The intricate three-dimensional (3D) conformations of two-dimensional (2D) macromolecules play fundamental roles in biology and materials. Diverse conformational phases of 2D macromolecules have been predicted in theory but remain unclear in experimental validation. We established a conformational phase map of 2D macromolecules in solution using single-layer graphene oxide as the experimental model. The map covers not only predictable intramolecular phases but also intermolecular behaviors beyond theoretical prediction. We identified a symmetry-selection rule that discriminates anisotropic one-dimensional folding and isotropic 3D crumpling phases determined by the surface interaction. These symmetry-selective behaviors indicate a strong path-dependent competition between the elastic distortion and surface adhesion. The phase map offers a unified description of the conformational behaviors of 2D macromolecules that bridges the gap between theories and experiments, as well as a general guidance to precisely control multiscale condensed conformations of 2D nanomaterials.

二维（2D）大分子的复杂的三维（3D）构象在生物学和材料中起着基本作用。理论上已经预测了2D大分子的不同构象相，但在实验验证中仍不清楚。我们使用单层氧化石墨烯作为实验模型，建立了溶液中二维大分子​​的构象相图。该图不仅涵盖了可预测的分子内相，而且涵盖了超出理论预测范围的分子间行为。我们确定了一个对称选择规则，该规则可以区分由表面相互作用确定的各向异性一维折叠和各向同性3D皱缩相。这些对称选择行为表明弹性变形和表面附着力之间存在强烈的路径依赖竞争。