Isolate, segregate, seclude, insulate, sequester are comparable when they mean to separate from the usual or natural environment, but they are rarely interchangeable because their other and differentiating implications are often stressed.
Isolate implies a detachment of someone or something from his or its usual environment so that he or it will not affect or be affected by others. The word is sufficiently general that it may be employed in reference either to an actual separation or to a separation that is merely virtual, arbitrary, or speculative.
Segregate also applies to both persons and things and usually refers to them as a group separated from the mass or main body; its secondary implication is often, therefore, a collection in one place, one class, or one mass and it may in addition imply a holding incommunicado.
Seclude implies a removal or withdrawal from external influences; it is therefore often used reflexively or at least in such a way as to imply acceptance of the protection afforded by such removal or withdrawal.
Insulate means to isolate, especially by something which serves as a barrier to the escape of what is within or the entrance of what is without. Consequently it implies retention of some power in a condition approaching fullness or purity.
Insulate is employed technically to imply the use of something to cut off free passage (as of electricity or heat or sound).
Basically sequester implies a setting apart (as from others or for a particular purpose) and in itself, as apart from context, ordinarily conveys no more than this.
Colored by context it may take the place of isolate or of segregate or of seclude.
Sometimes, however, it may imply a setting apart by taking into one's possession or by confiscating. In legal use sequester implies a separation, usually for the time being, of property or income from the owner until some claim or obligation has been satisfied.