What is xerogel used for?
SiO(2) xerogels are potential biomaterials to be used as matrix materials for the extended and controlled release of different kinds of biologically active agents administered by various routes.
What is xerogel made of?
Silica aerogel/xerogel made from tetraethoxysilane (TEOS) as a precursor in the sol–gel process is a typical inorganic aerogel and could be made via both acid catalyst (Li et al., 2008a) and base catalyst (Hribernik et al., 2007) methods.
What is the difference between hydrogel and xerogel?
Hydrogel and alcogel terms are used when the liquid (solvent) in the gel network is water and alcohol, respectively. When the liquid from the gel is evaporated at room temperature, the solid gels left behind are called xerogels.
What is xerogel in sol gel method?
Xerogels are a type of solid-formed gels, which are being prepared through drying slowly at the room temperature with an unconstrained shrinkage (Czarnobaj, 2008). Xerogels generally possess the properties of higher porosity and larger surface area together with very smaller pore sizes.
How do you make xerogel?
Xerogel Preparation Silica gels were prepared by means of the hydrolysis and polycondensation of tetraethoxysilane (TEOS; Fluka) with different catalysts (30% hydrochloric acid; Fluka, pHsol = 4 or 25% ammonia solution; Fluka, pHsol = 9), in ethanol (96% EtOH; POCh Gliwice) solution, at room temperature.
What is silica xerogel?
Silica xerogel with an average pore size of 2.4 nanometers has a strong affinity for water molecules and is widely used as a desiccant. It is hard and translucent, but considerably softer than massive silica glass or quartz; and remains hard when saturated with water.
What are the advantages of gel formulation?
Gels are currently present in the form of different formulations, the latter, unlike liquid substances or ointments, have the main advantage of remaining stable on the area to be treated and resisting evaporation for longer, so as to achieve their effect; for example, some gel formulation could be used in mucosae …
What is the classification of gels?
Gels are classified into elastic and non elastic gels. Elastic gels: These are those gels which posses the property of elasticity i.e. they change to solid mass on dehydration which can again be converted into gel by addition of water followed by heating and cooling.
What is gel and its types?
A gel is a colloidal system in which the dispersed phase is liquid and the dispersion medium is solid. e.g. when warm sol of gelatin is cooled, it sets to a semi-solid mass which is a gel. Jellies, jams, curd, butter, shoe polish, etc. are gels.
How many types of gels are there?
There are two types of gels: Soft gel and hard gel.
What is the role of silica in chromatography?
It is a polar absorbent with slight acidity, enabling it to absorb basic contents in a material that needs separation during chromatography, while also remaining neutral and maintaining its own structure throughout the process.
How many types of gel are there?
There are two types of gels: Soft gel and hard gel. The main difference in the two products has to do with how they are removed. Soft gel nails are known as “soak-off gels” because the nail polish can be removed with acetone. Hard gel is used to add nail length over soft gel that is used soley as a polish.
What is silica and its uses?
Industrial silica is used in a vast array of industries, the main ones being the glass, foundries, construction, ceramics, and the chemical industry. Silica in its finest form is also used as functional filler for paints, plastics, rubber, and silica sand is used in water filtration and agriculture.
What is a xerogel?
Xerogels are a type of solid-formed gels, which are being prepared through drying slowly at the room temperature with an unconstrained shrinkage (Czarnobaj, 2008 ). Xerogels generally possess the properties of higher porosity and larger surface area together with very smaller pore sizes.
How can I get xerogel powder?
The xerogel, a light yellow coloured powder, can thus be obtained. The xerogel is insensitive to moisture and can be steadily stored for very long time. By dissolving 10–40 wt% xerogel into 2-methoxyethanol solvent, PZT precursor solution can be obtained.
What is the difference between xerogel and slurry?
The slurry includes the gel and a liquid vehicle (e.g., isopropyl alcohol), which is evaporated or burnt off prior to sintering. A xerogel is a solid formed from a gel by drying, which is accompanied with shrinkage. A xerogel typically has high porosity (15–50%), high-surface area (150–900 m 2 /g), and small pore size (1–10 nm).