Prathima Nalam

University at Buffalo, State University of New York | SUNY Buffalo · Department of Materials Design and Innovation

Hydrophobic interaction is a prevalent sorption mechanism of poly- and perfluoroalkyl substances (PFAS) in natural and engineered environments. In this study, we combined quartz crystal microbalance with dissipation (QCM-D), atomic force microscope (AFM) with force mapping, and molecular dynamics (MD) simulation to probe the molecular behavior of P...

Lead contamination poses significant and lasting health risks, particularly in children. This study explores the efficacy of dried mycelium membranes, distinct from live fungal biomass, for the remediation of lead (Pb(II)) in water. Dried mycelium offers unique advantages, including environmental resilience, ease of handling, biodegradability, and...

Gradient porous structures (GPS) are characterized by structural variations along a specific direction, leading to enhanced mechanical and functional properties compared to homogeneous structures. This study explores the potential of mycelium, the root part of a fungus, as a biomaterial for generating GPS. During the intentional growth of mycelium,...

Gradient porous structures (GPS) are characterized by structural variations along a specific direction, leading to enhanced mechanical and functional properties compared to homogeneous structures. This study explores the potential of mycelium, the root part of a fungus, as a biomaterial for generating GPS. During the intentional growth of mycelium,...

This comprehensive review focuses on polyetheretherketone (PEEK), a synthetic thermoplastic polymer, for applications in dentistry. As a high-performance polymer, PEEK is intrinsically robust yet biocompatible, making it an ideal substitute for titanium—the current gold standard in dentistry. PEEK, however, is also inert due to its low surface ener...

Bulk layered materials, such as graphite and molybdenum disulfide, have long been used as solid lubricants in various industrial applications. The weak interlayer van der Waals interactions in these materials generate a low shear slip-plane, which reduces the interfacial friction. The cumulative trends toward device miniaturization have increased t...

Fibrinogen interactions with cathodically polarized gold surfaces were characterized by electrochemical methods. Electrochemical Quartz Crystal Microbalance (eQCM) studies showed that fibrinogen desorption from gold surfaces occurred in a voltage-dependent manner. This study evaluated the cathodic-voltage-controlled electrical stimulation (CVCES) o...

Sliding‐induced friction behavior of a single‐asperity silica probe against few‐layer (FL) graphene and bulk graphite is measured in the presence of n‐hexadecane using an atomic force microscope (AFM). The load‐dependent nanoscale friction measurements display friction hysteresis, i.e., higher friction forces during unloading of the contact than lo...

Atomic-scale friction of graphene supported on silica as a function of immersion time in non-polar n-hexadecane is investigated using atomic force microscope (AFM) and molecular dynamics (MD) simulations. With an increase in immersion time, n-hexadecane molecules diffuse and intercalate at the graphene-silica confinement initially, decreasing frict...

β‐Ga2O3 nanomembranes are a quasi‐two‐dimensional form of bulk β‐Ga2O3. In article number 2000763, Jung‐Hun Seo and co‐workers present a systematical investigation of the layer delaminations and fractures in β‐Ga2O3 nanomembrane under strain. The performance degradation is recovered by a water vapor treatment, meaning that this result provides a vi...

A free‐standing β‐Ga2O3, also called β‐Ga2O3 nanomembrane (NM), is an important next‐generation wide bandgap semiconductor that can be used for myriad high‐performance future flexible electronics. However, details of structure‐property relationships of β‐Ga2O3 NM under strain conditions have not yet investigated. In this paper, the electrical prope...

While many mechanistic studies have focused on the lubricious properties of ionic liquids on ideally smooth surfaces, little is known about the mechanisms by which ionic liquids lubricate contacts with nanoscale roughness. Here, substrates with controlled density of nanoparticles were prepared to examine the influence of nanoscale roughness on the...

Several two-dimensional (2D) materials such as graphene, molybdenum disulfide, or boron nitride are emerging as alternatives for lubrication additives to control friction and wear at the interface. On the other hand, the initiative to accelerate materials discovery through data-driven computational methods has identified numerous novel topologies a...

In addition to student assessment, curriculum assessment is a critical element to any pedagogy. It helps the educator assess the teaching of concepts, determine what may be lacking, and make changes for continual improvement. Meaningful assessment can be complicated when disciplines converge or when new approaches are implemented. To facilitate thi...

----------SHAREDIT LINK to view full article: https://rdcu.be/bYe5g -------------- Surface adsorption of amphiphilic molecules is a vital mechanism of boundary lubrication on stainless steel surfaces. The self-assembly of four fatty acid-based organic friction modifiers in two alkane solvents and their adsorption onto stainless steel surfaces was...

The authors have found typographical errors in eqs 6, 7, 11 and 12: The term (Formula Presented) in these equations should be read as (Formula Presented).

This work describes the effect of the adsorption behavior of fatty amine-based organic friction modifiers on their tribological performance. The adsorption of four different fatty amines with a varying number of amine functional groups (two vs. three) and different anchoring structures (straight vs. branched) on stainless steel surfaces in n-hexade...

We report the comparative aggregation behavior of three emerging inorganic 2D nanomaterials (NMs): MoS2, WS2, and h-BN in aquatic media. Their aqueous dispersions were subjected to aggregation under varying concentrations of monovalent (NaCl) and divalent (CaCl2) electrolytes. Moreover, Suwanee River Natural Organic Matter (SRNOM) has been used to...

Long‐term stability of hydrophilic surface coatings that prevent fouling, cell adhesion and present a lubricious interface for biomaterials has been widely investigated in recent years. As an alternative to the gold standard poly(ethylene glycol) (PEG), poly(2‐oxazoline)‐based coatings are promising due to their higher stability against oxidative d...

Mycelium is a new biomaterial whose microstructure consists of fibers, the hyphae, that grow and eventually connect, creating a mesh that resembles an open cell foam structure. The purpose of this study was to extract structural features and develop a QSPR for mycelium transport properties with the aim to design a mycelium-based high performance me...

Recognizing the limitations of solid-supported lipid bilayers to reproduce the behavior of cell membranes, including bendability, transmembrane protein inclusion and virus entry, this study describes a novel biomimetic system for cell membranes with the potential to overcome these and other limitations. The developed strategy utilizes a hydrogel wi...

A current effort in preventive dentistry is to inhibit surface attachment of bacteria using antibacterial polymer coatings on the tooth surface. For the antibacterial coatings, the physisorption of anionic and cationic polymers directly onto hydroxyapatite (HA) and saliva treated HA surfaces was studied using quartz crystal microbalance, force spec...

Stimuli-responsive polymer films play an important role in the development of smart antibacterial coatings. In this study, we consider complementary architectures of polyelectrolyte films including a thin chitosan layer (CH), poly (acrylic acid) (PAA) brushes and a bilayer structure of CH grafted to PAA brushes (CH/PAA) as possible candidates for t...

We present a magnetic force-based direct drive modulation method to measure local nano-rheological properties of soft materials across a broad frequency range (10 Hz to 2 kHz) using colloid-attached atomic force microscope (AFM) probes in liquid. The direct drive method enables artefact-free measurements over several decades of excitation frequency...

Torsional mode dynamic force microscopy can be used for a wide range of studies including mapping lateral contact stiffness, torsional frequency or amplitude modulation imaging, and dynamic friction measurements of various materials. Piezo-actuation of the cantilever is commonly used, but it introduces spurious resonances, limiting the frequency ra...

Stratified polyacrylamide films featuring polymer-brush and polymer-gel blocks are fabricated by sequential, surface-initiated, photoiniferter-mediated polymerization. Use of selective solvent mixtures during re-initiation allows the formation of well-defined brush and gel layers with graded properties. Nano-mechanical and tribological characteriza...

Stratified polyacrylamide films featuring polymer-brush and crosslinked-brush- hydrogel blocks are fabricated by se- quential, surface-initiated, photoiniferter- mediated polymerization. Use of selective solvent mixtures during re-initiation al- lows the formation of well-defined brush and gel layers with graded properties. Nano-mechanical and trib...

The effect of nano-scale surface roughness on the lubrication properties of a polymer brush in a good solvent has been investigated. Friction and adhesion forces were measured by means of polyethylene colloid-probe AFM across a 12-nm-silica-particle gradient before and after the adsorption of a poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) pol...

Nano-tribological properties of surface-adsorbed, brush-like copolymers of poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) and poly(L-lysine)-graft-dextran (PLL-g-dextran) have been investigated in aqueous viscous solvent mixtures by means of colloid-probe lateral force microscopy. Lateral forces for PEG/dextran brushes have been measured as...

We have investigated the response of dextran brushes in aqueous dimethyl sulfoxide (DMSO) mixtures under normal compression using the extended surface forces apparatus. The hydrophilic, tethered polymer chains extend significantly in the studied aqueous mixtures and two brush-covered surfaces exhibit repulsive forces upon compression against each o...

A new approach, involving a two-fluid model, has been developed to interpret the quartz crystal microbalance response of adsorbed viscoelastic polymers. The model utilizes the Navier–Stokes–Brinkmann equation to describe the motion of a porous, semirigid, viscoelastic polymer-brush film with a viscous solvent flowing through it. The two phases, sol...

We have investigated the response of dextran brushes in aqueous dimethyl sulfoxide (DMSO) mixtures under normal compression using the extended surface forces apparatus. The hydrophilic, tethered polymer chains extend significantly in the studied aqueous mixtures and two brush-covered surfaces exhibit repulsive forces upon compression against each o...

We have previously investigated the dependence of adhesion on nanometer-scale surface roughness by employing a roughness gradient. In this study, we correlate the obtained adhesion forces on nanometer-scale rough surfaces to their frictional properties. A roughness gradient with varying silica particle (diameter = 12 nm) density was prepared, and a...

The oscillatory force profile, observed in liquids due to molecular ordering at interfaces, has been extensively investigated by means of atomic force microscopy, but it remains unclear whether molecular ordering is present at the tip apex. Using a displacement-sensitive, low-noise atomic force microscope (AFM) operated in dynamic mode, with a tip...

In micro-solid oxide fuel cells (μ-SOFCs) ceramic thin films are integrated as free-standing membranes on micromachinable substrates such as silicon or Foturan® glass ceramic wafers. The processing of μ-SOFCs involves unavoidable dry- or wet-chemical etching for opening the substrate below the free-standing fuel cell membranes. In the first part of...

We have investigated the tribological properties of surfaces with adsorbed poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) sliding in aqueous glycerol solutions under different lubrication regimes. Glycerol is a polar, biocompatible liquid with a significantly higher viscosity than that of water. Macrotribological performance was investigate...

Dioctyldithiophosphoric acid was deposited on 7 nm (RMS) rough steel surfaces at 150 C to create a densely packed (area-95%) deposit of glassy phosphate islands of maximum 500 nm height. This standard substrate was subjected to dry lubricated ball-on-disc tribology using a 2 mm diameter steel ball in the 25–500 mN normal load range at a sliding vel...

The thermal stability of short alkanethiol CH(3)(CH(2))(7)SH (C(8)) and long C(18) self-assembled monolayers (SAMs) is investigated using grazing angle reflection-absorption infrared spectroscopy, cyclic voltammetry, and molecular dynamics simulation. We track the disordering of SAM by untilting and gauche defect accumulation with increasing temper...

We have investigated the response of dextran brushes in aqueous dimethyl sulfoxide (DMSO) mixtures under normal compression using the extended surface forces apparatus. The hydrophilic, tethered polymer chains extend significantly in the studied aqueous mixtures and two brush-covered surfaces exhibit repulsive forces upon compression against each o...