Rediscovering Silicones: The Anomalous Water Permeability of "Hydrophobic" PDMS Suggests Nanostructure and Applications in Water Purification and Anti-Icing.

Cross-linked polydimethylsiloxane (PDMS) is simultaneously water-repellent and highly permeable to water vapor. Unfilled and silica-free cross-linked PDMS films of variable thickness (8-160 µm) are prepared and their water vapor transmission rates and permeability values are determined. Vapor transmission rate increases as membrane thickness decreased from 160 to 15 µm, but does not increase further when the film thickness is decreased to 8 µm. Rate-limiting sorption is implicated as the cause of this effect and substantiated by a surface modification to enhance adsorption rate. Water vapor does not macroscopically condense on films thin enough to operate in this kinetic regime, and vapor transmission rates as high as 60% of the transmission rates through air are measured. A mechanism for water permeation is offered based on those proposed for nanoscopically confined water in carbon nanotubes and aquaporins.

Sessile Liquid Features as Molds for Silicone Elastomers.

Liquid applied to a chemically patterned (wetting/nonwetting, lyophilic/lyophobic) substrate forms a 3-dimensional contoured surface, the shape of which depends on the volume of liquid applied and the shape of the three-phase contact lines of air (or other phase in contact), liquid, and the wetted pattern. The resulting binary contoured interface with air, which consists of flat unwetted regions of the substrate and the mean curvature liquid-vapor interfaces of the sessile structures, can be used as a mold for imprinting solid polymers by curing liquid resins in contact. The success, flexibility with regard to shape, and reproducibility of this molding process depend on numerous issues. These include the substrate surface chemistry, the liquid application method, properties of the liquid (vapor pressure, surface tension, viscosity, and permeability in the resin), the contact angles of the liquid on the patterned substrate, and the resin curing chemistry and conditions. We investigate the room temperature platinum(0)-catalyzed curing of the most commonly studied commercial silicone elastomer, Sylgard 184, using molds composed of sessile drops of liquids on circular wetting features (bare silicon wafer) patterned on covalently attached fluoroalkylsilyl monolayers. Liquids reported are water, glycerol, an ethylene glycol oligomer, and an ionic liquid. The vapor pressure of water and its permeability in dimethyl silicone were important (and problematic) issues that could be controlled by adjusting humidity. The ionic liquid N-ethyl-N'-methylimidazolium methanesulfonate poisoned/inhibited the curing chemistry and affected silicone cross-link density and the resulting feature shape, but its lack of vapor pressure was useful in studying flow coating as a scalable liquid application method. The ethylene glycol oligomer exhibited compatibility with (and diffusion into) the silicone. Glycerol proved to be the most well-behaved and controllable liquid studied and was used to demonstrate that condensation/evaporation can be used to adjust feature shape.

A Different Silica Surface: Radical Oxidation of Poly(methylsilsesquioxane) Thin Films and Particles (Tospearl).

Surfaces that exhibit the reactivity of silica toward surface modification (silanol condensation) were prepared by treating thin films and particles of poly(methylsilsesquioxane) with aqueous potassium persulfate at elevated temperature. Parallel experiments were carried out using a highly cross-linked poly(dimethylsiloxane). Advancing (θA) and receding (θR) water contact angles for all of these oxidized surfaces were θA/θR = ∼10/∼0°, and these low values remain unchanged for months. Reactions of these silica-like surfaces with a range of functional silane reagents indicate that the surface silanol concentration is sufficient to prepare covalently attached monolayers of similar surface density to those prepared using silicon wafers as substrates.

Identifying Injury Patterns Associated With Physical Elder Abuse: Analysis of Legally Adjudicated Cases.

STUDY OBJECTIVE: Elder abuse is common and has serious health consequences but is underrecognized by health care providers. An important reason for this is difficulty in distinguishing between elder abuse and unintentional trauma. Our goal was to identify injury patterns associated with physical elder abuse in comparison with those of patients presenting to the emergency department (ED) with unintentional falls. METHODS: We partnered with a large, urban district attorney's office and examined medical, police, and legal records from successfully prosecuted cases of physical abuse of victims aged 60 years or older from 2001 to 2014. RESULTS: We prospectively enrolled patients who presented to a large, urban, academic ED after an unintentional fall. We matched 78 cases of elder abuse with visible injuries to 78 unintentional falls. Physical abuse victims were significantly more likely than unintentional fallers to have bruising (78% versus 54%) and injuries on the maxillofacial, dental, and neck area (67% versus 28%). Abuse victims were less likely to have fractures (8% versus 22%) or lower extremity injuries (9% versus 41%). Abuse victims were more likely to have maxillofacial, dental, or neck injuries combined with no upper and lower extremity injuries (50% versus 8%). Examining precise injury locations yielded additional differences, with physical elder abuse victims more likely to have injuries to the left cheek or zygoma (22% versus 3%) or on the neck (15% versus 0%) or ear (6% versus 0%). CONCLUSION: Specific, clinically identifiable differences may exist between unintentional injuries and those from physical elder abuse. This includes specific injury patterns that infrequently occur unintentionally.

Carbon Nanotubes Readily Disperse in Linear Silicones and Improve the Thermal Stability of Dimethylsilicone Elastomers.

Stable silicone fluid-carbon nanotube dispersions were prepared in minutes by simple mixing processes, without the addition of solvents or surfactants and without the chemical modification of the nanotubes. With linear silicones of sufficient viscosity, a dual asymmetric centrifuge (SpeedMixer) was sufficient for dispersion; lower viscosity silicones required a brief ultrasound treatment. Optical microscopy indicates a homogeneous dispersion of multiwalled carbon nanotube (MWCNT) bundles in linear poly(dimethylsiloxane) (PDMS) oils. The facile dispersion of carbon nanotubes in PDMS has been reported in several previous publications and this appears to be general for silicones. MWCNTs also disperse readily, and to a greater extent, as assessed by optical microscopy, in poly(methylphenylsiloxane) and, in particular, poly(diethylsiloxane). Linear PDMS/MWCNT dispersions are stable against agglomeration for months. Platinum-catalyzed hydrosilylation of MWCNT-containing vinyl-/hydride-functionalized PDMS liquids yielded filled elastomers that unexpectedly exhibit significantly increased thermal stability. This enhancement occurs with only fractions of a weight percent of MWCNTs. Thermal gravimetric analysis shows a 54 °C increase in peak weight loss temperature (446-500 °C), an increased decomposition activation energy (158-233 kJ/mol), a second higher temperature decomposition process, and doubled char formation (20-40%) with only 0.5 wt %-added MWCNT. Pyrolysis combustion flow calorimetry confirmed the enhancement in thermal stability. Improvements in electrical conductivity were observed at loadings as low as 0.025 wt %. Spontaneous adsorption of dialkylsiloxane chains to MWCNT surfaces (wetting) and the resulting changes in the composite structure are implicated as the basis for dispersion and thermal behavior changes.

Amoebae Assemble Synthetic Spherical Particles To Form Reproducible Constructs.

Difflugia are testate amoebae that use particulate inorganic matter to build a protective shell (generally called a test or theca). Difflugia globulosa were grown both in culture containing only naturally occurring theca-building materials and under conditions where synthetic particles were present also. The presence of monodisperse Stöber silica microspheres of 1, 3, and 6 µm in diameter or 4 µm polystyrene spheres dramatically increased the rate of Difflugia growth, and foreign microspheres became the overwhelmingly dominant construction material. Optical and electron microscopy of the 6 µm particle studies revealed that Difflugia construct spherical vase-shaped thecae with strikingly reproducible composition, morphology, and size. Time-lapse photography revealed construction techniques and masonry skills as Difflugia herded particles together, trapped them using phagocytosis, and applied the particles with biocement from inside the developing theca. The reported observations identify taxonomy complications, biomicrofabrication possibilities, and a discrete environmental impact of synthetic particle pollutants.

Capillary-bridge-derived particles with negative Gaussian curvature.

We report the preparation of millimeter-scale particles by thermal polymerization of liquid monomer capillary bridges to form catenoid-shaped particles that exhibit negative Gaussian curvature. The shape of the capillary bridges and resulting particles can be finely tuned using several addressable parameters: (i) the shape, size, and orientation of lithographic pinning features on the spanned surfaces; (ii) the distance between opposing support surfaces; and (iii) the lateral displacement (shear) of opposing features. The catenoid-shaped particles exhibit controllable optical properties as a result of their concave menisci, the shape of which can be easily manipulated. The particles self assemble in the presence of a condensing liquid (water) to form reversible neck-to-neck pairs and less reversible end-to-end aggregates. We argue that this approach could be scaled down to micrometer dimensions by fabricating an array of micrometer-scale particles. We also argue, with a discussion of dynamic wetting, that these particles will exhibit interesting anisotropic adhesive properties.

Emergency department provider perspectives on elder abuse and development of a novel ED-based multidisciplinary intervention team.

BACKGROUND: An ED visit provides a unique opportunity to identify elder abuse, which is common and has serious medical consequences. Despite this, emergency providers rarely recognise or report it. We have begun the design of an ED-based multidisciplinary consultation service to improve identification and provide comprehensive medical and forensic assessment and treatment for potential victims. METHODS: We qualitatively explored provider perspectives to inform intervention development. We conducted 15 semistructured focus groups with 101 providers, including emergency physicians, social workers, nurses, technologists, security, radiologists and psychiatrists at a large, urban academic medical centre. Focus groups were transcribed, and data were analysed to identify themes. RESULTS: Providers reported not routinely assessing for elder mistreatment and believed that they commonly missed it. They reported 10 reasons for this, including lack of knowledge or training, no time to conduct an evaluation, concern that identifying elder abuse would lead to additional work, and absence of a standardised response. Providers believed an ED-based consultation service would be frequently used and would increase identification, improve care and help ensure safety. They made 21 recommendations for a multidisciplinary team, including the importance of 24/7 availability, the value of a positive attitude in a consulting service and the importance of feedback to referring ED providers. Participants also highlighted that geriatric nurse practitioners may have ideal clinical and personal care training to contribute to the team. CONCLUSIONS: An ED-based multidisciplinary consultation service has potential to impact care for elder abuse victims. Insights from providers will inform intervention development.

Rapid and Clean Covalent Attachment of Methylsiloxane Polymers and Oligomers to Silica Using B(C6F5)3 Catalysis.

The rapid, room-temperature covalent attachment of alkylhydridosilanes (R3Si-H) to silicon oxide surfaces to form monolayers using tris(pentafluorophenyl)borane (B(C6F5)3, BCF) catalysis has recently been described. This method, unlike alternative routes to monolayers, produces only unreactive H2 gas as a byproduct and reaches completion within minutes. We report the use of this selective reaction between surface silanols and hydridosilanes to prepare surface-grafted poly(dimethylsiloxane)s (PDMSs) with various graft architectures that are controlled by the placement of hydridosilane functionality at one end, both ends, or along the chain of PDMS samples of controlled molecular weight. We also report studies of model methylsiloxane monolayers prepared from pentamethyldisiloxane, heptamethyltrisiloxane (two isomers), heptamethylcyclotetrasiloxane, and tris(trimethylsiloxy)silane. These modified silica surfaces with structurally defined methylsiloxane groups are not accessible by conventional silane surface chemistry and proved to be useful in exploring the steric limitations of the reaction. Linear monohydride- and dihydride-terminated PDMS-grafted surfaces exhibit increasing thickness and decreasing contact angle hysteresis with increasing molecular weight up to a particular molecular weight value. Above this value, the hysteresis increases with increasing molecular weight of end-grafted polymers. Poly(hydridomethyl-co-dimethylsiloxane)s with varied hydride content (3-100 mol %) exhibit decreasing thickness, decreasing contact angle, and increasing contact angle hysteresis with increasing hydride content. These observations illustrate the importance of molecular mobility in three-phase contact line dynamics on low-hysteresis surfaces. To calibrate our preparative procedure against both monolayers prepared by conventional approaches as well as the recent reports, a series of trialkylsilane (mostly, n-alkyldimethylsilane) monolayers was prepared to determine the reaction time required to achieve the maximum bonding density using dynamic contact angle analysis. Monolayers prepared from hydridosilanes with BCF catalysis have lower bonding densities than those derived from chlorosilanes, and the reactions are more sensitive to alkyl group sterics. This lower bonding density renders greater flexibility to the n-alkyl groups in monolayers and can decrease the contact angle hysteresis.

Achieving high aspect ratio wrinkles by modifying material network stress.

Wrinkle aspect ratio, or the amplitude divided by the wavelength, is hindered by strain localization transitions when an increasing global compressive stress is applied to synthetic material systems. However, many examples from living organisms show extremely high aspect ratios, such as gut villi and flower petals. We use three experimental approaches to demonstrate that these high aspect ratio structures can be achieved by modifying the network stress in the wrinkle substrate. We modify the wrinkle stress and effectively delay the strain localization transition, such as folding, to larger aspect ratios by using a zero-stress initial wavy substrate, creating a secondary network with post-curing, or using chemical stress relaxation materials. A wrinkle aspect ratio as high as 0.85, almost three times higher than common values of synthetic wrinkles, is achieved, and a quantitative framework is presented to provide understanding the different strategies and predictions for future investigations.

Describing visible acute injuries: development of a comprehensive taxonomy for research and practice.

BACKGROUND: Little literature exists classifying and comprehensively describing intentional and unintentional acute injuries, which would be valuable for research and practice. In preparation for a study of injury patterns in elder abuse, our goal was to develop a comprehensive taxonomy of relevant types and characteristics of visible acute injuries and evaluate it in geriatric patients. METHODS: We conducted an exhaustive review of the medical and forensic literature focusing on injury types, descriptions, patterns and analyses. We then prepared iteratively, through consensus with a multidisciplinary, national panel of elder abuse experts, a comprehensive classification system to describe these injuries. RESULTS: We designed a three-step process to fully describe and classify visible acute injuries: (1) determining the type of injury, (2) assigning values to each of the characteristics common to all geriatric injuries and (3) assigning values to additional characteristics relevant for specific injuries. We identified nine unique types of visible injury and seven characteristics critical to describe all these injuries, including body region(s) and precise anatomic location(s). For each injury type, we identified two to seven additional critical characteristics, such as size, shape and cleanliness. We pilot tested it on 323 injuries on 83 physical elder abuse victims and 45 unintentional fall victims from our ongoing research to ensure that it would allow for the complete and accurate description of the full spectrum of visible injuries encountered and made modifications and refinements based on this experience. We then used the classification system to evaluate 947 injuries on 80 physical elder abuse victims and 195 unintentional fall victims to assess its practical utility. CONCLUSIONS: Our comprehensive injury taxonomy systematically integrates and expands on existing forensic and clinical research. This new classification system may help standardise description of acute injuries and patterns among clinicians and researchers.

Emergency Medical Services Perspectives on Identifying and Reporting Victims of Elder Abuse, Neglect, and Self-Neglect.

BACKGROUND: Emergency Medical Services (EMS) providers, who perform initial assessments of ill and injured patients, often in a patient's home, are uniquely positioned to identify potential victims of elder abuse, neglect, or self-neglect. Despite this, few organized programs exist to ensure that EMS concerns are communicated to or further investigated by other health care providers, social workers, or the authorities. OBJECTIVE: To explore attitudes and self-reported practices of EMS providers surrounding identification and reporting of elder mistreatment. METHODS: Five semi-structured focus groups with 27 EMS providers. RESULTS: Participants reported believing they frequently encountered and were able to identify potential elder mistreatment victims. Many reported infrequently discussing their concerns with other health care providers or social workers and not reporting them to the authorities due to barriers: 1) lack of EMS protocols or training specific to vulnerable elders; 2) challenges in communication with emergency department providers, including social workers, who are often unavailable or not receptive; 3) time limitations; and 4) lack of follow-up when EMS providers do report concerns. Many participants reported interest in adopting protocols to assist in elder protection. Additional strategies included photographically documenting the home environment, additional training, improved direct communication with social workers, a dedicated location on existing forms or new form to document concerns, a reporting hotline, a system to provide feedback to EMS, and community paramedicine. CONCLUSIONS: EMS providers frequently identify potential victims of elder abuse, neglect, and self-neglect, but significant barriers to reporting exist. Strategies to empower EMS providers and improve reporting were identified.

Sulfone-Containing Methacrylate Homopolymers: Wetting and Thermal Properties.

Although the sulfonyl functional group has a large dipole moment and compounds containing them (sulfones) have correspondingly high dielectric constants, this chemical structure has been neglected for use as a functional group to render surfaces hydrophilic. We have prepared three methacrylate polymers containing side chains capped with sulfolane, methylsulfone, and ethylsulfone functionality. The sulfolane-containing polymer exhibits an unusually high glass transition temperature (Tg = 188°C) for a methacrylate polymer and slightly different thermal degradation behavior than the other two sulfone-containing polymers, likely due to the bulky structure of the sulfolane group in the polymer side chain. At macroscopic polymer film/water interfaces, the sulfone-containing side chains exposed to the interface impart hydrophilic properties as assessed by contact angle analysis. The hydrophilicities of sulfolane and methylsulfone surfaces are similar, and greater than the ethylsulfone surface. Although the chemical compositions of the sulfolane and ethylsulfone polymers are almost identical, the five-membered ring structure of sulfolane allows the sulfonyl moiety to be exposed at the interface in a manner similar to that of the methylsulfone polymer. The sulfonyl group at the ethylsulfone polymer/water interface is slightly masked by the ethyl group. Interestingly, the sulfolane surface displays a higher affinity to methylene iodide and n-hexadecane probe fluids compared to the other sulfone surfaces, suggesting that the five-membered ring structure of the sulfolane moiety can orient in a manner that shelters the sulfonyl group at hydrophobic interfaces.

Radiologists' Training, Experience, and Attitudes About Elder Abuse Detection.

OBJECTIVE: Elder abuse is underrecognized, and identification of subtle cases requires a high index of suspicion among all health care providers. Because many geriatric injury victims undergo radiographic imaging, diagnostic radiologists may be well positioned to identify injury patterns suggestive of abuse. Little is known about radiologists' experience with elder abuse. Our goal was to describe knowledge, attitudes, training, and practice experience in elder abuse detection among diagnostic radiologists. SUBJECTS AND METHODS: We conducted 19 interviews with diagnostic radiologists at a large urban academic medical center using a semistructured format. Data from these sessions were coded and analyzed to identify themes. RESULTS: Only two radiologists reported any formal or informal training in elder abuse detection. All subjects believed they had missed cases of elder abuse. Even experienced radiologists reported never having received a request from a referring physician to assess images for evidence suggestive of elder abuse. All subjects reported a desire for additional elder abuse training. Also, subjects identified radiographic findings or patterns potentially suggestive of elder abuse, including high-energy injuries such as upper rib fractures, injuries in multiple stages of healing, and injuries inconsistent with reported mechanism. CONCLUSION: Radiologists are uniquely positioned to identify elder abuse. Though training in detection is currently lacking, providers expressed a desire for increased knowledge. In addition, radiologists were able to identify radiographic findings suggestive of elder abuse. On the basis of these findings, we plan to conduct additional studies to define pathognomonic injury patterns and to explore how to empower radiologists to incorporate detection into their practice.

Covalently Attached Liquids: Instant Omniphobic Surfaces with Unprecedented Repellency.

Recent strategies to prepare "omniphobic" surfaces have demonstrated that minimizing contact angle hysteresis (CAH) is the key criterion for effectiveness. CAH is affected by chemistry and topography defects at the molecular and higher levels, thus most surfaces exhibit significant CAH. Preparative methods for stable coatings on smooth substrates with negligible CAH (<2°) for a broad range of liquids have not been reported. In this work, we describe a simple and rapid procedure to prepare omniphobic surfaces that are stable under pressure and durable at elevated temperatures. Consistent with theory, they exhibit sliding angles that decrease with liquid surface tension. Slippery omniphobic covalently attached liquid (SOCAL) surfaces are obtained through acid-catalyzed graft polycondensation of dimethyldimethoxysilane. The smooth, stable, and temperature-resistant coatings show extremely low CAH (≤1°) and low sliding angles for liquids that span surface tensions from 78.2 to 18.4 mN m(-1).

Near infrared radiation protects against oxygen-glucose deprivation-induced neurotoxicity by down-regulating neuronal nitric oxide synthase (nNOS) activity in vitro.

Near infrared radiation (NIR) has been shown to be neuroprotective against neurological diseases including stroke and brain trauma, but the underlying mechanisms remain poorly understood. In the current study we aimed to investigate the hypothesis that NIR may protect neurons by attenuating oxygen-glucose deprivation (OGD)-induced nitric oxide (NO) production and modulating cell survival/death signaling. Primary mouse cortical neurons were subjected to 4 h OGD and NIR was applied at 2 h reoxygenation. OGD significantly increased NO level in primary neurons compared to normal control, which was significantly ameliorated by NIR at 5 and 30 min post-NIR. Neither OGD nor NIR significantly changed neuronal nitric oxide synthase (nNOS) mRNA or total protein levels compared to control groups. However, OGD significantly increased nNOS activity compared to normal control, and this effect was significantly diminished by NIR. Moreover, NIR significantly ameliorated the neuronal death induced by S-Nitroso-N-acetyl-DL-penicillamine (SNAP), a NO donor. Finally, NIR significantly rescued OGD-induced suppression of p-Akt and Bcl-2 expression, and attenuated OGD-induced upregulation of Bax, BAD and caspase-3 activation. These results suggest NIR may protect against OGD at least partially through reducing NO production by down-regulating nNOS activity, and modulating cell survival/death signaling.

Near infrared radiation rescues mitochondrial dysfunction in cortical neurons after oxygen-glucose deprivation.

Near infrared radiation (NIR) is known to penetrate and affect biological systems in multiple ways. Recently, a series of experimental studies suggested that low intensity NIR may protect neuronal cells against a wide range of insults that mimic diseases such as stroke, brain trauma and neurodegeneration. However, the potential molecular mechanisms of neuroprotection with NIR remain poorly defined. In this study, we tested the hypothesis that low intensity NIR may attenuate hypoxia/ischemia-induced mitochondrial dysfunction in neurons. Primary cortical mouse neuronal cultures were subjected to 4 h oxygen-glucose deprivation followed by reoxygenation for 2 h, neurons were then treated with a 2 min exposure to 810-nm NIR. Mitochondrial function markers including MTT reduction and mitochondria membrane potential were measured at 2 h after treatment. Neurotoxicity was quantified 20 h later. Our results showed that 4 h oxygen-glucose deprivation plus 20 h reoxygenation caused 33.8 ± 3.4 % of neuron death, while NIR exposure significantly reduced neuronal death to 23.6 ± 2.9 %. MTT reduction rate was reduced to 75.9 ± 2.7 % by oxygen-glucose deprivation compared to normoxic controls, but NIR exposure significantly rescued MTT reduction to 87.6 ± 4.5 %. Furthermore, after oxygen-glucose deprivation, mitochondria membrane potential was reduced to 48.9 ± 4.39 % of normoxic control, while NIR exposure significantly ameliorated this reduction to 89.6 ± 13.9 % of normoxic control. Finally, NIR significantly rescued OGD-induced ATP production decline at 20 min after NIR. These findings suggest that low intensity NIR can protect neurons against oxygen-glucose deprivation by rescuing mitochondrial function and restoring neuronal energetics.

Dip-coating deposition on chemically patterned surfaces: a mechanistic analysis and comparison with topographically patterned surfaces.

Chemically patterned surfaces containing hydrophilic features on a hydrophobic background have been used by a number of groups to deposit arrays of particles/crystals/substances by dip-coating deposition. In this technique, a substrate is simply withdrawn from a solution (or dispersion) of the desired substance, the solution dewets from the hydrophobic region and wets the hydrophilic features, and the particles/crystals/substances deposit on the hydrophilic features after solvent evaporation. An apparently similar approach, recently described by several groups, involves dip-coating deposition of substances from solutions onto hydrophobic topographic features (arrays of posts on superhydrophobic surfaces) that are separated by air. We report results of dip-coating deposition using chemically patterned surfaces and compare them directly with results from post-containing superhydrophobic surfaces. This comparison involves the analysis of events at receding three-phase contact lines; these events differ significantly in the two approaches with the key difference being tensile (normal to the surface) versus sessile (parallel to the surface) capillary bridge failure. Tensile failure occurs with the post-containing superhydrophobic surfaces and sessile failure with chemically patterned surfaces. The solvent evaporation stages of the processes, that occur subsequent to the capillary bridge failure events, also vary significantly in the two approaches and depend on the receding contact angles of the hydrophobic post tops and the hydrophilic chemically patterned features. These differences, as the adjectives suggest, are pronounced. Controlling the evaporation rate (adjusting the vaporization/condensation equilibrium) by raising the partial pressure of the solvent is identified as a useful variable for chemically patterned surfaces.

Liquid marbles supported by monodisperse poly(methylsilsesquioxane) particles.

The preparation of model, well-controlled colloidal assemblies has been a central approach to understanding and optimizing the characteristics and functionality of complex colloidal dispersion systems. This approach, which has created a significant literature and rather deep understanding for emulsions and foams, has yet to be established for the liquid marble (water-in-air) motif. In this article we report the preparation of well-controlled liquid marbles using monodisperse micron-size particles of poly(methylsilsesquioxane) (PMSQ). The low cohesive nature of the stabilizing particles, their narrow size distribution, and their hydrophobicity permit the formation of liquid marbles containing a particulate monolayer with a hexagonally close-packed (HCP) structure. The "cleaning process" by rolling of liquid marbles under a flow of air on a hydrophobic substrate was useful to obtain the monolayer structure. Moreover, the monolayer structure was only obtained from liquids with high surface energy, whereas the others were not useful even though multilayered structure was formed from liquids that have intermediate surface energy.