∗,𝑉,𝑁1,𝑁2,𝑓∗1,𝑓∗2)�(�*,�,�1,�2,�1*,�2*) is the function of the following parameters of state: a non-equilibrium entropy 𝑆∗�*, volume V, number of particles of the first component, 𝑁1�1, number of particles of the second component 𝑁2�2 and the renormalized degrees of freedom. The parameters 𝑓∗1,𝑓∗2�1*,�2*, 𝑁1,𝑁2�1,�2 satisfy the relation (𝑁1/(𝑁1+𝑁2))𝑓∗1/𝑓1+(𝑁2/(𝑁1+𝑁2))𝑓∗2/𝑓2=1(�1/(�1+�2))�1*/�1+(�2/(�1+�2))�2*/�2=1 (𝑓1�1 and 𝑓2�2 are the degrees of freedom for each component respectively). Thus, only 5 parameters of state describe the non-equilibrium state of the binary mixture in the heat flow. We calculate the non-equilibrium entropy 𝑆∗�* and new thermodynamic parameters of state 𝑓∗1,𝑓∗2�1*,�2* explicitly. The latter are responsible for heat generation due to the concentration gradients. The theory reduces to equilibrium thermodynamics, when the heat flux goes to zero. As in equilibrium thermodynamics, the steady-state fundamental equation also leads to the thermodynamic Maxwell relations for measurable steady-state properties

Equilibrium thermodynamics describes the energy exchange of a body with its environment. Here, we describe the global energy exchange of an ideal gas in the Coutte flow in a thermodynamic-like manner. We derive a fundamental relation between internal energy as a function of parameters of state. We analyze a non-equilibrium transition in the system and postulate the extremum principle, which determines stable steady states in the system. The steady-state thermodynamic framework resembles equilibrium thermodynamics.

We formulate the first law of global thermodynamics for stationary states of the ideal gas in the gravitational field subjected to heat flow. We map the non-uniform system (described by profiles of the density and temperature) onto the uniform one and show that the total internal energy 𝑈(𝑆∗,𝑉,𝑁,𝐿,𝑀∗)�(�*,�,�,�,�*) is the function of the following parameters of state: the non-equilibrium entropy 𝑆∗�*, volume V, number of particles, N, height of the column L along the gravitational force, and renormalized mass of a particle 𝑀∗�*. Each parameter corresponds to a different way of energy exchange with the environment. The parameter 𝑀∗�* changes internal energy due to the shift of the centre of mass induced by the heat flux. We give analytical expressions for the non-equilibrium entropy 𝑆∗�* and effective mass 𝑀∗�*. When the heat flow goes to zero, 𝑆∗�* approaches equilibrium entropy. Additionally, when the gravitational field vanishes, our fundamental relation reduces to the fundamental relation at equilibrium.

There is a long-standing question of whether it is possible to extend the formalism of equilibrium thermodynamics to the case of nonequilibrium systems in steady-states. We have made such an extension for an ideal gas in a heat flow. Here, we investigated whether such a description exists for the system with interactions: the van der Waals gas in a heat flow. We introduced a steady-state fundamental relation and the parameters of state, each associated with a single way of changing energy. The first law of nonequilibrium thermodynamics follows from these parameters. The internal energy U for the nonequilibrium states has the same form as in equilibrium thermodynamics. For the van der Waals gas, 𝑈(𝑆∗,𝑉,𝑁,𝑎∗,𝑏∗)�(�*,�,�,�*,�*) is a function of only five parameters of state (irrespective of the number of parameters characterizing the boundary conditions): the effective entropy 𝑆∗�*, volume V, number of particles N, and rescaled van der Waals parameters 𝑎∗�*, 𝑏∗�*. The state parameters, 𝑎∗�*, 𝑏∗�*, together with 𝑆∗�*, determine the net heat exchange with the environment. The net heat differential does not have an integrating factor. As in equilibrium thermodynamics, the steady-state fundamental equation also leads to the thermodynamic Maxwell relations for measurable steady-state properties.

We present a carbon oxide decomposition (COD) method of growing ZnO nanowires (NWs). The “ordinary” carbothermal process of ZnO NW production involves a reduction of ZnO by carbon to the Zn vapor form and the subsequent reaction of the Zn vapor with additionally introduced oxygen in a large volume furnace. In the case of the COD method, the reaction between carbon (graphite) and ZnO produces Zn vapor and CO/CO₂ gas mixtures, which subsequently react in a reduced reaction volume to produce the ZnO NWs. Studies conducted on individual NWs confirm that the ZnO NWs obtained by the COD method exhibit very good structural and optical properties, such as the ultranarrow spectral linewidth (0.5 meV) of the acceptor-bound exciton transition. By performing thermodynamic calculations based on free Gibbs energy and equilibrium constants of 10 theoretical reactions, we confirm that in a system without oxygen, the most preferable reaction to grow ZnO NWs is the reduction of CO by Zn.

The nanotechnology shift from static toward stimuli-responsive systems is gaining momentum. We study adaptive and responsive Langmuir films at the air/water interface to facilitate the creation of two-dimensional (2D) complex systems. We verify the possibility of controlling the assembly of relatively large entities, i.e., nanoparticles with diameter around 90 nm, by inducing conformational changes within an about 5 nm poly(N-isopropyl acrylamide) (PNIPAM) capping layer. The system performs reversible switching between uniform and nonuniform states. The densely packed and uniform state is observed at a higher temperature, i.e., opposite to most phase transitions, where more ordered phases appear at lower temperatures. The induced nanoparticles’ conformational changes result in different properties of the interfacial monolayer, including various types of aggregation. The analysis of surface pressure at different temperatures and upon temperature changes, surface potential measurements, surface rheology experiments, Brewster angle microscopy (BAM), and scanning electron microscopy (SEM) observations are accompanied by calculations to discuss the principles of the nanoparticles’ self-assembly. Those findings provide guidelines for designing other adaptive 2D systems, such as programable membranes or optical interfacial devices.

We present a simple, fast, and single-step approach for fabricating hybrid semiconductor-metal nanoentities through liquid-assisted ultrafast (∼50 fs, 1 kHz, 800 nm) laser ablation. Femtosecond (fs) ablation of Germanium (Ge) substrate was executed in (i) distilled water (ii) silver nitrate (AgNO₃—3, 5, 10 mM) (iii) Chloroauric acid (HAuCl₄—3, 5, 10 mM), yielding the formation of pure Ge, hybrid Ge-silver (Ag), Ge-gold (Au) nanostructures (NSs) and nanoparticles (NPs). The morphological features and corresponding elemental compositions of Ge, Ge-Ag, and Ge-Au NSs/NPs have been conscientiously studied using different characterization techniques. Most importantly, the deposition of Ag/Au NPs on the Ge substrate and their size variation were thoroughly investigated by changing the precursor concentration. By increasing the precursor concentration (from 3 mM to 10 mM), the deposited Au NPs and Ag NPs’ size on the Ge nanostructured surface was increased from ∼46 nm to ∼100 nm and from ∼43 nm to ∼70 nm, respectively. Subsequently, the as-fabricated hybrid (Ge-Au/Ge-Ag) NSs were effectively utilized to detect diverse hazardous molecules (e.g. picric acid and thiram) via the technique of surface-enhanced Raman scattering (SERS). Our findings revealed that the hybrid SERS substrates achieved at 5 mM precursor concentration of Ag (denoted as Ge-5Ag) and Au (denoted as Ge-5Au) had demonstrated superior sensitivity with the enhancement factors of ∼2.5 × 10⁴, 1.38 × 10⁴ (for PA), and ∼9.7 × 10⁵ and 9.2 × 10⁴ (for thiram), respectively. Interestingly, the Ge-5Ag substrate has exhibited ∼10.5 times higher SERS signals than the Ge-5Au substrate.

Using Monte Carlo simulations we study the two-dimensional Ising model on closed manifolds of various topologies near the critical point of the planar bulk system. To this end we consider triangular, square, and hexagonal lattices. We find that the corresponding universal scaling functions of the magnetic susceptibility �, as well as those of the specific heat �, differ for distinct Euler characteristics � of the manifold. In particular, for each lattice decoration the maxima of the scaling functions of � grow as � increases. For the specific heat this relationship is inverted: e.g., for each lattice decoration the maxima of the scaling functions of � on the spherical surface (Euler characteristic �=2) is smaller than on the projective plane (�=1) which, in turn, is smaller than on the torus and on the Klein bottle (both with �=0). We find that if the aspect ratio of the lattices is conform to a square geometrical shape, the magnetic susceptibility scaling functions for different lattice types differ only by a non-universal amplitude.

We study a model of a lipid bilayer membrane described by two order parameters: the chemical composition described using the Gaussian model and the spatial configuration described with the elastic deformation model of a membrane with a finite thickness or, equivalently, for an adherent membrane. We assume and explain on physical grounds the linear coupling between the two order parameters. Using the exact solution, we calculate the correlation functions and order parameter profiles. We also study the domains that form around inclusions on the membrane. We propose and compare six distinct ways to quantify the size of such domains. Despite its simplicity, the model has many interesting features like the Fisher-Widom line and two distinct critical regions.

Adopting a spintronics-inspired approach, we study the reciprocal coupling between ionic charge currents and nematic texture dynamics in a uniaxial nematic electrolyte. Assuming quenched fluid dynamics, we develop equations of motion analogously to spin torque and spin pumping. Based on the principle of least dissipation of energy, we derive the adiabatic “nematic torque” exerted by ionic currents on the nematic director field as well as the reciprocal motive force on ions due to the orientational dynamics of the director. We discuss several simple examples that illustrate the potential functionality of this coupling. Furthermore, using our phenomenological framework, we propose a practical means to extract the coupling strength through impedance measurements on a nematic cell. Exploring further applications based on this physics could foster the development of nematronics—nematic iontronics.

In the paper, “Fluorimetric sensing of ATP in water by an imidazolium hydrazone based sensor,” Farshbaf and Anzenbacher presented the application of bisantrene as a fluorescent ATP sensor in organic–inorganic mixtures of solvents. Encouraged by the results presented in the parent study, we aimed to apply this strategy for physiologically relevant water-based buffers and – preferably – intracellular application. Here we present the results of our investigations and point to the limitations of bisantrene applications in vivo as the ATP sensor.

The objective of this study is to explore the effects of microplastics on the viability of the bacteriophages in an aqueous environment. Bacteriophages (phages), that is, viruses of bacteria, are essential in homeostasis. It is estimated that phages cause up to 40% of the death of all bacteria daily. Any factor affecting phage activity is vital for the whole food chain and the ecology of numerous niches. We hypothesize that the number of active phages decreases due to the virions’ adsorption on microplastic particles or by the released leachables from additives used in the production of plastic, for example, stabilizers, plasticizers, colorants, and reinforcements. We exposed three diverse phages, namely, T4 (tailed), MS2 (icosahedral), and M13 (filamentous), to 1 mg/mL suspension of 12 industrial-grade plastics [acrylonitrile butadiene styrene, high-impact polystyrene, poly-ε-caproamide, polycarbonate, polyethylene, polyethylene terephthalate, poly(methyl methacrylate), polypropylene, polystyrene, polytetrafluoroethylene, polyurethane, and polyvinyl chloride] shredded to obtain microparticles of radius ranging from 2 to 50 μm. The effect of leachables was measured upon exposure of phages not to particles themselves but to the buffer preincubated with microplastics. A double-overlay plaque counting method was used to assess phage titers. We employed a classical linear regression model to verify which physicochemical parameters (65 variables were tested) govern the decrease of phage titers. The key finding is that adsorption mechanisms result in up to complete scavenging of virions, whereas leachables deactivate up to 50% of phages. This study reveals microplastic pollution’s plausible and unforeseen ecotoxicological effect causing phage deactivation. Moreover, phage transmission through adsorption can alter the balance of the food chain in the new environment. The effect depends mainly on the zeta potentials of the polymers and the phage type.

Sedimentation is a ubiquitous phenomenon across many fields of science, such as geology, astrophysics, and soft matter. Sometimes, sedimentation leads to unusual phenomena, such as the Brazil-nut effect, where heavier (granular) particles reside on top of lighter particles after shaking. We show experimentally that a Brazil-nut effect can be realized in a binary colloidal system of long-range repulsive charged particles driven purely by Brownian motion and electrostatics without the need for activity. Using theory, we argue that not only the mass-per-charge for the heavier particles needs to be smaller than the mass-per-charge for the lighter particles but also that at high overall density, the system can be trapped in a long-lived metastable state, which prevents the occurrence of the equilibrium Brazil-nut effect. Therefore, we envision that our work provides valuable insights into the physics of strongly interacting systems, such as partially glassy and crystalline structures. Finally, our theory, which quantitatively agrees with the experimental data, predicts that the shapes of sedimentation density profiles of multicomponent charged colloids are greatly altered when the particles are charge-regulating with more than one ion species involved. Hence, we hypothesize that sedimentation experiments can aid in revealing the type of ion adsorption processes that determine the particle charge and possibly the value of the corresponding equilibrium constants.

Bevacizumab is a biological drug that is now extensively studied in clinics against various types of cancer. Although bevacizumab’s action is preferably extracellular, there are reports suggesting its internalization into cancer cells, consequently decreasing its therapeutic potential. Here we are solving this issue by applying fluorescence correlation spectroscopy in living cells. We tracked single molecules of fluorescent bevacizumab in MDA-MB-231 and HeLa cells and proved that mobility measurements bring significant added value to standard imaging techniques. We confirmed the presence of the drug in intracellular vesicles. Additionally, we explicitly excluded the presence of a free cytosolic fraction of bevacizumab in both studied cell types. Extracellular and intracellular concentrations of the drug were measured, giving a partition coefficient on the order of 10–5, comparable with the spontaneous uptake of biologically inert nanoparticles. Our work presents how techniques and models developed for physics can answer biological questions.

The reaction kinetics between like-charged compounds in water is extremely slow due to Coulomb repulsions. Here, we demonstrate that by screening these interactions and, in consequence, increasing the local concentration of reactants, we boost the reactions by many orders of magnitude. The reaction between negatively charged Coenzyme A molecules accelerates ~5 million-fold using cationic micelles. That is ~104 faster kinetics than in 0.5 M NaCl, although the salt is ~106 more concentrated. Rate enhancements are not limited to micelles, as evidenced by significant catalytic effects (104–105-fold) of other highly charged species such as oligomers and polymers. We generalize the observed phenomenon by analogously speeding up a non-covalent complex formation—DNA hybridization. A theoretical analysis shows that the acceleration is correlated to the catalysts’ surface charge density in both experimental systems and enables predicting and controlling reaction rates of like-charged compounds with counter-charged species.