Crosslinking of Pressure-Sensitive Adhesives with Polymer-Grafted Nanoparticles.

Nanocomposite filler particles provide multiple routes to mechanically reinforce pressure-sensitive adhesives (PSAs), as their large surface area to volume ratios provide a means of effectively crosslinking multiple polymer chains. A major advancement could therefore be enabled by the design of a particle architecture that forms multiple physical and chemical interactions with the surrounding polymer matrix, while simultaneously ensuring particle dispersion and preventing particle aggregation. Understanding how such multivalent interactions between a nanoparticle crosslinking point and the PSA polymer affect material mechanical performance would provide both useful scientific knowledge on the mechanical structure-property relationships in polymer composites, as well as a new route to synthesizing useful PSA materials.

Ordered polymer composite materials: challenges and opportunities.

Polymer nanocomposites containing nanoscale fillers are an important class of materials due to their ability to access a wide variety of properties as a function of their composition. In order to take full advantage of these properties, it is critical to control the distribution of nanofillers within the parent polymer matrix, as this structural organization affects how the two constituent components interact with one another. In particular, new methods for generating ordered arrays of nanofillers represent a key underexplored research area, as emergent properties arising from nanoscale ordering can be used to introduce novel functionality currently inaccessible in random composites.

Manual wheelchair users gradually face fewer postural stability and control challenges with increasing rolling resistance while maintaining a rear-wheel wheelie.

Teaching manual wheelchair users to perform wheelies using various rolling resistances is expected to facilitate learning of this advanced wheelchair skill. However, limited scientific evidence is available to support this approach. This study aimed to measure and compare postural stability and control requirements when maintaining a stationary wheelie on different rolling resistances.

Unmatched speed perceptions between overground and treadmill manual wheelchair propulsion in long-term manual wheelchair users.

Background: Manual wheelchair (MWC) propulsion is increasingly assessed on a motorized treadmill (TM), which is often considered more ecologically valid than stationary rollers. However, no clear consensus on the similarities between overground (OG) and TM propulsion has yet been reached. Furthermore, no study has investigated the participants' perceptions of propelling a MWC on a TM compared to OG.

Characterization of humeral head displacements during dynamic glenohumeral neuromuscular control exercises using quantitative ultrasound imaging: A feasibility study.

The objectives of the present study were to test the feasibility of measuring humeral head displacements using quantitative ultrasound imaging during the performance of two different dynamic glenohumeral neuromuscular control exercises and to investigate the influence of these exercises on the acromiohumeral distance (AHD) and anterior-posterior distance (APD). Ten individuals who have no history of shoulder injury at the non-dominant shoulder completed three repetitions of an active humeral head lowering exercise and three repetitions of a posteriorisation exercise in a random order in a seated position. The AHD and the APD of the humeral head relative to the glenoid cavity were measured continuously using an ultrasound imaging system during each exercise.