Abstract:
The invention relates to a process for the preparation of monolithic silica aerogels by drying silica gels under hypercritical conditions, which is characterized by the absence of washing of the silica gel, a high heating rate in the autoclave and purging of the autoclave after substantial removal of the solvent. Other preferred conditions are the use of an amount of water not exceeding 1.5 times the stoichiometric amount for the hydrolysis, hypercritical conditions corresponding to a temperature of 265 DEG -275 DEG C. and to a pressure of 150-200 bars, and so on. Use of the aerogels for the preparation of silica glass bodies or articles and of heat-insulating materials.
Abstract:
A material system and method for imparting non-stick and non-wetting properties to an inorganic article having hydroxyl groups on its surface, the system comprising a silane having the formula RnSiX4-n, wherein n is 1-2 and X is a hydrolyzable group, a colloidal metal oxide sol, and an acidified aqueous mixture with a lower alkanol.
Abstract translation:一种赋予其表面上具有羟基的无机制品不粘和不润湿性能的材料体系和方法,该体系包含具有式R n SiX 4-n的硅烷,其中n为1-2,X为可水解基团 ,胶态金属氧化物溶胶,和具有低级链烷醇的酸化水性混合物。
Abstract:
A material system and method for imparting non-stick and non-wetting properties to an inorganic article having hydroxyl groups on its surface, the system comprising a silane having the formula RnSiX4-n, wherein n is 1-2 and X is a hydrolyzable group, a metal alkoxide having at least three hydrolyzable branches and a formula R MX3 or MX4, wherein M is a metal and X is a hydrolyzable branch, and an acidified aqueous mixture with a lower alkanol.
Abstract:
L'invention concerne un procédé de préparation d'aérogels de silice monolithiques par séchage de gels de silice dans des conditions hypercritiques qui se caractérise par l'absence de lavage du gel de silice, une vitesse élevée de chauffage dans l'autoclave et une purge de l'autoclave après élimination substantielle du solvant. D'autres conditions préférées sont l'emploi d'une quantité d'eau ne dépassant pas 1,5 fois la stoechiométrie pour l'hydrolyse, des conditions hypercritiques correspondant à une température de 265-275°C et à une pression de 150-200 bars, etc... Utilisation des aérogels pour la préparation de corps ou articles en verre de silice, et de matériaux thermiquement isolants.
Abstract:
A material system and method for imparting non-stick and non-wetting properties to an inorganic article having hydroxyl groups on its surface, the system comprising a silane having the formula RnSiX4-n, wherein n is 1-2 and X is a hydrolyzable group, a metal alkoxide having at least three hydrolyzable branches and a formula R MX3 or MX4, wherein M is a metal and X is a hydrolyzable branch, and an acidified aqueous mixture with a lower alkanol.
Abstract translation:一种赋予其表面上具有羟基的无机制品不粘和不润湿性能的材料体系和方法,该体系包含具有式R n SiX 4-n的硅烷,其中n为1-2,X为可水解基团 具有至少三个可水解分支和式R MX3或MX4的金属醇盐,其中M是金属,X是可水解的分支,和具有低级烷醇的酸化含水混合物。
Abstract:
According to the invention, a) at least the first and second compositions of this material in the fluid phase are prepared, b) a sheet (61) of the first composition is poured continuously onto a flat support (4), c) a sheet (62) of the second composition is poured continuously onto sheet (61) of the first composition, and d) the thermal interdiffusion of the materials of the two sheets is ensured so as to obtain the desired gradient of composition in the cooled bar.
Abstract:
A method is provided for sealing one or more fill holes (42, 44) in a glass plate (14) of an organic dye solar cell and other glass packages by covering the hole(s) (42, 44) with a laser absorbing glass patch (52, 54). The outer perimeter of the glass patch (52, 54) is melted with a laser such that the outer perimeter of the glass patch (52, 54) is hermetically sealed to the glass plate (14). Another method is provided in which the fill holes (42, 44) are covered with a glass patch (52, 54) having a loop of absorbing frit around the outer periphery thereof. The loop of frit is melted with a laser such that the outer perimeter of the glass patch (52, 54) is hermetically sealed to the glass plate (14). In both process, the laser beam is either (1) formed into a loop shape beam around the perimeter of the glass patch (52, 54) or (2) quickly travels around the perimeter of the glass patch (52, 54) in such a manner that the loop of frit or the entire perimeter of the absorbing glass patch (52, 54) is uniformly heated to substantially the same temperature to minimize thermal stresses crated during heating and sealing.