Poor-solvent brush height
= Poor-solvent brush height
{title2=$h\sim Nv_0\sigma/\phi$}
In a laterally uniform dense <polymer brush> with approximately fixed polymer <volume fraction> $\phi$, conservation of occupied <volume> gives $\phi h=Nv_0\sigma$, with repeat-unit <volume> $v_0$. At fixed solvent quality this gives $h\propto N\sigma$, unlike the <good-solvent brush height>. Isolated collapsed <polymer globules> and laterally segregated grafted layers need not obey this uniform-layer model.