An improved design for an athletic helmet incorporating non-Newtonian fluid shock absorbing structures.

The present invention relates to a method for producing a silica aerogel and a silica aerogel produced thereby. More specifically, a first water glass solution is used to form a first silica wet gel, and then a second water glass solution is additionally added to form a second silica wet gel organically bonded to the first silica wet gel which serves as a basic skeleton, so that a silica aerogel with enhanced physical properties is formed to increase the resistance to shrinkage in ambient drying. Thus, a low-density silica aerogel may be formed, and the concentrations of the first and second water glass solutions may be adjusted to control the physical properties of the silica aerogel.

A method for manufacturing an aerogel sheet according to the present invention includes: a step (a) of preparing a blanket having a plate shape; a step (b) of mixing silica sol with gelling catalyst to prepare a silica sol precursor; and a step (c) of injecting the silica sol precursor prepared in the step (b) to a surface of the blanket prepared in the step (a) through an injection device to gelate the silica sol precursor, wherein, in the step (c), the injection device injects the silica sol precursor while moving from one side to the other side of the surface of the blanket.

A suspension fluid prepared by dispersing polyethylene oxide particles into a solvent including water and one or more types of compounds selected from the group consisting of ethylene glycol and propylene glycol, and a method for manufacturing the same. The phase-change suspension fluid can be a shear-thinning fluid showing a constant newtonian behavior in a low shear rate or low frequency region, but showing a non-newtonian behavior appearing as liquid-like suspension in a high shear rate or high frequency region due to viscosity decrease, and is capable of reversible phase changes by the vibration of a vehicle, and therefore, may provide effects of having advantages of a hydraulic bush in a low frequency region and also having advantages of a solid bush in a high frequency region.

A thermothickening fluid is provided which comprises a liquid phase; a first polymer comprising functional groups and having a room temperature solubility in the liquid phase; and a second, different polymer comprising functional groups and having a room temperature solubility in the liquid phase, wherein functional groups on the first polymer are capable of associating with functional groups on the second polymer to form complexes, and the room temperature solubility of the first polymer is greater than the room temperature solubility of the second polymer. The fluid is a colloid at room temperature, a solution at an elevated temperature, and exhibits a thermothickening/thinning transition viscosity value at a thermo-thickening/thinning transition temperature between room temperature and the elevated temperature.