  We study frustrated, two-dimensional, quantum antiferromagnets in the
vicinity of a quantum transition from a non-collinear, magnetically-ordered
ground state to a quantum disordered phase. The general scaling properties of
this transition are described. A detailed study of a particular field-theoretic
model of the transition, with bosonic spin-1/2 spinon fields, is presented.
Explicit universal scaling forms for a variety of observables are obtained and
the results are compared with numerical data on the spin-1/2 triangular
antiferromagnet. Universal properties of an alternative field-theory, with
confined spinons, are also briefly noted.
